Risk factors for glaucoma are reflected in abnormal responses to frequency-doubling technology screening in both normal and glaucoma eyes.

The frequency-doubling technology (FDT) screening test (FDT-C-20-1) has adopted in many recent population-based glaucoma surveys, but factors associated with false-positive (FP) responses to FDT-C-20-1 in normal eyes and false-negative (FN) responses in glaucoma eyes were not known. These factors were investigated in a population-based setting using the data from 3805 normal eyes (2381 subjects) and 272 eyes with definite glaucoma (215 subjects) in the Kumejima Study participants with reliable FDT-C-20-1 results. Considering the presence of at least one abnormal test point (P < 0.01) as abnormal, the specificity and sensitivity of FDT-C-20-1 for glaucoma were 91.8% (95% confidence interval, 91.1 ~ 92.5) and 56.3% (47.0 ~ 62.5), respectively. Multivariate linear mixed-model logistic regression analysis showed correlations with older age, worse visual acuity, greater ß-peripapillary area (P < 0.001 for all comparisons) and more myopic refraction (P = 0.030) with the FP responses in normal eyes, and normal-tension glaucoma (P = 0.043), a better mean deviation value of Humphrey perimetry (P = 0.001), larger rim area (P = 0.041), and absence of disc hemorrhage (P = 0.015) with the FN responses in glaucoma eyes. In a population-based setting, abnormal responses to FDT-C-20-1 indicate the presence of a risk factor for glaucoma in normal eyes and risk factors for more rapid progression in glaucoma eyes.

The Inferior, Superior, Temporal Rim Width Pattern (IST Rule) Detects Glaucoma in a Japanese Population.

PRCIS: The inferior>superior>temporal rim width rate (IST pattern) rather than inferior≥superior≥nasal≥temporal (ISNT) pattern was suited for screening glaucoma in Japanese subjects. Failure of the IST pattern was associated with several important risk factors for glaucoma. PURPOSE: The purpose of this study was to find a rim width rate pattern to yield the highest positive likelihood ratio (LR+) in detecting glaucoma eyes and to identify risk factors for glaucoma correlating with its failure in a population-based setting. METHODS: Disc stereophotographs of 2474 eyes of 2474 normal subjects and 237 eyes of 237 glaucoma subjects found in the Kumejima Study were analyzed using computer-assisted planimetry. Among all combinations of the inferior (I), superior (S), nasal (N) and/or temporal (T) rim width rate, a pattern showing the highest LR+ was selected and risk factors for glaucoma correlating with its failure were determined using multiple logistic regression analysis. RESULTS: The average I, S, N, and T rim widths (SD) were 0.45 (0.10), 0.39 (0.09), 0.47 (0.11), and 0.27 (0.07) mm. Among all combinations, the I>S>T rim width rate pattern (IST pattern) disregarding the N rim width showed the highest LR+ of 2.002 (95% confidence interval, 1.778-2.253). Failure of the IST pattern in normal eyes correlated with a smaller disc area (P<0.001) and disc ovality (P=0.005) and larger ß-peripapillary area (P<0.001) and compliance with in glaucoma eyes with a smaller ß-PPA area (P=0.027), thicker central corneal thickness (P=0.017), lower intraocular pressure (P=0.019), and higher body mass index (P=0.037). CONCLUSION: Among all combinations, the I>S>T rim width pattern, the IST pattern, yielded the highest LR+ in detecting glaucoma in Japanese glaucoma eyes and its failure of or compliance with the pattern significantly correlated with several known risk factors for glaucoma.

Differentiating Diagnosed and Undiagnosed Primary Angle-Closure Glaucoma and Open-Angle Glaucoma: A Population-Based Study.

