Publications by authors named "David Kuerten"

27 Publications

  • Page 1 of 1

Failure of XEN Gel Stent Implantation as a Stand-Alone Procedure in Congenital Glaucoma: Case Report of Secondary Congenital Glaucoma in Neurofibromatosis Type 1.

Case Rep Ophthalmol Med 2021 23;2021:9947167. Epub 2021 Jul 23.

Department of Ophthalmology, Universitätsklinikum Aachen, Pauwelsstr. 30, 52057 Aachen, Germany.

A XEN gel stent implant procedure was performed in a one-year-old child with severe unilateral congenital glaucoma. At the age of 6 weeks, an uncomplicated 360° trabeculotomy had been performed, which resulted in intraocular pressure (IOP) control for only 4 months. The gel stent implantation was performed ab interno without complications. However, 1 month later, the stent was repelled into the anterior chamber due to the elasticity of Tenon's layer. A first revision surgery was performed, with excision of Tenon's layer and implantation of a new gel stent under sight. At the age of 18 months, a second revision surgery was performed because of an encapsulated Tenon cyst with insufficient IOP control, again with the implantation of a new stent. At that time, a progressive upper eyelid swelling was apparent. Eyelid biopsy led to the diagnosis of neurofibromatosis type 1, presenting with an orbital plexiform neurofibroma. Further insufficient IOP control resulted in a cyclodestructive procedure and loss of light perception during follow-up. XEN gel stent implantation in congenital glaucoma in infants is more challenging than that in adult patients. Gel stent implantation ab interno may be difficult due to the thickness and elasticity of Tenon's layer. Gel stent dislocation may occur, even months after surgery. Trabeculectomy might be a better approach after failed trabeculotomy in congenital glaucoma. An underlying systemic disease might become apparent late during follow-up.
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http://dx.doi.org/10.1155/2021/9947167DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8325593PMC
July 2021

Non-invasive Assessment of Neurovascular Coupling After Aneurysmal Subarachnoid Hemorrhage: A Prospective Observational Trial Using Retinal Vessel Analysis.

Front Neurol 2021 14;12:690183. Epub 2021 Jun 14.

Department of Neurosurgery, RWTH Aachen University, Aachen, Germany.

Delayed cerebral ischemia (DCI) is a common complication after aneurysmal subarachnoid hemorrhage (aSAH) and can lead to infarction and poor clinical outcome. The underlying mechanisms are still incompletely understood, but animal models indicate that vasoactive metabolites and inflammatory cytokines produced within the subarachnoid space may progressively impair and partially invert neurovascular coupling (NVC) in the brain. Because cerebral and retinal microvasculature are governed by comparable regulatory mechanisms and may be connected by perivascular pathways, retinal vascular changes are increasingly recognized as a potential surrogate for altered NVC in the brain. Here, we used non-invasive retinal vessel analysis (RVA) to assess microvascular function in aSAH patients at different times after the ictus. Static and dynamic RVA were performed using a Retinal Vessel Analyzer (IMEDOS Systems GmbH, Jena) in 70 aSAH patients during the early (d), critical (d), late (d) phase, and at follow-up (f/u > 6 weeks) after the ictus. For comparison, an age-matched cohort of 42 healthy subjects was also included in the study. Vessel diameters were quantified in terms of the central retinal arterial and venous equivalent (CRAE, CRVE) and the retinal arterio-venous-ratio (AVR). Vessel responses to flicker light excitation (FLE) were quantified by recording the maximum arterial and venous dilation (MAD, MVD), the time to 30% and 100% of maximum dilation (tMAD, tMVD; tMAD, tMVD, resp.), and the arterial and venous area under the curve (AUC, AUC) during the FLE. For subgroup analyses, patients were stratified according to the development of DCI and clinical outcomes after 12 months. Vessel diameter (CRAE, CRVE) was significantly smaller in aSAH patients and showed little change throughout the whole observation period ( < 0.0001 vs. control for all time periods examined). In addition, aSAH patients exhibited impaired arterial but not venous responses to FLE, as reflected in a significantly lower MAD [2.2 (1.0-3.2)% vs. 3.6 (2.6-5.6)% in control subjects, = 0.0016] and AUC [21.5 (9.4-35.8)%s vs. 51.4 (32.5-69.7)%s in control subjects, = 0.0001] on d. However, gradual recovery was observed during the first 3 weeks, with close to normal levels at follow-up, when MAD and AUC amounted to 3.0 [2.0-5.0]% ( = 0.141 vs. control, = 0.0321 vs. d) and 44.5 [23.2-61.1]%s ( = 0.138 . control, < 0.01 vs. d & d). Finally, patients with clinical deterioration (DCI) showed opposite changes in the kinetics of arterial responses during early and late phase, as reflected in a significantly lower tMAD on d [4.0 (3.0-6.8) s vs. 7.0 (5.0-8.0) s in patients without DCI, = 0.022) and a significantly higher tMAD on d (24.0 (21.0-29.3) s . 18.0 (14.0-21.0) s in patients without DCI, = 0.017]. Our findings confirm and extend previous observations that aSAH results in sustained impairments of NVC in the retina. DCI may be associated with characteristic changes in the kinetics of retinal arterial responses. However, further studies will be required to determine their clinical implications and to assess if they can be used to identify patients at risk of developing DCI. ClinicalTrials.gov Identifier: NCT04094155.
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http://dx.doi.org/10.3389/fneur.2021.690183DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8236540PMC
June 2021

Association of ocular blood flow and contrast sensitivity in normal tension glaucoma.

Graefes Arch Clin Exp Ophthalmol 2021 Aug 21;259(8):2251-2257. Epub 2021 May 21.

Department of Ophthalmology, Uniklinik RWTH Aachen, Pauwelsstr. 30, 52057, Aachen, Germany.

Purpose: To investigate the relationship of ocular blood flow (via arteriovenous passage time, AVP) and contrast sensitivity (CS) in healthy as well as normal tension glaucoma (NTG) subjects.

Design: Mono-center comparative prospective trial METHODS: Twenty-five NTG patients without medication and 25 healthy test participants were recruited. AVP as a measure of retinal blood flow was recorded via fluorescein angiography after CS measurement using digital image analysis. Association of AVP and CS at 4 spatial frequencies (3, 6, 12, and 18 cycles per degree, cpd) was explored with correlation analysis.

