Spatial distribution of diabetic capillary non-perfusion.

OBJECTIVE: To evaluate the distribution of capillary non-perfusion (CNP) in superficial and deep capillary plexuses (SCP and DCP) in eyes with diabetic retinopathy (DR). METHODS: In this retrospective case series, macular optical coherence tomography angiography (OCTA) images were obtained from eyes with DR without diabetic macular edema (DME). The area of CNP in SCP and DCP was delineated using an automated approach after excluding the foveal avascular zone (FAZ) and major retinal vessels. The distribution and spatial correlation of the CNP in each layer were analyzed. RESULTS: Forty-three eyes of 27 patients with DR with a mean age of 59.10 ± 9.05 years were included. The mean CNP area in SCP was statistically significantly higher than DCP (0.722 ± 0.437 mm2 vs. 0.184 ± 0.145 mm2 , respectively, p < .001). There was a statistically significant association between mean BCVA (0.28 ± 0.21 logMAR) and CNP area in DCP (p = .01). After automated subtraction of CNP areas in DCP from SCP, 25.43 ± 15.05% of CNP areas in the DCP had co-localized CNP areas in SCP. The CNP percentage was statistically significantly different between the concentric rings on foveal center, both in SCP and in DCP (both p < .001) showing a decreasing trend from the outer ring toward the center. CONCLUSION: In DR, SCP is more ischemic than DCP. This is in contrast to the previously described oxygenation-dependent ischemic cascade following acute retinal vascular occlusions. This study provides further insight into the retinal ischemia in DR.

Optical Coherence Tomography Angiography Findings after Acute Intraocular Pressure Elevation in Patients with Diabetes Mellitus versus Healthy Subjects.

Purpose: To assess the changes in optic nerve head and macular microvascular networks after acute intraocular pressure (IOP) rise in healthy eyes versus the eyes of diabetic patients. Methods: In this prospective, interventional, comparative study, 24 eyes of 24 adults including 12 eyes of healthy nondiabetic subjects and 12 eyes with mild or moderate non-proliferative diabetic retinopathy (NPDR) were enrolled. IOP elevation was induced by a suction cup attached to the conjunctiva. IOP and optical coherence tomography angiographic (OCTA) images of the optic disc and macula were obtained before and immediately after the IOP rise. Results: Baseline and post-suction IOPs were not significantly different between the two groups (all P > 0.05). The mean IOP elevation was 13.93 ± 3.41 mmHg among all eyes and was statistically significant as compared to the baseline in both groups (both P < 0.05). After IOP elevation, healthy eyes demonstrated a reduction in the vessel density in the whole image deep and superficial capillary plexuses and parafoveal deep capillary plexus (DCP) (all P < 0.05). In diabetic retinopathy, foveal vessel density at DCP decreased significantly following IOP rise (P = 0.003). In both groups, inside disc vessel density decreased significantly after IOP rise (both P < 0.05), however, no significant change was observed in peripapillary vessel density (both P > 0.05). Conclusion: Acute rise of IOP may induce different levels of microvascular changes in healthy and diabetic eyes. Optic disc microvasculature originating from the posterior ciliary artery may be more susceptible to IOP elevation than that of retinal microvasculature.

Acute retinal necrosis: Clinical manifestation and long-term visual outcomes in a series of polymerase chain reaction-positive patients.

PURPOSE: To report the clinical spectrum, viral etiologies, therapeutic interventions, timing of rhegmatogenous retinal detachments (RRD), and visual outcomes in acute retinal necrosis (ARN) syndrome in a series of polymerase chain reaction (PCR)-positive eyes. METHODS: From January 2010 to January 2017, consecutive patients with the clinical diagnosis of ARN and a positive aqueous viral PCR were included in this observational, retrospective study. RESULTS: Nineteen eyes found to have a clinical diagnosis of ARN, of which 18 (94.7%) had a positive viral PCR. ARN was unilateral, except in one patient. None of the fellow eyes manifested ARN during follow-up. Varicella-zoster virus (VZV) was detected in 78.0% of ARN eyes. 61.1% of eyes experienced RRD. The median time for the occurrence of RRD was 12 weeks (range: 6-25 weeks) after disease onset. No correlation was found between the etiologic viral agent (VZV vs non-VZV; p = 1.000), extent of retinitis (1-2 quadrant vs 3-4 quadrants; p = 0.326), administration of intravitreal ganciclovir (injected vs not injected; p = 0.332), application of prophylactic laser retinopexy (applied vs not applied; p = 0.326), and subsequent occurrence of RRD.At a 2-year follow-up, visual impairment (VA ⩽ 20/200) and severe visual loss (VA ⩽ light perception) were significantly higher in those complicated by RRD compared to non-RRD eyes (81.8% vs 28.6%; p = 0.047, and 45.4% vs 0.0%; p = 0.004, respectively). CONCLUSION: Aqueous PCR results are highly consistent with the clinical diagnosis of ARN. Regardless of the method of management, the rate of RRD is high and is associated with a poor visual outcome.

