Asymmetry in optic disc parameters: the Blue Mountains Eye Study.
(1/183)
PURPOSE: To examine asymmetry in vertical optic disc parameters among subjects classified as normal, as having ocular hypertension (OH), and as having open-angle glaucoma (OAG) in a population-based sample. METHODS: The Blue Mountains Eye Study examined 3654 people aged 49 to 97 years, including 2929 normal subjects, 118 with OH, and 79 with OAG in the groups of interest for the asymmetry study. Optic disc parameters were measured in a masked manner from stereo optic disc photographs. RESULTS: Vertical disc diameter asymmetry (the absolute value of left minus right disc diameters) was similar among normal, OH, and OAG groups (median, 0.07-0.08 mm). Vertical cup- disc ratio asymmetry was higher in patients with OAG (median, 0.11) than in normal subjects (median, 0.06; P < 0.0001) and in those with OH (median, 0.05; P < 0.0001) but was similar between normal subjects and patients with OH (P = 0.17). A cup- disc ratio asymmetry of 0.2 or more was found in 24% of patients with OAG, compared with 1% of patients with OH and 6% of normal subjects. Corresponding rates for cup- disc ratio asymmetry of 0.3 or more in these three groups were 10%, 0%, and 1%, respectively. Using multiple linear regression, cup-disc ratio asymmetry was associated with disc diameter asymmetry and intraocular pressure asymmetry. However, these two factors explained only 3% of the variability of cup- disc ratio asymmetry and 20% of cup diameter asymmetry. CONCLUSIONS: Despite differences between the OAG group and either the OH or normal groups, asymmetry alone was not useful in identifying patients with OAG. At all levels of asymmetry, subjects were more likely to be classified as normal than with OH or OAG. (+info)
Gonioscopy.
(2/183)
Gonioscopy forms part of a complete ophthalmic examination and is mandatory for the diagnosis and management of glaucoma. Gonioscopy permits identification of eyes at risk for closure and detects angle abnormalities that could have diagnostic and therapeutic implications. The technique of gonioscopy, its value in management, and guidelines for routine use are discussed in this paper. (+info)
Prevalence of glaucoma in a rural East African population.
(3/183)
PURPOSE: To determine the prevalence of glaucoma in an adult population in rural central Tanzania. METHODS: Six villages were randomly selected from eligible villages in the Kongwa district, and all residents more than 40 years of age were enumerated and invited to a comprehensive eye examination including presenting visual acuity, refraction, automated 40-point Dicon (San Diego, CA) suprathreshold screening field test, Tono-Pen (Bio-Rad, Inc., Boston, MA) intraocular pressure (IOP) measurement, and standardized examination by an ophthalmologist of anterior segment, optic nerve head, and retina after pupil dilation. Gonioscopy and Glaucoma-Scope (Ophthalmic Imaging Systems, Sacramento, CA) optic disc imaging were performed on those with IOP higher than 23 mm Hg and cup-to-disc ratio (c/d) more than 0.6 and on a 20% random sample of participants. RESULTS: Of 3641 eligible persons, 3268 (90%) underwent ophthalmic examination. The prevalence of glaucoma of all types was 4.16% (95% confidence interval [CI] = 3.5, 4.9%). Primary open-angle glaucoma (OAG) was diagnosed in 3.1% (95% CI = 2.5, 3.8%), primary angle-closure glaucoma (ACG) in 0.59% (95% CI = 0.35, 0.91%), and other forms of glaucoma in 0.49%. The prevalence of glaucoma was found to be sensitive to changes in the diagnostic criteria. CONCLUSIONS: The high prevalence of OAG in this group was similar to that of African-derived persons in the United States but less than in African-Caribbean populations. ACG was more prevalent in east Africans than suggested by anecdotal reports. (+info)
Detection of gonioscopically occludable angles and primary angle closure glaucoma by estimation of limbal chamber depth in Asians: modified grading scheme.
(4/183)
AIM: To evaluate the performance of limbal chamber depth estimation as a means of detecting occludable drainage angles and primary angle closure, with or without glaucoma, in an east Asian population, and determine whether an augmented grading scheme would enhance test performance. METHOD: A two phase, cross sectional, community based study was conducted on rural and urban areas of Hovsgol and Omnogobi provinces, Mongolia. 1800 subjects aged 40 to 93 years were selected and 1717 (95%) of these were examined. Depth of the anterior chamber at the temporal limbus was graded as a percentage fraction of peripheral corneal thickness. An "occludable" angle was one in which the trabecular meshwork was seen in less than 90 degrees of the angle circumference by gonioscopy. Primary angle closure (PAC) was diagnosed in subjects with an occludable angle and either raised pressure or peripheral anterior synechiae. PAC with glaucoma (PACG) was diagnosed in cases with an occludable angle combined with glaucomatous optic neuropathy and consistent visual morbidity. RESULTS: Occludable angles were identified in 140 subjects, 28 of these had PACG. The 15% grade (equivalent to the traditional "grade 1") yielded sensitivity and specificity of 84% and 86% respectively for the detection of occludable angles. The 5% grade gave sensitivity of 91% and specificity of 93% for the detection of PACG. The interobserver agreement for this augmented grading scheme was good (weighted kappa 0.76). CONCLUSIONS: The traditional limbal chamber depth grading scheme offers good performance for detecting occludable drainage angles in this population. The augmented scheme gives enhanced performance in detection of established PACG. The augmented scheme has potential for good interobserver agreement. (+info)
Ocular findings and corticosteroid responsiveness in parents of children with primary infantile glaucoma.
