Prevalence and Causes of Low Vision and Blindness in a Japanese Adult Population

Missing X and Y: a review of participant ages in population-based eye studies

Ophthalmic population-based studies have been used to establish the frequency of eye disease and the associated environmental and genetic factors that cause vision impairment and blindness. Most of these studies have concentrated on the diseases of ageing: cataract, age-related macular degeneration, glaucoma and diabetic retinopathy. Other studies have identified eye diseases in children but few studies of young adult eye disease exist. We conducted a systematic review of the ophthalmic literature to identify potential population-based eye studies and then note the age of participants in the studies. We then summarized the disease specific to young adults to show there is a need for further research to identify eye disease in this important and often-neglected group in the community. Eighty-four large population-based studies have been conducted worldwide: 9 in North America, 2 in South America, 17 in Africa, 35 in Asia, 11 in Australia and the Pacific, 6 in Europe, 4 in the Middle East and 1 that covered 3 continents. No studies specifically examined young adults. Twenty-six per cent of studies included young adults as part of all ages examined but none of these examined a large number of young adults.

The long-term results of using low-concentration atropine eye drops for controlling myopia progression in schoolchildren

PURPOSE

The purpose of this article was to evaluate the long-term efficacy of a low-concentration (LC) atropine eye drop regimen (0.05%-0.1%) for controlling myopia progression in schoolchildren.

METHODS

This retrospective, case-control study enrolled myopic schoolchildren who had been followed-up for at least 3 years from 1999 to 2007. Children who received LC doses of atropine eye drops [initial prescription 0.05%, if progression over -0.5 diopter (D) during a 6-month follow-up then changed to 0.1% atropine] every night at bedtime were included in the LC atropine group, and untreated children served as controls.

RESULTS

A total of 117 children were included in this study. The mean age was 8.4 years. There were 97 children in the LC atropine group and 20 children in the control group. The mean follow-up duration was 4.5 years. In a mixed model analysis, the adjusted myopia progression in the LC atropine group was -0.23 D/year, significantly lower than that of the control group, which was -0.86 D/year (P<0.001). About 80% of the treatment group had slow myopia progression (less than -0.5 D progression per year). In a multivariate analysis, factors such as initial spherical refraction with less myopia and treatment with LC atropine were significantly associated with less myopia progression, but age, sex, and initial astigmatism were not significantly associated (P<0.001, P<0.001, P=0.442, 0.494, and 0.547, respectively).

CONCLUSION

The results of this study demonstrate that long-term and regular instillation of LC atropine eye drops is effective for controlling myopia progression and provides a possible strategy for an initial myopia regimen.

Effects of corneal thickness and axial length on intraocular pressure and ocular pulse amplitude before and after cataract surgery

OBJECTIVE

To investigate the relationship between the biophysical properties of the cornea and eye on the intraocular pressure (IOP) and ocular pulse amplitude (OPA) before and after cataract surgery.

DESIGN

Intervention study.

PARTICIPANTS

The left eyes of 311 patients.

METHODS

The left eyes of 338 patients undergoing cataract surgery without other eye pathology were studied. IOP and OPA were recorded by dynamic contour tonometry (DCT) 1 week before and 14 weeks after cataract surgery. The axial length, corneal curvature, central corneal thickness, anterior chamber depth, and anterior chamber angle were measured 1 week before cataract surgery. Multiple regression analyses of these factors to the preoperative OPA were performed. The difference between the pre- and postoperative IOP and OPA were investigated by paired t tests.

RESULTS

Three hundred and eleven of 338 eyes were analyzed. The preoperative OPA was negatively correlated with axial length (β = -0.24, p < 0.0001) and positively correlated with the preoperative IOP (β = 0.13, p < 0.0001). The average OPA was significantly decreased after cataract surgery (p < 0.0001). The mean change in postoperative OPA was -0.45 ± 0.63 mm Hg (95% CI -0.52 to -0.38 mm Hg).

CONCLUSIONS

The preoperative OPA was negatively correlated with axial length as reported. A significant decrease in OPA was observed after the cataract surgery.

Prevalence and causes of visual impairment and blindness in an urban Indian population: the Singapore Indian Eye Study

PURPOSE

To describe the prevalence and causes of visual impairment and blindness in an urban Indian population.

DESIGN

Population-based study.

PARTICIPANTS

Ethnic Indians aged more than 40 years living in Singapore.

METHODS

Participants underwent standardized ophthalmic assessments for visual impairment and blindness, defined using best-corrected visual acuity (BCVA) and presenting visual acuity (PVA), according to US and modified World Health Organization (WHO) definitions.

MAIN OUTCOME MEASURES

Unilateral visual impairment or blindness was defined on the basis of the worse eye, and bilateral visual impairment or blindness was defined on the basis of the better eye. Primary causes of visual impairment were determined.