Intravitreal Injection Of The Granulocyte-Colony Stimulating Factor For The Treatment Of Non-Arteritic Anterior Ischemic Optic Neuropathy: A Pilot Study.

Purpose To investigate the efficacy of intravitreal injection of granulocyte colony-stimulating factor (G-CSF) for the treatment of non-arteritic anterior ischemic optic neuropathy (NAION).Methods: Patients with acute NAION were enrolled in this prospective interventional case series. They received an intravitreal injection of 60 micrograms in 0.1 ml of G-CSF within 2 weeks of the onset of the disease. Visual acuity, visual field, intraocular pressure (IOP), corneal endothelial cell density, and peripapillary retinal nerve fiber layer (RNFL) thickness were recorded before injections and 1 week, 1 month, 3 months, 6 months, and one year after the injections. Full-field electroretinography (ERG) was obtained at the baseline, 1 month, and 12 months post- injections.Results: Fourteen eyes of 14 patients entered the study. Best-corrected visual acuity (BCVA) significantly improved in the first month following injections (p = .007), decreased subsequently, and the final BCVA showed no significant improvement (p = .278) compared to the baseline measurements. A significant decrease in RNFL thickness was observed in all quadrants compared to the baseline measurements. Also, no improvement in the visual field parameters was observed. From the toxicity aspect, no significant changes in the corneal endothelial cell density, IOP, and ERG recordings were observed.Conclusion: Intravitreal injection of G-CSF seems to be safe. The effect may last for one month and then decline.

Effect of segmentation error correction on optical coherence tomography angiography measurements in healthy subjects and diabetic macular oedema.

PURPOSE: To evaluate the impact of segmentation error on vessel density measurements in healthy eyes and eyes with diabetic macular oedema (DMO). METHODS: In this prospective, comparative, non-interventional study, enface optical coherence tomography angiography (OCTA) images of the macula from healthy eyes and eyes with DMO were acquired. Two expert graders assessed and corrected the segmentation error. The rate of segmentation error and the changes in vessel density and inner retinal thickness after correction of the segmentation error were recorded and compared between the two groups. RESULTS: 20 eyes with DMO and 24 healthy eyes were evaluated. Intergrader agreement was excellent (intraclass correlation coefficient ≥0.9) for all parameters in both groups. The rate of segmentation error was 33% and 100% in healthy and diabetic eyes, respectively (p<0.001). Nine healthy eyes (37.5%) and all eyes with DMO (100%) were noted to exhibit a change in at least one of the foveal or parafoveal vessel density measurements. The rate of any change in foveal and parafoveal vessel densities in both the superficial and deep capillary plexus was statistically significantly higher in the diabetic group (all p<0.001). No statistically significant change was observed in mean vessel density (superficial and deep capillary plexuses) after correction of the segmentation error in healthy and DMO eyes (All p>0.05). However, the mean absolute change in the vessel density measurements was statistically significantly higher in the diabetic group (all p<0.05). The mean absolute change in superficial and deep inner retinal thickness was statistically significantly higher in DMO (p=0.02 and p=0.002, respectively). CONCLUSIONS: In this study, misidentification of retinal layers and consequent vessel density measurement error occurred in all eyes with DMO and in one-third of healthy eyes. The segmentation error should be checked and manually corrected in the OCTA vessel density measurements, especially in the presence of macular oedema.

Optical coherence tomography angiography features of optic nerve head drusen and nonarteritic anterior ischemic optic neuropathy.

OBJECTIVE: To evaluate the optic disc microvasculature in optic nerve head drusen (ONHD) vasculature in comparison to acute nonarteritic anterior ischemic optic neuropathy (NAION) and normal eyes using optical coherence tomography angiography (OCT-A). METHODS: Ten eyes with ONHD, 10 eyes with acute NAION, and 10 healthy eyes were included in this prospective, comparative, observational case series. OCT-A imaging was performed on the optic discs. Qualitative grading was performed for dilation and tortuosity of the peripapillary vessels by 3 graders. Quantitative comparison was performed for peripapillary and inside disc vessel densities in nerve head (NH) and retinal peripapillary capillary (RPC) slabs. RESULTS: The intergrader agreement for dilation and tortuosity of the peripapillary vessels was poor (0.313 and 0.182 for vascular dilation in nerve head and radial peripapillary capillary enface images, respectively, and 0.478 and 0.490 for vascular tortuosity in nerve head and radial peripapillary capillary enface images, respectively). In NH en face images, the vessel density measurements were statistically significantly different between the 3 groups (all p < 0.05). In RPC en face images, the vessel density measurements were statistically significantly different between the 3 groups (all p < 0.05) except for nasal peripapillary sector (0.08). CONCLUSION: Despite poor intergrader agreement in qualitative analysis, quantitative OCT-A evaluation may differentiate optic disc edema due to NAION from pseudodisc edema due to ONHD.