Preliminary study on the association of vessel diameter variation and glaucoma.

In this paper, the relation between retinal vessel diameters and glaucoma by means of advanced image processing techniques is examined. Eighteen (18) patients with ocular hypertension who converted to early glaucoma (converters) and nineteen (19) patients with ocular hypertension who remain stable (non-converters) were imaged with a fundus camera at regular intervals. The first acquired image serves as the reference image, which is compared to each follow-up image. The proposed methodology involves the extraction of vessel centerlines by means of differential calculus, the geometrical alignment (registration) of the images using the chamfer matching algorithm, the estimation of vessel diameters by fitting a Gaussian function to intensity profiles. The statistical analysis of the variations of the vessels diameters revealed a significant difference between the two populations. This difference indicates a probable association between glaucoma and variations of the vessel diameter.

Is combined phacoemulsification and trabeculectomy as effective as trabeculectomy alone?

We reviewed the charts of 60 consecutive patients with open-angle glaucoma who underwent a trabeculectomy (T) or a single-site combined glaucoma and cataract procedure (phaco-trabeculectomy = PT) to compare the pressure lowering effect of both techniques. The pressure lowering effect after 12 months was significant in both groups: 11.44 +/- 5.94 mm Hg in the T-group and 5.00 +/- 4.51 mm Hg in the PT-group (p < 0.001). The pressure levels one year postoperatively were significantly lower in the T-group compared to the PT-group: 11.08 +/- 2.80 mm Hg versus 15.04 +/- 2.40 mm Hg (p < 0.001). Our results suggest that the combined procedure, although proven to be effective in lowering the intraocular pressure, is less effective than trabeculectomy alone.

Priority of test locations for automated perimetry in glaucoma.

PURPOSE: Static threshold automated perimetry is a demanding test which can be tiring for some patients. The authors investigate how to optimize early stages of the test which can shorten examination time and improve performance. The effectiveness of measuring every point twice to improve diagnostic precision (proportion of eyes correctly diagnosed as normal or glaucomatous) also was evaluated. METHODS: The authors evaluated the relative contributions of individual test locations to the sensitivity and specificity of static threshold perimetry. One hundred visual fields (Octopus Program G1) of 100 patients with open-angle glaucoma and early glaucomatous defects were used to rank the most frequently defective test locations. This sequence was modified so that highly correlated points were not ranked together. The sensitivities and specificities of the defined sequence of test presentations were then measured in a separate database of 70 normal controls and 70 patients with early glaucomatous visual field defects. RESULTS: Sensitivity and specificity were, respectively, 80% and 80% after 12 locations, 89% and 89% after 26 locations, and 97% and 99% after all 59 test locations. The information obtained with the first phase alone approximates that of both phases. CONCLUSION: Staging of locations tested with automated perimetry in glaucoma may be a valuable method to reduce examination time, minimize fatigue effects, and optimize diagnostic information. Retesting every point does not improve diagnostic precision.

Progression of disc and field damage in early glaucoma.

To assess the temporal relationship between visual field progression and optic disc deterioration in early glaucoma, we studied 15 patients with unilateral visual field loss from primary open angle glaucoma. Planimetric optic disc measurements were compared with automated static threshold perimetry during a mean follow-up of 6.1 years. Eight (53%) of 15 eyes with an initially normal visual field showed progression of the disc; six of these eyes did not develop field abnormalities. The mean rates of rim-area loss were 1.7%/y in eyes with initially normal fields and 2.1%/y in eyes with initial field loss. The mean rate of visual field deterioration (change in corrected loss variance) was lower in the eyes with an initially normal field (0.3 dB2/y) than in eyes with initial field loss (3.6 dB2/y; P = .016). This longitudinal study documents progressive disc damage prior to field loss in early glaucoma.

Disc and field damage in patients with unilateral visual field loss from primary open-angle glaucoma.

To assess the temporal relationship between field and disc change in early glaucoma, 24 patients with unilateral visual field loss from primary open angle glaucoma were identified for planimetric optic disc measurements. Cross-sectional analysis of disc rim area was performed and compared to 25 age-matched normal controls. The mean (+/- SD) disc rim area in eyes with normal visual fields (1.10 +/- 0.31 mm2) was slightly larger than that of eyes with visual field loss (0.90 +/- 0.33 mm2). The mean disc rim area in the control group (1.49 +/- 0.19 mm2) was significantly different from both sets of eyes in the asymmetric primary open angle glaucoma patients (p = 0.000). These findings support the hypothesis that loss of the optic disc rim can be detected before perimetric abnormalities develop in patients with glaucoma.

Takayasu's disease and atherosclerosis.

The aortic arch syndrome characterised by diminished or absent pulses in the arteries arising from the aortic arch has many etiologies, such as syphilitic aortitis, dissection of the aorta, atherosclerosis and Takayasu's arteritis. The diagnostic criteria of Takayasu's arteritis often do not mention histological investigations. We observed a case of an aortic arch syndrome, presenting as a classical case of Takayasu's arteritis but caused by a severe form of atherosclerosis.