PURPOSE: To study and compare factors contributing to the differentiation between diagnosed and undiagnosed primary angle-closure glaucoma (PACG) and primary open-angle glaucoma (POAG) in the same population. DESIGN: Population-based survey. PARTICIPANTS: All residents 40 years of age and older in Kumejima, Japan. METHODS: Primary angle-closure glaucoma and POAG were diagnosed according to the criteria of the International Society of Geographical and Epidemiological Ophthalmology. Factors contributing significantly to the differentiation between diagnosed and undiagnosed PACG and POAG were selected from various systemic, ocular, visual function, and fundus planimetric parameters using multivariate logistic regression analysis and were compared between the two diseases. MAIN OUTCOME MEASURES: Factors contributing significantly to the differentiation between diagnosed and undiagnosed PACG and POAG. RESULTS: The prevalence rates of PACG and POAG were 2.2% and 4.0%, respectively. A greater proportion of patients with PACG (34.1%) received a diagnosis previously compared with patients with POAG (17.2%; P = 0.004). Worse mean deviation on visual field (VF) testing (odds ratio, 0.869; 95% confidence interval, 0.788-0.959; P = 0.006) and the presence of signs suggestive of previous acute angle closure (odds ratio, 4.35; range, 1.66-11.36; P = 0.003) contributed to a established diagnosis of PACG at the time of screening. A greater vertical cup-to-disc ratio (3.74; range, 1.38-10.17; P = 0.012) contributed with marginal significance to an established diagnosis of POAG at the time of screening. CONCLUSIONS: Primary angle-closure glaucoma was more likely to have been diagnosed previously than POAG during a screening examination. Examination of the anterior segment and VF may contribute more to the detection of PACG, and disc examination may contribute more to the detection of POAG.

Evaluation of anterior chamber angle by van Herick grading and ultrasound biomicroscopy in light and dark conditions for finding appositional angle closure and plateau iris configuration.

PURPOSE: To evaluate association of the van Herick (VH) grades with the ultrasound biomicroscopic (UBM) parameters, appositional irido-trabecular contact (A-ITC) and plateau iris (PI) in a randomly sampled population. METHODS: A 10% random sample of all residents aged 40 or older of the Kumejima study underwent UBM under dark and light conditions in the four quadrants of right eyes. RESULTS: Of 301 right eyes with eligible UBM images, 101 (33.6%) and 200 (66.4%) were classified as VH ≤ 2 and VH ≥ 3, respectively. The UBM parameters on angle width and ciliary body configuration were significantly different between VH ≤ 2 and VH ≥ 3 eyes (p < 0.001). A-ITC was found in at least one quadrant in 54.5% and 75.2% of VH ≤ 2 eyes under light and dark conditions, respectively; and 20.5% and 45.5% of VH ≥ 3 eyes. When 'VH ≤ 2' was used to screen eyes with A-ITC in three or more quadrants, the sensitivity and specificity were 74.1% and 75.3%, respectively. A-ITC was significantly associated with shallower anterior chamber (p = 0.018) and higher intraocular pressure (p = 0.044) in VH ≥ 3 eyes. Plateau iris (PI) was found in 15.8% and 6.0% of VH ≤ 2 and VH ≥ 3 eyes, respectively. Plateau iris (PI) was significantly associated with the UBM parameters on angle width and ciliary body configuration. When 'VH ≤ 2' was used to screen eyes with PI, the sensitivity and specificity were 57.1% and 68.9%, respectively. CONCLUSIONS: The VH grade of ≤2 and ≥3 showed significant association with UBM angle width and ciliary body configuration parameters. The VH ≤ 2 criterion should be useful for screening of A-ITC and PI.

Pseudoexfoliation syndrome and relating factors in a rural Japanese population: the Kumejima Study.

PURPOSE: To report the prevalence of pseudoexfoliation (PEX) syndrome and glaucoma associated with PEX (PEX-G) and their relating factors of them in a south-western island of Japan. METHODS: A population-based survey of all residents aged ≥ 40 years was conducted in Kumejima, Okinawa, Japan, and 3762 subjects (participation rate, 81.2%) underwent detailed ophthalmic examinations. Presence of PEX material on the lens capsule, iris surface and/or pupillary margin was determined by slit-lamp biomicroscopy. Glaucoma was diagnosed according to the criteria of the International Society of Geographical and Epidemiological Ophthalmology. RESULTS: In subjects aged ≥ 40 years, prevalence rates of PEX syndrome, PEX without glaucoma and PEX-G in at least one eye were 1.5% (95% confidence interval [CI]: 1.0-1.9%), 1.3% (95% CI: 0.9-1.7%) and 0.1% (95% CI: 0.0-0.2%), respectively, excluding eyes after cataract surgery; and 2.8% (95% CI: 2.3-3.3%), 2.2% (95% CI: 1.8-2.6 %) and 0.4% (95% CI: 0.2-0.6%), respectively, including eyes after cataract surgery. Cataract surgery had been performed in 61% of subjects with PEX in at least one eye; presence of PEX showed no significant effects on the intraocular pressure (IOP). A multivariate analysis showed that PEX was associated with older age (p < 0.0001, odds ratio: 1.10 [95% CI: 1.07-1.13]) and working outdoors (p = 0.0395, odds ratio: 2.18 [95% CI: 0.99-4.82]). CONCLUSIONS: The prevalence rates of PEX syndrome and PEX-G in a south-western island of Japan were reported. PEX showed no significant effect on IOP, and age and working outdoors were significantly related with PEX.

