Quantification of macular perfusion following panretinal photocoagulation for diabetic retinopathy: An optical coherence tomography angiography study.

PURPOSE: To assess the effects of panretinal photocoagulation (PRP) on the microvascular structure of the macula and central thickness of the macula and choroid via optical coherence tomography angiography (OCTA). METHODS: In this prospective clinical study, 43 eyes of 31 patients with severe non-proliferative diabetic retinopathy or early proliferative diabetic retinopathy were included. Before and at the third and sixth months after PRP, the foveal avascular zone (FAZ) area, acircularity index (AI), foveal density (FD), and vascular density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were evaluated using OCTA. The central macular thickness (CMT) and subfoveal choroidal thickness (SCT) were also measured after PRP. RESULTS: There was no difference between the FAZ area, AI, FD, and vessel density of the SCP and DCP before and at the third and sixth months after PRP (all p>0.05). The CMT value was higher at the third and sixth months than at baseline (p = 0.002 and p = 0.001, respectively). The SCT value was lower at the third and sixth months than at baseline (p = 0.002 and p = 0.001, respectively). CONCLUSION: PRP is a beneficial and reliable method that supports the integrity of the macular microvascular structure. After PRP, the CMT increases, and the SCT decreases.

A novel duplication involving PRDM13 in a Turkish family supports its role in North Carolina macular dystrophy (NCMD/MCDR1).

Purpose: To clinically and molecularly investigate a new family with North Carolina macular dystrophy (NCMD) from Turkey, a previously unreported geographic origin for this phenotype. Methods: Clinical ophthalmic examinations, including fundus imaging and spectral domain-optical coherence tomography (SD-OCT), were performed on eight members of a two-generation non-consanguineous family from southern Turkey. Whole genome sequencing (WGS) was performed on two affected subjects, followed by variant filtering and copy number variant (CNV) analysis. Junction PCR and Sanger sequencing were used to confirm and characterize the duplication involving PRDM13 at the nucleotide level. The underlying mechanism was assessed with in silico analyses. Results: The proband presented with lifelong bilateral vision impairment and displayed large grade 3 coloboma-like central macular lesions. Five of her six children showed similar macular malformations, consistent with autosomal dominant NCMD. The severity grades in the six affected individuals from two generations are not evenly distributed. CNV analysis of WGS data of the two affected family members, followed by junction PCR and Sanger sequencing, revealed a novel 56.2 kb tandem duplication involving PRDM13 (chr6:99560265-99616492dup, hg38) at the MCDR1 locus. This duplication cosegregates with the NCMD phenotype in the five affected children. No other (likely) pathogenic variants in known inherited retinal disease genes were found in the WGS data. Bioinformatics analyses of the breakpoints suggest a replicative-based repair mechanism underlying the duplication. Conclusions: We report a novel tandem duplication involving the PRDM13 gene in a family with NCMD from a previously unreported geographic region. The duplication size is the smallest that has been reported thus far and may correlate with the particular phenotype.