Effect of Aging on Retinal Macular Microcirculation: A Blue Field Simulation Study

Purpose. Structural changes in the retina are known to occur with aging. This study was performed to investigate whether aging also affects the retinal macular microcirculation. Methods. Healthy volunteers with ages ranging from 20 to 78 years (mean ± SD, 49 ± 19 years) were included in this study. The retinal macular microcirculation was assessed with the blue field simulation technique, based on the blue field entoptic phenomenon. Subjects were asked to match the velocity and density of computer-simulated particles displayed on a screen with those of their entoptically observed leukocytes. Ten matching trials were performed, and an average leukocyte velocity and density were calculated. Results. Significant negative linear correlations were observed between velocity and age (P = 0.0001) and density and age (P = 0.009). Older subjects (50 to 78 years of age) had a significantly slower velocity (0.61 ± 0.21 mm/s) and smaller density (90 ± 43 particles per field of view) than younger subjects (0.92 ±0.12 mm/s and 135 ± 65 particles, respectively; unpaired Student's t-test, P = 0.001 and P = 0.01, respectively). Conclusions. These results suggest that, in normal subjects, retinal macular blood flow decreases with age. The 20% decrease in average velocity with age is very similar to the age-related decrease in number of cells observed in the human foveal ganglion cell layer. Invest Ophthalmol Vis Sci. 1993;34:3609-3613. X he retina undergoes several structural changes with aging

Detection and prognostic significance of optic disc hemorrhages during the Ocular Hypertension Treatment Study

To compare the rates of detection of optic disc hemorrhages by clinical examination and by review of optic disc photographs at the Optic Disc Reading Center (ODRC), to assess the incidence of and the predictive factors for disc hemorrhages in the annual disc photographs of the Ocular Hypertension Treatment Study (OHTS), and to determine whether optic disc hemorrhages predict the development of primary open-angle glaucoma (POAG) in the OHTS. Cohort study. Three thousand two hundred thirty-six eyes of 1618 participants. Both eyes of participants were examined for optic disc hemorrhages every 6 months by clinical examination, with dilated fundus examinations every 12 months, and by annual review of stereoscopic disc photographs at the ODRC. Incidence of optic disc hemorrhages and POAG end points. Median follow-up was 96.3 months. Stereophotography-confirmed glaucomatous optic disc hemorrhages were detected in 128 eyes of 123 participants before the POAG end point. Twenty-one cases (16%) were detected by both clinical examination and review of photographs, and 107 cases (84%) were detected only by review of photographs (P<0.0001). Baseline factors associated with disc hemorrhages were older age, thinner corneas, larger vertical cup-to-disc ratio, larger pattern standard deviation index on perimetry, family history of glaucoma, and smoking status. The occurrence of a disc hemorrhage increased the risk of developing POAG 6-fold in a univariate analysis (P<0.001; 95% confidence interval, 3.6-10.1) and 3.7-fold in a multivariate analysis that included baseline factors predictive of POAG (P<0.001; 95% confidence interval, 2.1-6.6). The 96-month cumulative incidence of POAG in the eyes without optic disc hemorrhage was 5.2%, compared with 13.6% in the eyes with optic disc hemorrhage. In eyes with a disc hemorrhage in which a POAG end point developed, the median time between the 2 events was 13 months. Review of stereophotographs was more sensitive at detecting optic disc hemorrhage than clinical examination. The occurrence of an optic disc hemorrhage was associated with an increased risk of developing a POAG end point in participants in the OHTS. However, most eyes (86.7%) in which a disc hemorrhage developed have not experienced a POAG end point to date

Utility of Digital Stereo Images for Optic Disc Evaluation

The utility of digital stereo optic disc images for glaucoma was assessed by comparing primary digital stereo images to 35-mm slides and scanned and grayscale images. Whereas color seemingly adds little to stereo grayscale images, digital images are useful for evaluating the optic disc in stereo and should allow the application of advanced image processing techniques

Asymmetries and visual field summaries as predictors of glaucoma in the ocular hypertension treatment study

PURPOSE. To evaluate whether baseline visual field data and asymmetries between eyes predict the onset of primary open-angle glaucoma (POAG) in Ocular Hypertension Treatment Study (OHTS) participants. METHODS. A new index, mean prognosis (MP), was designed for optimal combination of visual field thresholds, to discriminate between eyes that developed POAG from eyes that did not. Baseline intraocular pressure (IOP) in fellow eyes was used to construct measures of IOP asymmetry. Age-adjusted baseline thresholds were used to develop indicators of visual field asymmetry and summary measures of visual field defects. Marginal multivariate failure time models were constructed that relate the new index MP, IOP asymmetry, and visual field asymmetry to POAG onset for OHTS participants. RESULTS. The marginal multivariate failure time analysis showed that the MP index is significantly related to POAG onset (P &lt; 0.0001) and appears to be a more highly significant predictor of POAG onset than either mean deviation (MD; P = 0.17) or pattern standard deviation (PSD; P = 0.046). A 1-mm Hg increase in IOP asymmetry between fellow eyes is associated with a 17% increase in risk for development of POAG. When threshold asymmetry between eyes existed, the eye with lower thresholds was at a 37% greater risk of development of POAG, and this feature was more predictive of POAG onset than the visual field index MD, though not as strong a predictor as PSD. CONCLUSIONS. The MP index, IOP asymmetry, and binocular test point asymmetry can assist in clinical evaluation of eyes at risk of development of POAG.</p