Indian Journal of Ophthalmology最新文献

Purpose: To compare the corneal biomechanical parameters, visual outcome, and epithelial remodeling after small-incision lenticule extraction (SMILE) and photorefractive keratectomy (PRK) for low to moderate myopia.

Design: Prospective, interventional, randomized, comparative study.

Methods: Eighty eyes of 40 patients undergoing bilateral SMILE or PRK for low to moderate myopia (<-5 D SE) were included. They were divided into two groups based on the planned refractive surgery. Visual acuity, corneal biomechanics using Corvis-ST, epithelial mapping via anterior segment optical coherence tomography, and higher-order aberrations were recorded both preoperatively and postoperatively at 6 months and compared.

Results: At 6 months follow-up, the corrected distance visual acuity as well as the postoperative spherical equivalent of both the groups were comparable ( P = 0.13 and P = 0.32, respectively). The biomechanical parameters like deformation amplitude ratio ( P < 0.01), inverse concave radius ( P = 0.006), integrated ratio ( P < 0.01), stress-strain index ( P < 0.01), Ambrosio's relational thickness (ArTH) ( P < 0.01), and corneal biomechanical index-laser vision correction ( P = 0.02) were altered more in the SMILE group than in the PRK group, while the biomechanically corrected intraocular pressure ( P = 0.16) was comparable. Epithelial remodeling ( P = 0.59), higher-order aberrations ( P = 0.53), and stromal keratocyte loss ( P = 0.16) in both the groups were comparable.

Conclusion: Both SMILE and PRK are comparably effective procedures for correction of low to moderate myopia in terms of visual outcomes; however, the corneal biomechanical stability in PRK is superior than that in SMILE.

Purpose: To develop a novel external limiting membrane (ELM) and ellipsoid zone (EZ) restoration-based grading system after successful macular hole surgery (MHS) and to evaluate EZ as a structural biomarker for the final visual outcome.

Methods: In a tertiary care center-based retrospective study, 34 consecutive cases of successful MHS for full-thickness macular holes (FTMHs) were included. Spectral domain optical coherence tomography (SD-OCT) cross-sectional analysis was performed on preoperative and postoperative data of weeks 1, 4, 12, and 24, respectively. Sequential measurements of FTMH size, ELM and EZ defect were performed using the caliper function of SD-OCT. MHS was uniquely graded as grade 0: persistence of ELM and EZ defect; grade 1: partial or complete restoration of ELM with shortening of EZ defect; and grade 2: complete restoration of ELM and EZ. Data were statistically analyzed on Statistical Package for the Social Sciences software-version 24.

Results: MHS was graded as grade 0 ( n = 8), grade 1 ( n = 15), and grade 2 ( n = 11). Best corrected visual activity (BCVA) was found to be 1.13 ± 0.19 in grade 0, 0.59 ± 0.09 in grade 1, and 0.26 ± 0.06 in grade 2. One-way analysis of variance showed improvement in final BCVA among the three grades ( P < 0.001) Postoperative visual acuity and residual EZ defect had a statistically significant linear correlation ( r = 0.899, P < 0.001). EZ was found to be an excellent structural biomarker for final BCVA (area under the curve = 0.99).

Conclusion: Successful MHS is associated with better visual outcomes in eyes with restored EZ. ELM restoration preceded EZ regeneration. MHS novel grading system is physician friendly, incorporates pathoanatomic aspects, and correlates well with visual outcomes.

The field of retinal genetics has seen remarkable advancements lately, reshaping our understanding of various retinal conditions, including age-related macular degeneration, diabetic retinopathy, and inherited retinal dystrophies. The purpose of this review is to provide an overview of the current status of genetics in the retina, covering the progress made, the expected future developments, and the challenges yet to be overcome. We highlight key advancements such as the advent of next-generation sequencing, which has exponentially enhanced the discovery of genetic mutations, thus also enabling personalized medicine/therapeutic approaches. Stem cells, gene augmentation, and gene-editing techniques such as CRISPR/Cas9 are discussed, in which we highlight ongoing research as well as their potential in the targeted treatment of retinal diseases. Despite these promising advancements, the field faces significant challenges, such as the complex interpretation of genetic data, ethical considerations, and the translational gap from bench to bedside. This review serves as a comprehensive guide not only to ophthalmologists but also to other healthcare professionals, scientists, and policymakers, providing insights into the rapidly evolving landscape of retinal genetics. It aims to stimulate further research and collaboration to surmount existing challenges and harness the full potential of genetic advancements for retinal health.

Purpose: To report the long-term anatomical and functional results of lens-sparing vitrectomy (LSV) for stage 4 retinopathy of prematurity (ROP).

Design: Retrospective study.

Methods: This is a study of 23 eyes of 16 patients with stage 4 ROP who underwent lens-sparing vitrectomy at a tertiary care center and had a minimum of 2 years of follow-up. The main outcome measures are the retinal status and visual outcome at the final follow-up.

Results: After a mean follow-up of 7.36 years, the lenses remained clear in 69.57%; anatomical success in terms of the attached retina was achieved in 19/23 eyes (82.61%) and vision of ≥6/24 was achieved in 8/23 eyes (34.78%), whereas navigational vision (≥1/60) was achieved in 16/23 (69.56%). The mean spherical equivalent was -8.50 + 6.39 diopters. High myopia (≥7 dsph) was noted in 43.47% of patients. The severity of myopia was not related to previous lasers and was less severe in eyes with posterior pole residual folds compared to normalized fundus or eyes with macular drag but no fold. At the final follow-up, 3/16 (18.75%) patients had bilateral blindness due to total retinal detachments and 11/16 (68.75%) had recorded functional vision in one or both eyes, whereas two others could potentially be having vision but could not be evaluated.

