Publications by authors named "Peter S Hersh"

38 Publications

Descemetocele Management With Therapeutic Scleral Lens Wear.

Eye Contact Lens 2021 May;47(5):314-316

Cornea and Laser Eye Institute-Hersh Vision Group (J.D.G., V.P.B., S.A.G., M.S., P.S.H.), CLEI Center for Keratoconus, Teaneck, NJ; and Department of Ophthalmology (J.D.G., V.P.B., S.A.G., P.S.H.), Rutgers-New Jersey Medical School, Newark, NJ.

Objectives: This case reports on the use of scleral lens therapy for a patient with a descemetocele secondary to exposure and neurotrophic keratopathy.

Methods: Case report and literature review.

Results: A 31-year-old man had undergone emergency surgery to repair a ruptured arteriovenous malformation resulting in left facial and trigeminal nerve palsies. The patient reported to our clinic with a central descemetocele secondary to exposure and neurotrophic keratopathy. Given the poor prognosis of a therapeutic penetrating keratoplasty in this case, the descemetocele was treated with therapeutic scleral lens wear. After 1 year, the patient has remained stable without corneal perforation.

Conclusions: This case illustrates the use of extended scleral lens wear, followed by maintenance with daily scleral lens wear, to manage a descemetocele in a patient with neurotrophic and exposure keratopathy. For patients at high risk of postsurgical complications, therapeutic scleral lens wear may be used as an alternative or as a supplement to corneal transplantation and tarsorrhaphy in patients with descemetocele formation.
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http://dx.doi.org/10.1097/ICL.0000000000000765DOI Listing
May 2021

Corneal higher-order aberrations after crosslinking and intrastromal corneal ring segments for keratoconus.

J Cataract Refract Surg 2020 Jul;46(7):979-985

From the Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus (Greenstein, Chung, Rosato, Gelles, Hersh), Teaneck, and the Department of Ophthalmology, Rutgers-New Jersey Medical School (Greenstein, Hersh), Newark, New Jersey, USA.

Purpose: To assess anterior corneal higher-order aberrations (HOAs) after corneal crosslinking (CXL) and intrastromal corneal ring segments (Intacs) used adjunctively.

Setting: Cornea and refractive surgery practice.

Design: Prospective, randomized clinical trial.

Methods: One hundred fifty-eight eyes of 150 patients were randomized into 2 groups: concurrent, Intacs and CXL during the same session (n = 81), or sequential, Intacs followed by CXL 3 months later (n = 77). Outcomes included changes in total, coma, trefoil, and spherical anterior corneal HOA 6 months after Intacs/CXL. The change in anterior corneal HOAs was correlated with the change in uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and topography indices of maximum keratometry (Kmax), maximum flattening keratometry (Kmaxflat), and inferior-superior (I-S) ratio. A subjective visual function questionnaire was also analyzed.

Results: UDVA, CDVA, Kmax, I-S, and Kmaxflat all improved 6 months after treatment (UDVA = -0.22 ± 0.34, P < .001; CDVA = -0.13 ± 0.24, P < .001; Kmax = -3.1 ± 3.0D, P < .001; I-S = -4.2 ± 5.0 diopters [D], P < .001; Kmaxflat = -7.9 ± 4.0 D, P < .001). Total anterior corneal HOA, vertical coma, and horizontal coma anterior corneal HOAs significantly improved by -1.05 ± 0.93 μm (P < .001), -1.53 ± 1.18 μm (P < .001), and -0.35 ± 0.57 μm (P < .001), respectively. Spherical anterior corneal HOAs increased by 0.24 ± 0.70 μm (P < .001) at 6 months after Intacs/CXL. The change in trefoil was not statistically significant (Ptrefoil0 = .06, Ptrefoil30 = .2). There were no significant differences between the changes in anterior corneal HOAs in the sequential and same-day Intacs/CXL groups. The change in total anterior corneal HOAs was correlated with Kmax, Kmaxflat, and the I-S ratio. There was no correlation between the change in anterior corneal HOAs and the change in visual acuity or visual function survey responses.

Conclusions: Total, horizontal coma, and vertical coma anterior corneal HOAs improved after Intacs/CXL. Spherical anterior corneal HOAs increased postoperatively, and there was no change in trefoil. Improvement of anterior corneal HOAs did not correlate with visual acuity improvement or subjective visual satisfaction outcomes.
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http://dx.doi.org/10.1097/j.jcrs.0000000000000209DOI Listing
July 2020

Corneal Haze After Transepithelial Collagen Cross-linking for Keratoconus: A Scheimpflug Densitometry Analysis.

Cornea 2020 Sep;39(9):1117-1121

The Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus, Teaneck, NJ; and.

Purpose: To quantitate corneal haze and analyze the postoperative time course of corneal haze after transepithelial corneal collagen cross-linking (TECXL) in patients with keratoconus.

Methods: Patients underwent TECXL and were randomized into 2 groups. One group received intraoperative riboflavin 0.10% every minute, and the second group received riboflavin 0.10% every 2 minutes during ultraviolet exposure. Scheimpflug densitometry was measured preoperatively, and at 1, 3, 6, and 12 months to assess the postoperative time course. Densitometry measurements were also correlated with visual acuity, pachymetry, and topography outcomes.

Results: Fifty-nine eyes of 43 patients with keratoconus were analyzed. Preoperative mean corneal densitometry was 20.45 ± 2.79. Mean densitometry increased at 1 month (22.58 ± 3.79; P < 0.001), did not significantly change between 1 and 3 months (22.64 ± 3.83; P = 0.8), and significantly improved between 3 and 12 months postoperatively (mean6 21.59 ± 3.39; P = 0.002, mean12 20.80 ± 3.27; P = 0.002). There was no difference between preoperative and 1-year densitometry measurements (P = 0.21). There was no significant difference between the 1-minute and 2-minute subgroups. In addition, corneal densitometry at either 3 months or 1 year did not correlate with uncorrected distance visual acuity (P = 0.4), corrected distance visual acuity (P = 0.1), or maximum keratometry (P = 0.5), 1 year after corneal collagen cross-linking (CXL).

Conclusions: After TECXL, corneal haze increased slightly at 1 month, plateaued between 1 and 3 months, and returned to baseline between 3 and 12 months. In general, corneal haze in this study was substantially less than the haze previously reported for the standard cross-linking procedure. CXL-associated corneal haze did not correlate with the postoperative visual or topographic outcomes 1 year after CXL.
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http://dx.doi.org/10.1097/ICO.0000000000002334DOI Listing
September 2020

Corneal crosslinking and intracorneal ring segments for keratoconus: A randomized study of concurrent versus sequential surgery.

