Anterior chamber depth in elderly Chinese: the Liwan eye study.

PURPOSE: To assess the anterior chamber depth (ACD) and its variation with age, gender, and angle width in elderly Chinese in an urban area of southern China. DESIGN: Cross-sectional study. PARTICIPANTS: Adults 50 and older were identified using cluster random sampling in Liwan District, Guangzhou. METHODS: Gonioscopy was performed before ACD measurements to estimate the geometric angle width according to the Shaffer system. ACD was measured using optical pachymetry. True ACD was calculated by subtracting central corneal thickness from the distance between the anterior corneal epithelium and the anterior lens capsule. Data were presented for the right phakic eyes. MAIN OUTCOME MEASURES: Anterior chamber depth and gonioscopy. RESULTS: Among 1405 participants in the study, data from 1248 right eyes were available for analysis. The mean ACD values for men and women were 2.59 mm (95% confidence interval [CI], 2.56-2.62; 25th-75th percentile, 2.37-2.82) and 2.42 mm (95% CI, 2.39-2.44; 25th-75th percentile, 2.21-2.63). Mean ACD declined by 0.09 mm (95% CI, -0.011 to -0.008) per decade (adjusted for gender) and was 0.18 mm (95% CI, -0.213 to -0.141) shallower in women than men (adjusted for age). The ACD was found to be monotonically associated with gonioscopic angle width, decreasing from 2.73 mm (standard deviation [SD], 0.26) in Shaffer grade 4 to 1.94 mm (SD, 0.27) in Shaffer grade 0. There was also a relationship between ACD and refractive error; mean spherical equivalent decreased by 0.030 mm ACD per diopter. CONCLUSIONS: This study confirms an inverse association between ACD and age, female gender, and spherical refractive error. Eyes with shallower ACDs had narrower angles.

The utility of symptoms in identification of primary angle-closure in a high-risk population.

OBJECTIVE: To examine the frequency of symptoms associated with primary angle closure in an East Asian population with high rates of disease. DESIGN: Population-based survey. PARTICIPANTS: One thousand adults from rural and urban provinces of Mongolia were examined. METHODS: A standard questionnaire was used to determine a history of symptoms of angle closure. All participants underwent applanation tonometry, gonioscopy, and slit-lamp examination by the same observer. The frequency of symptoms was compared between normal subjects and those in 3 high-risk or affected groups: gonioscopically confirmed occludable angles, peripheral anterior synechiae (PAS) detected on gonioscopy, and anterior chamber depth of less than 2.5 mm. MAIN OUTCOME MEASURES: The frequency of symptoms associated with primary angle closure. RESULTS: Symptoms of visual disturbance and ocular pain traditionally linked with angle closure were reported frequently by both normal and potentially affected people. Intermittent blurring of vision at night was the only common symptom of angle closure that was significantly more frequent in people with narrow angles and PAS (P = 0.004, 48.4% vs. 31.0% narrow angles; P = 0.001, 54.3% vs. 30.6% PAS), but not in those with shallow anterior chambers (P = 0.670, 38.3% vs. 30.9%). CONCLUSIONS: Direct questioning about symptoms associated with angle closure identified high rates of positive responses in both affected and unaffected groups. Although the rate of symptoms tended to be higher in affected people, none of these symptoms were specific enough to be considered useful as a diagnostic criterion.

Prevalence of age-related maculopathy and age-related macular degeneration among the inuit in Greenland. The Greenland Inuit Eye Study.

PURPOSE: To examine the age- and gender-specific prevalence and describe the common phenotype of early age-related maculopathy (ARM) and late-stage age-related macular degeneration (AMD) among the Inuit in Greenland. DESIGN: Population-based cross-sectional study. PARTICIPANTS: All > or =60-year-olds born in Greenland and living in the communities of Nuuk and Sisimiut, Greenland. METHODS: The presence and form of early (ARM) and late age-related macular disease (AMD) were determined by grading color fundus photographs using the international classification and grading system for ARM and AMD. MAIN OUTCOME MEASURES: Prevalences of ARM and AMD were assessed by masked grading of fundus photographs. RESULTS: Overall, 695 persons were included in the study (response rate, 74.8%). Prevalence of any ARM was 52.3%. Age-related maculopathy was present in the worse eye in 50.0%, 58.8%, and 44.7% of age groups 60 to 69, 70 to 79, and > or =80, respectively. Prevalence of any AMD was 9.5%. Any AMD was present in the worse eye in 3.9%, 14.6%, and 43.2% of age groups 60 to 69, 70 to 79, and > or =80. Prevalences of pure geographic atrophy (GA) in one or both eyes, exudative degeneration in one or both eyes, and GA in one eye and exudative degeneration in the other eye were 2.3%, 6.1%, and 1.1%, respectively. CONCLUSIONS: The prevalence of ARM is higher than in most other populations studied, and the prevalence of AMD in the oldest age group is higher than in most other populations studied. The prevalence of exudative degeneration is higher than the prevalence of GA, in contrast to findings in some of the Nordic countries-particularly Iceland-and earlier observations in Greenland.

