1,198 results match your criteria Corneal Topography and Imaging

Effect of intracorneal ring segments on posterior corneal topography in eyes with keratoconus.

Arch Soc Esp Oftalmol (Engl Ed) 2022 Jun 22. Epub 2022 Jun 22.

Professor of Ophthalmology and Ophthalmic Surgery, Faculty of Medicine, Ain Shams University, Cairo, Egypt.

Purpose: To analyze the changes in the anterior and posterior corneal surfaces measured with a Scheimpflug imaging device in keratoconus patients implanted with intracorneal ring segments (ICRS) and to correlate those changes with the visual outcomes.

Methods: This prospective interventional case series study included 92 eyes of 60 patients with keratoconus who underwent Kerarings (Mediphacos, Belo Horizonte, Brazil) ICRS implantation. Keratometric (K) readings, corneal asphericity (Q value) and elevations of both anterior and posterior corneal surfaces were evaluated using a Scheimpflug imaging device preoperatively and at 1, 3, 6 and 12 months after surgery. Read More

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Oxidation-mediated scaffold engineering of hyaluronic acid-based microcarriers enhances corneal stromal regeneration.

Carbohydr Polym 2022 Sep 27;292:119668. Epub 2022 May 27.

Graduate Institute of Biomedical Engineering, Chang Gung University, Taoyuan 33302, Taiwan; Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taoyuan 33305, Taiwan; Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan; Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 33303, Taiwan. Electronic address:

The functional design of scaffolding biomaterials with potent capabilities of promoting cell adhesion and proliferation is critically important for tissue repair and regeneration. Here, we exploit the effects of oxidation level of aldehyde hyaluronic acid (oHA) on gelatin microcarriers for repairing corneal injuries. Specifically, high oxidation levels can endow the microcarrier surface with large oHA grafting amount, smooth topography, and strong stiffness, consequently formulating biocompatible scaffolding materials with superior affinities for keratocyte attachment and growth. Read More

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September 2022

Clinical Study on the Differential Diagnosis of High Myopia Astigmatism and Subclinical Keratoconus in Adolescents by Pentacam Anterior Segment Analyzer.

Contrast Media Mol Imaging 2022 16;2022:6370791. Epub 2022 May 16.

Department of Ophthalmology, Xiaoshan Hospital Affiliated to Hangzhou Normal University, No. 728, Yucai North Road, Xiaoshan District, Hangzhou 311002, Zhejiang, China.

To explore the clinical value of Pentacam anterior segment analyzer in differential diagnosis of high myopia astigmatism and subclinical keratoconus in adolescents. The study included 100 teenagers with ophthalmic diseases treated at our hospital between July 2015 and August 2021, including 58 individuals with simple high myopia astigmatism (73 eyes in the simple high myopia astigmatism group) and 42 teenagers with subclinical keratoconus (51 eyes in the subclinical keratoconus group). The corneal parameters of the two groups were measured with a Pentacam anterior segment analyzer, and we compared the thinnest corneal thickness, anterior (posterior) vertex height of the thinnest point of the cornea, index of vertical asymmetry (IVA), index of height descent (IHD), and the average corneal pachymetric progression index. Read More

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Agreement of total corneal power between 2 swept-source optical coherence tomography and Scheimpflug tomography in normal and keratoconic patients.

PLoS One 2022 24;17(5):e0268856. Epub 2022 May 24.

Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.

Purpose: To evaluate agreement of total corneal power (TCP) measured by swept-source anterior segment optical coherence tomography (CASIA 2), Scheimpflug tomography (Pentacam AXL), and swept-source optical biometer (IOLMaster 700) in normal and keratoconic patients.

Methods: This is a prospective observational study conducted at King Chulalongkorn Memorial Hospital, Bangkok, Thailand. Biometric values were measured by each device for three times by two operators to evaluate repeatability and reproducibility of TCP. Read More

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Repeatability and reproducibility of the galilei G6 and its agreement with the pentacam® AXL in optical biometry and corneal tomography.

Expert Rev Med Devices 2022 Apr 19;19(4):375-383. Epub 2022 May 19.

Zeimer Ophthalmic Systems AG, Port, Switzerland.

Objectives: To assess the repeatability and reproducibility of corneal measurements performed by the Galilei G6 and determine its agreement with the Pentacam® AXL.