RESULTS

A total of 3400 eligible individuals (75.6% response rate) participated. On the basis of US definitions, the age-standardized prevalence was 0.4% for bilateral blindness (≤20/200, better eye) and 3.4% for bilateral visual impairment (<20/40 to >20/200, better eye). Another 0.3% of bilateral blindness and 13.4% of bilateral visual impairment were correctable with refraction. Cataract was the principal cause of best-corrected bilateral blindness (60.0%) and bilateral visual impairment (65.7%). Other major causes of blindness and visual impairment included diabetic retinopathy, age-related macular degeneration, glaucoma, corneal opacity, and myopic maculopathy.

CONCLUSIONS

The prevalence of bilateral blindness and visual impairment in Indians living in Singapore is lower than estimates from populations living in India, but similar to estimates obtained from Singapore Malay and Chinese populations. Cataract is the leading cause of blindness and visual impairment. One in 20 cases of bilateral blindness and 1 in 10 cases of bilateral visual impairment are attributable to diabetic retinopathy. These data may have relevance to many ethnic Indian persons living outside India.

The analysis of lacquer crack in the assessment of myopic choroidal neovascularization

OBJECTIVE

The aim of this study was to clarify the characteristic findings in myopic choroidal neovascularization (CNV) and the relationship with lacquer crack (LC).

METHODS

In all, 66 consecutive myopic CNV patients treated with photodynamic therapy and/or intravitreal anti-vascular endothelial growth factor injection in one eye were reviewed. Data from fluorescein angiography (FA) and indocyanine green angiography (ICGA), obtained simultaneously using the Heidelberg retina angiograph 2 (HRA2), were analyzed.

RESULTS

LCs were associated with a relatively large extent (≥3000 μm) of peripapillary choroidal atrophy and a dark rim, the proliferation of retinal pigment epithelial cells surrounding the neovascular membrane was accompanied by a small extent. Myopic CNV usually developed in the LC area surrounded by tiny crack fragments. In all, 35 patients with LCs received FA and ICGA at least twice during follow-up. LC progression was observed in nine (25.7%) treated eyes and six (23.1%) non-CNV fellow eyes. Crack fragments progressed in three distinct forms such as elongation, branching, or bridging pattern. Newly diagnosed myopic CNV was reported in 18 treated eyes and 3 fellow eyes. Progression of LCs and development of CNV occurred simultaneously in eight eyes. By multivariate Cox's regression, a statistically significant association was observed between recurrence of myopic CNV and the absence of a dark rim on ICGA.

CONCLUSIONS

The HRA2 instrument affords detailed high-resolution images of FA and ICGA. Notably, recurrence of myopic CNV developed in areas surrounded by new small crack fragments and LCs are considered to be important in the development of myopic CNV.

Prevalence of visual impairment, cataract surgery and awareness of cataract and glaucoma in Bhaktapur district of Nepal: the Bhaktapur Glaucoma Study

BACKGROUND

Cataract and glaucoma are the major causes of blindness in Nepal. Bhaktapur is one of the three districts of Kathmandu valley which represents a metropolitan city with a predominantly agrarian rural periphery. This study was undertaken to determine the prevalence of visual impairment, cataract surgery and awareness of cataract and glaucoma among subjects residing in this district of Nepal.

METHODS

Subjects aged 40 years and above was selected using a cluster sampling methodology and a door to door enumeration was conducted for a population based cross sectional study. During the community field work, 11499 subjects underwent a structured interview regarding awareness (heard of) and knowledge (understanding of the disease) of cataract and glaucoma. At the base hospital 4003 out of 4800 (83.39%) subjects underwent a detailed ocular examination including log MAR visual acuity, refraction, applanation tonometry, cataract grading (LOCSΙΙ), retinal examination and SITA standard perimetry when indicated.

RESULTS

The age-sex adjusted prevalence of blindness (best corrected <3/60) and low vision (best corrected <6/18 ≥ 3/60) was 0.43% (95%C.I. 0.25 - 0.68) and 3.97% (95% C.I. 3.40 - 4.60) respectively. Cataract (53.3%) was the principal cause of blindness. The leading causes of low vision were cataract (60.8%) followed by refractive error (12%). The cataract surgical coverage was 90.36% and was higher in the younger age group, females and illiterate subjects. Pseudophakia was seen in 94%. Awareness of cataract (6.7%) and glaucoma (2.4%) was very low. Among subjects who were aware, 70.4% had knowledge of cataract and 45.5% of glaucoma. Cataract was commonly known to be a 'pearl like dot' white opacity in the eye while glaucoma was known to cause blindness. Awareness remained unchanged in different age groups for cataract while for glaucoma there was an increase in awareness with age. Women were significantly less aware (odds ratio (OR): 0.63; 95%, confidence interval (CI): 0.54 - 0.74) for cataract and (OR: 0.64; 95% CI: 0.50 - 0.81) for glaucoma. Literacy was also correlated with awareness.