Results: Significant differences regarding AVP, visual field defect, intraocular pressure, and CS measurement were recorded in-between the control group and NTG patients. In NTG patients, AVP was significantly correlated to CS at all investigated cpd (3 cpd: r =  - 0.432, p< 0.03; 6 cpd: r =  - 0.629, p< 0.0005; 12 cpd: r =  - 0.535, p< 0.005; and 18 cpd: r =  - 0.58, p< 0.001), whereas no significant correlations were found in the control group. Visual acuity was significantly correlated to CS at 6, 12, and 18 cpd in NTG patients (r =  - 0.68, p< 0.002; r =  - 0.54, p< .02, and r =  - 0.88, p< 0.0001 respectively), however not in healthy control patients. Age, visual field defect MD, and PSD were not significantly correlated to CS in in the NTG group. MD and PSD were significantly correlated to CS at 3 cpd in healthy eyes (r = 0.55, p< 0.02; r =  - 0.47, p< 0.03).

Conclusion: Retinal blood flow alterations show a relationship with contrast sensitivity loss in NTG patients. This might reflect a disease-related link between retinal blood flow and visual function. This association was not recorded in healthy volunteers.
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http://dx.doi.org/10.1007/s00417-021-05235-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8352838PMC
August 2021

Does hemispheric vascular regulation differ significantly in glaucoma patients with altitudinal visual field asymmetry? A single-center, prospective study.

Int Ophthalmol 2021 Sep 19;41(9):3109-3119. Epub 2021 May 19.

Department of Ophthalmology, Uniklinik RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany.

Purpose: Vascular risk factors and ocular perfusion are heatedly discussed in the pathogenesis of glaucoma. The retinal vessel analyzer (RVA, IMEDOS Systems, Germany) allows noninvasive measurement of retinal vessel regulation. Significant differences especially in the veins between healthy subjects and patients suffering from glaucoma were previously reported. In this pilot-study we investigated if localized vascular regulation is altered in glaucoma patients with altitudinal visual field defect asymmetry.

Methods: 15 eyes of 12 glaucoma patients with advanced altitudinal visual field defect asymmetry were included. The mean defect was calculated for each hemisphere separately (-20.99 ± 10.49 profound hemispheric visual field defect vs -7.36 ± 3.97 dB less profound hemisphere). After pupil dilation, RVA measurements of retinal arteries and veins were conducted using the standard protocol. The superior and inferior retinal vessel reactivity were measured consecutively in each eye.

Results: Significant differences were recorded in venous vessel constriction after flicker light stimulation and overall amplitude of the reaction (p < 0.04 and p < 0.02 respectively) in-between the hemispheres. Vessel reaction was higher in the hemisphere corresponding to the more advanced visual field defect. Arterial diameters reacted similarly, failing to reach statistical significance.

Conclusion: Localized retinal vessel regulation is significantly altered in glaucoma patients with asymmetric altitudinal visual field defects. Veins supplying the hemisphere concordant to a less profound visual field defect show diminished diameter changes. Vascular dysregulation might be particularly important in early glaucoma stages prior to a significant visual field defect.
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http://dx.doi.org/10.1007/s10792-021-01876-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8364541PMC
September 2021

Intraocular lens power calculation for plus and minus lenses in high myopia using partial coherence interferometry.

Int Ophthalmol 2021 May 1;41(5):1585-1592. Epub 2021 Feb 1.

Department of Ophthalmology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany.

Purpose: We assessed the accuracy of lens power calculation in highly myopic patients implanting plus and minus intraocular lenses (IOL).

Methods: We included 58 consecutive, myopic eyes with an axial length (AL) > 26.0 mm, undergoing phacoemulsification and IOL implantation following biometry using the IOLMaster 500. For lens power calculation, the Haigis formula was used in all cases. For comparison, refraction was back-calculated using the Barrett Universal II (Barrett), Holladay I, Hill-RBF (RBF) and SRK/T formulae.

Results: The mean axial length was 30.17 ± 2.67 mm. Barrett (80%), Haigis (87%) and RBF (82%) showed comparable numbers of IOLs within 1 diopter (D) of target refraction. Visual acuity (BSCVA) improved (p < 0.001) from 0.60 ± 0.35 to 0.29 ± 0.29 logMAR (> 28-days postsurgery). The median absolute error (MedAE) of Barrett 0.49 D, Haigis 0.38, RBF 0.44 and SRK/T 0.44 did not differ. The MedAE of Haigis was significantly smaller than Holladay (0.75 D; p = 0.01). All median postoperative refractive errors (MedRE) differed significantly with the exception of Haigis to SRK/T (p = 0.6): Barrett - 0.33 D, Haigis 0.25, Holladay 0.63, RBF 0.04 and SRK/T 0.13. Barrett, Haigis, Holladay and RBF showed a tendency for higher MedAEs in their minus compared to plus IOLs, which only reached significance for SRK/T (p = 0.001). Barrett (p < 0.001) and RBF (p = 0.04) showed myopic, SRK/T (p = 002) a hyperopic shift in their minus IOLs.

Conclusions: In highly myopic patients, the accuracies of Barrett, Haigis and RBF were comparable with a tendency for higher MedAEs in minus IOLs. Barrett and RBF showed myopic, SRK/T a hyperopic shift in their minus IOLs.
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http://dx.doi.org/10.1007/s10792-020-01684-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8087604PMC
May 2021

[Endophthalmitis after perforation of the conjunctiva by a glaucoma gel-stent implant].

Ophthalmologe 2020 Dec;117(12):1229-1233

Klinik für Augenheilkunde, Uniklinik RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Deutschland.

Intraocular infections associated with Abiotrophia defectiva are rare. This article reports the case of a 57-year-old woman with endophthalmitis associated with Abiotrophia defectiva 3 months after uncomplicated cataract surgery combined with the implantation of a glaucoma gel-stent in the right eye. The patient had complained of redness of the right upper nasal conjunctiva and pain for 2 weeks prior to the endophthalmitis. A topical steroid eyedrop treatment without antibiotic additives had temporarily improved the situation. The patient presented with hypopyon, acute deterioration of vision and severe periocular pain of the right eye since the early morning. The gel-stent had spontaneously perforated the conjunctiva. The patient was immediately started on local and systemic antibiotics and underwent pars plana vitrectomy with intravitreal antibiotic application 6 h after presentation. Unlike other ocular infections with Abiotrophia defectiva, this case had a relatively benign course most likely due to the prompt intervention. In clinical routine, patients, who present with acute deterioration of vision and pain after glaucoma surgery, should be examined urgently considering a possible spontaneous conjunctival perforation and late onset endophthalmitis. Additionally, conjunctivitis of unclear origin following ocular surgery should always be treated with antibiotics, particularly when steroids are administered and monitored closely.
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http://dx.doi.org/10.1007/s00347-020-01077-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7717055PMC
December 2020

[Treatment success of canaloplasty and trabeculectomy by the same surgeon with the same level of experience in the long-term course].