J Cataract Refract Surg 2019 06 27;45(6):830-839. Epub 2019 Mar 27.

Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus, Teaneck, New Jersey, USA; Department of Ophthalmology, Rutgers-New Jersey Medical School, Newark, New Jersey, USA.

Purpose: To assess outcomes of corneal crosslinking (CXL) and intracorneal ring segments (ICRS) (Intacs) used adjunctively, and then compare the safety and efficacy of concurrent versus sequential surgery.

Setting: Cornea and refractive surgery subspecialty practice.

Design: Prospective randomized clinical trial.

Methods: Patients were randomized to one of two groups: ICRS first, immediately followed by CXL during the same session (n = 104), or ICRS followed by CXL 3 months later (n = 94). Outcomes included changes in maximum keratometry (K) and topographic inferior-superior (I-S) difference, maximum flattening of topographic K, and changes in uncorrected (UDVA) and corrected (CDVA) distance visual acuities. These were analyzed in the entire cohort, in the two randomized groups, and in subgroups stratified to ICRS size and placement. Patients were followed for 6 months.

Results: The study comprised 198 eyes of 198 patients. Overall, maximum K decreased by an average of 2.5 D, I-S difference improved by 3.9 D, and there was an average maximum flattening of -7.5 D. The UDVA improved by 2.0 logarithm of the minimum angle of resolution lines, on average, and the CDVA improved by 1.1 lines. There was no significant difference between the sequential and concurrent groups in any of the outcomes analyzed. There were 6 clinically significant adverse events.

Conclusions: CXL and ICRS can be used adjunctively with substantial improvement in corneal topography, and with no increase in safety concerns over each procedure alone. Sequential and concurrent treatment with ICRS and CXL show equivalent outcomes. Both thicker segment size and single segment placement seem to result in greater topographic improvement.
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http://dx.doi.org/10.1016/j.jcrs.2019.01.020DOI Listing
June 2019

Incidence and associations of intracorneal ring segment explantation.

J Cataract Refract Surg 2019 02 30;45(2):153-158. Epub 2018 Nov 30.

Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus, Teaneck, New Jersey, USA; Department of Ophthalmology, Rutgers-New Jersey Medical School, Newark, New Jersey, USA. Electronic address:

Purpose: To assess the incidence and motivating determinants of explantation of intracorneal ring segments (ICRS) (Intacs) used for the treatment of keratoconus and corneal ectasia.

Setting: Cornea and refractive surgery subspecialty practice.

Design: Retrospective case series.

Methods: Consecutive cases of ICRS implantation performed to treat keratoconus or corneal ectasia were reviewed to determine the number that were eventually explanted and the motivating factors for explantation. Cases were assigned to 1 of 2 groups: (1) medical complications requiring removal and (2) refractive/topographic problem, with the explantation being elective. The corrected distance visual acuity, uncorrected distance visual acuity, maximum keratometry, and inferior-superior topography power difference before and after ICRS removal were also evaluated.

Results: The ICRS were explanted from 35 eyes of 31 patients from a total cohort of 572 eyes (6.1%). Of these, 15 ICRS (2.6%) were removed for medical complications and 20 (3.5%) for refractive/topographic considerations.

Conclusions: A large proportion of ICRS were generally well tolerated on a long-term basis. The incidence of explantation secondary to medical complications was low, with the most frequent complication being infiltration around the segment. Explantation was effective in ameliorating medical complications and can be effective in improving corneal topography and clinical outcomes in some cases.
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http://dx.doi.org/10.1016/j.jcrs.2018.09.021DOI Listing
February 2019

Addendum.

Ophthalmology 2018 09 21;125(9):1473. Epub 2018 Aug 21.

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http://dx.doi.org/10.1016/j.ophtha.2018.06.005DOI Listing
September 2018

Transepithelial corneal crosslinking for keratoconus.

J Cataract Refract Surg 2018 Mar;44(3):313-322

From the Cornea and Laser Eye Institute-Hersh Vision Group (Hersh), CLEI Center for Keratoconus (Hersh, Lai, Gelles), Teaneck, and the Department of Ophthalmology, Rutgers-New Jersey Medical School (Hersh, Lesniak), Newark, New Jersey, USA.

Purpose: To evaluate outcomes of corneal crosslinking (CXL) using a transepithelial technique for the treatment of keratoconus.

Setting: Cornea and refractive surgery subspecialty practice.

Design: Prospective case series.

Methods: Transepithelial CXL was performed in keratoconic eyes using riboflavin 0.1% and topical anesthetic containing benzalkonium chloride to facilitate riboflavin diffusion through the epithelium. Eyes were randomized to receive riboflavin administration either every 1 minute or every 2 minutes during ultraviolet-A exposure at 3mW/cm. The principal outcome was change in maximum keratometry (K) and secondary outcomes included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, mean K, and comparison of randomized groups.

Results: Eighty-two eyes of 56 patients were treated. At 1 year, maximum K decreased significantly by 0.45 diopters (D) ± 1.94 (SD); it improved by 2.0 D or more in 11 eyes (13%) and worsened by 2.0 D or more in 4 eyes (5%). The mean UDVA significantly improved by 0.7 lines, whereas the CDVA improved by 0.2 lines. Two eyes showed both continued progression with loss of CDVA. Only the 1-minute subgroup showed significant improvements in maximum K (-0.73 D) and UDVA. Transient corneal erosion and epitheliopathy were reported in 21% of eyes.

Conclusions: Transepithelial CXL resulted in significant improvements in maximum K and UDVA over 1 year. There was a suggestion that increased riboflavin dosing might improve procedure outcomes. Further study is required to determine the relative advantages and disadvantages of different transepithelial approaches to the standard CXL protocol with epithelial removal.
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http://dx.doi.org/10.1016/j.jcrs.2017.12.022DOI Listing
March 2018

U.S. Multicenter Clinical Trial of Corneal Collagen Crosslinking for Treatment of Corneal Ectasia after Refractive Surgery.

Ophthalmology 2017 10 24;124(10):1475-1484. Epub 2017 Jun 24.

Avedro Inc., Waltham, Massachusetts; See Clearly Vision Group, Mclean, Virginia.

Purpose: To evaluate the safety and efficacy of corneal collagen crosslinking (CXL) for the treatment of corneal ectasia after laser refractive surgery.

Design: Prospective, randomized, multicenter, controlled clinical trial.

Participants: One hundred seventy-nine subjects with corneal ectasia after previous refractive surgery.

Methods: The treatment group underwent standard CXL, and the sham control group received riboflavin alone without removal of the epithelium.

