Distance and near vision changes after intravitreal anti-vascular endothelial growth factor injection in eyes with center-involving diabetic macular edema.

Purpose: To elucidate distance and near vision changes after intravitreal injections in center-involving diabetic macular edema (CIDME) in phakic and pseudophakic groups. Methods: A retrospective study was done on 148 eyes (72 phakic and 76 pseudophakic) with center-involving DME. All eyes were treated with intravitreal anti-vascular endothelial growth factor (VEGF) injection. All patients underwent distance best-corrected visual acuity (BCVA) testing, near BCVA testing, dilated fundus examination, and optical coherence tomography (OCT) at baseline and follow-up visits. Eyes that could not improve after the first injection were given 2nd, 3rd, and more injections in the subsequent visits. Results: On follow-up, post injections in the phakic group (n = 72), there were 65 eyes (90.3%) with stable/improved near vision and 59 eyes (81.9%) with stable/improved distance vision, whereas in the pseudophakic group (n = 76), 63 eyes (82.9%) and 60 eyes (78.9%), respectively. Both in phakic and pseudophakic eyes, 7.7%-13% of the cohort showed only near vision improvement. Conclusion: In DME, besides the changes in distance vision, there are also changes in near vision. These changes should be taken into account while determining the response to anti-VEGF in DME treatment.

Optical Coherence Tomography-Based Prevalence of Diabetic Macular Edema and its Associated Risk Factors in Urban South India: A Population-Based Study.

BACKGROUND: To estimate the prevalence of optical coherence tomography (OCT)-defined diabetic macular oedema (DME) in urban South Indian population and to elucidate their associated risk factors. METHODS: Of 911 participants from the Sankara Nethralaya Diabetic Retinopathy and Molecular Genetics Study-II (SN-DREAMS-), 759 who underwent OCT were analysed. The participants underwent a comprehensive examination and retinal photography following a standard protocol for diabetic retinopathy (DR) grading. The subjects were categorized into centre-involving DME (CI-DME), non-centre involving DME (NCI-DME), and No-DME based on the mean retinal thickness at the central 1 mm, inner and outer ETDRS subfields. RESULTS: The prevalence of CI-DME and NCI-DME in the Chennai population was 3.03% (95% CI: 3.01-3.05) and 10.80% (95% CI: 10.7-11.02). NCI-DME was found to be higher by 9.5% (95% CI: 0.07-0.11) in the early stages of DR. A greater number of subjects with CI DME were aged >60 years and had diabetes mellitus (DM) for >10 years. The significant risk factors for NCI-DME are diastolic blood pressure, serum total cholesterol, serum triglyceride, insulin use and neuropathy (OR (95% CI): 0.97 (0.94-100), 1.00 (1.00-1.01), 0.99 (0.98-0.99), 2.32 (1.15-4.68) and 4.24 (1.22-14.69), respectively) and for CI DME are duration of diabetes, anaemia, neuropathy and insulin use (OR (95% CI): 2.49 (0.96-6.40), 3.41 (1.34-8.65), 10.58 (1.68-66.56) and 3.51 (1.12-10.95), respectively). CONCLUSIONS: The prevalence of NCI-DME was found to be higher than that of CI-DME in patients with DR.

Visual rehabilitation using microperimetric acoustic biofeedback training in individuals with central scotoma.

BACKGROUND: Patients with central scotoma have poor fixation stability and poor visual acuity. Acoustic biofeedback training can be an effective way to train such patients to eccentrically fixate. This study analyses the mean retinal sensitivity, saccadic velocity, and fixation stability after acoustic biofeedback training and shows correlation with age and scotoma size. METHODS: Patients with irreversible central scotoma in both the eyes secondary to macular diseases were selected. After undergoing comprehensive low vision assessment, 19 patients who were willing were recruited for the acoustic biofeedback training to the better eye in 10 sessions, using the MP-1 Microperimeter. Mean retinal sensitivity, saccadic velocity, fixation stability before and after the acoustic biofeedback were recorded. RESULTS: There were 17 men and two women. Ages ranged from 19-94 years (mean 54.63 ± 24.66). The scotoma size ranged from four to 20 degrees. Ten patients had age-related macular degeneration, four had Stargardt disease, three had traumatic macular scar, two had scarred myopic choroidal neovascular membrane, and one had myopic macular degeneration. The vision improved from 1.06 ± 0.36 to 0.86 ± 0.33 logMAR (p < 0.0001). The mean retinal sensitivity improved from 2.1 ± 2.9 dB to 2.7 ± 3.1 dB (p = 0.01), with negative correlation with age (p = 0.01) and scotoma size (p = 0.02). Fixation stability improved with reduction in the bivariate contour ellipse area (p = 0.01). It showed negative correlation with age (p = 0.02) and scotoma size (p = 0.10). The saccadic velocity reduced from 0.34°/second to 0.26°/second but was not significant (p > 0.99). The majority (58 per cent) had their preferred retinal locus superior to the fovea. There was good agreement between bivariate contour ellipse area and MP-1 Microperimeter inbuilt fixation parameters. The effect was maintained at six months with slight reduction in fixation stability. CONCLUSION: Acoustic biofeedback can improve fixation behaviour, visual acuity and retinal sensitivity in patients with central scotoma. The results are better with younger age and smaller scotoma size.