Ophthalmologe 2020 Oct;117(10):1025-1032

Klinik für Augenheilkunde, Uniklinik RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Deutschland.

Background: Trabeculectomy (TE) with the use of antimetabolites is the standard procedure in glaucoma surgery, whereas canaloplasty (CP) is a nonpenetrating and potentially less invasive alternative.

Objective: The aim of this retrospective case series was to compare the long-term success of CP and TE under the same conditions and with the same levels of experience of the surgeon as well as to investigate whether preoperative intraocular pressure (IOP) and postoperative IOP correlate with eachother.

Methods: The study included 57 eyes that underwent either CP or TE (CP n = 27; male = 50.0% age 60.7 ± 13.2 years; TE n = 30; male = 55.6% age 68.0 ± 9.1 years). Each of the procedures was performed by the same surgeon with comparable levels of experience. The comparison included preoperative and postoperative visual field damage, preoperative and postoperative IOP (mm Hg) after 1 and 6 weeks, 6 and 12 months as well as in the long-term course (1-3 years) and the necessary local treatment at the corresponding times.

Results: With both methods no worsening of the visual field could be detected and the patient groups showed comparable preoperative and postoperative mean deviations (MD). The CP showed a positive correlation between preoperative and postoperative 1‑year IOP (r = 0.4; p = 0.022), whereas TE showed no significant correlation between preoperative and postoperative IOP. The count of local antiglaucoma medication in long-term comparison (1-3 years after surgery) was higher after CP than after TE (1.5 ± 1.6 vs. 0.5 ± 0.8; p = 0.003). In both groups there were no severe postoperative complications. The overall success rates (without treatment) were higher at all time points after TE.

Discussion: With both methods conducted by the same surgeon with the same levels of experience, an effective reduction of the IOP was achieved. It seems that the higher the preoperative IOP before CP, the higher the achievable pressure after 1 year and in the long term. In contrast, after TE the IOP was effectively reduced in the long term regardless of the initial IOP. The CP seems to be inferior to TE under the same conditions with respect to complete surgical success (without local treatment).
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http://dx.doi.org/10.1007/s00347-020-01045-1DOI Listing
October 2020

Development of visual acuity under hyperbaric oxygen treatment (HBO) in non arteritic retinal branch artery occlusion.

Graefes Arch Clin Exp Ophthalmol 2020 Feb 20;258(2):303-310. Epub 2019 Dec 20.

Department of Ophthalmology, University Hospital RWTH Aachen, Aachen, Germany.

Purpose: Nonperfusion of retinal tissue due to arterial occlusion leads inevitably to mostly irreversible retinal damage. Until today no evidence-based treatment exists. Inhalation of 100% oxygen at high atmospheric pressure causes an increased solubility of oxygen in the blood that helps the retinal tissue to survive through diffusion in case of an artery occlusion till vascular recanalization occurs. Hence the purpose of this study is to compare the visual outcome in patients with retinal branch artery obstruction treated with hyperbaric oxygen versus patients treated with hemodilution only.

Methods: Non-randomized, monocentric, retrospective study. Patients with diagnosis of non-arteritic retinal branch artery occlusion (BRAO) treated with hyperbaric oxygen therapy between 1997 and 2017. Exclusion criteria were central retinal artery occlusion, presence of a cilioretinal artery and arteritic cases. The control group was matched based on visual acuity (VA) at admission, age, and delay between symptoms and beginning of clinical care.

Results: The control group and the matching oxygen group contained 14 patients each. Initial VA in the matched HBO group was 0.18 ± 0.19 and 0.23 ± 0.19 in the control group (p = 0.57). Final VA at discharge was 0.69 ± 0.29 in the matched oxygen group and 0.32 ± 0.23 in the control group (p = 0.0009). HBO-treated patients had a significant visual increase compared with the control group. The most common comorbidities were arterial hypertension and vascular sclerosis.

Conclusion: HBO treatment appears to have a beneficial effect on visual outcome in patients with retinal branch artery occlusion. HBO treatment could be a rescue therapy at an early stage of BRAO, especially to bridge the time of a potential reperfusion. However, further, prospective, randomized clinical trials are required to verify this assumption.
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http://dx.doi.org/10.1007/s00417-019-04568-9DOI Listing
February 2020

Reproducibility and reliability of central corneal thickness determination in more and less profound corneal edema using ultrasound pachymetry, a Scheimpflug camera and anterior segment OCT.

Graefes Arch Clin Exp Ophthalmol 2020 Feb 21;258(2):351-358. Epub 2019 Nov 21.

Dept. of Ophthalmology, RWTH Aachen University, Pauwels Str. 30, 52074, Aachen, Germany.

Purpose: The purpose of this study is to determine the influence of different degrees of corneal edema on the reliability and reproducibility of central corneal thickness(CCT) measurements by a Scheimpflug camera (Pentacam), anterior segment optical coherence tomography(AS-OCT) and ultrasound pachymetry(USP).

Methods: Forty-four patients undergoing ophthalmic surgery were included in this prospective study. All measurements were acquired by two investigators. The Pentacam and AS-OCT measurements were performed in randomized order followed by USP. Two measurements were taken by each investigator with each device. CCT was evaluated by using the apex value provided by the Pentacam, the corneal apex cut in the AS-OCT and averaging 2 cycles of 4 measurements for USP. Coefficients of variation (COV) and intraclass correlation coefficients (ICC) were determined. To investigate the reproducibility in different degrees of corneal edema, patients were subdivided into edema more/less than 10% of CCT, ≥/< 600 μm and > 650 μm CCT.

Results: No significant differences were recorded for each individual investigator and measuring device. However, overall the devices differed significantly in the < 600 μm group (ANOVA p < 0.04). The reproducibility decreased with higher degrees of corneal edema in particular for investigator 1 and USP measurements. No significant overestimation of corneal thickness by the Pentacam was recorded in higher degrees of corneal edema.

Conclusion: USP measurements are highly user dependent especially in higher degrees of corneal edema. Nevertheless, all methods were able to reach a high level of agreement in CCT measurement in higher degrees of corneal edema. Interestingly lower degrees of corneal edema revealed the only significant differences in-between the 3 devices.
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http://dx.doi.org/10.1007/s00417-019-04536-3DOI Listing
February 2020

Ocular Hemodynamics in Acute Nonarteritic Anterior Ischemic Optic Neuropathy Compared With Normal Tension Glaucoma.

J Glaucoma 2019 12;28(12):e180-e181

Department of Ophthalmology, RWTH Aachen University, Aachen, Germany.

