Primary angle-closure glaucoma among Alaskan Eskimos

Rewiring mitochondrial metabolism to counteract exhaustion of CAR-T cells

Short persistence and early exhaustion of T cells are major limits to the efficacy and broad application of immunotherapy. Exhausted T and chimeric antigen receptor (CAR)-T cells upregulate expression of genes associated with terminated T cell differentiation, aerobic glycolysis and apoptosis. Among cell exhaustion characteristics, impaired mitochondrial function and dynamics are considered hallmarks. Here, we review the mitochondrial characteristics of exhausted T cells and particularly discuss different aspects of mitochondrial metabolism and plasticity. Furthermore, we propose a novel strategy of rewiring mitochondrial metabolism to emancipate T cells from exhaustion and of targeting mitochondrial plasticity to boost CAR-T cell therapy efficacy.

Cyclodestructive procedures for refractory glaucoma

BACKGROUND

Cyclodestructive procedures are often used in patients with refractory glaucoma who have failed to achieve lower intraocular pressure (IOP) from filtration procedures and maximal medical therapy. Destruction of the ciliary body helps to lower IOP by reducing aqueous humor formation. Of the many types of cyclodestructive procedures, laser cyclophotocoagulation (CPC) has become the most common surgical method for reducing aqueous inflow. Options for CPC are wide-ranging: they can be performed using a neodymium:yttrium-aluminum-garnet (Nd:YAG) or diode laser and laser energy can be delivered by either the contact or non-contact method. Another cyclodestructive procedure is endoscopic cyclophotocoagulation (ECP), which the ophthalmologist can use selectively to target the ciliary epithelium and ablate ciliary body tissue. There is debate regarding which cyclodestructive method is best and how they compare to other glaucoma surgeries.

OBJECTIVES

To assess the relative effectiveness and safety of cyclodestructive procedures compared with other procedures in people with refractory glaucoma of any type and to assess the relative effectiveness and safety of individual cyclodestructive procedures compared with each other.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2018, Issue 9); Ovid MEDLINE; Embase.com; PubMed; LILACS BIREME; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 21 September 2018.

SELECTION CRITERIA

We included randomized controlled trials or quasi-randomized trials in which participants underwent a secondary procedure for refractory glaucoma. We included trials with any laser type, route of administration, and laser settings. The primary comparison was any cyclodestructive procedure versus another glaucoma treatment, and the secondary comparisons were individual cyclodestructive procedures versus another cyclodestructive procedure.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed the titles and abstracts from the database searches, and after retrieving the full-text reports of those that were potentially relevant, classified the full-text articles as included or excluded. Two review authors independently extracted data from the included studies and assessed the risk of bias. Discrepancies were resolved by discussion or by consultation with a third review author when necessary.

MAIN RESULTS

We included five trials reporting data for 330 eyes (326 participants). One study to had a low risk of bias for most domains and the other studies had an overall unclear risk of bias. This review includes four different comparisons: 1) ECP versus Ahmed implant, 2) micropulse CPC versus continuous-wave CPC; 3) CPC with a diode versus Nd:YAG laser; and 4) CPC with an Nd:YAG laser emitting 8J versus 4J.No study reported data for our primary outcome, change from baseline in pain severity as reported by the participant or change in number of pain medications.For our primary comparison, we included one trial that compared ECP with the Ahmed implant. At 12-month follow-up, the mean difference (MD) in IOPs between groups was -1.14 mmHg (95% confidence interval (CI) -4.21 to 1.93; 58 participants; low-certainty evidence (LCE)). At 24 months postintervention, we found very LCE suggesting that visual acuity may be better among participants in the ECP group than in the Ahmed implant group (MD -0.24 logMAR, 95% CI -0.52 to 0.04; 54 participants), and the difference in the mean number of glaucoma medications used by participants in each group was unclear (MD -0.50, 95% CI -1.17 to 0.17; 54 participants; very LCE). Reported adverse events in the ECP group (34 participants) were one case each of hypotony, phthisis bulbi, retinal detachment, and choroidal detachment; in the Ahmed implant group (34 participants) there was one case of endophthalmitis, two cases of retinal detachment, and six cases of choroidal detachment.Three types of comparisons from four included studies provided data for our secondary comparisons. In the study that compared micropulse with continuous-wave CPC, median IOP was reported to be similar between the two groups at all time points. At 18 months postintervention, the median number of IOP-lowering medications was reduced from two to one in both groups. One participant in the micropulse and two in the continuous group exhibited worsened visual acuity. One case of prolonged inflammation was seen in the micropulse group (23 participants). Seven cases of prolonged inflammation, five cases of hypotony, and one case of phthisis bulbi were seen in the continuous group (23 participants).Two studies compared CPC using a semiconductor diode versus an Nd:YAG laser. At 12 months postintervention, the MD in IOP was 1.02 mmHg (95% CI -1.49 to 3.53) in one study (LCE). The second study did not report mean IOP beyond three months of follow-up. Neither study reported the mean change in best-corrected visual acuity or number of glaucoma medications. Both studies reported hypotony as an adverse event in three participants in each study.One study compared different energy settings of the same Nd:YAG laser. At 12-month follow-up, visual acuity was unchanged or improved in 21 of 33 participants in the 8J group and 20 of 27 participants in the 4J group (risk ratio 0.86, 95% CI 0.61 to 1.21; very LCE). More participants in the 8J group reduced the number of medications taken compared with the 4J group (RR 1.49, 95% CI 0.76 to 2.91; 50 participants; very low-certainty evidence). The presence of fibrin or hyphema were seen in five participants who received 8J and none who received 4J. There was a severe anterior chamber reaction in 11 of 26 (42%) participants who received 8J of energy and 2 of 21 (10%) participants who received 4J of energy.

