ABSTRACT
Purpose: To analyze the topographic distribution of neovascularization (NV) and capillary nonperfusion (CNP) using ultra?wide field fluorescein angiography (UWFFA) in patients with proliferative diabetic retinopathy (PDR). Methods: This was a prospective, single?center, observational study in which all patients who presented between March 2019 and December 2020 and satisfied the inclusion criteria were recruited. In our study, patients with treatment?naïve PDR without any fibrovascular proliferation underwent UWFFA. The images were analyzed qualitatively for the topographic distribution of NV and the CNP area was quantified. The number of lesions picked by UWFFA was compared with 7 standard field (7SF) image using overlay of 7SF. The main outcome measure was characteristics of neovascularization, such as the number, location, and area of CNP, measured using UWFFA, which was considered with 95% confidence intervals (CI). Results: Two hundred and fifty?three eyes of 187 patients with a mean age of 56.03 ± 8 years were included. Mean neovascularization elsewhere (NVE) was 2.91 ± 3.43. Maximum NVEs were seen in the superotemporal (ST; 0.9 ± 1.13) quadrant, followed by the inferotemporal (IT; 0.7 ± 1.08), inferonasal (IN; 0.66 ± 1.02) and superonasal (SN; 0.66 ± 1.01) quadrants. Maximum CNP area was seen in the SN (13.75 ± 8.83 disc diameter square [DD2]) quadrant, followed by the IN (13.48 ± 8.59 DD2), IT (11.34 ± 8.37 DD2), and ST (11.3 ± 8.34 DD2) quadrants. Mean CNP area was maximum in patients with only neovascularization of disc (NVD; 64.99 ± 41.47 DD2), followed by both NVD and NVE (61.37 ± 35.61 DD2), and was minimum in patients with only NVE (36.44 ± 22.03 DD2). Eighty?one (32%) eyes out of 253 had NVE and 189 (75%) out of 253 had CNP area outside 7SF (overlay) of Early Treatment Diabetic Retinopathy Study (ETDRS). Conclusion: Diabetic NV lesions and CNP areas are distributed asymmetrically throughout the retina and are not restricted to the posterior pole. Compared to conventional 7SF imaging, UWFFA reveals significantly more retinal vascular pathology in patients with PDR.
ABSTRACT
Purpose: To study the effect of subthreshold micropulse yellow laser treatment on central serous chorioretinopathy (CSC) and to compare two laser protocols. As per our knowledge, there are no studies comparing the two protocols of subthreshold laser. Methods: Twenty-three patients with non-resolving CSC of at least three months duration were treated with subthreshold laser (577 nm). Ten patients were treated with 5% duty cycle (group A) and 13 patients with 10% duty cycle (group B). At one month, best corrected visual acuity (BCVA), central macular thickness (CMT), subretinal fluid (SRF), choroidal thickness (CT) and choroidal vascularity index (CVI) were evaluated. Results: In group A, BCVA improved from 0.508 ± 504 to 0.174 ± 0.171 (P = 0.0058), CMT improved from 349.8 ± 168.9 micrometers (mm) to 183.3 ± 70.312 mm (P = 0.0093) and SRF reduced from 202.4 ± 158.024 to 43.8 ± 46.599 mm (P = 0.0069). In group B, BCVA improved from 0.437 ± 0.426 to 0.289 ± 0.470 (P = 0.0026), CMT improved from 280.846 ± 72.668 to 196.769 ± 72.62 mm (P = 0.0002) and SRF reduced from 110.385 ± 57.687 mm to 52.538 ± 52.111 mm (P = 0.0064). No significant difference was found in BCVA and CMT between the groups (P = 0.8716 and P = 0.8523, respectively). CSC completely resolved in 50% of cases in group A and in 69.2% of cases in group B. This difference was not statistically significant (0.423); however, the odds ratio of resolution was 2.25 times more with 10% duty cycle. No change was observed on fundus autofluorescence (FAF) following laser. Conclusion: Subthreshold micropulse laser can lead to resolution of SRF in 60.87% of cases (groups A and B combined). Ten per cent duty cycle had higher odds of resolution without causing any RPE damage.