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http://dx.doi.org/10.1097/IJG.0000000000001404DOI Listing
December 2019

Automated, Noncontact Intraocular Pressure Home Monitoring after Implantation of a Novel Telemetric Intraocular Pressure Sensor in Patients with Glaucoma: A Feasibility Study.

Biomed Res Int 2018 6;2018:4024198. Epub 2018 Dec 6.

Dept. of Ophthalmology, RWTH Aachen University, Aachen, Germany.

Purpose: Reliable and regular assessment of intraocular pressure (IOP) is important for the monitoring of patients with glaucoma. The purpose of this study was to evaluate the feasibility of a novel system for the automated, noncontact measurement of IOP.

Patients And Methods: A first-generation telemetric IOP sensor was previously implanted in the ciliary sulcus of six patients with open-angle glaucoma during cataract surgery. Using this technology, automated noninvasive tonometry may be performed in a home setting. In the present study, a modified sleep mask and a modified eyepatch with incorporated coil antennae for measurements during nighttime and daytime, respectively, were tested on a single patient.

Results: In this feasibility study, the 24 h wear of the prototype measuring apparatus was well tolerated. Three sequences of 24 h IOP measurements with at least 200 IOP measurements per day were performed (Sequence 1: mean 19.6 ± 2.7 mmHg, range 13.4-28.7 mmHg; Sequence 2: mean 21.0 ± 3.0 mmHg, range 13.1-30.5 mmHg; Sequence 3: mean 19.9 ± 2.4 mmHg, range 12.6-27 mmHg).

Conclusions: For the first time, repeated and automated 24-hour measurements are possible using a prototype noncontact reading system after implantation of a novel telemetric IOP sensor in patients with glaucoma.
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http://dx.doi.org/10.1155/2018/4024198DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6304593PMC
April 2019

Ocular Hemodynamics in Acute Nonarteritic Anterior Ischemic Optic Neuropathy Compared With Normal Tension Glaucoma.

J Glaucoma 2019 04;28(4):334-340

Department of Ophthalmology, RWTH Aachen University, Pauwelsstr., Aachen, Germany.

Purpose: The purpose of this study was to evaluate ocular hemodynamics in patients with a disease believed to be related to a chronic vascular damage [ie, normal tension glaucoma (NTG)] in comparison with an entity with an acute ischemic impact on the optic nerve [ie, acute nonarteritic anterior ischemic optic neuropathy (NAION)].

Materials And Methods: Blood-flow velocities [peak systolic velocity (PSV), enddiastolic velocity (EDV)] of the ophthalmic artery (OA), central retinal artery (CRA), and nasal and temporal posterior ciliary arteries were measured using color Doppler imaging. Resistive index (RI) of all vessels was calculated (PSV-EDV/PSV). A total of 41 patients suffering from acute NAION (onset of symptoms <10 d) and 64 age-matched patients suffering from NTG were included in this prospective study.

Results: No significant differences were recorded for either age or intraocular pressure inbetween the 2 groups. Systolic blood pressure was significantly higher in the NAION group, whereas no significant differences were recorded for the diastolic blood pressure. Only 3 color Doppler imaging parameters were found to differ significantly. The PSV (P<0.005) and EDV (P<0.02) in the CRA were significantly higher in NTG patients. Furthermore, the RI in the OA was significantly higher in the NAION patients (P<0.005).

Conclusions: Decreased blood-flow velocities in the CRA and a higher RI in the OA can be recorded in NAION patients as compared with NTG. No differences with regard to the posterior ciliary arteries' velocities were recorded. Ocular hemodynamics are suspected to play a critical role in NAION and NTG, whereas the blood-flow disturbances seem to be more severe in NAION than in NTG.
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http://dx.doi.org/10.1097/IJG.0000000000001177DOI Listing
April 2019

Blood Pressure and Heart Rate Variability in Primary Open-Angle Glaucoma and Normal Tension Glaucoma.

Curr Eye Res 2018 12 15;43(12):1507-1513. Epub 2018 Aug 15.

a Department of Ophthalmology , RWTH Aachen University , Aachen , Germany.

Purpose: Vascular dysfunction and ischemia are believed to play an important part in the pathogenesis of glaucoma and especially of normal tension glaucoma (NTG). The aim of the present study was to analyze the blood pressure (BP) and heart rate variability patterns in patients with primary open-angle glaucoma (POAG) and NTG compared with controls.

Methods: In total, 37 patients with POAG, 27 patients with NTG, and 82 control subjects were included in a prospective clinical validation study. Continuous BP and heart rate were simultaneously recorded over 30 min (Glaucoscreen, aviant GmbH, Jena, Germany) under resting conditions. Time series of heart rate, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were extracted and analyzed calculating univariate linear (time domain, frequency domain), nonlinear (symbolic dynamics), and bivariate (joint symbolic dynamics) indices.

Results: Overall, 12 parameters could be identified that were significantly different when comparing POAG patients and controls, whereas 80 parameters were significantly different in NTG patients compared with controls. The optimum set consisting of three indices showed a sensitivity of 81.5% at a specificity of 86.6% for NTG patients compared with a sensitivity of 62.2% at a specificity of 82.9% for POAG patients.

Conclusions: Alterations in BP variability and coupling with heart rate suggest impaired patterns of autonomic cardiovascular regulation in glaucoma patients especially in patients with NTG.
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http://dx.doi.org/10.1080/02713683.2018.1506036DOI Listing
December 2018

Acute Effect of Hypervolemic Hemodilution on Retrobulbar Hemodynamics in Anterior Ischemic Optic Neuropathy.

Biomed Res Int 2018 6;2018:4756313. Epub 2018 Feb 6.

Department of Ophthalmology, Uniklinik RWTH Aachen, Aachen, Germany.

Purpose: Ischemic ocular disorders may be treated by hypervolemic hemodilution. The presumed therapeutic benefit is based on a volume effect and improved rheological factors. The aim was to investigate the acute effect of intravenous hydroxyethyl starch on retrobulbar hemodynamics in patients with nonarteritic anterior ischemic optic neuropathy (NAION).

Methods: 24 patients with acute NAION were included. Retrobulbar hemodynamics were measured using color Doppler imaging before and 15 min after intravenous infusion of 250 cc 10% hydroxyethyl starch (HES). Peak systolic velocity (PSV), end diastolic velocity (EDV), and Pourcelot's resistive index (RI) were measured in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (PCAs).