Relationship between ocular risk factors for glaucoma and optic disc rim in normal eyes.

AIM: To study relationships between reported risk factors for glaucoma and neuroretinal rim area in normal eyes. METHODS: The Kumejima study participants, 3762 of the 4632 eligible Kumejima residents 40 years and older, underwent a detailed ocular examination including sequential disc stereo photography. In a randomly chosen eye of a subject whose both eyes met the inclusion criteria, fundus photographs of 2474 ophthalmologically normal eyes of the 2474 subjects were analysed by computer-assisted planimetry to measure the disc, rim and ß-peripapillary atrophy (PPA) areas. The rim was divided into the superior and inferior halves by a line connecting the fovea and disc centre. RESULTS: The disc, superior and inferior halves rim and ß-PPA areas averaged 2.53±0.50 (SD), 0.82±0.15, 0.84±0.16 and 0.45±0.66 mm2. After adjustment for other systemic and ocular factors including age, disc and ß-PPA areas, disc-fovea distance (p=0.013, 0.016) correlated positively and intraocular pressure (IOP) (p=0.004, 0.006) and axial length (AL) (p<0.000, 0.004) negatively with the superior and inferior halves rim area, respectively; central corneal thickness (CCT) (p=0.008) and mean blood pressure (mBP) (p=0.020) correlated positively and male gender (p=0.012) negatively only with the superior half rims. CONCLUSIONS: Besides previously reported risk factors for glaucoma such as age or IOP, thinner CCT, lower mBP and male gender were newly found to significantly correlate with smaller rim area only in the superior half disc, and a greater disc-fovea distance with greater superior and inferior half rim areas in normal adult eyes.

Refractive errors in an elderly rural Japanese population: The Kumejima study.

The prevalence of refractive errors, which closely relates to visual function difficulties, several ocular disorders, and decreased quality of life, varies among countries and populations. One of the highest prevalence of myopia (spherical equivalent [SE] < -0.5 diopters [D], 41.8%) has been reported in an urban city (Tajimi) in central Japan. Here, we assess refractive conditions in a rural southwestern island (Kumejima) of Japan, where a high prevalence of glaucoma, especially angle-closure glaucoma, has been found. In Kumejima, the prevalence of myopia (SE < -0.5 D), high myopia (SE < -5 D), hyperopia (SE > +0.5 D), refractive astigmatism (cylinder > 0.5 D), and anisometropia (difference in SE between eyes > 1.0 D) were 29.5%, 1.9%, 34.1%, 38.8%, and 15.5%, respectively. Myopia decreased with age up to 70 years old but increased slightly thereafter, whereas hyperopia increased up to 70 years old and was unchanged thereafter. The prevalence of astigmatism and anisometropia was higher in older subjects. The prevalence of myopia and high myopia was higher than most of white, Hispanic, and other Asian populations, while was considerably lower than in the urban city of Japan. The high prevalence of hyperopia should be associated with high prevalence of angle closure glaucoma in this island.

Prevalence and factors associated with age-related macular degeneration in a southwestern island population of Japan: the Kumejima Study.

AIMS: To evaluate the prevalence of and factors associated with age-related macular degeneration (AMD) in a rural population of southwestern Japan. METHODS: This population-based cross-sectional study of all residents aged 40 years or older was conducted on the island of Kumejima, Okinawa, Japan. Of 4632 eligible residents, 3762 completed a comprehensive questionnaire and underwent ocular examination (participant rate, 81.2%). A non-mydriatic fundus photograph was used to grade AMD lesions according to the Wisconsin protocol. Prevalence of AMD was calculated and factors associated with AMD were identified by logistic regression. RESULTS: Of 3068 subjects with gradable photographs, 469 had early AMD and 4 had late AMD. Age-adjusted prevalence was 13.4% for any AMD, 13.3% for early AMD and 0.09% for late AMD. In multivariate analysis, any AMD was positively associated with age (OR 1.04 per year, 95% CI 1.03 to 1.05), male sex (OR 1.42, 95% CI 1.14 to 1.75) and history of cataract surgery (OR 1.35, 95% CI 1.00 to 1.82) and was negatively associated with longer axial length (OR 0.85 per millimetre, 95% CI 0.74 to 0.96). Early AMD similarly showed significant associations with these same factors. CONCLUSIONS: Prevalence of early or late AMD in a southwestern island population of Japan was 13.4% or 0.09%. Our data suggest relatively high prevalence for early AMD and low prevalence for late AMD in this sample of rural Japanese population. Significant factors associated with any or early AMD were mostly similar to that of previous studies.