Main Outcome Measures: The primary efficacy criterion was the change over 1 year of topography-derived maximum keratometry (K), comparing treatment with control groups. Secondary outcomes evaluated were corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent, endothelial cell count, and adverse events.

Results: In the crosslinking treatment group, the maximum K value decreased by 0.7 diopters (D) from baseline to 1 year, whereas there was continued progression in the control group (1.3 D difference between treatment and control, P < 0.0001). In the treatment group, the maximum K value decreased by 2.0 D or more in 14 eyes (18%) and increased by 2.0 D or more in 3 eyes (4%). The CDVA improved by an average of 5.0 logarithm of the minimum angle of resolution (logMAR) letters. Twenty-three eyes (32%) gained and 3 eyes (4%) lost 10 or more logMAR letters. The UDVA improved 4.5 logMAR letters. Corneal haze was the most frequently reported crosslinking-related adverse finding.

Conclusions: Corneal collagen crosslinking was effective in improving the maximum K value, CDVA, and UDVA in eyes with corneal ectasia 1 year after treatment, with an excellent safety profile. CXL is the first approved procedure to diminish progression of this ectatic corneal process.
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http://dx.doi.org/10.1016/j.ophtha.2017.05.036DOI Listing
October 2017

United States Multicenter Clinical Trial of Corneal Collagen Crosslinking for Keratoconus Treatment.

Ophthalmology 2017 09 7;124(9):1259-1270. Epub 2017 May 7.

Avedro, Inc., Waltham, Massachusetts; See Clearly Vision Group, McLean, Virginia.

Purpose: To evaluate the safety and efficacy of corneal collagen crosslinking (CXL) for the treatment of progressive keratoconus.

Design: Prospective, randomized, multicenter, controlled clinical trial.

Participants: Patients with progressive keratoconus (n = 205).

Methods: The treatment group underwent standard CXL and the sham control group received riboflavin alone without removal of the epithelium.

Main Outcome Measures: The primary efficacy criterion was the change over 1 year of topography-derived maximum keratometry value, comparing treatment with control group. Secondary outcomes evaluated were corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent, endothelial cell count, and adverse events.

Results: In the CXL treatment group, the maximum keratometry value decreased by 1.6 diopters (D) from baseline to 1 year, whereas keratoconus continued to progress in the control group. In the treatment group, the maximum keratometry value decreased by 2.0 D or more in 28 eyes (31.5%) and increased by 2.0 D or more in 5 eyes (5.6%). The CDVA improved by an average of 5.7 logarithm of the minimum angle of resolution (logMAR) units. Twenty-three eyes (27.7%) gained and 5 eyes lost (6.0%) 10 logMAR or more. The UDVA improved 4.4 logMAR. Corneal haze was the most frequently reported CXL-related adverse finding. There were no significant changes in endothelial cell count 1 year after treatment.

Conclusions: Corneal collagen crosslinking was effective in improving the maximum keratometry value, CDVA, and UCVA in eyes with progressive keratoconus 1 year after treatment, with an excellent safety profile. Corneal collagen crosslinking affords the keratoconic patient an important new option to decrease progression of this ectatic corneal process.
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http://dx.doi.org/10.1016/j.ophtha.2017.03.052DOI Listing
September 2017

Removal and Repositioning of Intracorneal Ring Segments: Improving Corneal Topography and Clinical Outcomes in Keratoconus and Ectasia.

Cornea 2017 Feb;36(2):244-248

CLEI Center for Keratoconus, Cornea and Laser Eye Institute-Hersh Vision Group, Teaneck, and the Department of Ophthalmology, Rutgers New Jersey Medical School, Newark, NJ.

Purpose: To evaluate the efficacy of removal and relocation of intracorneal ring segments for improving outcomes in treatment of keratoconus and corneal ectasia.

Methods: This is a retrospective case series conducted at a cornea and refractive surgery subspecialty practice setting. Patients with previous insertion of 2 intracorneal ring segments underwent surgical removal and repositioning of segments because of unsatisfactory visual and topographic outcomes. The principal outcomes included uncorrected and corrected visual acuities, manifest refraction, topography-derived maximum keratometry (Kmax), inferior-superior topography power difference (I - S), and higher-order aberration profile derived from wavefront analysis.

Results: Three patients are presented in this case series. Uncorrected visual acuity improved in all eyes by an average of 2.75 lines. Corrected visual acuity improved in 2 eyes and remained unchanged in 1 eye. Refractive astigmatism decreased in all patients by an average of 2.50 D. Kmax decreased by an average of 1.43 D. All patients had improvement in the I - S value with a mean decrease of 5.13 D.

Conclusions: Topography-guided repositioning and/or replacement of corneal ring segments can result in improved topographic, optical, and visual outcomes in patients in whom the initial result is suboptimal. In these cases, a single segment repositioned beneath the cone resulted in an improved outcome. Analysis of corneal topography can guide the surgeon in treatment planning and can suggest patients in whom such an effort will be rewarded with better results.
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http://dx.doi.org/10.1097/ICO.0000000000001075DOI Listing
February 2017

Intraoperative corneal thickness change and clinical outcomes after corneal collagen crosslinking: Standard crosslinking versus hypotonic riboflavin.

J Cataract Refract Surg 2016 04;42(4):596-605

From the Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus, Teaneck, and the Department of Ophthalmology, Rutgers-New Jersey Medical School, Newark, New Jersey, USA. Electronic address:

Purpose: To determine intraoperative changes in corneal thickness and outcomes of corneal collagen crosslinking (CXL) using 2 intraoperative regimens: riboflavin-dextran or hypotonic riboflavin.

Setting: Cornea and refractive surgery practice, Teaneck, New Jersey, USA.

Design: Prospective randomized case series.

Methods: Eyes with keratoconus or corneal ectasia were treated. All eyes received preloading with riboflavin 0.1% in 20% dextran. During ultraviolet-A (UVA) exposure, patients were randomly assigned to 1 of 2 study arms; that is, riboflavin-dextran or hypotonic riboflavin. Intraoperative pachymetry was measured before and after the corneal epithelium was removed, after initial riboflavin loading, and after UVA light exposure. Patients were evaluated for maximum keratometry (K), uncorrected distance visual acuity (UDVA), corrected distance visual acuity, corneal thickness, and endothelial cell count (ECC).

Results: Forty-eight eyes were treated. After removal of the epithelium and riboflavin loading, the mean pachymetry was 430 μm and 432 μm in the standard group and hypotonic group, respectively. Immediately after 30-minute UVA administration, the mean pachymetry was 302 μm and 342 μm, respectively. There was no statistically significant difference in the postoperative maximum K change, UDVA, corneal thickness, or ECC between the 2 groups.