Ocular biometry and refraction in Mongolian adults.

OBJECTIVE: To describe the variation in ocular biometry and its association with refraction in adult Mongolians. METHODS: The study included 1800 subjects, aged 40 years or more, who were selected in two Mongolian provinces-Hövsgöl and Omnögobi-to participate in this population survey. Axial length (AL) and its components, as well as noncycloplegic autorefraction and corneal power (CP), were measured. RESULTS: Of those selected, 1617 subjects (90.0%) were examined. Mean +/- SD of AL was 23.13 +/- 1.15 mm. There was a very small but significant increase in mean AL with age (0.05 mm per decade, P = 0.03). Autorefraction was performed on 620 of 675 subjects of those examined in Omnögobi. The age and gender standardized prevalences of myopia (< -0.5 D), emmetropia, hyperopia (> +0.5 D), astigmatism (< -0.5 D of cylinder) and anisometropia (>1.0 D difference between eyes) were 17.2%, 49.9%, 32.9%, 40.9%, and 10.7%, respectively. Prevalence of myopia showed no clear trend with increasing age, whereas hyperopia, astigmatism, and anisometropia all increased monotonically. Multiple regression models revealed that AL (P < 0.001) and VCD (P < 0.001) were the strongest determinants of refractive error. CONCLUSIONS: In this cross-sectional study of adult Mongolians, a much lower prevalence of myopia was found than in other East Asian populations studied to date. The mean AL differed little between age groups, in marked contrast to data on Chinese people.

Strategy for decentralised prevention of angle closure glaucoma in Greenland.

In 1962 a blindness survey showed glaucomas to be responsible for 64% of all blindness in Greenland. In 1968 primary angle closure glaucoma was found to be the major glaucoma problem. Population studies using gonioscopy, optical anterior chamber depth, corneal thickness, diameter- and curvature measurements as well as ultrasound biometry were gradually performed. Prevalence was estimated at 5.1% in women and 1.6% in men aged 40+. Main findings were eye traits associated with increased risk of angle closure glaucoma: shallow anterior chamber depth and small corneal diameters. A high heritability (70%) was found. Surgical iridectomies and later YAG-laser iridotomies were introduced as routine procedures by travelling consultants and at the referral centre Rigshospitalet in Copenhagen. Eventually, in 1993-96 a surgical eye clinic was established in the capital Nuuk, also introducing phakoemulsification cataract surgery. Blindness due to glaucomas had fallen to about 9% of the registrations in Greenland per 1999. In 1999 an outreach model had to be established again, including consultants covering the 16 districts in 45 weeks and surgical teams of 2 surgeons 3 x 3 weeks per year. In 2002 the coverage was reduced to 31 weeks and only two surgical tours.--The possible consequences for glaucoma blindness will be discussed.

Sequels of Purtscher's retinopathy imaged by enhanced optical coherence tomography.

PURPOSE: To report the optical coherence tomography (OCT) findings in a case of Purtscher's retinopathy. METHODS: Enhanced optical coherence tomography, fundus photography, multifocal electroretinography. RESULTS: A 27-years-old female parachutist demonstrated outer retinal opacification with small intraretinal hemorrhages and corresponding binocular pericentric ring scotomata one day after suffering an unusually abrupt arrest of a free fall upon the unfolding of her parachute. When seen 20 years later, the scotomata were unchanged and optical coherence tomography showed bilateral disorganization at the transition between the retinal photoreceptor outer segments and the retinal pigment epithelium plus attenuation of the outer nuclear layer. CONCLUSIONS: Our observations document that the long term sequels of Purtscher's retinopathy are located in the outer segments of the photoreceptors.