scholarly journals Implantable collamer lens with a central hole for residual refractive error correction after corneal refractive surgery

2019 ◽  
Author(s):  
Zhang Jing ◽  
Zhenzhen Zhang ◽  
Zhu Yi ◽  
DongQin Zhu ◽  
Fan Xianqun
Keyword(s):  
Visual Acuity ◽  
Error Correction ◽  
Refractive Error ◽  
Refractive Surgery ◽  
Cutoff Frequency ◽  
Strehl Ratio ◽  
Implantable Collamer Lens ◽  
Corneal Refractive Surgery ◽  
Icl V4c ◽  
The Mean

Abstract PURPOSE: To assess the visual and refractive outcomes of an implantable collamer lens with a central hole (ICL V4c) for residual refractive error correction after corneal refractive surgery in individuals with myopia. DESIGN: Prospective, nonrandomized observational case series (self-controlled). METHODS: We investigated 16 eyes of eight consecutive patients with myopia undergoing ICL V4c implantation after corneal refractive surgery. The uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) were examined before surgery and 1 month, 3 months, and 6 months after surgery. We quantitatively assessed the postoperative values of the modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scattering index (OSI), and OQAS values (OVs) by using an Optical Quality Analysis System. RESULTS: At 6 months after surgery, the mean uncorrected logMAR VA was 0.06 ± 0.10, and the values had improved in 100% of the eyes. The mean MTF cutoff frequency, Strehl ratio, OSI, OV 100%, OV 20%, and OV 9%, were 31.29 ± 4.32 cycles/degree (c/d), 0.18 ± 0.04, 1.469 ± 0.47, 0.97 ± 0.26, 0.75 ± 0.29, and 0.51 ± 0.23 at 6 months after ICL V4c implantation, respectively. CONCLUSION: ICL V4c implantation was safe and effective for the correction of residual refractive error after corneal refractive surgeries, and it had excellent optical performance.

scholarly journals Prevalence of amblyopia and patterns of refractive error in the amblyopic children of a tertiary eye care center of Nepal

2013 ◽  
Vol 5 (1) ◽  
pp. 38-44 ◽  
Author(s):  
K Sapkota ◽  
A Pirouzian ◽  
NS Matta
Keyword(s):  
Visual Acuity ◽  
Refractive Error ◽  
Chart Review ◽  
Care Center ◽  
Retrospective Chart Review ◽  
Ophthalmological Examination ◽  
Eye Care ◽  
Common Cause ◽  
Ocular Pathology ◽  
The Mean

Introduction: Refractive error is a common cause of amblyopia. Objective: To determine prevalence of amblyopia and the pattern and the types of refractive error in children with amblyopia in a tertiary eye hospital of Nepal. Materials and methods: A retrospective chart review of children diagnosed with amblyopia in the Nepal Eye Hospital (NEH) from July 2006 to June 2011 was conducted. Children of age 13+ or who had any ocular pathology were excluded. Cycloplegic refraction and an ophthalmological examination was performed for all children. The pattern of refractive error and the association between types of refractive error and types of amblyopia were determined. Results: Amblyopia was found in 0.7 % (440) of 62,633 children examined in NEH during this period. All the amblyopic eyes of the subjects had refractive error. Fifty-six percent (248) of the patients were male and the mean age was 7.74 ± 2.97 years. Anisometropia was the most common cause of amblyopia (p < 0.001). One third (29 %) of the subjects had bilateral amblyopia due to high ametropia. Forty percent of eyes had severe amblyopia with visual acuity of 20/120 or worse. About twothirds (59.2 %) of the eyes had astigmatism. Conclusion: The prevalence of amblyopia in the Nepal Eye Hospital is 0.7%. Anisometropia is the most common cause of amblyopia. Astigmatism is the most common types of refractive error in amblyopic eyes. Nepal J Ophthalmol 2013; 5(9):38-44 DOI: http://dx.doi.org/10.3126/nepjoph.v5i1.7820

scholarly journals Correlation between Central Corneal Thickness and Degree of Myopia among Malaysian Patients Undergoing Laser Keratorefractive Surgery

2020 ◽  
pp. 52-58
Author(s):  
Sagili Chandrasekhara Reddy ◽  
Mohd Mansor Shariff ◽  
Aina Malindri Dasrilsyah
Keyword(s):  
Optical Coherence Tomography ◽  
Refractive Surgery ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Military Hospital ◽  
Moderate Degree ◽  
Optical Coherence ◽  
Corneal Refractive Surgery ◽  
The Mean