CONCLUSION

The low prevalence of visual impairment and the high cataract surgical coverage suggests that cataract intervention programs have been successful in Bhaktapur. Awareness and knowledge of cataract and glaucoma was very poor among this population. Eye care programs needs to be directed towards preventing visual impairment from refractive errors, screening for incurable chronic eye diseases and promoting health education in order to raise awareness on cataract and glaucoma among this population.

Five-year incidence of visual impairment and blindness in adult Chinese the Beijing Eye Study

PURPOSE

To describe the cumulative 5-year incidence of visual impairment and blindness in adult Chinese in greater Beijing.

DESIGN

Population-based study.

PARTICIPANTS

The Beijing Eye Study 2006 included 3251 subjects who had participated in the Beijing Eye Study 2001 and returned for re-examination.

METHODS

Using the World Health Organization (WHO) definition, low vision and blindness were defined as best corrected visual acutiy (BCVA) <20/60 to 20/400 and as BCVA <20/400 in the better-seeing eye, respectively. Using the United States standard, low vision and blindness were defined as BCVA <20/40 to 20/200 and as BCVA <20/200 in the better-seeing eye, respectively.

MAIN OUTCOME MEASURES

Incidence of low vision and blindness.

RESULTS

Visual acuity measurements were available for 3249 (99.9%) participants. Using WHO and United States definitions, the incidences of low vision and blindness were 0.5 ± 0.1% (mean ± standard error) and 0.1 ± 0.04%, and 1.1 ± 0.2% and 0.1 ± 0.04%, respectively. In multivariate analysis, incidence of BCVA visual impairment or blindness increased significantly with greater age (P = 0.01), but was not associated with gender, region, or level of education. Causes of BCVA visual impairment or blindness were cataract (39%), glaucoma (17%), and degenerative myopia (11%). Using the WHO and the United States criteria, incidences of low vision and blindness based on presenting visual acuity, were 1.7 ± 0.2% and 0.1 ± 0.06%, and 3.8 ± 0.3% and 0.2 ± 0.08%, respectively. Incidence of visual impairment or blindness (presenting visual acuity, WHO definition) increased significantly with higher age (P < 0.001) and less education (P = 0.018) and was greater in women (P = 0.015). The major cause of presenting VA visual impairment or blindness was undercorrected refractive error (76%).

CONCLUSIONS

In adult Chinese in greater Beijing, the 5-year cumulative incidence of BCVA visual impairment or blindness was 0.6 ± 0.1% (BCVA in better-seeing eye, <20/60) or 1.7 ± 0.2% (presenting VA in better-seeing eye, <20/60), which increased significantly with age. Measured as presenting VA, this also was associated with female gender and rural region. The major cause (76%) of decreased presenting VA was undercorrected refractive error, followed by cataract. Treating undercorrection of refractive error may be the easiest and most efficient method to improve vision in this community.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Long-term results of photodynamic therapy for choroidal neovascularization in Japanese patients with pathologic myopia

OBJECTIVE

To determine the results of photodynamic therapy (PDT) in highly myopic eyes with choroidal neovascularization (CNV).

DESIGN

Open-label, consecutive, interventional case series.

METHODS

Forty-eight eyes of 46 consecutive Japanese patients with a myopic CNV were studied. The eyes were treated with PDT and were followed up from 1 to 4 years. The best-corrected visual acuities (BCVAs) at the baseline and after the PDT were compared. Multivariate regression analyses were used to determine the factors that were significantly associated with the BCVA at 3 or 4 years.

RESULTS

The mean follow-up period was 3.2 years. Sixty-nine percent of the patients obtained angiographic closure by a single PDT treatment, and the average number of PDT treatments was 1.4. Chorioretinal atrophy developed in 61% of the eyes at 3 years and in 70% of the eyes at 4 years. The BCVA did not change significantly after the PDT. Multivariate regression analyses showed that the BCVA at 3 years was significantly correlated with the baseline BCVA and area of chorioretinal atrophy. Analyses of the 20 patients at 4 years or more showed that in 5 of 7 (71.4%) patients with juxtafoveal CNV, chorioretinal atrophy did not develop and that all had BCVA of 0.5 or better. However, in 12 of the 13 patients with a subfoveal CNV, chorioretinal atrophy developed at 4 years, and 10 of these patients had BCVA of 0.1 or worse.

CONCLUSIONS

In highly myopic patients, 69% obtained angiographic closure by a single PDT treatment, and recurrence was rare. These findings indicate that PDT is still a good option for treating CNVs in highly myopic patients.

Increased serum total antioxidant status and decreased urinary 8-hydroxy-2'-deoxyguanosine levels in patients with normal-tension glaucoma

PURPOSE

To investigate the amount of systemic oxidative stress-related DNA damage and serum total antioxidant status of patients with normal-tension glaucoma compared with healthy controls.

