Citation: Zahid S, Dolz-Marco R, Freund KB, et al. Fractal dimensional analysis of optical coherence tomography angiography in eyes with diabetic retinopathy. Invest Ophthalmol Vis Sci. 2016;57:4940-4947. DOI:10.1167/iovs.16-19656 PURPOSE. We used fractal dimensional analysis to analyze retinal vascular disease burden in eyes with diabetic retinopathy using spectral-domain optical coherence tomography angiography (OCTA). METHODS.A retrospective study was performed of 13 eyes with diabetic retinopathy without diabetic macular edema and 56 control eyes. Optical coherence tomography angiography images were acquired using the RTVue XR Avanti. Automated segmentation was obtained through the superficial and deep capillary plexuses for each eye. Grayscale OCTA images were standardized and binarized using ImageJ. Fractal box-counting analyses were performed using Fractalyse. Fractal dimensions (FD) as well as software-generated vascular density analyses of the superficial and deep capillary plexuses were compared between diabetic and control eyes using 2-tailed t-tests and 1-way multivariate ANOVA (MANOVA) analyses. RESULTS.The superficial and deep plexuses from diabetic and control eyes were analyzed. The average FD for diabetic eyes was significantly lower than control eyes for the superficial (P ¼ 4.513 3 10 À3 ) and deep (P ¼ 2.653 3 10 À3 ) capillary plexuses. In diabetic eyes, the vascular density also was significantly reduced in the superficial (P ¼ 8.068 3 10 À5 ) and deep (P ¼ 3.120 3 10 À6 ) capillary plexuses. One-way MANOVA showed a significant difference between diabetic and control eyes.CONCLUSIONS. The OCTA FD is significantly reduced in the superficial and deep capillary plexuses in eyes with diabetic retinopathy. Applying fractal analysis to OCTA imaging holds the potential to establish quantitative parameters for microvascular pathology.

Précis: This study addresses the paucity of literature examining glaucoma patients’ distance from clinic on postoperative follow-up outcomes. Greater distance from clinic was associated with higher likelihood of loss to follow-up and missed appointments. Purpose: To investigate the relationship of patient travel distance and interstate access to glaucoma surgery postoperative follow-up visit attendance. Methods and Participants: Retrospective longitudinal chart review of all noninstitutionalized adult glaucoma patients with initial trabeculectomies or drainage device implantations between April 4, 2014 and December 31, 2018. Patients were stratified into groups on the basis of straight-line distance from residence to University of North Carolina at Chapel Hill’s Kittner Eye Center and distance from residence to interstate access. Corrective procedures, visual acuity, appointment cancellations, no-shows, and insurance data were recorded. Means were compared using 2-tailed Student t-test, Pearson χ2, analysis of variance, and multivariate logistical regression determined odds ratios for loss to follow-up. Results: In total, 199 patients met all inclusion criteria. Six-month postoperatively, patients >50 miles from clinic had greater odds of loss to follow-up compared with patients <25 miles (odds ratios, 3.47; 95% confidence interval, 1.24–4.12; P<0.05). Patients >50 miles from clinic had significantly more missed appointments than patients 25 to 50 miles away, and patients <25 miles away (P=0.008). Patients >20 miles from interstate access had greater loss to follow-up than those <10 miles (t (150)=2.05; P<0.05). Mean distance from clinic was 12.59 miles farther for patients lost to follow-up (t (197)=3.29; P<0.01). Patients with Medicaid coverage had more missed appointments than those with Medicare plans (t (144)=−2.193; P<0.05). Conclusions: Increased distance from clinic and interstate access are associated with increased missed appointments and loss to follow-up. Glaucoma specialists should consider these factors when choosing surgical interventions requiring frequent postoperative evaluations.

Precis: Ahmed and Baerveldt implants succeed in 90.7% of cases for lowering intraocular pressure (IOP) <21 mm Hg at 1 year when used for the treatment of juvenile open-angle glaucoma. Purpose: The purpose of this study was to report the 1-year outcomes of Ahmed and Baerveldt tubes as the treatment for juvenile open-angle glaucoma at an academic institution. Patients and Methods: Patients 18 to 40 years of age at the time of juvenile open-angle glaucoma diagnosis, who had inadequately controlled glaucoma with an IOP of 18 mm Hg or more on maximum tolerated antiglaucoma therapy that underwent tube shunt surgery with at least 6 months of follow-up were eligible for the study. Exclusion criteria included evidence of neovascular, uveitic or inflammatory, steroid-induced or primary congenital glaucoma, or if they did not have light perception vision. Postoperative failure was defined as an IOP, with or without antiglaucoma drops, >21 mm Hg for 2 consecutive visits after 3 months from surgery, <20% decrease in IOP at 1 year, no light perception, or revision of an implant due to high IOP. Results: The study population included 32 eyes from 25 patients who underwent tube shunt surgery. The failure rate at 1-year follow-up was 9.3%, and the postoperative complication rate at 1-year follow-up was 9.3%. The average change from baseline to 1 year for IOP was a decrease of 9.8±9.10, for the number of antiglaucoma drops number was a decrease of 0.38±1.06, and for the visual acuity was an increase of 0.03±0.27. Conclusions: Ahmed and Baerveldt implantation succeeded in lower IOP in 90.7% of patients at 1 year. Continuation of antiglaucoma drops to maintain the IOP after surgery is likely required.

Purpose of reviewThe aim of this article is to summarize up-to-date research on the diagnosis and management of juvenile open-angle glaucoma (JOAG). Recent findingsJOAG can be subclassified into four clinical phenotypes, and faster myopic shift is a risk factor for disease progression. Vessel density is associated with structural damage and worsening visual acuity in JOAG and can be monitored with optical coherence tomography angiography. Genetic studies have revealed molecular causes of JOAG including variants in CPAMD8, MYOC, and CYP1B1. Tube shunt surgeries as well as gonioscopy-assisted transluminal trabeculotomy have been shown to be successful in JOAG. SummaryAlthough genetic advances may improve future screening, intraocular pressure monitoring and fundoscopic exam remain the current mainstay of diagnosis. Medical treatment alone for JOAG is typically insufficient with patients requiring surgical management. Selective laser trabeculoplasty may delay or decrease the need for surgery. Trabeculectomy has traditionally been shown to be effective in JOAG, but tube shunt surgery and microinvasive glaucoma surgery are effective alternatives.

Bannayan-Zonana syndrome is an autosomal-dominant, hamartomatous disease characterized by a mutation spectrum that involves genes responsible for vascular development. Retinal vascular abnormalities and exudation can be a manifestation of this syndrome.