AUTHORS' CONCLUSIONS

Evidence from five studies included in this review was inconclusive as to whether cyclodestructive procedures for refractory glaucoma result in better outcomes and fewer complications than other glaucoma treatments, and whether one type of cyclodestructive procedure is better than another. The most commonly reported adverse events across all five studies were hypotony and phthisis bulbi. Large, well-designed randomized controlled trials are needed. Patient-reported outcomes such as pain and quality of life should be considered as primary outcomes or important secondary outcomes of future trials.

Angle closure glaucoma in rural and urban populations in eastern India-The Hooghly River Glaucoma Study

Purpose:

To estimate the prevalence, features, and associations of primary angle closure disease (PACD) in rural and urban populations from West Bengal in eastern India.

Methods:

This was a population-based cross-sectional study with two arms, rural and urban. The rural study area consisted of 28 contiguous villages from 13 gram panchayats in Balagarh Police Station, with rural base hospital at Dhobapara, Balagarh Police Station, in the village Kuliapara of Hooghly district. A tertiary eye hospital in central Kolkata was the urban study center. Individuals residing in the study area aged 40 years and above were included in this study using multistage random cluster sampling. All subjects underwent a detailed ophthalmic examination at our base hospitals including applanation tonometry, ultrasound pachymetry, gonioscopy, and frequency doubling technology perimetry. Data collected were analyzed using SPSS 13. Multiple logistic regressions were used to analyze risk factors for PACD.

Results:

A total of 7,408 and 7,248 subjects aged 40 years or older were enumerated from Hooghly district and Kolkata city, respectively. PACD was detected in 1.9% subjects in rural arm and 1.54% subjects in the urban arm (P < 0.001). In rural arm, 0.3% had PACS, 0.56% had PAC, and 1.03% had PACG. In urban arm, 0.22% had PACS, 0.35% had PAC, and 0.97% had PACG.

Conclusion:

The study concludes that higher age, higher CCT, and shorter axial length/presence of hyperopia are important independent predictors of ACD. ACD is more common in eastern India than previous estimates.

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.

Genetic Associations of Primary Angle-Closure Disease: A Systematic Review and Meta-analysis

TOPIC

Systematic review and meta-analysis of the genetic associations of primary angle-closure disease (PACD).

CLINICAL RELEVANCE

To confirm the genetic biomarkers for PACD, including primary angle-closure glaucoma (PACG) and related phenotypes.

METHODS

We searched in the MEDLINE and EMBASE databases for genetic studies of PACG or other PACD published from the start dates of the databases to May 11, 2015. We estimated the summary odds ratios (ORs) and 95% confidence intervals (CIs) for each polymorphism in PACG, primary angle-closure suspect (PACS), and primary angle-closure (PAC) using fixed- or random-effect models. We also performed sensitivity analysis to test the robustness of the results.