Optic disc, rim and peripapillary chorioretinal atrophy in normal Japanese eyes: the Kumejima Study.

PURPOSE: To report reference data for optic disc, neuroretinal rim and ß-peripapillary atrophy (ß-PPA) in normal Japanese. METHODS: In the Kumejima study, all participants underwent disc stereo-photography; 2208 normal subjects had good-quality disc stereo and ß-PPA photographs OU. The disc and rim area and the area and angular extent of ß-PPA were evaluated by computer-assisted planimetry. RESULTS: The disc, rim, and ß-PPA area and its angular extent OD (OS) averaged 2.54 ± 0.50 (2.53 ± 0.49), 1.67 ± 0.29 (1.67 ± 0.30), 0.47 ± 0.66 (0.42 ± 0.59) mm2, and 99 ± 85 (92 ± 82) degrees (mean ± standard deviation) with bilateral Pearson's correlation coefficient of 0.890, 0.769, 0.679 and 0.632 (P < 0.001), respectively, while the 95th percentiles of the absolute inter-eye differences were 0.48, 0.41, 0.96 mm2, and 153°. The correlation coefficient between ß-PPA area and its angular extent was 0.963 (P < 0.001). Age showed negative correlation with the rim area and positive correlation with ß-PPA area (P < 0.001). Among ocular factors, disc area showed positive correlation and intraocular pressure negative correlation with the rim area (P ≤ 0.001), axial length and disc area positive correlation with ß-PPA area (P < 0.001 and P = 0.051). CONCLUSIONS: The averages and distribution of the optic disc and rim area, ß-PPA area and its angular extent in normal Japanese are reported, which will facilitate screening of glaucoma in Japanese. In normal Japanese eyes, the disc size and intraocular pressure significantly correlated with the rim area, and the axial length with ß-PPA area.

The effect of the extent of the incision in the Schlemm canal on the surgical outcomes of suture trabeculotomy for open-angle glaucoma.

PURPOSE: To examine the relationship between the extent of the incision in the Schlemm canal during suture trabeculotomy (S-LOT) for open-angle glaucoma and the associated reduction in intraocular pressure (IOP). METHODS: Forty-eight consecutive eyes (primary open-angle glaucoma: 28; exfoliation glaucoma: 20) scheduled to undergo S-LOT were studied. A 320-degree opening in the Schlemm canal was planned when total circumferential cannulation had been achieved, and the remaining 40-degree region under the scleral flap was not incised. When the cannulation was incomplete, the canal was incised up to the point reached by the cannula, and the extent of the incision was measured. Logistic regression analysis was performed to identify potential predictors of surgical success (IOP ≤ 15 mmHg). RESULTS: A 320-degree incision was achieved in 23 eyes, and the mean extent of the incision was 275 ± 52.3°. The mean IOP fell from 34.0 ± 8.8 mmHg at baseline to 14.5 ± 4.0 mmHg at 1 year postoperatively (P < 0.0001). An IOP reduction of ≥30% was achieved in 46 eyes. Simple correlation analysis indicated that the extent of the incision in degrees did not correlate with IOP or with the reduction in IOP at 1 year postoperatively (P = 0.7665 and 0.693, respectively). Lower preoperative IOP values and concomitant cataract extraction were found to be associated with surgical success. CONCLUSIONS: The extent of the incision in the Schlemm canal during S-LOT does not correlate with postoperative reduction in IOP.

Subretinal Fluid Drainage and Vitrectomy Are Helpful in Diagnosing and Treating Eyes with Advanced Coats' Disease.