METHODS

Forty-three patients with normal-tension glaucoma selected from 60 consecutive newly diagnosed patients with primary open-angle glaucoma were enrolled. Each patient's intraocular pressure (IOP) was measured seven times over a 24-hour period. Those whose highest IOP was over 21 mmHg were excluded. Forty control subjects were recruited. The serum total antioxidant status was assessed colorimetrically by its ability to reduce the generation of the radical cation ABTS (2,2-azinobis-3-ethylbenzthiazoline sulphonate). The urinary 8-hydroxy-2'-deoxyguanosine was measured as a marker of oxidative DNA damage and normalized to creatinine. The results were compared between healthy subjects and patients with normal-tension glaucoma.

RESULTS

The control and normal-tension glaucoma groups did now show significant differences for age, gender, serum fructosamine, cholesterol and triglyceride levels; systolic and diastolic blood pressure, body mass index; and prevalence of hypertension. The serum total antioxidant status was significantly higher (p = 0.01) and the urinary 8-hydroxy-2'-deoxyguanosine/creatinine level significantly lower (p = 0.03) in the patients with normal-tension glaucoma compared with the controls. Even after we adjusted the data for independent variables, the incidence of normal-tension glaucoma was significantly correlated with high serum total antioxidant levels (p = 0.03; odds ratio, 1.007; 95% confidence interval, 1.001-1.013) and low urinary 8-hydroxy-2'-deoxyguanosine/creatinine (p = 0.02; odds ratio 0.76; 95% confidence interval, 0.61-0.96).

CONCLUSIONS

Increased serum total antioxidant and decreased 8-hydroxy-2'-deoxyguanosine may reflect compensatory alterations in response to increased systemic oxidative stress in patients with normal-tension glaucoma.

Long-term changes in axial length in adult eyes with pathologic myopia

OBJECTIVE

To examine the long-term changes of the axial length in adults with high myopia.

DESIGN

Open-label, consecutive, retrospective case series.

METHODS

The medical records of 101 patients (184 eyes) with high myopia (myopia ≥-6 diopters or axial length ≥26.5 mm) were studied. The axial length of the eye was measured by A-scan ultrasonography. The significance of the changes in the axial length during follow-up was determined. The effects of the age, axial length, and the presence of a posterior staphyloma at the initial examination on the axial length elongation were determined.

RESULTS

The mean follow-up period was 8.2 years. The median axial length increased significantly from 28.6 mm at the initial examination to 29.4 mm at the final examination in the 184 eyes. The axial length remained stable (≤1-mm difference) in 69%, whereas the axial length increased by more than 1 mm in 31% of the eyes. For these 31%, the median axial length increased by 1.55 mm. An increase of the axial length per year was significantly greater in older patients than their younger cohorts, and the increase in eyes with a posterior staphyloma was significantly greater than in eyes without a staphyloma. Multiple regression analyses showed that the axial length elongation was positively and significantly correlated with patient age at the initial examination.

CONCLUSIONS

In highly myopic adult patients, the axial length continued to increase. Older individuals with posterior staphyloma were more susceptible to having a larger increase in the axial length. A progression of posterior staphyloma with increasing age is considered a key factor for the continuous increase of axial length in adults with high myopia.

Prevalence and causes of visual impairment in a rural North-east China adult population: a population-based survey in Bin County, Harbin

PURPOSE

To investigate the prevalence and causes of visual impairment in a rural population in north-east China.

METHODS

  A population-based study was conducted within Bin County, Harbin of north-east China. Low vision and blindness were defined using the World Health Organization categories of visual impairment. The prevalence of visual impairment was estimated, and causes were identified based on best-corrected visual acuity (BCVA) as well as presenting visual acuity (VA).

RESULTS

Out of 5764 people, 4956 (86.01%) aged older than 40 participated in the study. The prevalence of visual impairment, low vision and blindness based on presenting VA was 9.6% (BCVA, 6.6%), 7.7% (BCVA, 4.9%) and 1.9% (BCVA, 1.7%), respectively. Taking the presenting VA, cataract (44%) was the most common cause for visual impairment followed by uncorrected refractive error (24%), treatable causes of visual impairment accounted for 68% of the total cases. Cataract (59%) and glaucoma (15%) were leading causes for blindness based on presenting VA. According to BCVA, cataract was the leading cause of visual impairment and blindness (58% and 60%, respectively), followed by glaucoma (17% and 15%, respectively). The prevalence of visual impairment was higher among women than men (p<0.0001) and increasing with age (p<0.0001) and decreasing with increasing education level (p=0.0075).

CONCLUSION

  Visual impairment was a serious public health problem in this rural population, with most of it easily remedied. Results highlighted the need for visual impairment prevention programs to an increasing number of elderly people, with a special emphasis on female and those with little or no education.

Ocular findings among young men: a 12-year prevalence study of military service in Poland

PURPOSE

To determine the prevalence of ocular diseases among young men and to assess the main ocular causes reflecting discharge from military service in Poland.

METHODS

A retrospective review of the medical records of 105 017 men undergoing a preliminary examination for military service during the period 1993-2004. Sample size for the study was calculated with 99% confidence within an error margin of 5%. All of the study participants were White men of European origin, most of whom live or lived in Poland. Data regarding the vision status were assessed in 1938 eyes of 969 participants. Two groups were distinguished based on the age of the participants: group I aged 18-24 years, and group II aged 25-34 years.