Results: After infusion of HES blood flow velocities significantly increased in the CRA (PSV from 7.53 ± 2.33 to 8.32 ± 2.51  ( < 0.001); EDV from 2.16 ± 0.56 to 2.34 ± 0.55  ( < 0.05)) and in the PCAs (PSV from 7.18 ± 1.62 to 7.56 ± 1.55  ( < 0.01); EDV from 2.48 ± 0.55 to 2.66 ± 0.6 cm/sec ( < 0.01)). The RI of all retrobulbar vessels remained unaffected. Blood pressure and heart rate remained unchanged.

Conclusions: Hypervolemic hemodilution has an acute effect on blood flow velocities in the CRA and PCAs in NAION patients. Increased blood flow in the arteries supplying the optic nerve head may lead to a better perfusion in NAION patients. This trial is registered with DRKS00012603.
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http://dx.doi.org/10.1155/2018/4756313DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5818917PMC
August 2018

Retrobulbar and intraocular blood flow in anterior ischaemic optic neuropathy are linked to the functional impairment.

Int Ophthalmol 2019 Mar 13;39(3):597-604. Epub 2018 Feb 13.

Department of Ophthalmology, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany.

Purpose: Evaluation of ocular haemodynamics in patients with acute non-arteritic anterior ischaemic optic neuropathy (NAION) by colour Doppler imaging and fluorescein angiography and correlation of blood flow parameters to visual field loss and visual acuity.

Methods: Blood flow velocities (peak systolic velocity (PSV), end-diastolic velocity (EDV)) of the ophthalmic artery (OA), central retinal artery (CRA) and nasal and temporal posterior ciliary arteries (PCAs) were measured via colour Doppler imaging. Resistive index (RI) of all vessels was calculated (PSV-EDV/PSV). Retinal arteriovenous passage times (AVP) were evaluated using fluorescein angiography (scanning laser ophthalmoscope) and digital image analysis. The visual field global index mean deviation (MD, 30-2 programme, Humphrey Field Analyzer) and visual acuity (logMar) was used for analysis of functional impairment after NAION.

Results: Twenty patients (age: 64.62 ± 11.63 years) with acute NAION were included. Mean duration of symptoms was 7.6 ± 6.9 days. Mean defect was 15.4 ± 8.9 dB, AVP was determined with 1.66 ± 0.37 s. EDV of the CRA was significantly correlated to visual field MD (r = 0.52, p = 0.017) and AVP (r = - 0.49, p = 0.025). The RI of the OA was significantly correlated to visual acuity (r = 0.493, p < 0.037). No significant correlations were recorded for the PCAs. A significant correlation was found between AVP and the EDV of the CRA (r = - 0.49, p = 0.025).

Conclusion: Decreased EDV in the CRA and increased RI in the OA seem to be linked to the functional damage in NAION. An improvement of the retrobulbar circulation might be beneficial in the treatment of NAION.
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http://dx.doi.org/10.1007/s10792-018-0846-xDOI Listing
March 2019

Evaluation of Long-term Anatomic Changes Following Canaloplasty With Anterior Segment Spectral-domain Optical Coherence Tomography and Ultrasound Biomicroscopy.

J Glaucoma 2018 01;27(1):87-93

Department of Ophthalmology, RWTH Aachen University, Aachen, Germany.

Background: To analyze long-term structural changes in conjunctiva, sclera and Schlemm canal (SC) with anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) following uncomplicated canaloplasty.

Materials And Methods: Fifteen patients with planned canaloplasty and no intraoperative complications were included in this prospective study. AS-OCT images were acquired at 1, 3, 6 months and at a long-term time point (20±4.9 mo) postsurgery. UBM images were acquired at 3, 6 months and long-term after canaloplasty. The surgical site was evaluated for the presence of SC, transscleral filtration, a scleral lake, and the visibility of intra-Schlemm sutures. The SC's height and width were measured at the 3 and 9 o'clock limbus position.

Results: Following canaloplasty, the intraocular pressure was successfully reduced from 23.43±5.52 to 12.6±1.78 mm Hg (P<0.0001) at the final control visit. Topical medication was reduced from 2.9±1.1 to 0.4±0.6 over the same period. SC's increase in height was higher than that in width at the last visit (height: +351%, P=0.0004, width: +144%, P=0.002). With the UBM the SC was easily identifiable by the reflection of the tractions sutures in 75% of the patients at the last visit. Transscleral filtration was detectable in 42% of the patients at the last visit using AS-OCT and a scleral lake was still detectable by OCT in 25% of the patients and even in 42% of the patients by UBM.

Conclusions: Persisting anatomic changes of SC, a transscleral filtration and a scleral lake can be recorded by AS-OCT and UBM long-term after successful canaloplasty.
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http://dx.doi.org/10.1097/IJG.0000000000000827DOI Listing
January 2018

[Diagnostic Precision of the Confocal Scanning Laser Ophthalmoscopy in the Large Optic Disc with Physiological Excavation - a Long-Term Study].

Klin Monbl Augenheilkd 2019 Jan 6;236(1):88-95. Epub 2017 Jul 6.

Augenklinik, Uniklinik RWTH Aachen.

We repeatedly examined 17 subjects with presumed bilateral physiological excavation labeled as pathological and/or borderline via HRT to verify the diagnosis of physiological cupping or to monitor the long-term progression into normal tension glaucoma.

Patients And Methods: 17 Subjects with presumed bilateral physiological cupping and large optic discs were included in this long-term follow-up study. All subjects underwent regular detailed ophthalmologic examinations, including intraocular pressure measurement via Goldmann applanation tonometry (GAT), retinal nerve fiber layer imaging via optical coherence tonometry (OCT) and visual field testing and optic disc imaging using the HRT. Glaucomatous progression was identified using the HRT's tools (stereometric trend analysis [STA] and topographic change analysis [TCA]).

Results: In the initial examination, all 17 subjects were classified as "pathological", by the HRT's Moorfield's Regression Analysis (MRA). Over the observation period of 9.2 ± 5 years, only 1 of the 17 subjects showed an ensured conversion to normal tension glaucoma with glaucomatous visual field defects. The remaining 16 subjects show no visual field defects to date. STA showed significant changes in 3 subjects alone, in 1 subject TCA showed a significant change alone, and in 1 subject both analyses showed a progressive change.

Conclusion: After 9 years of regular examinations, 16 of the 17 subjects that were classified as "pathological" using MRA showed no glaucomatous visual field defects. In 5 out of these 16 subjects, progressive changes of the optic disc could be recorded via HRT. Therefore, the diagnostic precision of the HRT measurements seems to be limited in patients with large discs and physiological cupping.
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http://dx.doi.org/10.1055/s-0043-111798DOI Listing
January 2019

Three-Year Follow-Up of Trabeculectomy with 5-Fluorouracil.

Ophthalmic Res 2017 28;58(2):74-80. Epub 2017 Apr 28.