(5/183)
Aqueous humor dynamics, visual fields, optic discs, anterior chamber angles, and topical cortidosteroid responsiveness were studied in twenty parents of children having primary congenital glaucoma. The findings indicate that parents of children with primary congenital glaucoma resemble the general population with respect to the parameters tested, and do not resemble close relatives of patients with primary open-angle glaucoma. (+info)
Open angle glaucoma as a manifestation of Waardenburg's syndrome.
(6/183)
Waardenburg's syndrome is a rare, autosomal dominant disorder, with several clinical signs, each with variable penetrance. We report this case of Waardenburg's syndrome with bilateral open-angle glaucoma with unique gonioscopic findings. (+info)
Fellow eye in angle-closure glaucoma.
(7/183)
118 consecutive patients with angle-closure glaucoma (ACG) were investigated. The primarily affected eye presented with acute ACG in 71 patients, with intermittent or chronic ACG in 41, and with acute ACG secondary to intumescent cataract in six. ACG was demonstrated in the fellow eye in 85 of the 118 patients (72 per cent.), including 72, 71, and 83 per cent. respectively of the three groups distinguished above. In 27 fellow eyes, ACG was demonstrable only by provocative testing. Eleven patients failed to return for follow-up investigation. A routine prophylactic peripheral iridectomy in the fellow eye is justified in patients who are unlikely to attend for follow-up examinations,, but may be avoided in about 23 per cent. of patients who attend regularly. (+info)
Comparison of the effects of two types of intraocular lens.
(8/183)
OBJECTIVE: To evaluate the effectiveness and safety of implantation of flexible open-loop anterior chamber intraocular lens (FOAC-IOLs) and scleral fixated posterior chamber intraocular lens (PC-IOLs). METHODS: Sixty-eight eyes of 68 patients with implanted intraocular lenses in the absence of posterior capsular support were reviewed retrospectively. According to the type of intraocular lens, patients were classified into two groups. In group I (30 eyes), FOAC-IOLs was implanted primarily or secondarily. In group II (38 eyes), scleral fixated PC-IOLs was implanted primarily or secondarily. By gonioscopy and ultrasound biomicroscopy (UBM), accurate positions of IOLs' haptics and the relationship between the haptics and surrounding tissues were observed postoperatively and used to evaluate the influence of the two types of IOLs on ocular anterior segments. Follow-up was 6 to 20 months. RESULTS: Best corrected visual acuity of 20/40 or better was achieved in 27 eyes (90.0%) in group I, and 35 eyes (92.1%) in group II and the difference was not statistically significant (P > 0.05). In group I, 23 eyes (76.7%) had a total of 40 complications, while 13 eyes (34.2%) had 19 complications in group II (P < 0.05). Gonioscopy and ultrasound biomicroscopy showed that in group I, all haptics of IOLs contacted with the iris completely and compressed the iris to different degrees, sometimes causing the anterior chamber angles to widen. Anterior synechia of the iris was caused by the haptics of FOAC-IOLs in 12 eyes. Among the 60 IOLs haptics, 39 foot plates of the haptics were properly fixed at the ciliary band; 21 haptics (12 eyes) penetrated through the iris into the stroma of the ciliary body with accompanying recurrent uveitis. In group II, among the 76 IOLs haptics, 52 were adequately fixed in the ciliary sulcus regions, and 8 (8 eyes) were placed below the iris, causing goniosynechia. This type of angle closure was localized, with an open angle on each side of the haptics. The remaining 16 haptics were fixed onto the ciliary crown. CONCLUSIONS: The current sutured mode of scleral fixated PC-IOLs can not ensure that IOLs haptics are placed in the ciliary sulcus. The haptics of FOAC-IOLs compress the iris and may penetrate through the iris into the stroma of the ciliary body. This can cause peripheral iris anterior synechia and chronic recurrent uveitis. The implantation of scleral fixated PC-IOLs is safer and shows better effects than that of FOAC-IOLs. (+info)