Severe forms of Coats' disease are often associated with total retinal detachment, and a differential diagnosis from retinoblastoma is critically important. In such eyes, laser- and/or cryoablation is often ineffective or sometimes impossible to perform. We report a case of advanced Coats' disease in which a rapid pathological examination of subretinal fluid was effective for the diagnosis, and external subretinal drainage combined with vitrectomy was effective in preserving the eye.

Suture Trabeculotomy Ab Interno for Secondary Glaucoma Combined With Scleromalacia.

PURPOSE: To report 2 cases of secondary glaucoma combined with scleromalacia that were successfully treated with trabeculotomy ab interno. DESIGN: Retrospective case report METHODS: : Trabeculotomy ab interno was used to treat secondary glaucoma combined with scleromalacia, which occurred due to refractory scleritis, in 2 cases. In case 2, goniosynechialysis was performed before the trabeculotomy to identify the trabecular meshwork. The sclera and conjunctiva were not incised in either case. RESULTS: The patients' postoperative intraocular pressure (IOP) levels (which were achieved without medication) were lower than their preoperative IOP levels (which were recorded during the administration of the maximum tolerable medication dosage); that is, they had dropped from 24 to 12 mm Hg in case 1 and from 33 to 11 mm Hg in case 2 by 12 postoperative months. No recurrent scleritis or postoperative worsening of the patient's scleromalacia was seen in either case. CONCLUSIONS: Trabeculotomy ab interno is a very valuable treatment for secondary glaucoma combined with scleromalacia.

Primary open-angle glaucoma in a population associated with high prevalence of primary angle-closure glaucoma: the Kumejima Study.

PURPOSE: To evaluate the prevalence of and risk factors for primary open-angle glaucoma (POAG) in a rural population of southwestern Japan. DESIGN: Population-based cross-sectional study. PARTICIPANTS: All residents 40 years of age and older in Kumejima, Okinawa, Japan. METHODS: Of the eligible 4632 residents 40 years of age and older, 3762 subjects (participant rate, 81.2%) underwent screening examinations, including visual acuity (VA) measurement, slit-lamp examination, Goldmann applanation tonometry, gonioscopy, undilated stereoscopic fundus photographs, autorefractometry, noncontact specular microscopy, pachymetry, and visual field (VF) testing using frequency-doubling technology. If glaucoma or other related ocular disorders were suspected, subjects were referred for definitive examinations including VF testing with the Humphrey Field Analyzer. The diagnosis of POAG was based on the criteria of the International Society for Geographical and Epidemiological Ophthalmology. MAIN OUTCOME MEASURES: Prevalence and risk factors of POAG. RESULTS: The prevalence of POAG was 4.0% (95% confidence interval [CI], 3.4%-4.7%); 82% of patients had an intraocular pressure (IOP) less than 22 mmHg, resulting in a prevalence of 3.3% (95% CI, 2.8%-3.9%). Because of POAG, 3 subjects had a VA worse than 20/400 in only 1 eye, and 1 subject had VA loss of worse than 20/400 bilaterally. The average IOP values (mean ± standard deviation) were 14.9 ± 3.2 and 14.6 ± 3.3 mmHg in the right and left eyes, respectively; the IOP values were higher in patients with POAG (15.4 ± 3.3 and 15.2 ± 3.3 mmHg, respectively) than in subjects without glaucoma (14.8 ± 3.1 and 14.4 ± 3.1 mmHg, respectively; P<0.045, Student t test). Multivariate analysis showed that male gender (P = 0.003), older age (P<0.001), higher IOP (P<0.001), longer axial length (P<0.001), and thinner central cornea (P = 0.006) were associated with POAG. CONCLUSIONS: High prevalence rates of POAG (4.0%) and POAG with normal IOP levels (3.3%), which were comparable with those on the Japanese mainland, were found in a southwestern rural island of Japan, where the prevalence of primary angle-closure glaucoma (previously reported as 2.2%) was considerably higher than on the Japanese mainland (0.6% in the Tajimi Study) or other countries. The risk factors for POAG included male gender, older age, higher IOP, myopia, and a thinner cornea.

Efficacy of short-term postoperative perfluoro-n-octane tamponade for pediatric complex retinal detachment.