Conclusions: The long-term results of lens-sparing vitrectomy for stage 4 ROP are favorable with a majority retaining clear lenses and attached retina and two-thirds having functional vision.

Purpose: To study tear film parameters and Meibomian glands in pediatric patients with vernal keratoconjunctivitis (VKC).

Methods: Forty-four eyes of 22 patients with VKC and 44 eyes of 22 age-matched controls were studied in a hospital-based cross-sectional study. Each subject underwent a complete ophthalmological examination including slit-lamp biomicroscopy, non-invasive break-up time (NIBUT), fluorescein break-up time (FBUT), corneal fluorescein staining, and Schirmer's test. Non-contact meibography was performed using a Sirius topographer.

Results: All patients had VKC grades between 1 and 3 (Bonini scale). The mean NIBUT for cases was 8.83 ± 4.02 s and in controls, it was 15 ± 2.8 s ( P value < 0.001). The mean FBUT for cases was 9.41 ± 3.45 s and in controls, it was 16.7 ± 2.5 s ( P value < 0.001). Schirmer's values were 32 ± 3.1 mm in cases and 21.4 ± 4.1 mm in controls, which were significantly higher ( P value < 0.001). Also, 22.72% of the cases had corneal fluorescein staining in the form of superficial punctuate keratitis, whereas none of the control groups showed corneal staining. The examination of Meibomian glands using non-contact meibography showed a mean Meibomian gland dropout in the upper lid to be 29.7 ± 14.4% in VKC cases and 10.5 ± 3.2% in controls ( P value < 0.001). Meibography of the lower lid showed 25.9 ± 10.2% dropout in cases and 20.5 ± 6.1% in controls ( P value = 0.004).

Conclusion: Tear film parameters were significantly deranged in children with VKC in the active stage as compared to age-matched controls. Children with VKC also had a higher Meibomian gland dropout.

Objective: This study aimed to investigate the effect of axial elongation on anterior scleral thickness (AST) in myopia.

Methods: The convenience sampling method was used to select 122 patients without ocular or systemic diseases affecting ametropia in Ya'an People's Hospital between March 2020 and January 2022. According to the diopter and axial length (AL), the patients were divided into an emmetropia group (32 cases), a low-to-moderate myopia group (40 cases), and a high myopia group (40 cases). Relevant data were collected and analyzed.

Results: The AST of the four diameter lines was highest at the scleral process and measured. The results, in descending order, were as follows: temporal side (716.45 ± 65.55 μm), lower side (692.32 ± 74.76 μm), nasal side (671.54 ± 61.76 μm), and superior side (550.76 ± 51.34 μm). There was a correlation between the AL and the average AST of the four diameter lines. The correlations, from highest to lowest, were as follows: the mean AST of the nasal side (r = -0.455, P < 0.001), the mean AST of the upper side (r = -0.431, P < 0.001), the mean AST of the lower side (r = -0.402, P < 0.001) and the mean AST of the temporal side (r = -0.363, P < 0.001). Age was associated with the average AST of the upper, nasal, and temporal sides. The correlations, from highest to lowest, were as follows: the average AST of the upper side (r = 0.545, P < 0.001), the average AST of the temporal side (r = 0.422, P < 0.001), and the average AST of the nasal side (r = 0.411, P < 0.001). There were significant differences in AST among the three groups at 0, 1, 2, 3, 4, 5, and 6 mm from the scleral bulge (P < 0.05). AST was positively correlated with age and negatively correlated with AL (R2= 0.432, F = 231.73, P < 0.05).

Conclusion: The thickness of the sclera changed with the AL and measurement position. AST was negatively correlated with the AL and positively correlated with age. Compared with emmetropia and low-to-moderate myopia, the anterior sclera in cases of high myopia was thinner. Myopia affects not only the thickness of the posterior sclera but also the AST.

Diabetic retinopathy (DR) is a predominant cause of vision impairment globally. Understanding risk factors is crucial for effective planning. The aim of this study is to comprehensively investigate the risk factors in the Indian population contributing to the increased incidence of DR, which is a potentially sight-threatening complication among diabetic individuals. A comprehensive literature search was done on PubMed, Embase, and Google Scholar databases for epidemiological studies reporting risk factors in the adult Indian population in the English language. Joanna Briggs Institute's (JBI) critical appraisal tools were used to assess the quality of the included studies. Analysis was performed using R studio. I2 statistic was used for the assessment of heterogeneity. Results are expressed as odds ratio (OR) and standardized mean difference (SMD) along with a 95% confidence interval (CI). Overall, 20 studies enrolling 4,12,421 patients with 1,04,104 DR-positive and 3,08,317 DR-negative adults were analyzed. Being male (OR: 1.38, 95% CI: 1.11-1.72), intake of insulin (OR: 2.05, 95% CI: 1.02-4.14), higher HbA1c levels (MD: 0.50, 95% CI: 0.06-0.94), higher random (MD: 0.32, 95% CI: 0.10-0.55), and fasting blood glucose levels (MD: 0.51, 95% CI: 0.10-0.93) were found to be significantly associated with increased risks of DR among diabetic patients, while age, body mass index, hypertension, lipid profile, and smoking status did not indicate any association with DR. Good glycemic control remains the most important modifiable risk factor to reduce the risk of progression of DR and vision loss.