Purpose: To determine the central corneal thickness in myopic adult patients scheduled for laser corneal refractive surgery and to explore its correlation with degree of refractive error. Materials and Methods: The case records of 130 myopic patients who underwent laser corneal refractive surgery in a military hospital over a period of two years were reviewed to determine the central corneal thickness. All patients had 6/6 vision with best correction, and did not have any other anterior segment or fundus diseases in both eyes. The central corneal thickness was measured with Visante Carl Zeiss anterior segment optical coherence tomography instrument.                                                                                                                        Results: Out of 130 patients, males were more (73, 56.2%); mean age of patients was 33.8 years (range 18-60 years) and majority were Malays (110, 84.6%).  The spherical power of myopia ranged from – 0.5 to – 10.00 D, and the cylindrical power ranged from – 0.25 to – 3.25 D. The mean central corneal thickness of both eyes was 528.2 µm (range 331- 615 µm); in the mild degree of myopia (- 0.50 to - 2.00 D) 527.9 µm, moderate degree (- 2.25 to -5.00 D) 529.4 µm, and high degree (-5.25 to -11.00 D) 523.9 µm. Conclusion: The anterior segment optical coherence tomography provides noncontact, rapid, pachymetry mapping of the corneal thickness. In Malaysian patients, the mean central corneal thickness of both eyes in myopia was 528.1 µm (range 331- 615 µm). There was no correlation between the mean central corneal thickness and degree of myopia, different genders, age groups, ethnic groups and two eyes.

Implantable collamer lens for the correction of post-keratoplasty myopia and astigmatism

2020 ◽  
Vol 1 (2) ◽  
pp. 113-116
Author(s):  
Nasser A Alsabaani ◽  
◽  
Salem Almalki ◽  
Keyword(s):  
Visual Acuity ◽  
Contact Lenses ◽  
Posterior Chamber ◽  
Implantable Collamer Lens ◽  
Distance Visual Acuity ◽  
Refractive Outcomes ◽  
Uncorrected Distance Visual Acuity ◽  
Single Center Study ◽  
Corrected Distance Visual Acuity ◽  
Corneal Refractive Surgery

AIM: To evaluate the safety, refractive outcomes and vision after phakic posterior chamber implantable collamer lens (ICL) after keratoplasty (KP). METHODS: This retrospective single center study evaluated 32 (35 eyes) patients who received an ICL for myopia and/or astigmatism after keratoplasty. Patients underwent ICL surgery if they were unable to wear glasses or contact lenses and excimer laser surgery was contraindicated. Data were collected on uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refraction and complications. Data were analyzed for the preoperative and last postoperative visits (16.7±13mo) (P<0.05). RESULTS: Preoperatively, spherical equivalent (SE) ranged from -4.00 to -20.00 D and cylinder from -2.00 to -9.00 D. The mean SE decreased statistically significantly from -11.41±3.62 D preoperatively to -1.95±1.78 D postoperatively (P<0.0001). Mean UDVA increased statistically significantly from 20/400 preoperatively to 20/25 postoperatively (P<0.0001). There was a mean improvement in postoperative CDVA of 1.5 lines compared to preoperatively, 37% of eyes had an increase of 2 or more lines. One eye (2.8%) lost ≥1 line of CDVA. There were no intraoperative or postoperative complications. CONCLUSION: Posterior chamber phakic intraocular lens implantation is a safe and effective treatment for post-keratoplasty myopia and astigmatism in patients unable to wear spectacles or contact lenses and where corneal refractive surgery is contraindicated.

Influence of refractive error on pupil diameters in highly myopic eyes with implantable collamer lenses

2019 ◽  
Vol 30 (6) ◽  
pp. 1328-1334
Author(s):  
Yi Zhu ◽  
Yu Yue ◽  
Haobin Zhu ◽  
Jili Chen ◽  
Jibo Zhou
Keyword(s):  
Refractive Error ◽  
High Myopia ◽  
Pupil Diameter ◽  
Spherical Equivalent ◽  
Implantable Collamer Lens ◽  
Lighting Conditions ◽  
Lens Implantation ◽  
Group A ◽  
Icl V4c ◽  
Percent Decrease

Purpose: To investigate the influence of refractive error on pupil diameters in highly myopic eyes with implantable collamer lenses. Setting: Shanghai, China. Design: A prospective consecutive observational study. Methods: Sixty-six eyes of 66 patients that underwent ICL V4c implantation were included. Pupil diameters before and 1 week, 1 month, and 3 months after surgery were measured using an automatic pupillometry system (MonCv3; Metrovision, Pérenchies, France) under four standardized illumination conditions: 0, 1, 10, and 100 cd/m2. The correlations between changes in pupil diameter and spherical equivalent values and patient age were investigated. Results: Based on preoperative spherical equivalent values, included eyes were divided into a high-myopia group (–6.3 to −9.9 D (diopters)) and a super-high-myopia group (–10 to −20 D). Pupil sizes remained unchanged after surgery in the high-myopia group and decreased at 1 and 10 cd/m2 in the super-high-myopia group. A between-group comparison showed that pupils were significantly smaller in the super-high-myopia group 1 week postoperatively under all illumination conditions and remained smaller at 1 month and 3 months under 1 and 10 cd/m2 lighting conditions. Preoperative spherical equivalent values were significantly correlated with the percent decrease in pupil diameter 1 week postoperatively under 0, 1, and 10 cd/m2 illumination conditions; the greater the degree of myopia, the greater the reduction in pupil diameter. Conclusion: Preoperative refractive error significantly affects pupil diameter in highly myopic eyes after implantable collamer lens implantation. Pupils of super highly myopic eyes remained smaller than preoperative levels under mesopic conditions after implantable collamer lens implantation.