Conclusions: The cornea thinned substantially during the CXL procedure. The use of hypotonic riboflavin rather than riboflavin-dextran during UVA administration decreased the amount of corneal thinning during the procedure by 30%, from 128 μm to 90 μm. However, there were no significant differences in clinical efficacy or changes in ECC or function between groups postoperatively. In general, corneal thinning during CXL did not seem to compromise the safety of the endothelium.

Financial Disclosures: Dr. Hersh is a consultant to Avedro, Inc. Dr. Rosenblat has no financial or proprietary interest in any material or method mentioned.
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http://dx.doi.org/10.1016/j.jcrs.2016.01.040DOI Listing
April 2016

Getting Double Crossed.

J Pediatr Ophthalmol Strabismus 2016 Jan-Feb;53(1):8-9

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http://dx.doi.org/10.3928/01913913-20151211-02DOI Listing
October 2016

Use of a hydrogel sealant in epithelial ingrowth removal after laser in situ keratomileusis.

J Cataract Refract Surg 2015 Dec;41(12):2768-71

From the Cornea and Laser Eye Institute-Hersh Vision Group, Teaneck, and the Department of Ophthalmology, Rutgers New Jersey Medical School, Newark, New Jersey, USA. Electronic address:

Unlabelled: We describe 2 cases in which clinically significant epithelial ingrowth was removed by debridement and followed by the use of a hydrogel sealant (Resure) to seal the flap edge. In both cases, the epithelial ingrowth was seen after otherwise uneventful laser in situ keratomileusis retreatment. The visual outcomes were good with no recrudescence of interface epithelium.

Financial Disclosure: Neither author has a financial or proprietary interest in any material or method mentioned.
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http://dx.doi.org/10.1016/j.jcrs.2015.11.024DOI Listing
December 2015

New intrastromal corneal reshaping procedure using high-intensity femtosecond laser pulses.

J Cataract Refract Surg 2015 Jun 19;41(6):1137-44. Epub 2015 Jun 19.

From the Department of Mechanical and Aerospace Engineering (Han, Suckewer), Princeton University, Princeton, and the Cornea and Laser Eye Institute (Hersh), Hersh Vision Group, Teaneck, New Jersey, USA; the State Key Laboratory of Precision Spectroscopy (Li), East China Normal University, Shanghai, China.

Unlabelled: A minimally invasive keratorefractive procedure using high-intensity, low-energy femtosecond laser pulses to perform intrastromal ablation is described. Because of the low pulse energy and the ultrashort duration, tissue in the corneal stroma can be ablated with almost no heat or shockwave generation. This technique obviates the need for the laser in situ keratomileusis (LASIK) flap but retains the advantages of the LASIK procedure. In the technique, a series of femtosecond laser pulses create temporary microchannels in the stroma, oriented perpendicular to the eye's optical axis. After the microchannels are created, a second series of femtosecond pulses directly ablate the desired amount of stromal tissue in a controlled fashion. The ablated material is ejected from the microchannels so the surface layer above the ablated regions collapses, with a consequent change in the refractive power of the cornea.

Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.
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http://dx.doi.org/10.1016/j.jcrs.2015.05.008DOI Listing
June 2015

Transepithelial corneal collagen crosslinking for keratoconus: six-month results.

J Cataract Refract Surg 2014 Dec 24;40(12):1971-9. Epub 2014 Nov 24.

From the Cornea and Laser Eye Institute-Hersh Vision Group (Hersh), CLEI Center for Keratoconus, Teaneck, and the Department of Ophthalmology (Hersh, Lesniak), Rutgers University, New Jersey Medical School, Newark, New Jersey, USA. Electronic address:

Purpose: To evaluate the safety and efficacy of corneal collagen crosslinking (CXL) using a transepithelial technique to treat keratoconus.

Setting: Cornea and refractive surgery subspecialty practice.

Design: Prospective clinical trial.

Methods: Transepithelial CXL was performed in eyes with keratoconus using proparacaine with benzalkonium chloride (BAK) 0.01% to facilitate riboflavin absorption and riboflavin 0.10% without dextran. Eyes were randomized to receive ultraviolet-A treatment (365 nm, 3 mW/cm(2)) with concurrent administration of riboflavin randomized to every 1 minute or every 2 minutes for 30 minutes. The principal outcomes included uncorrected (UDVA) and corrected (CDVA) distance visual acuities and topography-derived maximum keratometry (K) values. Patients were followed for 6 months.

Results: Thirty eyes of 25 patients were treated. The mean maximum K value flattened by 0.9 diopter (D) (baseline 58.7 D; 6 months 57.8 D) (P=.01). The maximum K worsened by 2.0 D or more in 1 patient. The mean CDVA improved by 0.83 Snellen lines (P=.03). One patient lost 2 lines of CDVA. There were no differences in the UDVA, CDVA, or keratometry outcomes between the 1-minute instillation subgroup and the 2-minute instillation subgroup.

Conclusions: Transepithelial CXL resulted in a statistically significant improvement in maximum K values and CDVA at the 6-month follow-up. Further follow-up is necessary to ascertain the ability of transepithelial CXL to achieve long-term stabilization of the cornea in eyes with keratoconus.
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http://dx.doi.org/10.1016/j.jcrs.2014.03.026DOI Listing
December 2014

Corneal collagen cross-linking: a review of 1-year outcomes.

Eye Contact Lens 2014 Nov;40(6):345-52

CLEI Center for Keratoconus (C.Y.C., P.S.H.), Cornea and Laser Eye Institute-Hersh Vision Group, Teaneck, NJ; Pennsylvania College of Optometry (C.Y.C.), Salus University, Elkins Park, PA; and Department of Ophthalmology (P.S.H.), Rutgers New Jersey Medical School, Newark, NJ.

Purpose: To review outcomes of corneal collagen cross-linking (CXL) for keratoconus (KC) or ectasia in a cornea subspecialty practice.

Methods: Results from controlled clinical trials at a single site cornea subspecialty practice, including 104 eyes (66 KC and 38 ectasia). Outcomes and the natural course of changes in postoperative parameters including maximum keratometry (KMax), uncorrected visual acuity (UCVA), and best-corrected visual acuity (BCVA) over 12 months are reviewed. In addition, corneal topography indices, wavefront higher-order aberrations, and the natural history of wound healing after CXL are discussed. Characteristics associated with CXL outcomes are reviewed as well. In predicting treatment outcomes for KMax and BCVA, the preoperative patient characteristics examined were gender, age, disease group, cone location, thinnest pachymetry, UCVA, BCVA, and KMax.

