Glaucoma in oculodermal melanocytosis

Oculodermal melanocytosis (ODM) is a developmental disorder of the embryonic neural crest involving virtually all of the structures of the eye derived from this tissue. The authors examined 194 previously unreported Thai patients with ODM. Elevated intraocular pressures (IOPs) developed in the ipsilateral eye of 15 patients at initial examination and in 5 others during follow-up, for a total of 10.3% of the patients. Three patients had congenital or late congenital glaucoma, 14 had ocular hypertension or open-angle glaucoma, and 3 had acute angle-closure glaucoma. Five of the patients with open angles had acute pressure rises accompanied by anterior uveitis. Melanocytic hyperpigmentation of the anterior chamber angle was extensive in all patients except those with acute angle-closure glaucoma. There was no consistent correlation between the extent or density of angle pigmentation and the development of elevated IOP. A larger cup-to-disc ratio in the involved eye, presumably congenital, was present in an additional 19 patients. Glaucoma is common in eyes with ODM and may develop at any age. Patients with ODM and initially normal IOP should be examined at regular intervals. Patients with open angles and acutely elevated IOP should be examined carefully for signs of anterior uveitis and treated medically.     

Reversal of autoimmune hemolytic anemia associated with chronic lymphocytic leukemia following high-dose immunoglobulin

An 85-year-old man with chronic lymphocytic leukemia developed severe warm antibody-type autoimmune hemolytic anemia. Initial therapy with high-dose corticosteroids had no discernible effect on the hemolytic process. Following treatment with high-dose intravenous immunoglobulin (0.4 g/kg/d for 5 consecutive days) there was an immediate and sustained increase in hematocrit accompanied by a progressive decline in reticulocyte count. A review of the literature reveals that some patients with steroid-resistant immune hemolysis may benefit from high-dose immunoglobulin. This approach should be considered in elderly patients with severe anemia whose medical status precludes splenectomy.     

Initial 5-fluorouracil trabeculectomy in young patients.

The effectiveness of initial trabeculectomy with adjunctive 5-fluorouracil (5-FU) for uncomplicated glaucoma in patients age 40 years or younger at the time of surgery was evaluated retrospectively in a consecutive series of 20 eyes of 20 patients. Fifteen patients had juvenile primary open-angle glaucoma, 4 had pigmentary glaucoma, and 1 had glaucoma associated with angle recession. Mean patient age was 26.8 +/- 9.7 years (range, 13 to 40 years) at the time of surgery. The mean total 5-FU dose administered was 27.8 +/- 8.8 mg (range, 15 to 45 mg). The intraocular pressure (IOP) decreased from 34.4 +/- 11.5 mmHg preoperatively to 10.5 +/- 4.0 mmHg postoperatively after a mean follow-up of 31.1 +/- 17.3 months (range, 11.5 to 70 months). Nineteen eyes (95%) had a postoperative IOP of 20 mmHg or less without pressure-lowering medications. One patient required additional medical therapy to control the IOP. Complications included bleb-related endophthalmitis (2 eyes) and hypotony maculopathy (1 eye).     

Analysis of myocilin mutations in 1703 glaucoma patients from five different populations

A glaucoma locus, GLC1A, was identified previously on chromosome 1q. A gene within this locus (encoding the protein myocilin) subsequently was shown to harbor mutations in 2-4% of primary open angle glaucoma patients. A total of 1703 patients was screened from five different populations representing three racial groups. There were 1284 patients from primarily Caucasian populations in Iowa (727), Australia (390) and Canada (167). A group of 312 African American patients was from New York City and 107 Asian patients from Japan. Overall, 61 different myocilin sequence variations were identified. Of the 61 variations, 21 were judged to be probable disease-causing mutations. The number of probands found to harbor such mutations in each population was: Iowa 31/727 (4.3%), African Americans from New York City 8/312 (2.6%), Japan 3/107 (2.8%), Canada 5/167 (3.0%), Australia 11/390 (2.8%) and overall 58/1703 (3. 4%). Overall, 16 (76%) of 21 mutations were found in only one population. The most common mutation observed, Gln368Stop, was found in 27/1703 (1.6%) glaucoma probands and was found at least once in all groups except the Japanese. Studies of genetic markers flanking the myocilin gene suggest that most cases of the Gln368Stop mutations are descended from a common founder. Although the specific mutations found in each of the five populations were different, the overall frequency of myocilin mutations was similar ( approximately 2-4%) in all populations, suggesting that the increased rate of glaucoma in African Americans is not due to a higher prevalence of myocilin mutations.     

