Optical coherence tomography angiography reveals progressive worsening of retinal vascular geometry in diabetic retinopathy and improved geometry after panretinal photocoagulation.

PURPOSE: To quantify vessel tortuosity and fractal dimension of the superficial capillary plexus (SCP) of the macula in different stages of diabetic retinopathy (DR), and following panretinal photocoagulation (PRP) using optical coherence tomography angiography (OCTA). METHODS: 75 eyes of 75 subjects were divided into five groups; healthy controls, diabetes with no clinical DR, non-proliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR) and patients who received PRP for PDR (PDR+PRP).For vessel tortuosity, SCP slabs from 3x3 mm macular OCTA scans were processed using imageJ (NIH, USA), where large perifoveal vessels were traced and their length was measured with tortuosity calculated as the ratio between the actual length and the straight Euclidean length. For fractal dimension, SCP slabs were processed and imported to Fractalyse (ThéMA, France), where box-counting analyses produced fractal dimension values. RESULTS: We found a significant difference in vessel tortuosity and fractal dimension between the five groups (one-way ANOVA, p < 0.001both). NPDR and PDR had significantly more tortuous vessels and lower fractal dimension compared to healthy controls (Tukey HSD: p = 0.02, 0.015,0.015 and <0.001, respectively). Fractal dimension was also significantly lower in NPDR and PDR compared to eyes with no clinical DR (p <0.001 both), and in PDR compared to NPDR (p = 0.014). Following PRP, vessel tortuosity was significantly lower and fractal dimension was higher in PDR+PRP compared to PDR (p = 0.001 and 0.031, respectively). CONCLUSIONS: We used macular OCTA scans to demonstrate significantly higher perifoveal large vessel tortuosity, and lower fractal dimension in NPDR and PDR compared to healthy controls. Vessel tortuosity shows more dramatic normalization than fractal dimension and could be explored as a sensitive marker for successful PRP.

Pattern of Childhood Uveitis in Egypt.

Purpose: To report the pattern of childhood-onset uveitis observed in Egypt from May 2010 to May 2017 Methods: Retrospective evaluation of the data of all patients with uveitis diagnosed before the age of 16 and visiting uveitis referral clinics in 5 Egyptian Governorates (Alexandria, Cairo, Al Bohayra (Damanhour), Al Gharbeya (Tanta), and Sohag) between May 2010 and May 2017. Results: A total of 413 uveitis patients were enrolled. These included 219 male and 194 female patients. Uveitis was bilateral in 68.3% of the patients. The most frequently observed ocular complications were cataract, glaucoma, and cystoid macular edema. The percentage of children with a visual acuity ≥1.00 logMAR in at least one eye by the final visit was 21.8%. Conclusion: Pediatric uveitis is a vision-threatening condition which caused more than one-fifth of the children in this study to lose vision in one or both eyes.