Topographic distribution of retinal neovascularization in proliferative diabetic retinopathy using ultra-wide field angiography

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.

Macular Ischemia Correlated with Final Visual Outcome in Retinal Vein Occlusion Patients

PURPOSE: To identify the correlation between final visual outcome after at least 6 months of follow-up and the extent of macular ischemia on the first visit. METHODS: We performed a retrospective clinical analysis of macular ischemia using clinical records, fundus examinations, and fluorescein angiographies in 83 patients (86 eyes) diagnosed with retinal vein occlusion from January 1998 to July 2012 and followed up for over 6 months. We evaluated the extent and the location of macular ischemia, macular edema, initial and final visual acuities and systemic disease based on fluorescein angiography and optical coherence tomography performed within 2 weeks of the first visit. The patients were divided into the following 4 groups based on the extent and location of macular ischemia and edema: superotemporal, superonasal, inferotemporal, and inferonasal. RESULTS: Retinal vein occlusions (RVOs) consisted of 24 central RVOs (CRVOs) and 62 branch RVOs (BRVOs). Mean initial acuity (log MAR) was 0.35 +/- 0.31 (36 eyes) in the no macular ischemia group, 0.40 +/- 0.21 (11 eyes) in the 1-quadrant macular ischemia group, 0.71 +/- 0.32 (26 eyes) in the 2-quadrant macular ischemia group and 0.73 +/- 0.36 (13 eyes) in the over 3 quadrants macular ischemia group. Mean final acuity (log MAR) was 0.23 +/- 0.23 in the no macular ischemia group, 0.40 +/- 0.30 in the 1-quadrant macular ischemia group, 0.51 +/- 0.32 in the 2-quadrant macular ischemic group and 0.73 +/- 0.31 in the over 3 quadrants macular ischemia group. CONCLUSIONS: The initial and final visual outcomes were worse when more quadrants were affected by macular ischemia. The extent of macular ischemia was correlated with initial visual acuity and final visual outcome but not with macular edema.

Ultrastructure of Rapidly Proliferating Preretinal Membrane of Very Extensive Ischemic Diabetic Retinopathy

PURPOSE: Using transmission electron microscopy (TEM), we studied the ultrastructures of rapidly proliferating preretinal membranes of young patients with very extensive ischemic proliferative diabetic retinopathy and diabetes with uncontrollable blood sugar level. METHODS: Nine cases of preretinal membranes were obtained from six eyes of five patients with rapidly progressed proliferative diabetic retinopathy (mean age, 35 years) during vitrectomy. We obtained each preretinal membrane bimanually as one single sheet membrane using intraocular scissors and forceps. Each tissue was fixed in 3% glutaraldehyde in the operating room. All specimens were prepared and studied using TEM. RESULTS: The preretinal membranes were composed of blood vessels and some interstitial cells. The blood vessels within the preretinal membranes varied in developmental stages, from the immature stage to the mature stage. The blood vessels were highly active, in that primitive cells showed a large nucleus and prominent chromatin clumping with abundant cytoplasm. Highly active fibroblast-like cells were also noted. CONCLUSIONS: We observed highly active angiogenesis in preretinal membranes, which rapidly proliferated in cases of severe retinal ischemia in young diabetes patients. This is the first report of such a finding, which may help to explain the poor prognosis of this disease modality.

The Relationship between the Capillary Nonperfusion Area and the Retinal Nerve Fiber Layer Defects in Branch Retinal Vein Occlusion Patients

PURPOSE: To determine the relationship between the capillary nonperfusion area and the retinal nerve fiber layer (RNFL) defects in branch retinal vein occlusion (BRVO) patients. METHODS: We compared the difference between the RNFL thickness of both eyes in unilateral BRVO patients using the scanning laser polarimeter (GDx R ). The mean RNFL thickness was calculated for each quadrant. Fluorescein angiography was done to determine the retinal capillary nonperfusion area and we evaluated the relationship between the retinal capillary nonperfusion area and the right-left difference of RNFL thickness. RESULTS: In left superior temporal BRVO group, the Average of RNFL was thinner (p=0.015) and the Integral was smaller (p=0.045) in the left BRVO eye than in the right normal eye in the superior temporal sector. In patients with the other sector BRVO, there was no significant difference of RNFL thickness between both eyes. As the retinal capillary nonperfusion area increased, the right-left difference of Average increased in the superior temporal sector in patients with left superior temporal BRVO (p=0.042). CONCLUSIONS: The scanning laser polarimeter allowed the quantification of RNFL defect in patients with BRVO, and it may help to evaluate the quantification of retinal ischemia.