scholarly journals Treating intrasurgical complications of corneal refractive operation with customized ablation. A clinical case

2021 ◽  
Vol 14 (3) ◽  
pp. 102-105
Author(s):  
N. V. Khodzhabekyan ◽  
A. T. Khandzhyan ◽  
A. V. Ivanova ◽  
K. B. Letnikova ◽  
A. S. Sklyarova
Keyword(s):  
Visual Acuity ◽  
Excimer Laser ◽  
Refractive Surgery ◽  
Clinical Case ◽  
Photorefractive Keratectomy ◽  
Corneal Surface ◽  
Surface Errors ◽  
Spherical Component ◽  
Uncorrected Visual Acuity ◽  
Corneal Refractive Surgery

Purpose: to evaluate the prospects of customized Finalfit based ablation for optical rehabilitation of a patient with corneal surface errors caused by intrasurgical microtome-induced damage of a corneal flap during a LASIK excimer laser correction of vision.Material and methods. In Helmholtz Center, a patient with such damage was given a phototherapeutic keratectomy (PTK) combined with topographyguided photorefractive keratectomy.Results. In two months after the surgery, the patient’s uncorrected visual acuity rose from 0.15 to 1.0; the spherical component of refraction changed from -3.5 to +1.0 D, the cylindrical component of refraction fell from 1.75 to 0.25 D. Aberrometry demonstrated a decrease of RMS from 2.19 to 0.61 D, Total HOAs from 2.281 to 0.829; Tilt from 0.406 to 0.313; HOA from 1.152 to 0.247, Coma from 0.298 to 0.124, Trefoil from 1.088 to 0.094, SA from 0,127 to 0,021.Conclusion. The clinical case demonstrates the expediency and efficiency of corneal remodeling for the rehabilitation of induced errors of the corneal surface by excimer laser correction of vision based on PTK (Flex scan) + FinalFit after corneal refractive surgery.

scholarly journals Functional optical zone after wavefront-optimized versus wavefront-guided laser in situ keratomileusis

2021 ◽  
Vol 10 (3) ◽  
pp. 129-137
Author(s):  
Mariam A Elshawarby ◽  
Ali Saad ◽  
Thanaa Helmy ◽  
Mouamen M. Seleet ◽  
Tamer Elraggal
Keyword(s):  
Visual Acuity ◽  
Refractive Error ◽  
Ablation Depth ◽  
Laser In Situ Keratomileusis ◽  
Treatment Modalities ◽  
Significant Difference ◽  
Corneal Asphericity ◽  
Optical Zone ◽  
The Mean

Background: Many studies have used functional optical zone (FOZ) as a measure to compare different refractive laser treatment modalities. However, to our knowledge, no study has compared wavefrontoptimized (WFO) and wavefront-guided (WFG) laser in situ keratomileusis (LASIK) using FOZ. We compared the FOZ after WFO versus WFG LASIK in patients with myopia and myopic astigmatism.Methods: In this prospective comparative study, we included 100 myopic eyes of 50 patients with or without astigmatism. They were divided into two groups according to the platform used: WFO or WFG femtosecond LASIK. Using Holladay’s equivalent keratometry reading (EKR) report of Pentacam HR, FOZ was defined as a zone centered on the pupil center with a standard deviation (SD) of 0.5 D, around the mean EKR. The differences in FOZ between the two platforms were analyzed at 3 months postoperatively. Visual acuity, refractive error, corneal asphericity (Q-value), and root mean square of higher-order aberrations (RMS for HOAs) were evaluated and compared.Results: The mean ± SD of patient age was 26.64 ± 5.67 years. The preoperative characteristics of the two groups were comparable (all P > 0.05). The intended optical zone (IOZ) was 6 mm in both groups. The mean laser ablation depth was significantly greater in the WFG group (18 ?m per D) than in the WFO group (16 ?m per D) (P = 0.035). At 3 months postoperatively, the mean ± SD of FOZ diameter was 4.32 ± 0.94 mm (71.99 ± 15.68% of intended optical zone) in the WFO group and 4.16 ± 1.13 mm (69.33 ± 18.78% of intended optical zone) in the WFG group, with no significant difference between the two groups (P = 0.622). The change in corneal asphericity was greater in the WFG group than in the WFO group (P = 0.034). Postoperative mean corrected and uncorrected distance visual acuity, manifest refraction, and RMS for HOAs showed no significant difference between the two groups (all P > 0.05).Conclusions: We found that WFG LASIK resulted in greater ablation depth and change in corneal asphericity than WFO LASIK at 3 months postoperatively. However, there was no significant difference in FOZ diameter, refractive error, and RMS for HOAs between the two groups. Further research is needed to confirm these findings.

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