RESULTS

Our literature search yielded 6463 reports. Among them, we identified 24 studies that fulfilled the eligibility criteria for meta-analysis, involving 28 polymorphisms in 11 genes/loci. We affirmed the association of PACG and combined PACS/PAC/PACG with 10 polymorphisms in 8 genes/loci, including COL11A1 (rs3753841-G, OR, 1.22; P = 0.00046), HGF (rs17427817-C, OR, 2.02; P = 6.9E-07; rs5745718-A, OR, 2.11; P = 9.9E-07), HSP70 (rs1043618, GG+GC, OR, 0.52; P = 0.0010), MFRP (rs2510143-C, OR, 0.66; P = 0.012; rs3814762-G, OR, 1.40; P = 0.0090), MMP9 (rs3918249-C, OR, 1.35; P = 0.034), NOS3 (rs7830-A, OR, 0.80; P = 0.036), PLEKHA7 (rs11024102-G, OR, 1.24; P = 8.3E-05), and PCMTD1-ST18 (rs1015213-A, OR, 1.59; P = 0.00013). Sensitivity analysis indicated that the results were robust.

CONCLUSIONS

In this study, we confirmed multiple polymorphisms in 8 genes/loci as genetic biomarkers for PACD, among which 3 were identified in a genome-wide association study (COL11A1, PLEKHA7, and PCMTD1-ST18), and 5 were identified in candidate gene studies (HGF, HSP70, MFRP, MMP9, and NOS3).

Age-related eye disease and gender

Worldwide, the prevalence of moderate to severe visual impairment and blindness is 285 millions, with 65% of visually impaired and 82% of all blind people being 50 years and older. Meta-analyses have shown that two out of three blind people are women, a gender discrepancy that holds true for both developed and developing countries. Cataract accounts for more than half of all blindness globally and gender inequity in access to cataract surgery is the major cause of the higher prevalence of blindness in women. In addition to gender differences in cataract surgical coverage, population-based studies on the prevalence of lens opacities indicate that women have a higher risk of developing cataract. Laboratory as well as epidemiologic studies suggest that estrogen may confer antioxidative protection against cataractogenesis, but the withdrawal effect of estrogen in menopause leads to increased risk of cataract in women. For the other major age-related eye diseases; glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy, data are inconclusive. Due to anatomic factors, angle closure glaucoma is more common in women, whereas the dominating glaucoma type; primary open-angle glaucoma (POAG), is more prevalent in men. Diabetic retinopathy also has a male predominance and vascular/circulatory factors have been implied both in diabetic retinopathy and in POAG. For AMD, data on gender differences are conflicting although some studies indicate increased prevalence of drusen and neovascular AMD in women. To conclude, both biologic and socioeconomic factors must be considered when investigating causes of gender differences in the prevalence of age-related eye disease.

Epidemiology of glaucoma: what's new?

Globally, there are an estimated 60 million people with glaucomatous optic neuropathy and an estimated 8.4 million people who are blind as the result of glaucoma. These numbers are set to increase to 80 million and 11.2 million by 2020. Glaucoma is the second leading cause of blindness globally. The highest prevalence of open-angle glaucoma occurs in Africans, and the highest prevalence of angle-closure glaucoma occurs in the Inuit. Population-based screening for open-angle glaucoma is not recommended. Screening for angle-closure may be feasible.

Changing trends of imaging in angle closure evaluation

Primary angle closure glaucoma (PACG) is a significant cause of visual disability worldwide. It predominantly affects the Eastern and South Asian population of the world. Early detection of anatomically narrow angles is important, and the subsequent prevention of visual loss from PACG depends on an accurate assessment of the anterior chamber angle (ACA). Gonioscopy has given way to modern day imaging technologies such as ultrasound biomicroscopy (UBM) and more recently, anterior segment optical coherence tomography (AS-OCT). Ultrasound biomicroscopy provides objective, high-resolution images of anterior segment anatomy, including the cornea, iris, anterior chamber, anterior chamber angle, and ciliary body. Optical coherence tomography (OCT) is a noncontact optical signal acquisition and processing device that provides magnified, high-resolution cross-sectional images of ocular tissues. Recent technological advances towards three-dimensional visualization broadened the scope of AS-OCT in ophthalmologic evaluation. Optical coherence tomography systems use low-coherence, near-infrared light to provide detailed images of anterior segment structures at resolutions exceeding that of UBM. This paper summarizes the clinical application of UBM and OCT for assessment of anterior segment in glaucoma.