Clinical Observation of the Bilateral Retinal Vein Occlusion

The clinical evaluation was done in eighteen eyes of nine patients with bilateral BRVO in aspects of onset, visual acuity, interval between onset of one eye and the other, sex ratio, associated systemic diseases, location of the affected vein, the effect of macular edema on visual acuity and ocular complications. The onset of age was from fifty one to sixty eight years. Eight patients were women, and one patient was man. Hypertension was the most common associated systemic disease. Ten eyes (55.5%) of bilateral BRVO were affected the superior temporal branch vein, the sites of occlusion were not more than two disc diameters from the optic disc in fifteen eyes (83.3%). The complications of seevere visual loss had macular edema, macular capillary nonperfusion, retinal neovascularization and vitreous hemorrhage. Among of six numbers who could be followed up more than one year, and visual acuity of five eyes with macula edema were decreased than five other eyes developed one year or later. Eyes that were more than five disc diameters of capillary nonperfusion, as visualized with fluorescence angiography were thirteen (72.2%). Of these eyes, six (46.1 %) eyes occured retinal neovascularization, five of those had macular capillary nonperfusion. four of those were 0.1 in final vision. Three of four eyes with vitreous hemorrhage were very slowly improved in visual acuity, but another was decreasing in visual acuity due to other ocular complications We thought that woman with history of BRVO due to hypertension in sixth and seventh decades should be followed up the other eye for three years.

Size of Capillary Nonperfusion and their Prognosis in Branch Retinal Vein Occlusion Patients

Sudden loss of visual acuity and visual field can occur in the vast majority of BRVO patients. One third to half of the patients recover from impared cision even without specific treatment, but it is unlikely when complication such as macula edema, capillary nonperfision, neovascularization and vitreous hemorrhage are accompanied. The authors reviewed 55 patients with branch retinal vein occlusion(55 eyes) in regard of the size of capillary non perfusion, and divided them into two groups; the perfused group(15 eyes) in which the area of capillary non perfusion is less than 5 disc diameter, and the nonperfused group(40 eyes) in which the area is more than 5 disc diameter. The freqnency of the development of neovascularization and vitreous hemorrhage, and the final visual outcome between two groups were compared. Neovascularization occurred in 3 eyes of perfused group and 23 eyes of nonperfused group, and vitreous hemorrhage occured in 4 eyes of nonperfused group, and vitreous hemorrhage occurred in 4 eyes of nonperfused group. There was no statistic al difference between two groups in the final visual acuity.

Clinical Research on the Branch Retinal Vein Occlusion

The clinical results in 102 eyes of 97 patients with Branch Retinal Vein Occlusion(BRVO) were evaluated in aspect of distribution, associated findings, sequelae, early and final visual acuities, and the effect of argon laser photocoagulation. There were no significant differences in morbidity rate between male and female or between right and left eye. 68.6% of all BRVO were affected in superotemporal branch veins. As sequelae, cystoid macular edema in 58 cases, retinal neovascularization in 22 cases, vitreous hemorrhages in 14 cases, vitreous tractional band in 2 cases, and non-rhegmatogenous retinal detachment in 2 cases were found. Photocoagulation was performed with an argon laser at retinal neovascularization in 20 eyes, capillary non-perfusion and cystoid macular edema in 5 eyes, and retinal detachment in 2 eyes. Photocoagulation was an affective means of reducing macular edema and decreased the risk of neovascularization and vitreous hemorrhages from sites of large capillary non-perfusion and retinal neovascularization.