RESULTS

Presented visual impairment [visual acuity (VA)<20/40)] followed by colour vision defects were the most common ocular disorders, accounting for 13.2%. There were statistically significant differences in uncorrected VA as well as in the rates of particular refractive errors in between the age groups (p<0.05). The prevalence of glaucoma and ocular hypertension was significantly higher in older participants. Six hundred and sixty-seven (68.8%) participants examined medically in the study period were accepted for military service. However, 302 (31.2%) failed their examination and were temporarily or permanently discharged from duty. Fifty-two of them (17.2%) were discharged because of various ocular disorders. The most common causes were high refractive errors, which accounted for 38.5% of all the ocular discharges, followed by chronic and recurrent diseases of the posterior segment of the eye, which accounted for 19.2%.

CONCLUSION

The prevalence of ocular disorders among young men in an unselected military population was closer to the results obtained in other population-based studies comprising both men and women in the same age group. High refractive errors followed by chronic and recurrent diseases of the posterior segment of the eye are important causes of medical discharges from military service in Poland.

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.

Gene profiling in experimental models of eye growth: clues to myopia pathogenesis

To understand the complex regulatory pathways that underlie the development of refractive errors, expression profiling has evaluated gene expression in ocular tissues of well-characterized experimental models that alter postnatal eye growth and induce refractive errors. Derived from a variety of platforms (e.g. differential display, spotted microarrays or Affymetrix GeneChips), gene expression patterns are now being identified in species that include chicken, mouse and primate. Reconciling available results is hindered by varied experimental designs and analytical/statistical features. Continued application of these methods offers promise to provide the much-needed mechanistic framework to develop therapies to normalize refractive development in children.

Long-term pattern of progression of myopic maculopathy: a natural history study

OBJECTIVE

To investigate the long-term progression pattern of myopic maculopathy and to determine the visual prognosis of each progression stage.

DESIGN

Retrospective, observational case series.

PARTICIPANTS

The medical records of 806 eyes of 429 consecutive patients with high myopia (refractive error more than -8.00 diopters [D] or axial length > or =26.5 mm) who were followed for 5-32 years were reviewed.

METHODS

Participants had complete ophthalmological examinations including best-corrected visual acuity, axial length measurements, fluorescein angiography, and color fundus photography, at least once a year. The presence and type of posterior staphyloma was determined by binocular stereoscopic ophthalmoscopy. The types of myopic maculopathy included tessellated fundus, lacquer cracks, diffuse chorioretinal atrophy, patchy chorioretinal atrophy, choroidal neovascularization (CNV), and macular atrophy. None of the patients had received any type of treatment for the maculopathy.

MAIN OUTCOME MEASURES

The longitudinal long-term progression pattern and the visual prognosis of each type of fundus lesion.

RESULTS

During the mean follow-up of 12.7 years, 327 of the 806 highly myopic eyes (40.6%) showed a progression of the myopic maculopathy. The most commonly observed patterns were from tessellated fundus to the development of diffuse atrophy and lacquer cracks, an increase in the width and progression to patchy atrophy in eyes with lacquer cracks, an enlargement of the diffuse atrophy, and the development of patchy atrophy in eyes with diffuse atrophy, and an enlargement and fusion of patches of atrophic areas in eyes with patchy atrophy. Eyes with tessellated fundus, lacquer cracks, diffuse atrophy and patchy atrophy at the initial examination progressed to the development of CNV. Eyes with CNV developed macular atrophy. The fusion of patchy atrophy, the development of CNV, and macular atrophy all led to significant visual decreases. A posterior staphyloma was observed more frequently in eyes that showed progression from tessellated fundus, diffuse atrophy, and patchy atrophy than those without a progression.

CONCLUSIONS

These findings indicate that myopic maculopathy tends to progress in approximately 40% of highly myopic eyes, and the pattern of progression affects the visual prognosis. Preventive therapy targeting posterior staphyloma should be considered to prevent the visual impairment caused by the progression of myopic maculopathy.

Prevalence of visual impairment in the adult Japanese population by cause and severity and future projections

PURPOSE

To present a comprehensive estimate of the total number of people with visual impairment in the adult Japanese population by age, gender, severity and cause, and to estimate future prevalence based on population projections and expected demographic changes.

METHODS

Definitions of visual impairment used in this study were based on the United States criteria. Total visual impairment was calculated as the sum of low vision and blindness. The prevalence estimates were based on input from a number of Japanese epidemiological surveys, census material and official population projections.

RESULTS

There were an estimated 1.64 million people with visual impairment in 2007 in Japan. Of these, 187,800 were estimated to be blind. The prevalence of visual impairment in Japan increased with age and half of the people with visual impairment were aged 70 years or older. The leading causes of visual impairment in Japan were glaucoma (24.3%), diabetic retinopathy (20.6%), degenerative myopia (12.2%), age-related macular degeneration (10.9%), and cataract (7.2%). These five major causes comprised three-quarters of all visual impairment. The prevalence of visual impairment was projected to increase from 1.3% of the population in 2007 to 2.0% by 2050.