Gender and glaucoma: what we know and what we need to know

PURPOSE OF REVIEW

With growing aging populations and an increase in cases of glaucoma and glaucoma blindness worldwide, aging populations are particularly at higher risk of glaucoma and glaucoma blindness. Awareness of the gender differences might increase attention toward populations at risk.

RECENT FINDINGS

Women not only outlive men, but also outnumber men in glaucoma cases worldwide. Women are at higher risks for angle closure glaucoma, but there is no clear gender predilection for open angle glaucoma. Of interest, there is some evidence suggesting that female sex hormones might be protective of the optic nerve. In addition, it is hypothesized that decreased estrogen exposure is associated with increased risk for open angle glaucoma, yet population-based studies present inconsistent results. Presently, there is insufficient evidence to support hormonal replacement therapy use in glaucoma prevention. In addition, it appears that women carry a larger burden of glaucoma blindness due to longevity and disadvantages in socioeconomic/health beliefs.

SUMMARY

Current evidence suggests that older women are at risk for glaucoma and glaucoma blindness. Further interdisciplinary research involving investigators, specialized in glaucoma, women's health and health disparities, will lead to better understanding of gender health disparities in glaucoma and better targeting populations at risk.

Sex- and gender-based differences in healthy and diseased eyes

PURPOSE

The aim of this study was to identify sex- and gender-based differences in ocular anatomy, physiology, and disease susceptibility or manifestation.

METHODS

Review of current indexed literature was conducted.

RESULTS

Sex and sex hormones influence the lacrimal system, eyelids and blinking, corneal anatomy and disease, aqueous humor dynamics and glaucoma, crystalline lens and cataract, uveitis and retinal disease, ocular circulation, and optic nerve anatomy and disease. Systemic conditions, particularly autoimmune disease, and conditions that are unique to women, such as pregnancy and menopause, further illustrate the effects of sex hormones on the eye. Gender-based differences in ocular conditions and disease should be considered within the context of the underlying physical and social environment.

CONCLUSIONS

Many sex- and gender-based differences exist in healthy and diseased eyes.

Visual impairment and eye care among Alaska Native people

PURPOSE

To estimate the prevalence of visual impairment, eye disease and eye care in the Alaska Native (AN) population, by demographic and socioeconomic factors.

METHODS

Population-based cross-sectional study of 3,793 AN adults aged 18-94 years enrolled in the Education and Research Towards Health (EARTH) Study from March 2004-March 2006. Data on self-reported visual impairment, cataract, glaucoma, diabetic eye disease and previous dilated eye examinations were collected using audio computer-assisted self-administered questionnaires.

RESULTS

The unadjusted prevalence of self-reported visual impairment was 8.7% (95% confidence interval (CI): 7.9-9.7), cataract 5.9% (95% CI: 5.2-6.7), glaucoma 2.5% (95% CI: 2.0-3.0) and diabetic eye disease 1.3% (95% CI: 0.9-1.7). In all cases, age-sex adjusted prevalence estimates for the AN population were greater than available estimates for the general U.S. population. Prevalence of visual impairment and each eye disease increased with age (P < 0.01). Additional factors associated with visual impairment were education and annual household income. Overall, 70.0% (95% CI: 68.5-71.6) of participants reported a dilated eye examination within the previous two years. Dilated eye examination within the previous two years was associated with increasing age (P < 0.001). However, men and participants with lower formal education were less likely to report recent dilated eye examination. Among those with diabetes, only 67.7% (95% CI: 60.8-74.1) reported a dilated eye examination within the recommended previous one year.

CONCLUSIONS

Self-reported visual impairment, cataract, glaucoma and diabetic eye disease are prevalent in the AN population. These data may be useful in healthcare planning and education programs.

Causes of visual impairment and common eye problems in Northwest American Indians and Alaska Natives

OBJECTIVES

Little information exists regarding the causes of visual impairment and the most common eye problems in American Indians/Alaska Natives.

METHODS

We randomly sampled American Indians/Alaska Natives older than 40 years from 3 tribes within the Northwest region.

RESULTS

We found a higher prevalence of visual impairment and normal-tension glaucoma, as well as a lower prevalence of ocular hypertension, in American Indians/Alaska Natives compared with previous results in other racial/ethnic groups.

CONCLUSIONS

American Indians/Alaska Natives have a need for vision correction. Future interventions in American Indians/Alaska Natives should include providing spectacles for refractive error, detecting glaucoma, and preventing visual impairment from age-related maculopathy and cataracts.