Department of Ophthalmology, RWTH Aachen University, Aachen, Germany.

Purpose: To evaluate the long-term outcome of trabeculectomy with intra- and postoperative 5-fluorouracil (5-FU) application in glaucoma.

Methods: Eighty-six patients with glaucoma planned for primary trabeculectomy with 5-FU and a minimum follow-up of 3 years were retrospectively analyzed. Success rates, postsurgical 5-FU injections, needling procedures, and complications were analyzed.

Results: Mean intraocular pressure (IOP) decreased from 27.2 ± 6.7 to 13.2 ± 4.2 mm Hg at 1 year and 13.8 ± 3.7 mm Hg at the 3-year follow-up. The complete success rates (no IOP-lowering medication) were 83, 79, 73, and 45% at 1 year for IOP ≤21, ≤18, ≤16, and ≤12 mm Hg, respectively, and 64, 59, 56, and 20% for these criteria at 3 years. The average number of medications decreased from preoperatively 2.9 ± 1.4 to 0.2 ± 0.5 at 1 year and 0.7 ± 1.1 at 3 years. During the first 6 months, subconjunctival 5-FU injections were performed in 49 cases. Eleven patients underwent bleb needling during the first 6 months and 13 patients underwent the procedure between the 6th month and the 3rd year. Malignant glaucoma and bleb-related endophthalmitis occurred in 1 patient each.

Conclusions: Trabeculectomy with 5-FU is an efficient surgical procedure for glaucoma treatment when combined with intensified postsurgical care.
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http://dx.doi.org/10.1159/000464446DOI Listing
September 2017

The effect of air, SF6 and C3F8 on immortalized human corneal endothelial cells.

Acta Ophthalmol 2017 Jun 6;95(4):e284-e290. Epub 2016 Sep 6.

Department of Ophthalmology, RWTH Aachen University, Aachen, Germany.

Purpose: While anterior chamber air bubbles aid attachment during posterior lamellar surgery only for few days, these periods can be prolonged with gases in non-expanding concentrations. To test the effects of different gas compositions on immortalized human corneal endothelial cells (HCEC-12), we utilized Transwell inserts with semipermeable membranes as an artificial anterior chamber model.

Methods: Human corneal endothelial cells (HCEC-12) were cultured on Transwell inserts for 24 hr, then flipped, burdened and sunk with titanium rings in medium (M1), as well as filled with 2 ml of air (A), 20% sulphur hexafluoride (SF6) (S), or 12% C3F8 (C). After gas exposition for 24, 48 and 120 hr, cells were evaluated by live/dead staining, cell viability assay and Ki67 immunohistochemistry.

Results: Proliferation was significantly reduced (Ki67-positive fraction; M1, 14.8 ± 2.0%; A, 7.9 ± 1.4%; S, 8.1 ± 1.3%; C, 9.9 ± 2.3%; p-values; A, S, C versus M1 < 0.01), the total cell number decreased and the percentage of dead cells increased under gas exposition, independently of the type of gas (120 hr cell count/2.25 cm : M1 = 660.8 ± 57.0 cells; A = 125.5 ± 17.4 cells, S = 123.5 ± 17.0 cells, C = 118.8 ± 16.6 cells; p-value: M versus A/S/C < 0.001; 120 hr dead cells: M = 2.6 ± 1.0%, A = 8.4 ± 2.7%, S = 9.5 ± 3.2%, C = 11.3 ± 3.1%; p-value: M1 versus A/S/C < 0.01). Medium (M1)-control also proved significantly higher cell viability values in comparison with the gases, which did not differ significantly among them (120 hr luminescence: M1 = 1752.2 ± 91.4, A = 433.0 ± 30.3, S = 507.8 ± 23.3, C = 523.8 ± 20.3; p-value: M1 versus A/S/C < 0.01).

Conclusions: Gas exposition led to a reduction in proliferation and an increase in cell death in HCEC-12, independently of the gas composition.
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http://dx.doi.org/10.1111/aos.13256DOI Listing
June 2017

Gebauer SLc Original and Moria One-Use Plus automated microkeratomes for ultrathin Descemet's stripping automated endothelial keratoplasty preparation.

Acta Ophthalmol 2016 Dec 28;94(8):e731-e737. Epub 2016 May 28.

Department of Ophthalmology, RWTH Aachen University, Aachen, Germany.

Purpose: We compared the SLc Original (SLc) and One-Use Plus (OUP) microkeratomes for ultrathin Descemet's stripping automated endothelial keratoplasty (DSAEK) lamella preparation and storage, vis-à-vis accuracy, endothelial cell loss (ECL) and lamellar surface roughness (LSR).

Methods: Twenty-five human corneas were dissected with single-use heads of different sizes aiming for a posterior lamella (PL) thickness of 85 μm, after which they were incubated for 6 days in a 5% dextran medium. Before preparation (0 hr) and 1, 24, and 144 hr after dissection, ECL and corneal thickness (CCT) were measured by ultrasound pachymetry (USP) and optical coherence tomography (OCT). Lamellar surface roughness (LSR) was assessed by scanning electron microscopy (SEM) and evaluated by two masked observers.

Results: Prior to cutting, CCTs did not differ between OCT and USP measurements, with a high correlation between the two modalities (r  = 0.8; p < 0.0001). Both systems succeeded in UT lamella preparation (CCT 40-130 μm) in 88% of cases. The OUP heads cut significantly deeper than the according SLc counterparts (p = 0.001), while the variance did not differ. The mean PL thickness increased significantly in the following incubation period (p = 0.01) with no difference between the keratome groups. Endothelial cell density (ECD) decreased significantly from before to 1 hr after preparation (-5.6%; p = 0.04), with no changes in the following 144-hr incubation period and no differences between the OUP and SLc group. Lamellar surface roughness (LSR) did not differ between both systems.

Conclusions: The SLc and the OUP system are both suited for the preparation of UT-DSAEK lamellae. Neither system differed significantly in variability, LSR or ECL, which did not increase during a 6-day incubation period.
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http://dx.doi.org/10.1111/aos.13118DOI Listing
December 2016

Evaluation of early anatomical changes following canaloplasty with anterior segment spectral-domain optical coherence tomography and ultrasound biomicroscopy.

Acta Ophthalmol 2016 Aug 9;94(5):e287-92. Epub 2015 Dec 9.

Department of Ophthalmology, RWTH Aachen University, Aachen, Germany.

Purpose: To analyse structural changes in conjunctiva, sclera and Schlemm's canal (SC) following canaloplasty with optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM).