CONCLUSIONS

This comprehensive study presents the prevalence of total visual impairment in the adult Japanese population. The projected increases in the prevalence of visual impairment over time reflect the demographic changes of a declining and aging Japanese population. These projections highlight that the burden of disease due to visual impairment and imposed on society is likely to increase.

Two-year visual results for older Asian women treated with photodynamic therapy or bevacizumab for myopic choroidal neovascularization

PURPOSE

To compare the long-term visual and anatomic outcome of treatment with photodynamic therapy (PDT) or intravitreal bevacizumab (IVB; Avastin; Genentech Inc, South San Francisco, California, USA) for choroidal neovascularization attributable to pathologic myopia (mCNV).

DESIGN

An open-label, interventional case series.

METHODS

SETTING

Multi-institutional.

PATIENTS

Thirty-one eyes of Japanese women who received either PDT or IVB for mCNV. Inclusion criteria were age 50 years or older, greatest linear dimension (GLD) 1200 to 3000 microm, and baseline best-corrected visual acuity (BCVA) 20/200 to 20/40. INTERVENTION PROCEDURES: Patients received either PDT or IVB (1 mg/40 microL) throughout the study, with re-treatment when necessary.

MAIN OUTCOME MEASURES

BCVA and visual gain/loss at 3, 6, 12, 18, and 24 months after the initial treatment.

RESULTS

Age, BCVA, location of CNV, refractive error, and symptom duration at baseline did not differ significantly between groups. BCVA was significantly improved at 3 to 12 months (P < .05); however, the significance was lost at 18 and 24 months in the IVB group. The PDT group showed no significant improvement within the first year, and vision slowly worsened after 12 months, becoming significantly worse at 18 and 24 months compared to baseline (P< .01). BCVA was significantly higher in the IVB group at 6 months (P< .05), and 12 months or further (P < .01). Visual gain was significantly greater in the IVB group at 6, 12, 18, and 24 months (P < .05 for 6, 18, and 24 months and P < .01 for 12 months).

CONCLUSIONS

These findings indicate that the effects of PDT and IVB have a different time course, and that IVB provides a significantly better BCVA than PDT for mCNV over the long-term.

A multicenter study on the health-related quality of life of cataract patients: baseline data

PURPOSE

This study examines the impact of cataracts on health-related quality of life (HR-QOL) and health events in the older population.

METHODS

The study population consisted of 439 unoperated cataract patients aged 60 years or older who visited any of the facilities affiliated with the Cataract Survey Group of the National Hospital Organization of Japan, which has been conducting a prospective multicenter cohort study on cataract patients. HR-QOL of the patients was assessed using the Japanese version of Visual Function Questionnaire-25 (VFQ-25) and the 8-Item Short-Form Health Survey (SF-8). The health condition and health events of the patients were also investigated.

RESULTS

The average age of the 439 patients enrolled (126 men and 313 women) was 73.0 +/- 7.1 years. There were 323 patients with comorbidities (73.6%), 81 of whom (23.7%) felt it was hard to visit the hospital owing to their visual impairment. In the previous year, 74 patients (16.9%) had experienced a fall and 14 (3.2%) had been in a traffic accident. Of those, 43.2% and 8.3% respectively answered that the falls and the accident could have been triggered by their visual impairment. When the patients were classified according to visual acuity, most of the VFQ-25 subscale scores declined significantly with decreasing visual acuity, whereas the SF-8 scores showed no significant change.

CONCLUSIONS

The participants of this study were patients with unoperated cataract, and thus the decline of HR-QOL was modest. The survey of health events, however, revealed that the visual constraint has a certain impact on the daily lives of the older population.

A genome-wide association analysis identified a novel susceptible locus for pathological myopia at 11q24.1

Myopia is one of the most common ocular disorders worldwide. Pathological myopia, also called high myopia, comprises 1% to 5% of the general population and is one of the leading causes of legal blindness in developed countries. To identify genetic determinants associated with pathological myopia in Japanese, we conducted a genome-wide association study, analyzing 411,777 SNPs with 830 cases and 1,911 general population controls in a two-stage design (297 cases and 934 controls in the first stage and 533 cases and 977 controls in the second stage). We selected 22 SNPs that showed P-values smaller than 10⁻⁴ in the first stage and tested them for association in the second stage. The meta-analysis combining the first and second stages identified an SNP, rs577948, at chromosome 11q24.1, which was associated with the disease (P = 2.22×10⁻⁷ and OR of 1.37 with 95% confidence interval: 1.21–1.54). Two genes, BLID and LOC399959, were identified within a 200-kb DNA encompassing rs577948. RT–PCR analysis demonstrated that both genes were expressed in human retinal tissue. Our results strongly suggest that the region at 11q24.1 is a novel susceptibility locus for pathological myopia in Japanese.