Methods: 105 eyes underwent examination by both devices, measuring nine parameters. Paired t-tests, Deming Regression, and Bland-Altman plots were used to determine agreement. Read More

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Ray tracing biometry in post radial keratotomy eye.

Eur J Ophthalmol 2022 May 15:11206721221102268. Epub 2022 May 15.

Department of Ophthalmology, 29590AFMC, Pune, Maharashtra, India.

Objective: To report a case of post radial keratotomy (RK) cataract in a 55-year-old lady wherein biometry was done by ray-tracing method incorporated in scheimpflug topographer (Sirius + Scheimpflug Analyzer, CSO, Italy).

Method: In our case, we performed intraocular lens (IOL) power calculation using a recent concept of ray tracing with scheimpflug topographer and compared with traditional methods available at American Society of Cataract and Refractive Surgery(ASCRS) website (www.ascrs. Read More

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Biomechanical Evaluation of Topographically and Tomographically Normal Fellow Eyes of Patients With Keratoconus.

J Refract Surg 2022 May 1;38(5):318-325. Epub 2022 May 1.

Purpose: To determine the effectiveness of parameters and indices based on biomechanical measures at discriminating fellow eyes with topographically and tomographically normal corneas in patients with keratoconus from normal control corneas.

Methods: The study included 47 keratoconus suspect eyes, defined as the topographically and tomographically normal fellow eyes of patients with frank keratoconus in the other eye. Eyes were imaged using the Pentacam HR and Corvis ST (both Oculus Optikgeräte GmbH). Read More

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Anterior Ocular Biometrics Using Placido-scanning-slit System, Rotating Scheimpflug Tomography, and Swept-source Optical Coherence Tomography.

Korean J Ophthalmol 2022 06 6;36(3):264-273. Epub 2022 May 6.

The Institute of Vision Research, Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.

Purpose: To compare anterior biometry measurements using placido-scanning-slit topography, rotating Scheimpflug tomography, and swept-source optical coherence tomography.

Methods: A retrospective review consisted of 80 eyes of 49 participants who underwent anterior chamber depth (ACD), central corneal thickness (CCT), and keratometry examination on the same day. We used placido-scanning-slit topography (ORBscan II), rotating Scheimpflug tomography (Pentacam HR), and swept-source optical coherence tomography (CASIA SS1000). Read More

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Prediction of Pentacam image after corneal cross-linking by linear interpolation technique and U-NET based 2D regression model.

Comput Biol Med 2022 Jul 20;146:105541. Epub 2022 Apr 20.

Firat University, Faculty of Engineering, Computer Engineering, Elazig, Turkey. Electronic address:

Keratoconus is a common corneal disease that causes vision loss. In order to prevent the progression of the disease, the corneal cross-linking (CXL) treatment is applied. The follow-up of keratoconus after treatment is essential to predict the course of the disease and possible changes in the treatment. Read More

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Trends in Corneal Topography and Tomography Imaging for Keratoconus Management.

Clin Ophthalmol 2022 28;16:1357-1363. Epub 2022 Apr 28.

Department of Ophthalmology, University of California San Francisco, San Francisco, CA, USA.

Purpose: To describe trends in the use of corneal topography and tomography for the management of keratoconus patients at a single academic institution and to identify how these trends may be associated with different procedural interventions.

Patients And Methods: In this retrospective cohort study, keratoconus patients treated from 2012 to 2019 were identified. The electronic health record was reviewed for the presence of corneal topography or tomography imaging completed within seven days of the first visit and the highest level of intervention at the first and most recent visit. Read More

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Simultaneous Corneal Topography and Epithelial Thickness Mapping from a Single Measurement Using Optical Coherence Tomography.

J Ophthalmol 2022 21;2022:7339306. Epub 2022 Apr 21.

Department of Ophthalmology, Nicolaus Copernicus University, 9 M. Sklodowskiej-Curie Street, Bydgoszcz 85-309, Poland.

Purpose: To evaluate the performance of corneal epithelial thickness mapping (ETM) and demonstrate simultaneous measurement of ETMs and corneal topography using REVO NX (Optopol Technology, Zawiercie, Poland)-an OCT device for anterior and posterior segment imaging.

Methods: One hundred thirty-seven eyes of 137 normal subjects and patients with corneal diseases were recruited to the study. Each subject was scanned with REVO NX. Read More

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Intraobserver Repeatability of Tomographic, Pachymetric, and Anatomical Measurements in Healthy Eyes Using a New Swept-Source Optical Coherence Topographer.