Methods: Fifteen patients undergoing canaloplasty were included in this prospective study. AS-OCT images were acquired pre- and 1, 7, 30 and 90 days postoperatively. UBM was performed 3 months postoperatively. The surgical site was evaluated for the presence of SC, transscleral filtration, a scleral lake and the visibility of intra-Schlemm-sutures. The height and width of SC were measured at the 3 and 9 o'clock limbus position.

Results: After canaloplasty, SC was detectable with AS-OCT in 93% of the patients on day 1. The increase in height was higher than that in width (height: +369%, p = 0.0004, width: +152%, p = 0.002). IOP was negatively correlated to SC's width 1 week postoperatively (r = -0.63, p = 0.04) and to SC's height until 3 months (r = -0.66, p = 0.02) postoperatively. Using UBM, a reflection of the traction sutures indicated SC's position in all patients. Transscleral filtration was found in all patients using AS-OCT, demonstrating a peak 1 week postoperatively. At 3 months, a scleral lake could be visualized in 50% and 83% of patients using AS-OCT and UBM, respectively.

Conclusions: AS-OCT offers a high resolution for imaging superficial conjunctival areas and SC after canaloplasty, whereas UBM is capable of detecting deeper structures such as scleral lakes or intra-canal-sutures. The results imply a correlation of the dilation of SC with the IOP-lowering effect and an early pronounced transscleral filtration following canaloplasty.
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http://dx.doi.org/10.1111/aos.12917DOI Listing
August 2016

Blue-yellow and standard pattern visual evoked potentials in phakic and pseudophakic glaucoma patients and controls.

Graefes Arch Clin Exp Ophthalmol 2015 Dec 4;253(12):2255-61. Epub 2015 Sep 4.

Department of Ophthalmology, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany.

Purpose: Blue-yellow short wavelength testing (BY-VEPs) has proven diagnostic relevance in detecting early ganglion cell damage, e.g., in glaucoma. To date testing has generally been conducted using individual protocols without consideration of the lens status. In this study, we compared changes in BY-VEPs and standard pattern VEPs in phakic and pseudophakic glaucoma patients and controls.

Methods: The eyes of 57 healthy controls (18 pseudophakic and 39 phakic) and 67 glaucoma patients (29 pseudophakic and 38 phakic) were included in a prospective study. Phakic eyes were arranged in three groups according to the Lens Opacities Classification System III. Transient on/off isoluminant blue-yellow 2° checks were used for BY-VEPs, transient large 1° (M1) and small 0.25° (M2) black-white checks for standard pattern reversal VEPs, according to the ISCEV standards.

Results: Latencies and amplitudes of M1 and M2 did not differ significantly between groups or lens status. ANOVA analysis revealed significantly longer BY-VEP latencies in glaucoma compared to controls (p = 0.002), independently of the lens status. The amplitudes showed no such pattern (p = 0.93). Mean defect (MD) was significantly negatively correlated to BY-VEP latency (r = -0.54, p = 0.003) only in pseudophakic glaucoma patients. Different stages of cataract did not show a significant effect on the BY-VEP latencies.

Conclusions: Glaucoma led to a significant increase of BY-VEPs latencies, while standard pattern VEPs were not influenced. The correlation of MD and BY-VEP latency only in pseudophakic glaucoma patients indicates a substantial confounding effect of lens opacifications on the diagnostic value of BY-VEPs in glaucoma.
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http://dx.doi.org/10.1007/s00417-015-3152-6DOI Listing
December 2015

Retinochoroidal toxoplasmosis in a patient with cerebral post-transplant lymphoproliferative disease of Hodgkin's type: a diagnostic challenge.

J Ophthalmic Inflamm Infect 2015 Dec 4;5(1):55. Epub 2015 Aug 4.

Dalmia Ophthalmic Pathology Services, L.V. Prasad Eye Institute, Bhubaneswar, India,

Toxoplasmosis is a relatively rare complication in renal transplant patients and can pose diagnostic challenges, especially when it manifests as an ocular inflammation. Authors hereby report an unusual case of a 57-year-old male who developed retinochoroidal toxoplasmosis after 15 years of renal transplant, the diagnoses of which were challenging as the patient was also a known case of cerebral post-transplant lymphoproliferative disease (PTLD) of Hodgkin's type, which misled the ophthalmologists towards a clinical diagnosis of ocular PTLD. Histopathology examination of the enucleated eye revealed numerous toxoplasmosis cysts within the retina and choroid. No ocular PTLD was observed.
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http://dx.doi.org/10.1186/s12348-015-0055-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4523567PMC
December 2015

Central corneal thickness determination in corneal edema using ultrasound pachymetry, a Scheimpflug camera, and anterior segment OCT.

Graefes Arch Clin Exp Ophthalmol 2015 Jul 21;253(7):1105-9. Epub 2015 Apr 21.

Department of Ophthalmology, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany,

Purpose: The purpose of this study is to determine the influence of post-surgical corneal edema on the reliability and reproducibility of central corneal thickness (CCT) measurements by a Scheimpflug camera (Pentacam), ultrasound pachymetry (USP), and anterior-segment spectral-domain optical coherence tomography (AS-OCT).

Methods: Thirty-two patients planned for cataract surgery (n = 16) or vitrectomy (n =  6) were included in a prospective study. The non-surgery eye was used as control. Two investigators acquired two measurements each, with the Pentacam (Oculus, Germany) and the AS-OCT (Heidelberg Engineering, Germany) in a randomized order, followed by USP (Tomey SP-100, Germany). CCT was evaluated using the apex value for Pentacam, the corneal apex cut in AS-OCT and averaging eight single measurements for USP. Coefficients of variation (COV) and intra-class correlation coefficients (ICC) were determined.

Results: Post-surgery corneas showed a thickness of (investigators 1 and 2): Pentacam (615.9 ± 58.02 μm and 615.1 ± 60.17 μm), USP (601.4 ± 63.77 μm and 614.5 ± 70.91 μm), AS-OCT (608.8 ± 65.67 μm and 606.9 ± 64.41 μm) ,with no significant difference (ANOVA p > 0.99). The COVs (investigators 1 and 2) for control eyes were: Pentacam (0.78 ± 0.52 and 0.70 ± 0.76), USP (0.66 ± 0.29 and 0.98 ± 0.44), AS-OCT (0.59 ± 0.61 and 0.59 ± 0.40). The COVs (investigators 1 and 2) for post-surgical eyes were: Pentacam (0.98 ± 1.25 and 0.97 ± 0.73), USP (0.73 ± 0.64 and 1.35 ± 0.85), AS-OCT (1.34 ± 1.57 and 1.19 ± 1.18).The ICC was determined in post-surgery corneas (ICC > 0.96) and control corneas (ICC > 0.95).

