Effect of Light Emitting Diodes (LED) Exposure on Vitreous Metabolites-Rodent Study.

The exposure to blue and white Light emitting diodes (LED) light leads to damage in the visual system with short-term LED light exposure. Chronic exposure, adaptive responses to light, and self-protective mechanisms against LED light exposures need to be explored, and it would be essential to understand the repercussions of LED radiation on vitreous metabolites. A total of 24 male Wistar rats were used in this study, divided into four groups (n = 6 in each group). Three experimental groups of rats were exposed to either blue, white, or yellow LED light for 90 days (12:12 light-dark cycle routine) with uniform illumination (450−500 lux). Standard lab settings were used to maintain control rats. Vitreous fluids were subjected to untargeted metabolomics analysis using liquid chromatography-mass spectrometry (LC/MS). PLS-DA analysis indicated significant the separation of m metabolites among groups, suggesting that LED exposure induces metabolic reprogramming in the vitreous. Amino acids and their modifications showed significant alterations among groups which included D-alanine, D-serine (p < 0.05), lysine (p < 0.001), aspartate (p = 0.0068), glutathione (p = 0.0263), taurine (p = 0.007), and hypotaurine. In chronic light exposure, the self-protective or reworking system could be depleted, which may decrease the ability to compensate for the defending mechanism. This might fail to maintain the metabolomic structural integrity of the vitreous metabolites.

Blue Light-Induced Retinal Neuronal Injury and Amelioration by Commercially Available Blue Light-Blocking Lenses.

Blue light exposure-induced retinal damage has been extensively studied. Although many in vitro studies have shown the benefits of blue light-blocking lenses (BBL) there have been few comprehensive in vivo studies to assess the effects of BBL. We investigated the influence of blue light exposure using light-emitting diodes on retinal histology and visual cortex neurons in rodents. We also considered whether retinal and cortical changes induced by blue light could be ameliorated with blue light-blocking lenses. A total of n = 24 (n = 6 in each group; control, light exposure without lenses, two different BBLs)) male Wistar rats were subjected to blue light exposure (LEDs, 450-500 lux) without or with BBLs (400-490 nm) for 28 days on a 12:12 h light-dark cycle. Histological analysis of retinae revealed apoptosis and necrosis of the retinal pigment epithelium (RPE), photoreceptors, and inner retina in the light exposure (LE) group, along with increase caspase-3 immunostaining in the ganglion cell layer (p < 0.001). BBL groups showed less caspase-3 immunostaining compared with the LE group (p < 0.001). V1-L5PNs (primary visual cortex layer 5 pyramidal neurons) demonstrated reduced branching and intersections points for apical (p < 0.001) and basal (p < 0.05) dendrites following blue light exposure. Blue light-blocking lenses significantly improved the number of basal branching points compared with the LE group. Our study shows that prolonged exposure to high levels of blue light pose a significant hazard to the visual system resulting in damage to the retina with the associated remodeling of visual cortex neurons. BBL may offer moderate protection against exposure to high levels of blue light.

Has Spectral-Domain Optical Coherence Tomography Retinal Nerve Fiber Layer Assessment Become the Method of Choice for Glaucoma Evaluation in Clinical Practice?

AIM: The aim of the study was to assess the role of spectral-domain optical coherence tomography (SD-OCT) as a method of choice for early glaucoma diagnosis in glaucoma suspects. DESIGN: This was a retrospective cross-sectional study. MATERIALS AND METHODS: After a comprehensive ophthalmic examination and visual field analysis, 20 patients were included in each of the three groups: Normal group, possible glaucoma, definitive glaucoma, respectively. The optic nerve head (ONH) and peripapillary retinal nerve fiber layer parameters of participants were analyzed using SD-OCT optic disc cube protocol scans. Data was analyzed using one.way analysis of variance test. RESULTS: ONH RNFL defects in possible glaucoma patients were frequently found in superior, inferior, and temporal quadrants. CONCLUSION: Diagnostic capability of SD-OCT parameters for detection of structural changes in the ONH and retinal nerve fiber layer differed in three groups significantly. Hence, using SD-OCT has become an imperative and quick way of timely diagnosis of glaucoma in private practice.

Is LEA symbol better compared to Snellen chart for visual acuity assessment in preschool children?

Aim: To compare visual acuity using the LEA symbol chart with Snellen E test chart in preschool children of age 3-5 years. Patients and methods: Inclusion criteria: 50 emmetropic children aged 3 to 5 years. Exclusion criteria: Strabismus, amblyopia, ametropia, and any organic eye disease. A pseudo randomized protocol was used to test visual acuity (VA) in each subject monocularly on both eyes using Snellen E chart and LEA symbol chart. Visual acuity for both charts was scored as smallest optotype size which the child correctly identified 3 of maximum 4 optotypes. The strength of agreement on VA between two charts was tested using Interclass correlation coefficient (ICC). A Mann-Whitney U test was applied to compare both the groups. Results: Boys: Girls = 26:24 with a mean age and standard deviation of 4.12 + 0.79 years. ICC between Snellen's and LEA symbol chart was 0.256 and 0.213 for right and left eye respectively. Analysis of the two samples using Mann-Whitney test showed a significant difference between the two charts (p value <0.000). Conclusion: LEA symbol test showed only a fair agreement with Snellen E charts for visual acuity measurements. Visual acuity measurement with LEA symbol chart showed significantly higher scores as compared to Snellen's chart.

Outbreak of multidrug-resistant acute postoperative endophthalmitis due to Enterobacter aerogenes.

PURPOSE: To report the clinical features, management, and outcome of 7 cases of culture-proven multidrug-resistant Enterobacter postoperative endophthalmitis following cataract surgery. METHODS: Medical records of 7 cases of acute postoperative endophthalmitis after uneventful cataract surgery were reviewed. Details regarding age, gender, visual acuity and clinical features at presentation, microbiological profile, treatment interventions, and visual acuity and clinical features at 1 week, 1 month, and 3 months follow-up were collected. RESULTS: All patients reported decreased visual acuity and pain as presenting symptoms. All patients were resistant to intravitreal antibiotics such as vancomycin (1 mg/0.1 mL) and ceftazidime (2.25 mg/0.1 mL). Culture of aqueous and vitreous sample was positive for Enterobacter aerogenes and sensitive to co-trimoxazole, cefoperazone-sulbactam, imipenem-meropenem, and piperacillin-tazobactem. Two patients with panophthalmitis and no perception of light underwent evisceration. Three patients had visual acuity of ≥6/24 at the final follow-up. CONCLUSION: Multidrug-resistant Enterobacter acute postoperative endophthalmitis has a poor prognosis if not intercepted early.