Results: At 1 year, an average of 1.7 diopter (D) flattening in KMax was found. Mean BCVA improved slightly more than 1 line (from 0.35±0.24 to 0.23±0.21 logMAR). All postoperative parameters similarly follow a trend of worsening between baseline and 1 month, and improvement thereafter. More specifically, quantitative improvements are typically seen at 3 months and may continue between 3 and 12 months. A review of baseline patient characteristics indicated that (1) eyes with preoperative KMax of 55 D or steeper were 5.4 times more likely to gain 2 D or more of KMax flattening at 1 year after CXL, and (2) eyes with preoperative BCVA of 20/40 or worse were 5.9 times more likely to gain 2 or more Snellen lines at 1 year after CXL. Conversely, no baseline characteristic was found to correlate with treatment complications of continual topographic steepening or loss of vision.

Conclusions: Corneal collagen cross-linking seems to be effective in decreasing progression of KC, with improvements in optical measures in many patients. Postoperative parameters discussed within this review followed a seemingly reproducible trend in their natural course over 12 months. Generally, the trend observed was immediate worsening between baseline and 1 month, resolution at approximately 3 months, and improvement thereafter. In predicting outcomes after CXL, no patient characteristics showed correlations with negative treatment outcomes such as loss of vision or continual topographic steepening. However, steeper KMax (≥55 D) and poorer BCVA (≤20/40) at the time of treatment correlated with better postoperative KMax and BCVA outcomes at 1 year, respectively. These outcome predictors should be considered when offering CXL to patients with KC or postoperative corneal ectasia.
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http://dx.doi.org/10.1097/ICL.0000000000000094DOI Listing
November 2014

Characteristics influencing outcomes of corneal collagen crosslinking for keratoconus and ectasia: implications for patient selection.

J Cataract Refract Surg 2013 Aug;39(8):1133-40

Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus, Teaneck, and the Department of Ophthalmology, UMDNJ New Jersey Medical School, Newark, New Jersey 07666, USA.

Purpose: To determine preoperative patient characteristics that may predict topography and visual acuity outcomes of corneal collagen crosslinking (CXL).

Setting: Cornea and refractive surgery practice.

Design: Cohort study.

Methods: Crosslinking was performed in eyes with keratoconus or corneal ectasia. Multiple regression and odds ratio analyses were performed to determine independent predictors of changes in topography-derived maximum keratometry (K) and corrected distance visual acuity (CDVA) 1 year postoperatively. Preoperative characteristics included sex, age, uncorrected distance visual acuity (UDVA), CDVA, maximum keratometry (K), corneal thickness, corneal haze, disease group, and cone location. Postoperative improvement in maximum K was defined as flattening of 2.0 diopters (D) or more and worsening as steepening of 1.0 D or more. Improvement in CDVA was defined as a gain of 2 lines or more and worsening as a loss of 1 line or more.

Results: The study comprised 104 eyes (66 keratoconus; 38 corneal ectasia). Eyes with a preoperative CDVA of 20/40 or worse were 5.9 times (95% confidence interval [CI], 2.2-6.4) more likely to improve 2 Snellen lines or more. Eyes with a maximum K of 55.0 D or more were 5.4 times (95% CI, 2.1-14.0) more likely to have topographic flattening of 2.0 D or more. No preoperative characteristics significantly predicted worsening of visual acuity or corneal topography.

Conclusions: Patients with worse preoperative CDVA and higher K values, particularly with a CDVA of 20/40 or worse or a maximum K of 55.0 D or more, were most likely to have improvement after CXL. No preoperative characteristics were predictive of CXL failure.
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http://dx.doi.org/10.1016/j.jcrs.2013.06.007DOI Listing
August 2013

Effect of topographic cone location on outcomes of corneal collagen cross-linking for keratoconus and corneal ectasia.

J Refract Surg 2012 Jun;28(6):397-405

Cornea and Laser Eye Instiute-Hersh Vision Group, Teaneck, NJ, USA.

Purpose: To assess the effect of preoperative topographic cone location on 1-year outcomes of corneal collagen cross-linking (CXL).

Methods: In this prospective, randomized, controlled clinical trial, 99 eyes (66 keratoconus, 33 ectasia) from 76 patients underwent CXL. Cone location was defined by the coordinates of preoperative maximum keratometry (maximum K) using the anterior sagittal curvature topography map (Pentacam, Oculus Optikgeräte GmbH). Patients were divided into three groups: those with a maximum K located within the central 3-mm (central cone group), 3- to 5-mm (paracentral cone group), and outside the 5-mm (peripheral cone group) optical zones. Topography and visual acuity data were obtained preoperatively and at 1 year.

Results: In the combined cohort, maximum K and uncorrected and corrected distance visual acuity significantly improved by -1.60±3.40 diopters (D) (P<.001), -0.08±0.25 logMAR (P=.001), and -0.10±0.18 log-MAR (P<.001), respectively. Comparing cone groups, maximum K decreased by 2.60±4.50 D (P<.001) in the central cone group, 1.10±2.50 D (P=.02) in the paracentral cone group, and 0.40±1.20 D (P=.08) in the peripheral cone group. Differences among groups were statistically significant (P<.001). Uncorrected distance visual acuity improved by -0.07±0.3 logMAR (P=.1) (central cone group), -0.1±0.17 logMAR (P=.004) (paracentral cone group), and -0.1±0.25 logMAR (P=.04) (peripheral cone group). Corrected distance visual acuity improved by -0.14±0.21 logMAR (P<.001) (central cone group), -0.08±0.17 logMAR (P=.01) (paracentral cone group), and -0.08±0.12 logMAR (P=.002) (peripheral cone group). For both UDVA and CDVA outcomes, these differences among groups were not statistically significant.

Conclusions: After CXL, more topographic flattening occurs in eyes with centrally located cones and the least flattening effect occurs when the cone is located peripherally. This cone-location effect is found in eyes with both keratoconus and ectasia.
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http://dx.doi.org/10.3928/1081597X-20120518-02DOI Listing
June 2012

Patient subjective visual function after corneal collagen crosslinking for keratoconus and corneal ectasia.

J Cataract Refract Surg 2012 Apr 18;38(4):615-9. Epub 2012 Feb 18.

Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus, Teaneck, and Department of Ophthalmology, UMDNJ-New Jersey Medical School, Newark, New Jersey, USA.

Purpose: To assess subjective visual function after corneal collagen crosslinking (CXL).