Conclusion: USP measurements have the highest user dependence. Post-surgical corneal edema leads to higher intraobserver variability. All methods reached a high level of agreement in CCT determination in edematous as well as healthy corneas.
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http://dx.doi.org/10.1007/s00417-015-2998-yDOI Listing
July 2015

Comparison of Gebauer SLc and Moria CBm Carriazo-Barraquer ALK Microkeratomes for Descemet's Stripping Automated Endothelial Keratoplasty Preparation.

Curr Eye Res 2016 24;41(3):343-9. Epub 2015 Mar 24.

a Department of Ophthalmology , RWTH Aachen University , Aachen , Germany.

Purpose: We compared the hand-guided Moria Carriazo-Barraquer (CBm) microkeratome with the fully automatic SLc microkeratome for Descemet's stripping automated endothelial keratoplasty (DSAEK)-lamella preparation and storage, vis-à-vis accuracy, endothelial cell loss (ECL), and lamellar surface roughness (LSR).

Methods: A total of 18 human corneas were dissected with both the 300 μm CBm multi-use (n = 9) and the 300 µm SLc (n = 9) single-use heads, after which they were incubated for 6 d in a 5% dextran medium. Before preparation (0 h) and 1, 24, and 144 h after dissection, ECL and corneal thickness (CT) were measured by ultrasound pachymetry (USP) and optical coherence tomography (OCT). LSR was assessed by scanning electron microscopy (SEM) and evaluated by three masked observers.

Results: Prior to cutting, CTs did not differ significantly between OCT or USP measurements, with a high correlation between the two modalities (r(2)= 0.94, p < 0.0001). One hour after preparation the anterior lamella showed a significantly higher dissection depth with the CBm (429.4 ± 21.8 µm) than the SLc (311.7 ± 54.8 µm, p = 0.0006), with the variance of the SLc system showing a trend towards higher values (p = 0.07). Anterior and posterior lamellae swelled significantly in the subsequent culture period. Both groups showed a significant ECL 1 h after preparation (p < 0.0001) with no significant difference between the systems (1 h: p = 0.44; CBm: - 9.4%, SLc: -11.7%), which stabilized over 144 h (144 h CBm: -13.9%, 144 h SLc: -10.3%). LSR did not differ significantly between both systems (p = 0.60).

Conclusions: The SLc system agrees more with the designated cutting depth than the CBm. The dissection produced a comparable LSR and a ∼10% ECL independently of the system. Further incubation of the prepared lamellae led to a swelling, but no further ECL.
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http://dx.doi.org/10.3109/02713683.2015.1015141DOI Listing
December 2016

Transplantation of PEDF-transfected pigment epithelial cells inhibits corneal neovascularization in a rabbit model.

Graefes Arch Clin Exp Ophthalmol 2015 Jul 18;253(7):1061-9. Epub 2015 Feb 18.

Department of Ophthalmology, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany.

Background: The purpose of this study was to investigate the effect of recombinant pigment epithelium-derived factor (rPEDF), secreted by ARPE-19 cells transfected with the human PEDF gene and transplanted subconjunctivally in normal and in rabbits in which corneal neovascularization was elicited by a chemical burn.

Methods: Twenty grey Chinchilla Bastard rabbits were randomly assigned to four groups; neovascularization was induced in groups A, B, and C by alkali cauterization. Seven days later, group A received no cell implantation, non-transfected ARPE-19 cells were implanted subconjunctivally in group B, and PEDF-transfected ARPE-19 cells were implanted subconjunctivally in groups C and D (non-cauterized). In-vivo rPEDF secretion was analyzed by immunoblotting, and ELISA of extracts of conjunctival tissue samples taken at different time points. Digital photographs acquired on days 7, 14, and 21 after cauterization were evaluated for lead vessel length, vascular invasion area, and overall neovascularization rate.

Results: At days 14 and 21 after cauterization, significant differences were observed between groups A, B, and C in lead vessel length (day 21: 5.91 ± 0.45, 5.11 ± 1.22, 3.79 ± 0.59 mm, repectively), vascular invasion area (day 21: 35.5 ± 8.65, 34.86 ± 4.92, 19.2 ± 5.03 mm(2) respectively), and rate of corneal neovascularization. Compared to controls, neovascularization was reduced by 37.5 % on day 14 and 47 % on day 21. Analysis of conjunctival tissue extracts showed that rPEDF was secreted by the transplanted PEDF-transfected cells.

Conclusion: Subconjunctivally transplanted, PEDF-transfected ARPE-19 cells secrete rPEDF, which inhibits the corneal neovascularization elicited by alkali cauterization.
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http://dx.doi.org/10.1007/s00417-015-2954-xDOI Listing
July 2015

Long term effect of trabeculectomy on retrobulbar haemodynamics in glaucoma.

Ophthalmic Physiol Opt 2015 Mar 20;35(2):194-200. Epub 2014 Dec 20.

Department of Ophthalmology, RWTH Aachen University, Aachen, Germany.

Purpose: Previous reports showed increased flow velocities in retrobulbar vessels after glaucoma surgery in the first weeks. Colour Doppler imaging was performed to investigate the long-term effects of trabeculectomy on retrobulbar haemodynamics in patients with primary open-angle glaucoma (POAG).

Methods: In a prospective study 30 patients (mean age 63.2 ± 15.4 years) with POAG were included. Colour Doppler imaging was performed before 1-2 weeks, after 2 months, after 4-6 months, and up to 3 years after trabeculectomy to determine the peak systolic and end-diastolic velocities in the ophthalmic artery, central retinal artery, and the short nasal and temporal posterior ciliary arteries.

Results: Mean follow-up was 416 ± 246 days. In the first postsurgical period mean intraocular pressure (IOP) decreased after trabeculectomy from 25 ± 6 mmHg to 9 ± 4 mm Hg (p < 0.0001) and then increased in the further follow-up to 13 ± 3 mmHg (p < 0.05) without any anti-glaucomatous medication. Colour Doppler imaging revealed a significant increase of the end-diastolic velocities of the central retinal artery at all postoperative visits compared to pre-surgery (p < 0.003) and of the end-diastolic velocities in the temporal posterior ciliary arteries (p < 0.003). The change of blood flow parameters that increased during follow-up was significantly correlated to the change in ocular perfusion pressure and IOP.

Conclusions: End-diastolic velocities of the central retinal artery and of the temporal posterior ciliary arteries increased after successful trabeculectomy and remained stable in a longer period - even if IOP rose significantly in the follow-up.
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http://dx.doi.org/10.1111/opo.12188DOI Listing
March 2015
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