Pattern and distribution of neovascularization in proliferative diabetic retinopathy on fundus fluorescein angiography: A growing paradigm

Background

The objective of this study was to evaluate pattern and distribution of neovascularization of optic disc (NVD) and elsewhere (NVE) in proliferative diabetic retinopathy (PDR).

Methods

A cross-sectional study was conducted among freshly detected cases of PDR. Fundus fluorescein angiographic images of 61 eyes were assessed. Parameters studied for NVD were their number and location and for NVE were their number, location, type of leak, and distance from center of optic disc.

Results

Of 61 eyes, 29 eyes (47.5%) had NVD with a total of 49 leaks. Of these 49 NVD leaks, the maximum was concentrated in the superotemporal quadrant with 21 leaks (42.9%; 95%CI 28.8-57.8%). Of 61 eyes, 50 eyes (82%) had NVE with 97 leaks. Of 97 NVE leaks, 41 were found in the superotemporal quadrant (42.3%; 95%CI 32.3-52.7%). Maximum NVE was found within the circle of radius 3-6 mm centered on optic disc (p value = 0.001) with no leaks in central macula. Of 29 eyes with NVD, only 7 eyes had >1/3 area of disc involvement. Also, of 18 eyes with concurrent NVD and NVE, only 2 eyes had >1/3 area of disc involvement which is a high-risk characteristic of PDR.

Conclusion

Neovascular lesions have a predilection for superotemporal part for both NVD and NVE. NVE leaks were almost double the number of NVD leaks. Maximum NVE leaks were found at posterior pole with no central macular involvement. This study provides comprehensive data and further adds to knowledge of neovascularization for early diagnosis and management of PDR.

Differences in ocular blood flow in glaucoma between patients of African and European descent

PURPOSE

To investigate differences in ocular blood flow in individuals of African descent (AD) and European descent (ED) with open angle glaucoma (OAG).

PATIENTS AND METHODS

A retrospective data analysis was performed on OAG patients of AD and ED who were previously examined for ocular blood flow within the Department of Ophthalmology at Indiana University School of Medicine. Data analysis included blood pressure, heart rate, visual fields, intraocular pressure, ocular perfusion pressure, and color Doppler imaging of retrobulbar vessels. Color Doppler imaging measurements were performed on ophthalmic, central retinal, and nasal and temporal short posterior ciliary arteries, with peak systolic (PSV) and end diastolic velocities (EDV) as well as the Pourcelot vascular resistive index calculated for each vessel. Two-sample t tests of unequal variance were performed with P values <0.05 considered statistically significant.

RESULTS

OAG patients of AD had statistically significant lower retrobulbar blood flow values than patients of ED including lower ophthalmic artery PSV (P=0.0001), ophthalmic artery EDV (P=0.0008), central retinal artery PSV (P=0.01), temporal short posterior ciliary artery PSV (P=0.0037), and nasal short posterior ciliary artery PSV (P<0.0001). No significant differences were found in terms of intraocular pressure or visual field parameters.

CONCLUSIONS

Significantly lower blood flow values were identified in all retrobulbar blood vessels in AD compared with ED OAG patients. These findings suggest that the contribution of ocular blood flow to the disease process may be different in AD compared with ED OAG patients.

Korean normative database for time domain optical coherence tomography to detect localized retinal nerve fiber layer defects (preliminary study)

PURPOSE

To establish a Korean normative database of retinal nerve fiber layer (RNFL) thickness.

METHODS

Data was collected from 103 healthy volunteers. Total ophthalmologic examinations, including fast RNFL thickness analysis by time domain optical coherence tomography (STRATUS OCT) were performed. The RNFL thickness of 64 glaucoma patients with localized RNFL defects and 48 independent healthy subjects were collected. The RNFL thickness of both the glaucoma patients and the healthy subjects was evaluated using both normative databases.

RESULTS

The average RNFL thickness of Koreans was 108.3 +/- 10.3 microm. The sensitivity rates recorded in the Korean normative database with 5% and 1% significance were 0.984 and 0.984, with specificity values of 0.938 and 1.000. By comparison, the sensitivity rates in the conventional normative database with 5% and 1% significance are 0.984 and 0.953, and the specificity values are 1.000 and 1.000.

CONCLUSION

In detecting localized RNFL defects, the Korean database showed higher sensitivity than the conventional database.