Cornea 2022 May;41(5):598-603

Specialized Care Unit of Ophthalmology, Elche, Alicante, Spain.

Purpose: The purpose of this study was to evaluate the intraobserver repeatability of several corneal parameters in healthy eyes using a new swept-source optical coherence topographer.

Methods: Fifty right eyes of 50 subjects were enrolled in this study. A single examiner performed 3 consecutive measurements using the Anterion swept-source optical coherence tomography. Read More

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Keratoconus Classification with Convolutional Neural Networks Using Segmentation and Index Quantification of Eye Topography Images by Particle Swarm Optimisation.

Biomed Res Int 2022 22;2022:8119685. Epub 2022 Mar 22.

Department of Electronics and Communication Engineering, St Peter's Institute of Higher Education and Research, Chennai, India.

In keratoconus, the cornea assumes a conical shape due to its thinning and protrusion. Early detection of keratoconus is vital in preventing vision loss or costly repairs. In corneal topography maps, curvature and steepness can be distinguished by the colour scales, with warm colours representing curved steep areas and cold colours representing flat areas. Read More

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Detection of subclinical keratoconus using a novel combined tomographic and biomechanical model based on an automated decision tree.

Sci Rep 2022 03 29;12(1):5316. Epub 2022 Mar 29.

Aier Eye Hospital of Wuhan University, Wuhan, People's Republic of China.

Early detection of keratoconus is a crucial factor in monitoring its progression and making the decision to perform refractive surgery. The aim of this study was to use the decision tree technique in the classification and prediction of subclinical keratoconus (SKC). A total of 194 eyes (including 105 normal eyes and 89 with SKC) were included in the double-center retrospective study. Read More

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The false positive rates for detecting keratoconus and potential ectatic corneal conditions when evaluating astigmatic eyes with Scheimpflug Technology.

Eur J Ophthalmol 2022 Mar 21:11206721221081467. Epub 2022 Mar 21.

481087Gavin Herbert Eye Institute, University of California, Irvine, California, USA.

Purpose: To quantify the false positive rates for keratoconus (KC) and potential ectatic corneal conditions in highly astigmatism eyes when using published parameters/indices obtained from the Pentacam and Galilei units.

Setting: Oftalmosalud Instituto de Ojos, Lima, Peru.

Design: Prospective cohort study. Read More

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Optical Evaluation of Intracorneal Ring Segment Surgery in Keratoconus.

Transl Vis Sci Technol 2022 03;11(3):19

Instituto de Óptica "Daza de Valdés", Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.

Purpose: The purpose of this study was to assess the impact of different intracorneal ring segments (ICRS) combinations on corneal morphology and visual performance on patients with keratoconus.

Methods: A total of 124 eyes from 96 patients who underwent ICRS surgery were analyzed and classified into 7 groups based on ICRS disposition and the diameter of the surgical zone (5- and 6-mm). Pre- and postoperative complete ophthalmological examinations were conducted. Read More

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Acquisition Time for Swept-Source Optical Biometry Plus Corneal Power Measurement During Cataract Evaluation.

Clin Ophthalmol 2022 5;16:661-668. Epub 2022 Mar 5.

Cataract and Refractive Surgery Department, Oftalvist Jerez de la Frontera, Jerez de la Frontera, Spain.

Purpose: To compare the acquisition time necessary to obtain the optical biometry plus corneal power measurement using the IOLMaster 700 with central topography with that found using the standard IOLMaster 700 in combination with two corneal topographers, when acquiring biometry measurements during cataract evaluation.

Methods: This prospective, observational, controlled study included 96 eyes of 96 cataract patients. Acquisition times were registered for different conditions: time required for one complete measurement with IOLMaster 700 with central topography, time required for one complete measurement with standard IOLMaster 700 (without central topography), time required for one complete measurement with standard IOLMaster 700 plus time required for one complete measurement with Cassini, and time required for one complete measurement with standard IOLMaster 700 plus time required for one complete measurement with Pentacam HR. Read More

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Analysis of keratometric measurements in accordance with axial length in an aged population.

Sci Rep 2022 03 8;12(1):4087. Epub 2022 Mar 8.

Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea.