The epidemiology of primary angle closure and associated glaucomatous optic neuropathy

Angle closure glaucoma is emerging as a leading cause of blindness in the densely populated countries of Asia. It has a greater propensity to cause bilateral blindness than either primary open-angle glaucoma or secondary glaucoma. An estimated 9.4 million people in China aged 40 years and older have glaucomatous optic neuropathy. Approximately 5.2 million people (55%) would be blind in at least one eye. Around 1.7 million (18.1%) would be blind in both eyes. it is likely that PACG is responsible for the vast majority (91%) of bilateral glaucoma blindness in China. The number of Chinese people with an "occludable" drainage angle is in the region of 28.2 million, and of these 9.1 million have significant angle closure. There is a growing emphasis on a revised method of classifying the disease, which reserves the term "glaucoma" for cases with glaucomatous optic neuropathy. The term primary angle closure (PAC) is used in cases with a closed angle and peripheral anterior synechiae or raised intraocular pressure. Risk factors for PAC include older age, female gender, Chinese ethnicity, all of which are associated with anatomical risk factors of central and/or peripherally shallow anterior chambers (usually associated with a thicker, anteriorly-positioned lens), and a shorter axial length of the globe.

Glaucoma in China: how big is the problem?

AIMS

To derive preliminary estimates for the number of adults in China suffering from glaucoma, and project the burden of visual morbidity attributable to primary and secondary glaucoma.

METHODS

Age and sex specific data from two population surveys were applied to US Census Bureau population estimates for urban and rural China. It was assumed that data from Singapore were representative of urban China, and those from Mongolia were representative of rural China.

RESULTS

It was estimated that 9.4 million people aged 40 years and older in China have glaucomatous optic neuropathy. Of this number, 5.2 million (55%) are blind in at least one eye and 1.7 million (18.1%) are blind in both eyes. Primary angle closure glaucoma (PACG) is responsible for the vast majority (91%) of bilateral glaucoma blindness in China. The number of people with the anatomical trait predisposing to PACG (an "occludable" drainage angle) is in the region of 28.2 million, and of these 9.1 million have significant angle closure, indicated by peripheral anterior synechiae or raised intraocular pressure.

CONCLUSIONS

This extrapolation of data from two east Asian countries gives an approximate number of people in China suffering from glaucoma. It is unlikely that this crude statistical model is entirely accurate. However, the authors believe the visual morbidity from glaucoma in China is considerable. PACG is probably the leading cause of glaucoma blindness in both eyes, and warrants detailed investigation of strategies for prevention.

Prevalence of glaucoma in Ponza, Italy: a comparison with other studies

The purpose of this study was to determine the prevalence of glaucoma in Ponza, Italy. The design was a population-based prevalence survey of residents of Ponza aged 40 years or older. There were 1,296 official residents identified by a house-to-house census, of whom 1,226 were identified as eligible for the study. Of these, 1,034 individuals (449 males and 585 females), or 84.3% of the eligible population, participated in the ophthalmological examination. A two-stage method was adopted to identify cases of glaucoma. All subjects underwent a standardized initial examination. Glaucoma suspects and 50% of non-suspects were referred to a definitive examination which included visual field testing. Patients were defined as glaucoma cases if they presented abnormal visual fields and at least one of the following: high 10P, large or asymmetric cup-to-disc ratio. In addition to typical glaucomatous visual field defects such as paracentral scotoma, nasal step, arcuate scotoma and temporal and/or central islands fields, a visual field defect was identified as a decrease in sensitivity greater than 6 db in at least one location of the central 10 degrees, two locations of the central 20 degrees or three locations of the central 30 degrees. Prevalence rates of 2.51% of Primary Open Angle Glaucoma (1.72%-3.66%, CI 95%), 0.97% of Primary Closed Angle Glaucoma (0.53%-1.77%, CI 95%) and 0.29% of secondary glaucoma were found. Moreover, 2.13% of probable POAG (1.41%-3.20%, CI 95%) and 6.00% of High Intraocular Pressure (4.71%-7.61%, CI 95%) were found. The prevalence rates of POAG found in the Ponza Ophthalmological Survey are consistent with the results of other studies. Minor differences are most likely due to the different criteria adopted in the assessment of glaucomatous visual field damage.

A high prevalence of occludable angles in a Vietnamese population

PURPOSE

To assess the prevalence of occludable angles in a Vietnamese population.