PURPOSE: To evaluate the efficacy of perfluoro-n-octane as a postoperative short-term tamponade after vitrectomy in pediatric cases with complex retinal detachment (RD) and proliferative vitreoretinopathy (PVR). DESIGN: Prospective, noncomparative, interventional case series. METHODS: The medical records of 10 eyes of 9 children (6 boys and 3 girls), whose age ranged from 3 months to 11 years, with a median of 7.5 months, were reviewed. The cause of the PVR was retinopathy of prematurity (7 eyes of 6 patients); familial exudative vitreoretinopathy; or tractional RD associated with congenital optic nerve anomalies,(1) and persistent fetal vasculature. Perfluoro-n-octane was injected into the eyes at the primary surgery in 2 eyes and at the repeat surgeries in 8 eyes. The perfluoro-n-octane was removed after 1 to 4 postoperative weeks. The patients were followed for 5 to 43 months. RESULTS: At the last examination, the retinas were reattached in 8 eyes (80%). In the other two eyes, a retinal attachment was not obtained. Postoperatively, the best-corrected visual acuity improved from hand motion to 0.1 in 1 eye and could not be measured in the other 9 patients because of their ages. No apparent adverse events related to the use of perfluoro-n-octane were noted. CONCLUSIONS: Although cautions should be exercised regarding potential mechanical retinal injuries by heavy liquids in the eye, short-term perfluoro-n-octane tamponade was effective in pediatric cases with severe PVR in which retinal reattachment is considered to be difficult with conventional gas or silicone oil tamponade.

Planimetrically determined vertical cup/disc and rim width/disc diameter ratios and related factors.

PURPOSE: To evaluate the distribution and factors related to planimetrically determined vertical cup/disc (v-C/D) and rim width/disc diameter (Rw/Dd) ratios of the optic discs in a population-based study of Japanese subjects without glaucoma. METHODS: Of 4632 eligible residents 40 years of age and older, 3762 residents underwent a detailed ocular examination including sequential optic disc stereo photography with a digital nonmydriatic fundus camera. The photographs were assessed by computer-assisted planimetry. The authors studied both eyes of 2311 nonglaucomatous subjects and only one right (left) eye of 196 (175) subjects for whom disc stereo photographs were of acceptable quality. RESULTS: The median (2.5th and/or 97.5th percentile) disc area, v-C/D, its asymmetry, and the superior- and inferior-minimal Rw/Dd ratios were 2.56 (1.68, 3.71) mm(2), 0.56 (0.70), 0.05 (0.14), 0.18 (0.10), and 0.21 (0.12), respectively. Multiple regression analysis showed that males had larger discs and superior Rw/Dd and smaller inferior Rw/Dd ratios. Increased age was correlated with increased v-C/D and decreased superior and inferior Rw/Dd ratios. Higher intraocular pressure (IOP) and thinner central corneal thickness (CCT) were correlated with higher v-C/D and smaller inferior rim/disc ratios, and lower diastolic ocular perfusion pressure (OPP) with greater v-C/D and smaller superior Rw/Dd ratios. CONCLUSIONS: In nonglaucomatous eyes, increased v-C/D and decreased superior and inferior Rw/Dd ratios were significantly correlated not only with increased age and disc size but also with higher IOP, lower diastolic OPP, and thinner CCT, suggesting that these simple disc parameters also represent vulnerability to glaucoma insults in nonglaucomatous eyes.

Prevalence of primary angle closure and primary angle-closure glaucoma in a southwestern rural population of Japan: the Kumejima Study.