Ultrasound biomicroscopy dark room provocative testing: a quantitative method for estimating anterior chamber angle width

PURPOSE: To describe a quantitative method for measuring the iridocorneal angle recess area, and, using this, to evaluate factors associated with appositional angle-closure during dark room provocative testing using ultrasound biomicroscopy (UBM). METHODS: All patients (178 patients, 178 eyes) with clinically narrow angles referred for UBM dark room provocative testing between September 1996 and March 1998 were enrolled in this study. Images of the inferior quadrant of the angle taken under standardized dark and light conditions were analyzed. The angle recess area (ARA) was defined as the triangular area demarcated by the anterior iris surface, corneal endothelium, and a line perpendicular to the corneal endothelium drawn from a point 750 microm anterior to the scleral spur to the iris surface. ARA, and acceleration and gamma-intercept of the linear regression analysis of the ARA were calculated. In the linear regression formula, y = ax + b, the acceleration a describes the rate at which the angle widens from the scleral spur; the y-intercept b describes the distance from the scleral spur to the iris. RESULTS: Under dark conditions, the angles in 99 patients (55.6%) showed evidence of appositional angle-closure during testing. ARA (0.11 +/- 0.04 vs. 0.15 +/- 0.05 mm2, P < .0001, Student t-test), acceleration a (0.22 +/- 0.15 vs. 0.26 +/- 0.17, P = .068), and y-intercept b (66 +/- 46 vs. 92 +/- 47 microm, P = .0003) were smaller in eyes that were occluded. In the eyes that were not occluded, y-intercept b showed no significant difference between light and dark conditions (P = .1, paired t-test), while acceleration a did (P < .0001). In the eyes that were occluded, both decreased significantly under dark conditions (P < .0001). CONCLUSIONS The ARA linear regression formula provides useful quantitative information about angle recess anatomy. The more posterior the iris insertion on the ciliary face, the less likely the provocative test will be positive.     

Differential diagnosis of anterior segment cysts by ultrasound biomicroscopy

BACKGROUND: To describe the ultrasound biomicroscopic (UBM) features of anterior segment cysts. DESIGN: A retrospective case series. PARTICIPANTS: One hundred eighteen eyes with anterior segment cysts examined by UBM at The New York Eye and Ear Infirmary between August 1992 and November 1997 were included in this study. INTERVENTION: The authors reviewed demographic and diagnostic data from the medical record including ocular and medical history, age, race, gender, and intraocular pressure. Ultrasound data concerning the type, number, position, and acoustic characteristics of cysts were recorded. The authors then correlated the written, clinical, and UBM characteristics. RESULTS: One hundred eyes (92.6%) had neuroepithelial cysts. Ninety (83.3%) of these had primary neuroepithelial cysts, 10 (9.3%) had cysts associated with uveitis, 7 (6.5%) had implantation cysts, and 1 (0.9%) had a cavitated ciliary body tumor. Neuroepithelial cysts typically were round or ovoid, thin-walled, and echolucent. Of the 90 eyes with primary neuroepithelial cysts, 56 (62.2%) had 3 or fewer cysts; multiple cysts (>3 per eye) were found in 34 eyes (37.8%). The multiple cysts occupied more than 180 degrees in 12 patients (13.3%). Primary neuroepithelial cysts were located at the iridociliary junction (74.2%), pars plicata (14.0%), pars plana (6.8%), and iris (5.0%). Implantation cysts (seven eyes) tended to have thicker walls and two contained a copious, echogenic material. CONCLUSION: The UBM results provide important information regarding location and extent of anterior segment cystic lesions. Ultrasound characteristics may help differentiate between neuroepithelial, implantation, and neoplastic cysts.     

Increasing sampling density improves reproducibility of optical coherence tomography measurements.

PURPOSE: Published series of peripapillary retinal nerve fiber layer (RNFL) measurements using optical coherence tomography (OCT) have sampled 100 evenly distributed points on a 360 degrees peripapillary circular scan. The goal of this study was to determine whether a four-fold increase in sampling density improves the reproducibility of OCT measurements. METHODS: Complete ophthalmic examinations, achromatic automated perimetry, and OCT imaging were performed in all patients. The OCT scanning consisted of three superior and inferior quadrantic scans (100 sampling points/quadrant) and three circular scans (25 points/quadrant). The RNFL thickness measurements and coefficient of variation (CV) were calculated for the superior and inferior quadrants for each sampling density technique. RESULTS: The study included 22 eyes of 22 patients (3 control subjects; 2 patients with ocular hypertension; and 17 patients with glaucoma). Quadrants with associated glaucomatous visual field loss on automated achromatic perimetry had thinner RNFLs than quadrants without functional defects for both the 25- and 100-points/quadrant scans. For quadrants associated with normal visual hemifields (n = 22), there was no difference between the 25- and 100-points/quadrant scans in mean RNFL thickness and CV. Among quadrants with visual field defects (n = 22), RNFL thickness measurements were thinner in the 25-points/quadrant scans than in the 100-points/quadrant scans. The CV for the 25-points/quadrant scans (25.9%) was significantly higher than that for the 100-points/quadrant scans (11.9%). CONCLUSION: Increasing the sampling density of OCT scans provides less variable representation of RNFL thickness. The optimal sampling density to achieve maximal reliability of OCT scans remains to be determined.     

The use of scleral transillumination to localized the extent of a cyclodialysis cleft

Several techniques have been described to localize and repair cyclodialysis clefts. We describe a technique that may be used to easily and accurately localize a cyclodialysis cleft using scleral transillumination. We have verified the accuracy of this technique using high frequency ultrasound biomicroscopy. The location of the cleft was verified using high frequency ultrasound biomicroscopy. Scleral transillumination may facilitate the accurate location of cyclodialysis and may be a useful adjunct in planning the surgical repair of a cyclodialysis cleft.