METHODS

The authors retrospectively reviewed the angle status in 482 Vietnamese patients who presented to a general ophthalmology practice. All angles were graded by a glaucoma specialist according to the Shaffer method. Patients were excluded if they had known glaucoma or narrow angles, or a history of trauma or intraocular surgery.

RESULTS

A total of 29.5% of all patients surveyed and 47.8% of those 55 years of age or older had grade 0 to 2 angles. In the Framingham study, 3.8% of white patients 55 years of age or older had grade 0 to 2 angles. Of the patients in our study population, 8.5% had grade 0 to 1 angles and were considered at high risk for occlusion.

CONCLUSIONS

Vietnamese patients have a much higher prevalence of narrow angles and a greater risk of angle-closure glaucoma than white patients.

The anterior chamber angle is different in different racial groups: a gonioscopic study

The purpose of the study was to determine racial and sexual differences and age-related changes in the anterior chamber angle to evaluate the reliability of a standardised gonioscopic grading system. The anterior chamber angle was studied prospectively in 291 patients who included Afro-Americans, Caucasians and Far East Asians. No statistically significant difference was found between the angle width of these three groups, but the iris joins the scleral wall more anteriorly in Asians, slightly more posteriorly in Afro-Americans, and most posteriorly in Caucasians (p = 0.03). The anterior chamber tends to be narrower in females (p = 0.002) and to become narrower with increasing age (p < 0.0001) in all ethnic groups. Refractive error significantly affects both the level of iris insertion (p < 0.003) and the angle width (p < 0.001). The consistency of the angle grading system in this project is demonstrated by a close agreement between the examiners. It is concluded that the difference in the angle configuration may account for racial differences in the incidence of angle-closure glaucoma, this being least common in Caucasians, more common in Afro-Americans and most common in Asians.

Anatomical risk factors in primary angle-closure glaucoma. A ten year follow up survey based on limbal and axial anterior chamber depths in a high risk population

A population of 539 persons was examined in 1979, using LCD and ACD estimations acc. to van Herick et al. and by Haag Streit pachymetry, respectively. ACD had been measured already in 1969, due to a remarkable occurrence of primary angle-closure glaucoma (PACG) in the survey population of Greenland Eskimos (District of Uummannaq). The present follow up study in 1989 aimed at persons presently above age 40, who had shown either an LCD value graded as 0 (contact) or 1 (< 0.25 of corneal thickness = CT), or a value of 2 (= 0.25 CT) if an ACD value of < = 2.70 mm (CT included) had also been found. PACG patients or suspects known in 1979 already were excluded from the present analyses. A total of 75 persons was now examined. Five had developed acute (n = 2) or intermittent PACG (n = 3) during the ten year period. At the survey 3 intermittent and 4 latent PACG cases were detected, yielding in ten years a PACG prevalence of 12/75 = 16% (sex ratio: M/F = 2/10). One male case of severe secondary (partly inflammatory) ACG was also found. Past and present LCD and ACD values are given as well as gonioscopical status. Creeping, synechial angle-closure was frequent. Among probands who could not be examined, mostly due to death before 1989, 5/54 had developed PACG during the ten year period. Non-probands according to above criteria were mostly not examined. Yet their records were scrutinized for any event suspect of PACG. Thus among 258 persons above age 40 no PACG case was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Issues in the epidemiology and population-based screening of primary angle-closure glaucoma

Among Caucasians, it is well known that 75-95% of primary glaucoma is due to open-angle glaucoma (POAG), with angle-closure (PACG) comprising only a very small minority of cases. These figures are reversed among other groups such as Asians and Eskimos, where PACG makes up 80-90% of primary glaucoma. Among Eskimos, the prevalence of PACG has been reported as 2-8%, as compared to 0.1% among Caucasians. It appears that a population tendency toward shallow anterior chambers may explain the excess burden of PACG morbidity. Among Asians, the prevalence of PACG is intermediate between Caucasians and Eskimos. Existing biometrical data do not show a clear tendency toward shallower anterior chambers among Asians. PACG may be screened for on a population basis by means of various techniques that estimate axial or limbal anterior chamber depth, measure intraocular pressure, or evaluate the optic disc or visual fields. Demographic information and medical and family history will also be of great importance in screening for PACG in large populations. Groups at increased risk for the disease include women, individuals over 50, first-degree relatives of PACG probands, and hyperopes.