Setting: Cornea and refractive surgery subspecialty practice.

Design: Prospective randomized controlled clinical trial.

Methods: Patients completed a subjective questionnaire regarding visual symptoms administered preoperatively and 1 year after CXL. Patients ranked self-reported symptoms of photophobia, difficulty night driving, difficulty reading, diplopia, fluctuations in vision, glare, halo, starburst, dryness, pain, and foreign-body sensation on a scale from 1 to 5. Possible associations of symptoms with changes in corrected distance visual acuity (CDVA) and maximum keratometry were also analyzed.

Results: One hundred seven eyes of 76 patients had CXL for keratoconus (n = 71) or ectasia (n = 36). The mean preoperative to 1-year postoperative changes in night driving (3.2 ± 1.5 [SD] to 2.8 ± 1.5), difficulty reading (3.1 ± 1.5 to 2.9 ± 1.3), diplopia (2.5 ± 1.3 to 2.1 ± 1.2), glare (3.1 ± 1.4 to 2.7 ± 1.2), halo (2.9 ± 1.4 to 2.5 ± 1.3), starbursts (2.6 ± 1.5 to 2.4 ± 1.4), and foreign-body sensation (1.8 ± 1.1 to 1.6 ± 0.9) were statistically significant. There were no associations between the change in any symptom and changes in CDVA. There was a weak association between the change in night driving, pain, and foreign-body sensations and the change in maximum keratometry.

Conclusions: After CXL, patients noted subjective improvement in visual symptoms, specifically night driving, difficulty reading, diplopia, glare, halo, starbursts, and foreign-body sensation. These subjective outcomes corroborate quantitative clinical improvements seen after CXL.
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http://dx.doi.org/10.1016/j.jcrs.2011.11.029DOI Listing
April 2012

Higher-order aberrations after corneal collagen crosslinking for keratoconus and corneal ectasia.

J Cataract Refract Surg 2012 Feb;38(2):292-302

Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus, Teaneck, and Department of Ophthalmology, UMDNJ-New Jersey Medical School, Newark, New Jersey 07666, USA.

Purpose: To determine changes in higher-order aberrations (HOAs) after corneal collagen crosslinking (CXL).

Setting: Cornea and refractive surgery practice.

Design: Prospective randomized controlled clinical trial.

Methods: Corneal and ocular HOAs were measured and analyzed using the Pentacam device and Ladarwave aberrometer, respectively, at baseline and 12 months after CXL.

Results: Ninety-six eyes (64 keratoconus, 32 ectasia) of 73 patients had CXL. A fellow-eye control group comprised 42 eyes. The mean preoperative total anterior corneal HOAs, total coma, 3rd-order coma, and vertical coma were 4.68 μm ± 2.33 (SD), 4.40 ± 2.32 μm, 4.36 ± 2.30 μm, and 4.04 ± 2.27 μm, respectively. At 1 year, the mean values decreased significantly to 4.27 ± 2.25 μm, 4.01 ± 2.29 μm, 3.96 ± 2.27 μm, and 3.66 ± 2.22 μm, respectively (all P<.001). There were no significant changes in posterior corneal HOAs. The mean preoperative total ocular HOAs, total coma, 3rd-order coma, trefoil, and spherical aberration were 2.80 ± 1.0 μm, 2.60 ± 1.03 μm, 2.57 ± 1.03 μm, 0.98 ± 0.46 μm, and 0.90 ± 0.42 μm, respectively. At 1 year, the mean values decreased significantly to 2.59 ± 1.06 μm, 2.42 ± 1.07 μm, 2.39 ± 1.07 μm, 0.88 ± 0.49 μm, and 0.83 ± 0.38 μm, respectively (all P=.01). After CXL, HOAs were significantly improved compared with the control group. Changes in HOAs were not statistically associated with an improvement in visual acuity or most subjective visual symptoms, however.

Conclusion: Corneal and ocular HOAs decreased after CXL, suggesting an improvement in corneal shape.
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http://dx.doi.org/10.1016/j.jcrs.2011.08.041DOI Listing
February 2012

In vivo biomechanical changes after corneal collagen cross-linking for keratoconus and corneal ectasia: 1-year analysis of a randomized, controlled, clinical trial.

Cornea 2012 Jan;31(1):21-5

Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus, Teaneck, NJ 07666, USA.

Purpose: To investigate the in vivo, corneal, biomechanical changes after corneal collagen cross-linking (CXL) using the Ocular Response Analyzer (ORA) in patients with keratoconus and post-laser in situ keratomileusis (LASIK) ectasia.

Methods: Single-center, prospective, randomized, controlled, clinical trial. After CXL (69 eyes, 46 keratoconus and 23 post-LASIK), corneal hysteresis (CH) and corneal resistance factor (CRF) were measured using the ORA and analyzed in a treatment, sham control, and fellow eye control group at baseline and 1, 3, 6, and 12 months.

Results: There were no significant changes in CH (change = 0.05 ± 1.5; P = 0.78) or CRF (change = 0.29 ± 1.4; P = 0.1) at 1 year compared with preoperative values. Changes in CH and CRF were not correlated with changes in clinical outcomes of uncorrected visual acuity, best spectacle-corrected visual acuity, and maximum keratometry. There were no significant changes in CH in the sham or fellow eye control groups (P(sham) = 0.7; P(FE) = 0.3) or CRF (P(sham) = 0.6; P(FE) = 0.72).

Conclusions: Despite an increase in CRF at one month, there were no statistically significant changes in CH and CRF measurements 1 year after CXL. Development of other in vivo biomechanical metrics would aid in evaluating the corneal response to CXL.
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http://dx.doi.org/10.1097/ICO.0b013e31821eea66DOI Listing
January 2012

Corneal topography indices after corneal collagen crosslinking for keratoconus and corneal ectasia: one-year results.

J Cataract Refract Surg 2011 Jul;37(7):1282-90

Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus, Teaneck, New Jersey, USA.

Purpose: To evaluate changes in corneal topography indices after corneal collagen crosslinking (CXL) in patients with keratoconus and corneal ectasia and analyze associations of these changes with visual acuity.

Setting: Cornea and refractive surgery subspecialty practice.

Design: Prospective randomized controlled clinical trial.

Methods: Corneal collagen crosslinking was performed in eyes with keratoconus or ectasia. Quantitative descriptors of corneal topography were measured with the Pentacam topographer and included 7 indices: index of surface variance, index of vertical asymmetry, keratoconus index, central keratoconus index, minimum radius of curvature, index of height asymmetry, and index of height decentration. Follow-up was 1 year.