PURPOSE: To determine the prevalence and ocular biometry of primary angle closure (PAC) and primary angle-closure glaucoma (PACG) in a rural population in southwestern Japan. DESIGN: Population-based cross-sectional study. PARTICIPANTS: All residents aged 40 years or older in Kumejima, Okinawa, Japan. INTERVENTION: Of the 4632 residents 40 years of age or older, 3762 (participation rate, 81.2%) underwent a detailed ocular examination, including measurement of the best-corrected visual acuity, slit-lamp examination, Goldmann applanation tonometry, static and dynamic gonioscopy, undilated stereoscopic optic fundus photographs, autorefractometry, partial coherence laser interferometry, noncontact specular microscopy, and screening visual field (VF) testing using frequency-doubling technology. If glaucoma or related or other ocular disorders were suspected, the subject was referred for a definitive examination including VF testing with the 24-2 Swedish Interactive Thresholding Algorithm Standard program of the Humphrey Field Analyzer (Carl Zeiss Meditec, Dublin, CA). MAIN OUTCOME MEASURES: Prevalence rates of primary angle-closure suspects (PACS), PAC, PACG, and PACG suspects. RESULTS: Under the standard definitions of the International Society of Geographical and Epidemiological Ophthalmology, the prevalence rates of PACS, PAC, and PACG were 8.8%, 3.7%, and 2.0%. Extending the diagnosis of PAC and PACG to include people with narrow but open angles and primary peripheral anterior synechiae, the prevalence rates of PAC and PACG increased to 6.0% and 2.2%, respectively. Hence, broadening the diagnostic categories in PAC and PACG increased the prevalence rates by 62% and 10%. Twenty-three subjects (0.6%; 95% confidence interval, 0.4%-0.9%) had a history of or were diagnosed with acute PAC. Older age, female gender, hyperopic refractive error, short axial length, and shallow anterior chamber depth were independent predictors of an occludable angle. CONCLUSIONS: The prevalence of PACG in Kumejima (2.2%) was one of the highest reported in population-based studies, that is, 3.7 times higher than in the Tajimi Study carried out in an urban center located in the central area of the main island of Japan. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Anterior segment optical coherence tomography analysis of clinically unilateral pseudoexfoliation syndrome: evidence of bilateral involvement and morphologic factors related to asymmetry.

PURPOSE: To compare the morphology of the anterior chamber angle (ACA) and iris in eyes with pseudoexfoliation (PEX) syndrome to that of their clinically unaffected fellow eyes and normal control eyes. METHODS: Forty-two patients with unilateral PEX syndrome and 42 normal subjects were studied. Eyes were separated into those with PEX, their clinically unaffected fellow eyes, and normal eyes. The dark-light changes of the ACA and iris were documented by anterior segment optical coherence tomography (AS-OCT) video recordings. The nasal ACA parameters including the angle opening distance at 500 µm (AOD500), the trabecular-iris space at 500 µm (TISA500), and the trabecular-iris angle at 500 µm (TIA500); anterior chamber depth (ACD); iris-lens contact distance (ILCD), and iris configuration were analyzed with the built-in software and a customized program. RESULTS: The ACA parameters were not significantly different among all three groups in the dark. The PEX eyes had significantly smaller ACA parameters than their fellow eyes and normal control eyes in the light. PEX eyes also had significantly shallower ACD, longer ILCD, and greater iris convexity (both in dark and light), and thinner iris (in dark) than their fellow eyes. The fellow eyes had significantly lower ACD both in the dark and light, and smaller angle opening distance at 500 µm and ILCD in the light than normal controls. There were no significant differences in the iris area among the three groups. CONCLUSIONS: Differences in the anterior segmental morphology are present between PEX and fellow eyes. These disparities may be related to the asymmetry in patients with the unilateral PEX syndrome.

Comparison of ultrasound biomicroscopic configurations among primary angle closure, its suspects, and nonoccludable angles: the Kumejima Study.

PURPOSE: To quantitatively characterize the ultrasound biomicroscopy (UBM) configurations of the peripheral anterior chamber (AC) in primary angle closure (PAC) and its suspects and to evaluate the diagnostic performance of the UBM parameters to differentiate PAC/PAC suspects in a population-based setting. DESIGN: Cross-sectional study. METHODS: A random 461 of 4632 residents 40 years or older on a southwest island in Japan underwent UBM under light and dark conditions. RESULTS: Of the 374 eligible randomly sampled residents (after excluding 87 with a history of intraocular surgeries, ocular trauma, or iritis; a physical or mental disability making the UBM measurement difficult; or refusal to undergo UBM measurements), reliable UBM images were obtained in 301 right eyes (80.4%). In 45 eyes with PAC/PAC suspects compared to 256 with nonoccludable angles, the angle-opening distance (AOD), trabecular-iris angle (TIA), and trabecular-ciliary process distance (TCPD) under light and dark conditions were smaller (P < .001), while the iris thickness was smaller only under dark conditions (P = .040). Dark-light changes in the AOD and TIA were significantly smaller in the PAC/PAC suspects than in the nonoccludable angles (P < .03); the iris thicknesses did not differ significantly between them. Areas under the receiver operating characteristic curves of the AOD at 500 µm from the scleral spur (AOD500) and TIA in light were 0.94, suggesting these parameters were good for differentiating PAC/PAC suspects. The ideal cutoff values for the AOD500 and TIA under light conditions were 0.17 mm (sensitivity, 0.82; specificity, 0.96) and 15.2 degrees (sensitivity, 0.83, specificity, 0.93), respectively. CONCLUSIONS: Eyes with PAC/PAC suspects had shallow ACs, anteriorly located ciliary bodies, and smaller dark-light changes in the peripheral AC depth, while the iris thickness was similar to that in eyes with nonoccludable angles. The peripheral AC depth under light conditions could most clearly differentiate PAC/PAC suspects from nonoccludable angles.