Does neuronal damage precede vascular damage in subjects with type 2 diabetes mellitus and having no clinical diabetic retinopathy?

AIM: To investigate the occurrence of neuronal damage, as the earliest change occurring, before the clinical evidence of diabetic retinopathy. METHODS: 70 eyes of subjects with type 2 diabetes mellitus and with no evidence of diabetic retinopathy (cases) and 40 eyes of subjects with no diabetes mellitus (controls) were studied using spectral-domain OCT and microperimetry. The influence of age and gender on the outcome measures was also analyzed. RESULTS: Age- and gender-matched subjects showed a decreased mean retinal nerve fiber layer thickness in cases when compared to the controls (27 vs. 33 µm; p=0.018). Among the cases, subjects between 40 and 45 years of age showed a reduced mean central foveal thickness (175.1 vs. 198.1 µm; p=0.05), mean retinal thickness in the central 6-mm fundus (260.5 vs. 275.3 µm; p=0.006) and mean retinal nerve fiber layer thickness (29 vs. 39 µm; p=0.036) when compared to the controls. However, no differences were noted in the microperimetry outcomes in cases when compared to the controls. The duration of diabetes and the glycemic control did not show any significant changes on the outcome measures in cases, except for a significantly lower mean retinal sensitivity in diabetics with glycosylated hemoglobin values<7% as compared to those with glycosylated hemoglobin≥7% (14.1±2.9 vs. 15.4±1.7 dB; p=0.027). CONCLUSION: The results suggest that there is some evidence of early neuronal damage particularly on spectral-domain OCT, before the clinical evidence of diabetic retinopathy, in subjects with type 2 diabetes mellitus.

High-resolution optical coherence tomography correlates in ischemic radiation retinopathy.

PURPOSE: To find the abnormalities in various retinal layers caused by radiation retinopathy using spectral domain optical coherence tomography (SD-OCT). METHODS: We report a case of radiation retinopathy that was imaged using SD-OCT Copernicus (Optopol, Zawiercie, Poland). Analysis and synthesis of the OCT image were done using information both at the fovea and 2.5 mm temporal to the fovea. RESULTS: The layers that were reduced in thickness included the inner plexiform layer (47 microm vs. 74 microm), the inner nuclear layer (17 microm vs. 48 microm), and the outer plexiform layer (25 microm vs. 45 microm), whereas the layers with comparable thickness included the nerve fiber layer (24 microm vs. 25 microm), the outer nuclear layer (42 microm vs. 43 microm), the outer segment-inner segment junction (52 microm vs. 54 microm), and the retinal pigment epithelium (RPE) choriocapillaris layer (30 microm vs. 28 microm). CONCLUSION: This report suggests that the radiation-induced damage was confined to the inner layers of the retina. However, secondary outer retinal layer changes may also occur, as suggested by functional derangements.

Spectral-domain OCT and microperimeter characterization of morphological and functional changes in X-linked retinoschisis.

A case of X-linked retinoschisis with anatomic and functional issues correlated by a constellation of methods, including spectral-domain optical coherence tomography, microperimeter, electroretinography, and multifocal electroretinography, is described. This case highlights the importance of microperimetry in the presence of normal or subtle abnormalities in full-field electroretinography. The ability of spectral-domain optical coherence tomography in diagnosis and follow-up in cases with X-linked retinoschisis is demonstrated.