Myopia is one of the most common ocular disorders with elongation of axis of the eyeball. Pathological myopia or high myopia, a subset of myopia which is characterized with excessive axial elongation and degenerative changes of the eye, is a leading cause of visual impairment. Since genetic factors play significant roles in its development, identification of genetic determinants is an urgent and important issue. Although family-based linkage analyses have isolated at least 16 susceptible chromosomal loci for pathological or common myopia, no gene responsible for the disease has been identified. We conducted the first genome-wide case/control association study of pathological myopia in a two-stage design using 411,777 markers with 830 Japanese patients and 1,911 Japanese controls. We identified a region strongly suggestive for the disease susceptibility at chromosome 11q24.1 containing BLID and LOC399959. Their expression was confirmed in human retina with RT–PCR. BLID encodes an inducer of apoptotic cell death, and apoptosis is known to play an important functional role in pathological myopia. We believe that our study contributes to further dissect the molecular events underlying the development and progression of pathological myopia.

Intraocular pressure control with latanoprost/timolol and travoprost/timolol fixed combinations : a retrospective, multicentre, cross-sectional study

OBJECTIVE

The aim of this study was to confirm randomized clinical trial results showing that a fixed timolol/travoprost combination (TT; DuoTrav) controls intraocular pressure (IOP) better than a fixed timolol/latanoprost combination (TL; Xalacom) in everyday ophthalmic practice, when measured in the morning and >24 hours after instillation.

METHODS

Patients with ocular hypertension or primary open angle glaucoma stabilized on TT or TL were included in this retrospective cross-sectional study. Data on demographics, medical history and previous treatments were extracted from the patients' medical records. Last treatment instillation times and IOP values were recorded at clinic visits. Treatments were compared by analyses of variance, logistic regressions and propensity scores adjusted for confounding factors.

RESULTS

Out of 316 patients included, 124 instilled TT, 192 instilled TL and 266 (84.2%) overall had instilled their eye drops within 24 hours. The patients' mean age was 64.5 years and 51.6% were female. Treatment groups were comparable except for longer disease and treatment durations in TL recipients. Worse eye mean IOPs were 25.8 mmHg at diagnosis and 21.9 mmHg on starting their designated fixed combination treatment. The best IOP control was provided by TT instillations (mean IOP 17.1 and 19.0 mmHg in the TT and TL groups, respectively; p < 0.001). This difference was reinforced by results in the subgroup of patients who instilled treatment >24 hours prior to IOP measurement (mean IOP 17.0 and 20.3 mmHg in the TT and TL groups, respectively; p < 0.004). Also, 82.6% of TT patients satisfied their ophthalmologists' IOP targets versus 51.1% of TL patients (p < 0.001). All significant differences persisted after adjustment for confounding factors.

CONCLUSION

This study, conducted in routine ophthalmic practice, confirmed published clinical trial results showing that TT provides better IOP control than TL when measured in the morning, and that travoprost has longer-lasting residual effects than latanoprost when IOP is measured >24 hours after instillation. However, readers should interpret these findings in the context of a cross-sectional observational study conducted in a naturalistic setting.

Laser scanning tomography of optic discs of the normal Japanese population in a population-based setting

OBJECTIVE

To evaluate the optic disc characteristics using the Heidelberg retina tomograph (HRT) II in a large sample of normal Japanese subjects.

DESIGN

Cross-sectional study.

PARTICIPANTS

A total of 3576 eyes of 2036 normal subjects, with good-quality HRT II images, of 6042 eyes of 3021 subjects aged 40 years or more who participated in the Tajimi Study, a population-based eye study in Japan.

METHODS

Optic disc parameters were obtained using HRT II, and the association of gender, age, height, weight, blood pressure, ocular perfusion pressure, refraction, intraocular pressure (IOP), central corneal thickness (CCT), and disc size on HRT parameters was assessed using simple and multiple regression analyses.

MAIN OUTCOME MEASURES

HRT parameters, including disc area, cup area, rim area, cup-to-disc area ratio, cup volume, rim volume, mean cup depth, maximum cup depth, height variation contour, cup shape measure, mean retinal nerve fiber layer (RNFL) thickness, and RNFL cross-sectional area, and the crude and partial correlations of the potential confounders with the HRT parameters.

RESULTS

Disc area, cup-to-disc area ratio, and rim area averaged 2.06+/-0.41 mm(2) (mean+/-standard deviation), 0.23+/-0.13, and 1.55+/-0.29 mm(2), respectively. All HRT parameters were strongly or moderately correlated between right and left eyes (Pearson's correlation coefficients = 0.45-0.83, P<0.001). Absolute inter-eye differences in several HRT parameters were positively correlated with disc area (P<0.05). Multiple regression analyses adjusting for the confounders showed weak but significant correlations of height, refractive error, IOP, and CCT with several HRT parameters (partial correlation coefficient (absolute value) = 0.04-0.16, P<0.05), and moderate or weak but significant correlations of disc area with all HRT parameters (partial correlation coefficient [absolute value] = 0.05-0.73, P<0.05). Gender, weight, blood pressure, and ocular perfusion pressure did not significantly correlate with HRT parameters.