Results: The study comprised 71 eyes, 49 with keratoconus and 22 with post-LASIK ectasia. In the entire patient cohort, there were significant improvements in the index of surface variance, index of vertical asymmetry, keratoconus index, and minimum radius of curvature at 1 year compared with baseline (all P < .001). There were no significant differences between the keratoconus and ectasia subgroups. Improvements in postoperative indices were not correlated with changes in corrected or uncorrected distance visual acuity.

Conclusions: There were improvements in 4 of 7 topography indices 1 year after CXL, suggesting an overall improvement in corneal shape. However, no significant correlation was found between the changes in individual topography indices and changes in visual acuity after CXL.
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http://dx.doi.org/10.1016/j.jcrs.2011.01.029DOI Listing
July 2011

Corneal thickness changes after corneal collagen crosslinking for keratoconus and corneal ectasia: one-year results.

J Cataract Refract Surg 2011 Apr;37(4):691-700

Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus, Teaneck, New Jersey 07666, USA.

Purpose: To determine the changes in corneal thickness over time after corneal collagen crosslinking (CXL) for keratoconus and corneal ectasia.

Setting: Cornea and refractive surgery subspecialty practice.

Design: Prospective randomized controlled clinical trial.

Methods: Corneal thickness at the apex, thinnest point, and pupil center were measured using Scheimpflug imaging (Pentacam) at baseline and 1, 3, 6, and 12 months after CXL. The treatment group was compared with both a sham-procedure control group and a fellow-eye control group. Associations with clinical outcomes (uncorrected and corrected distance visual acuities and maximum keratometry) were analyzed.

Results: The study comprised 82 eyes, 54 with keratoconus and 28 with ectasia after laser in situ keratomileusis. The mean preoperative thinnest pachymetry was 440.7 μm ± 52.9 (SD). After CXL, the cornea thinned at 1 month (mean change -23.8 ± 28.7 μm; P<.001) and from 1 to 3 months (mean change -7.2 ± 20.1 μm, P=.002), followed by a recovery of the corneal thickness between 3 months and 6 months (mean +20.5 ± 20.4 μm; P<.001). At 1 year, apex and pupil-center thicknesses returned to baseline (P=.11 and P=.06, respectively); however, the thinnest pachymetry remained slightly decreased from baseline to 12 months (mean change -6.6 ± 22.4 μm; P=.01). The recovery of corneal thickness was more rapid in ectasia than in keratoconus. There was no association between the degree of corneal thinning at 3 months and clinical outcomes after CXL.

Conclusions: After CXL, the cornea thins and then recovers toward baseline thickness. The cause and implications of corneal thickness changes after CXL remain to be elucidated.

Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.
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http://dx.doi.org/10.1016/j.jcrs.2010.10.052DOI Listing
April 2011

Corneal collagen crosslinking for keratoconus and corneal ectasia: One-year results.

J Cataract Refract Surg 2011 Jan;37(1):149-60

Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus, Teaneck, New Jersey 07666, USA.

Purpose: To evaluate 1-year outcomes of corneal collagen crosslinking (CXL) for treatment of keratoconus and corneal ectasia.

Setting: Cornea and refractive surgery subspecialty practice.

Design: Prospective randomized controlled clinical trial.

Methods: Collagen crosslinking was performed in eyes with keratoconus or ectasia. The treatment group received standard CXL and the sham control group received riboflavin alone. Principal outcomes included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, astigmatism, and topography-derived outcomes of maximum and average keratometry (K) value.

Results: The UDVA improved significantly from 0.84 logMAR ± 0.34 (SD) (20/137) to 0.77 ± 0.37 logMAR (20/117) (P = .04) and the CDVA, from 0.35 ± 0.24 logMAR (20/45) to 0.23 ± 0.21 logMAR (20/34) (P<.001). Fifteen patients (21.1%) gained and 1 patient lost (1.4%) 2 or more Snellen lines of CDVA. The maximum K value decreased from baseline by 1.7 ± 3.9 diopters (D) (P<.001), 2.0 ± 4.4 D (P = .002), and 1.0 ± 2.5 D (P = .08) in the entire cohort, keratoconus subgroup, and ectasia subgroup, respectively. The maximum K value decreased by 2.0 D or more in 22 patients (31.0%) and increased by 2.0 D or more in 3 patients (4.2%).

Conclusions: Collagen crosslinking was effective in improving UDVA, CDVA, the maximum K value, and the average K value. Keratoconus patients had more improvement in topographic measurements than patients with ectasia. Both CDVA and maximum K value worsened between baseline and 1 month, followed by improvement between 1, 3, and 6 months and stabilization thereafter.

Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.
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http://dx.doi.org/10.1016/j.jcrs.2010.07.030DOI Listing
January 2011

Natural history of corneal haze after collagen crosslinking for keratoconus and corneal ectasia: Scheimpflug and biomicroscopic analysis.

J Cataract Refract Surg 2010 Dec;36(12):2105-14

Cornea and Laser Eye Institute-Hersh Vision Group, CLEI Center for Keratoconus, Teaneck, New Jersey, USA.

Purpose: To determine the natural history of collagen crosslinking (CXL)-associated corneal haze measured by Scheimpflug imagery and slitlamp biomicroscopy in patients with keratoconus or ectasia after laser in situ keratomileusis.

Setting: Cornea and refractive surgery subpecialty practice, United States.

Design: Prospective randomized controlled clinical trial.

Methods: The treatment group received ultraviolet-A/riboflavin CXL therapy. The control group received riboflavin alone without epithelial debridement. To objectively measure CXL-associated corneal haze, corneal densitometry using Scheimpflug imagery was measured and the changes in haze were analyzed over time. A similar analysis was performed using clinician-determined slitlamp haze. Correlation of CXL-associated corneal haze with postoperative outcomes was analyzed.

Results: The mean preoperative corneal densitometry was 14.9 ± 1.93 (SD) (Pentacam Scheimpflug densitometry units). Densitometry peaked at 1 month (mean 23.4 ± 4.40; P<.001), with little change at 3 months (mean 22.4 ± 4.79; P = .06) and decreased between 3 months and 6 months (19.4 ± 4.48; P<.001) and between 6 months and 12 months. By 12 months, densitometry had not completely returned to baseline in the entire cohort (mean 17.0 ± 3.82; P<.001) and the keratoconus subgroup; however, it returned to baseline in the ectasia group (16.1 ± 2.41; P = .15). The postoperative course of slitlamp haze was similar to objective densitometry measurements. Increased haze, measured by densitometry, did not correlate with postoperative clinical outcomes.