Prevalence of and risk factors for cornea guttata in a population-based study in a southwestern island of Japan: the Kumejima study.

OBJECTIVE: To examine the prevalence of and risk factors for cornea guttata in a rural southwestern island of Japan. DESIGN: Cross-sectional, population-based study. All residents of Kumejima Island, Japan, located in southwestern Japan (eastern longitude, 126° 48'; northern latitude, 26° 20'), 40 years or older were asked to undergo a comprehensive questionnaire and ocular examination, including noncontact specular microscopy of corneal endothelial cells. Of the 4632 residents, 3762 (81.2%) underwent the examination. The presence of guttata was determined when round or oval dark areas were observed in the specular microscopy images. Cornea guttata was graded from 0 to 4 depending on the total area of dark spots observed on the specular microscopy images. Diagnosis of primary cornea guttata was the main outcome measure. RESULTS: Of the 3060 eligible residents, 124 (4.1%; 95% confidence interval, 3.4%-4.8%) had cornea guttata in at least 1 eye. Logistic regression analysis with adjustment for age and/or sex indicated that older age, female sex, and thinner central corneal thickness were associated with an increased risk of cornea guttata. CONCLUSIONS: The prevalence of cornea guttata is 4.1% among residents 40 years or older in Kumejima by specular microscopic criteria only, which is lower than the prevalence reported in the Reykjavik, Iceland, study. A higher prevalence may have been determined if slitlamp biomicroscopy findings had been included. Older age, female sex, and a thinner cornea were independently associated with a higher risk of cornea guttata.

Prevalence and causes of low vision and blindness in a rural Southwest Island of Japan: the Kumejima study.

PURPOSE: To determine the prevalence and causes of low vision and blindness in an adult population on a rural southwest island of Japan. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: All residents of Kumejima Island, Japan, 40 years of age and older. METHODS: Of the 4632 residents 40 years of age and older, 3762 (response rate, 81.2%) underwent a detailed ocular examination including measurement of the best-corrected visual acuity (BCVA) with a Landolt ring chart at 5 m. The age- and gender-specific prevalence rates of low vision and blindness were estimated and causes were identified. MAIN OUTCOME MEASURES: Low vision and blindness were defined, according to the definition of the World Health Organization, as a BCVA in the better eye below 20/60 to a lower limit of 20/400 and worse than 20/400, respectively. RESULTS: The prevalence of bilateral low vision was 0.58% (95% confidence interval [CI], 0.38-0.89). The primary causes of low vision were cataract (0.11%), corneal opacity (0.08%), retinitis pigmentosa (RP; 0.06%), and diabetic retinopathy (0.06%). The prevalence of bilateral blindness was 0.39% (95% CI, 0.23-0.65). The primary causes of blindness were RP (0.17%) and glaucoma (0.11%). The primary causes of monocular low vision were cataract (0.65%), corneal opacity (0.16%), age-related macular degeneration (0.16%), and diabetic retinopathy (0.11%), whereas those of monocular blindness were cataract (0.29%), trauma (0.25%), and glaucoma (0.22%). Logistic analysis showed that female gender (P = 0.001; odds ratio [OR], 7.37; 95% CI, 2.20-24.71) and lower body weight (P = 0.015; OR, 0.94; 95% CI, 0.90-0.99) were associated significantly with visual impairment. CONCLUSIONS: The prevalences of low vision and blindness in the adult residents of an island in southwest Japan were 1.5 to 3 times higher than the prevalences reported in an urban city on the Japanese mainland. The prevalence of visual impairment caused by RP on this island was much higher than on the mainland, suggesting a genetic characteristic of the population. Furthermore, the prevalence of visual impairment resulting from cataract and corneal opacity was higher than that on the mainland. The prevalence of visual impairment resulting from myopic macular degeneration was less.