To investigate keratometric measurements according to axial length in an aged population. Patients requiring cataract surgery with keratometric measurements from four different ophthalmic devices (autorefractor/keratometer, Scheimpflug imaging, corneal topography/ray-tracing aberrometry, and partial coherence interferometry) between January 2016 and March 2021 were reviewed retrospectively. Cases for which four ophthalmic devices were deployed in the same order a day were included in this investigation. Read More

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Visual Corneal Photomechanical Analysis Is Combined with the Pentacam Correlation Index for the Diagnosis of Cone Corneas at Different Stages of Progression.

J Healthc Eng 2022 21;2022:4682901. Epub 2022 Feb 21.

Department of Ophthalmology, Taikang Tongji (Wuhan) Hospital, Sixin Road North, Wuhan 430050, China.

Cone-shaped corneas are blinding eye diseases characterised by dilated and thinning corneal tissue and forward conical protrusions, most often in adolescents. Early detection and intervention can prevent further dilatation of the cornea. The prevailing examination methods and techniques are not difficult to diagnose clinical cone corneas, but there are limitations in the diagnosis of early cone corneas (static cone corneas and subclinical cone corneas). Read More

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[Prospects for early detection of keratoconus based on systems built for computer-assisted diagnostics of structural changes in the cornea].

Vestn Oftalmol 2022 ;138(1):100-106

Research Institute of Eye Diseases, Moscow, Russia.

The article is devoted to the problem of diagnosing subclinical keratoconus (KK). The need to identify early signs of KK is primarily associated with the potential for the development of iatrogenic keratoectasia in cases of underdiagnosis of the disease when determining the conditions for laser keratorefractive surgery involving a decrease in the thickness of the cornea. Today generally accepted algorithms for early computer-assisted diagnosis of KK are mainly based on the analysis of various morphometric parameters of the cornea, reflecting changes in its shape and thickness induced by structural abnormalities. Read More

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Comparison of a New Optical Biometer That Combines Scheimpflug Imaging With Partial Coherence Interferometry With That of an Optical Biometer Based on Swept-Source Optical Coherence Tomography and Placido-Disk Topography.

Front Med (Lausanne) 2021 10;8:814519. Epub 2022 Feb 10.

Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, China.

Purpose: To evaluate measurement precision and to compare the Pentacam AXL (Oculus Optikgeräte, Wetzlar, German), a new optical biometer based on Scheimpflug imaging and partial coherence interferometry (PCI) with that of the OA-2000 biometer (Tomey, Nagoya, Japan), which combines swept-source optical coherence tomography (SS-OCT) and Placido-disk topography.

Methods: Axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), aqueous depth (AQD), mean keratometry (Km), astigmatism vectors J0, J45, and corneal diameter (CD) were measured in triplicate by two technical operators. Within-subject standard deviation (Sw), repeatability and reproducibility (2. Read More

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February 2022

Ocular anterior segment and corneal parameters evaluation in celiac disease.

Sci Rep 2022 02 9;12(1):2203. Epub 2022 Feb 9.

Celiac Centre At University Hospital San Giovanni Di Dio E Ruggi d'Aragona, University of Salerno, Salerno, Italy.

This observational case-control study evaluated the anterior ocular segment parameters of patients with celiac disease with a Scheimpflug imaging system and compared them with those of a healthy controls group, highlighting potential differences related to the underlying pathogenetic mechanisms of the disease. Seventy celiac patients and 70 healthy subjects were assessed with a comprehensive ophthalmological evaluation, including clinical history, Snellen best-corrected visual acuity, axial length (AL) measurements with IOLMaster, and anterior segment tomographic evaluation with Pentacam HR. The measurements of all keratometry values, astigmatism, steep axis, anterior and posterior Q value (asphericity), pupil diameter, pupil center, corneal apex, the thinnest point, corneal volume, anterior chamber depth from the epithelium, anterior chamber depth from endothelium, anterior chamber volume, and iridocorneal angle were also appraised. Read More

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February 2022

Changes in corneal densitometry after long-term orthokeratology for myopia and short-term discontinuation.

PLoS One 2022 4;17(2):e0263121. Epub 2022 Feb 4.

Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China.

Purpose: To quantify changes in corneal densitometry after long-term orthokeratology treatment in myopic children and to analyze the reversibility one month after discontinuation.

Methods: Seventy-four myopic subjects aged 8-16 years, who wore orthokeratology lenses for two years, were divided into relatively steep- (lens movement within 1.0-1. Read More

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A cross-sectional study to compare the normal corneal epithelial thickness in various age groups of Indian population using 9 mm wide optical coherence tomography scans.