Conclusions: The time course of corneal haze after CXL was objectively quantified; it was greatest at 1 month, plateaued at 3 months, and was significantly decreased between 3 months and 12 months. Changes in haze did not correlate with postoperative clinical outcomes.
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http://dx.doi.org/10.1016/j.jcrs.2010.06.067DOI Listing
December 2010

Relationship of age and refraction to central corneal thickness.

Cornea 2011 May;30(5):553-5

Department of Ophthalmology, UMDNJ-New Jersey Medical School, Newark, NJ, USA.

Purpose: To obtain descriptive statistics of central corneal thickness (CCT) in a large population of normal eyes undergoing refractive surgery and study the relationship of 2 variables, age and refraction, with CCT.

Setting: Cornea and Laser Eye Institute, Hersh Vision Group, Teaneck, NJ.

Methods: The CCT of 5158 patients was measured using an ultrasound pachymeter. Age and preoperative spherical equivalent were recorded for all patients. The entire population and subgroups stratified to age and spherical equivalent were analyzed.

Results: Mean CCT was 544 μm with an SD of 34 μm and a range of 415-695 μm. CCT did not correlate with either age (r = 0.00645) or refraction (r = 0.00072).

Conclusions: This study defines the CCT in a large population of patients undergoing refractive surgery. In this population, age and refraction did not affect CCT.
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http://dx.doi.org/10.1097/ICO.0b013e3181fb880cDOI Listing
May 2011

Model of accommodation: contributions of lens geometry and mechanical properties to the development of presbyopia.

J Cataract Refract Surg 2010 Nov;36(11):1960-71

Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, USA.

Purpose: To determine the relative importance of lens geometry and mechanical properties for the mechanics of accommodation and the role of these elements in the causes and potential correction of presbyopia.

Setting: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey, USA.

Design: Experimental study.

Methods: Finite element methods and ray-tracing algorithms were used to model the deformation and optical power of the human crystalline lens during accommodation. The mechanical model treats the lens as an axisymmetric object, and the optical model incorporates a gradient refractive index. Using these models, the accommodation of a broad range of lenses with different geometries and mechanical properties were investigated.

Results: The most significant result was that reshaping the 45-year-old lens to the geometry of the 29-year-old lens, while retaining the mechanical properties, restored the former's accommodation amplitude to 72% to 94% of that of the 29-year-old lens, depending on ciliary body displacement. That is, reshaping can add 1.8 to 3.7 diopters of accommodation. A sensitivity analysis showed that this result was robust over a wide range of mechanical and geometrical properties.

Conclusion: The study results suggest that a significant amount of the loss of accommodation is due to changes in lens geometry.
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http://dx.doi.org/10.1016/j.jcrs.2010.09.001DOI Listing
November 2010

Wavefront analysis and Scheimpflug imagery in diagnosis of anterior lenticonus.

J Cataract Refract Surg 2010 May;36(5):850-3

New Jersey Medical School-UMDNJ, Newark, New Jersey, USA.

We present the case of an Alport syndrome patient whose anterior lenticonus was detected by wavefront analysis and Scheimpflug imaging technology. The patient's lenticular abnormalities were too subtle to be detected by the initial slitlamp examination. Normal corneal topography and elevation maps with high total-eye aberrations pointed to internal optics as the source of aberrations, and predominant negative spherical aberrations suggested anterior lenticonus, a diagnosis confirmed by Scheimpflug images that showed central bulging of the anterior lens surface. Following diagnosis, uneventful phacoemulsification and intraocular lens implantation were performed. We recommend wavefront analysis and Scheimpflug imaging technology as effective tools in the detection of lens disorders, especially those that are too subtle to be observed by other examination methods.
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http://dx.doi.org/10.1016/j.jcrs.2009.09.043DOI Listing
May 2010

Optics of conductive keratoplasty: implications for presbyopia management.

Authors:
Peter S Hersh

Trans Am Ophthalmol Soc 2005 ;103:412-56

Department of Ophthalmology and Visual Sciences, UMDNJ-New Jersey Medical School, Newark, New Jersey, USA.

Purpose: To define the corneal optics of conductive keratoplasty (CK) and assess the clinical implications for hyperopia and presbyopia management.

Methods: Four analyses were done. (1) Multifocal effects: In a prospective study of CK, uncorrected visual acuity (UCVA) for a given refractive error in 72 postoperative eyes was compared to control eyes. (2) Surgically induced astigmatism (SIA): 203 eyes were analyzed for magnitude and axis of SIA. (3) Higher-order optical aberrations: Corneal higher-order optical aberrations were assessed for 36 eyes after CK and a similar patient population after hyperopic laser in situ keratomileusis (LASIK). (4) Presbyopia clinical trial: Visual acuity, refractive result, and patient questionnaires were analyzed for 150 subjects in a prospective, multicenter clinical trial of presbyopia management with CK.

Results: (1) 63% and 82% of eyes after CK had better UCVA at distance and near, respectively, than controls. (2) The mean SIA was 0.23 diopter (D) steepening at 175 degrees (P < .001); mean magnitude was 0.66 D (SD, 0.43 D). (3) After CK, composite fourth- and sixth-order spherical aberration increased; change in (Z12) spherical aberration alone was not statistically significant. When compared to hyperopic LASIK, there was a statistically significant increase in composite fourth- and sixth-order spherical aberration (P < .01) and spherical aberration (Z12) alone (P < .02); spherical aberration change was more prolate after CK. (4) After the CK monovision procedure, 80% of patients had J3 or better binocular UCVA at near; 84% of patients were satisfied. Satisfaction was associated with near UCVA of J3 or better in the monovision eye (P = .001) and subjectively good postoperative depth perception (P = .038).

Conclusions: CK seems to produce functional corneal multifocality with definable introduction of SIA and higher-order optical aberrations, and development of a more prolate corneal contour. These optical factors may militate toward improved near vision function.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1447583PMC
December 2006

Corneal edema and penetrating keratoplasty after anterior chamber phakic intraocular lens implantation.

J Cataract Refract Surg 2005 Nov;31(11):2212-5

University of Medicine and Dentistry of New Jersey, New Jersey Medical School, The Institute of Ophthalmology and Visual Science, Newark, New Jersey 07101-1709, USA.

Phakic intraocular lens (IOL) implantation is an increasingly popular option in surgical correction of refractive error. To date, reports of long-term morbidity are infrequent in the literature. We encountered 3 patients who experienced corneal decompensation and cataract progression following angle-fixated anterior chamber phakic IOL placement.
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http://dx.doi.org/10.1016/j.jcrs.2005.04.031DOI Listing
November 2005
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