Indian J Ophthalmol 2022 Feb;70(2):505-510

Clinical Optometry, Laxmi Eye Institute, Panvel, Maharashtra, India.

Purpose: To compare the corneal epithelial thickness among various age groups of normal Indians with 9-mm-wide optical coherence tomography scans.

Methods: This cross sectional, observational study recruited patients in the age groups of 5-20 years (group 1), 21-35 years (group 2), 36-50 years (group 3), and more than 51 years (group 4). They underwent a detailed ophthalmic examination and were excluded if found to have any ocular surface or intraocular disease (except cataract and refractive error), undergone any ophthalmic surgery, corneal topography changes suggestive of corneal ectasias, or been continuously using any topical medication in either eye for a period of 3 months or more with the last instillation being within 1 month of inclusion in the study. Read More

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February 2022

Effect of Pterygium Removal Combined with Conjunctival Autograft on Corneal Parameters in Swept-Source Imaging.

J Clin Med 2022 Jan 10;11(2). Epub 2022 Jan 10.

First Department of Ophthalmology, Pomeranian Medical University, 70-111 Szczecin, Poland.

Background: Both pterygium ingrowth and excision determine alterations in corneal topography. The aim of this study was to evaluate the influence of pterygium removal combined with conjunctival autografts in addition to the use of human fibrin tissue glue on changes in corneal parameters as measured by 3-D swept-source anterior segment optical coherence tomography (AS-OCT) imaging.

Methods: Sixteen eyes (16 patients) with pterygium that qualified for surgical treatment were enrolled in this study. Read More

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January 2022

Effect of white-to-white corneal diameter on biomechanical indices assessed by Pentacam Scheimpflug corneal tomography and corneal visualization Scheimpflug technology.

Int Ophthalmol 2022 May 6;42(5):1537-1543. Epub 2022 Jan 6.

Department of Refractive Surgery, Hefei Bright Eye Hospital, No. 299 Feixi Road, Hefei, 230000, China.

Purpose: To provide evidence for more accurate evaluation of refractive surgery candidates in clinics, this retrospective study investigated the effect of corneal diameter on the biomechanical indices assessed by Pentacam Scheimpflug cornea tomography (Pentacam) and corneal visualization Scheimpflug technology (Corvis ST).

Methods: The relevant data were collected of 132 eyes from 132 participants with moderate myopia who were candidates for refractive surgery. Eligible participants were apportioned to 2 groups based on the white-to-white (WTW) corneal diameter: Group A, ≤ 11. Read More

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Three-dimensional topographic changes of anterior chamber depth following phacoemulsification with intraocular lens implantation in cataract patients.

Int Ophthalmol 2022 May 5;42(5):1381-1389. Epub 2022 Jan 5.

Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Department of Ophthalmology, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing, 100191, China.

Purpose: To investigate the three-dimensional topographic changes of anterior chamber depth (ACD) following cataract surgery.

Methods: Seventy-eight eyes with age-related cataract undergoing phacoemulsification and intraocular lens (IOL) implantation were retrospectively enrolled. Participants were evaluated with Pentacam for ACD topography before and approximately four weeks after the surgery. Read More

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Evaluation of corneal, ocular surface, and meibomian gland changes in obstructive sleep apnea syndrome.

J Fr Ophtalmol 2022 Feb 24;45(2):191-200. Epub 2021 Dec 24.

Department of Neurology, University of Health Sciences, Yuksek Ihtisas Training and Research Hospital, Bursa, Turkey.

Purpose: To evaluate the ocular surface, eyelid changes, meibomian gland morphology, corneal endothelial morphology, and corneal topographic measurements in patients with obstructive sleep apnea syndrome (OSAS).

Methods: There were 47 patients diagnosed with OSAS and 47 healthy volunteers included in the study. Non-invasive tear break-up time (NITBUT), corneal topography, meibography, and specular microscopy were performed. Read More

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February 2022

Bilateral Differential Topography-A Novel Topographic Algorithm for Keratoconus and Ectatic Disease Screening.

Front Bioeng Biotechnol 2021 9;9:772982. Epub 2021 Dec 9.

Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China.

The purpose of this study was to establish a novel bilateral differential topographic algorithm and assess its efficacy for screening of keratoconus and corneal ectasia before corneal refractive surgery. One hundred and sixty-one consecutive patients (115 men and 46 women, aged 22.8 ± 6. Read More

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December 2021