CONCLUSIONS

This report presents reference data of normality for the HRT parameters based on a large sample of normal Japanese subjects. There were small but significant influences of height, refractive error, IOP, and CCT on several HRT parameters. Many HRT parameters were moderately or weakly affected by disc size.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

[Phacoemulsification in eyes with white cataracts: results and complications]

PURPOSE

To compare visual acuity and complications in phacoemulsification in eyes with white cataract and in eyes with immature senile cataract.

PATIENTS AND METHODS

This was a prospective study on 36 eyes in 34 patients with white cataract (group 1) and 36 eyes in 36 patients with immature senile cataract (group 2).

RESULTS

In group 1, mean preoperative visual acuity was 1/100 and mean postoperative visual acuity was 5/10 at 1 month. Posterior capsule tears occurred in four eyes (11%). In group 2, mean preoperative visual acuity was 2/10 and mean postoperative visual acuity was 7/10 at 1 month. No posterior capsule tear was observed. The preoperative visual acuity was significantly lower in group 1 (p=1.8x10(-14)). Postoperative visual acuities were not significantly different between the two groups (p=0.07). The increase in visual acuity was significantly higher in group 1 (p=2.2x10(-11)).

DISCUSSION

Our study shows that white cataract is not a risk factor of poor postoperative visual acuity and the increase in visual acuity is greater in the white cataract group than in the immature cataract group.

CONCLUSION

The results of phacoemulsification in white cataracts are satisfactory in spite of a high rate of posterior capsule rupture in our study.

Laser photocoagulation for neovascular age-related macular degeneration

BACKGROUND

Laser photocoagulation was the first treatment introduced to try to halt the progression of neovascular age-related macular degeneration (AMD), in which newly formed vessels or choroidal neovascularisation (CNV) grow under the macula leading to the occurrence of a scotoma or blind spot in the central visual field.

OBJECTIVES

The aim of this review was to examine the effects of laser photocoagulation for neovascular AMD.

SEARCH STRATEGY

We searched the CENTRAL, MEDLINE, EMBASE, LILACS, NRR and ZETOC in March 2007.

SELECTION CRITERIA

We included randomised trials of laser photocoagulation in people with CNV due to AMD.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data. The risk ratio (RR) of severe visual loss (loss of six or more lines of visual acuity) was estimated at three months and two years after treatment.

MAIN RESULTS

Fifteen trials were included in the review (2064 participants). Three types of photocoagulation were used in the trials: direct photocoagulation of the entire CNV (11 trials), perifoveal photocoagulation (one trial) and grid photocoagulation (three trials). In 12 trials the control group was observation only. One trial compared photocoagulation to submacular surgery and two trials compared different lasers. Data on the progression of visual loss could be extracted from five of the eight trials of direct photocoagulation of the CNV versus observation. The treatment effect was in the direction of harm in all studies at three months follow up (RR 1.41, 95% confidence intervals (CI) 1.08 to 1.82). After two years the treatment effect was in the direction of benefit (RR 0.67, 95% CI 0.53 to 0.83). These studies were clinically heterogeneous with participants having CNV lesions in different locations and different baseline visual acuities. There was little evidence of statistical heterogeneity at three months but substantial statistical heterogeneity at two years. However, all treatment effects in the individual trials were in the direction of benefit. One study comparing perifoveal photocoagulation or observation of subfoveal CNV found benefits that were statistically significant only at two years (RR 0.36, 95% CI 0.18 to 0.72). Other comparisons did not demonstrate differences.

AUTHORS' CONCLUSIONS

In the medium to long term laser photocoagulation of CNV slows the progression of visual loss in people with neovascular AMD. However, it is associated with an increased risk of visual loss immediately after treatment and this period may be longer in people with subfoveal AMD. With the advent of modern pharmacological therapies, and concern for the impact of iatrogenic scotoma in subfoveal CNV, laser photocoagulation of subfoveal CNV is not recommended. No studies have compared photocoagulation with modern pharmacological agents for AMD for non-subfoveal CNV.

Prevalence and causes of visual impairment in rural myanmar: the Meiktila Eye Study

OBJECTIVE

To determine the prevalence and causes of visual impairment in the Meiktila district of central, rural Myanmar.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

Random, stratified, cluster sampling of the inhabitants 40 years of age and older from villages in the Meiktila district was performed; 2481 eligible participants were identified and 2076 participated in the study.

METHODS

The ophthalmic examination included presenting and pinhole Snellen visual acuity with an illiterate E chart, slit-lamp examination of the anterior segment, and dilated stereoscopic fundus examination. The principal cause of visual impairment was recorded.

MAIN OUTCOME MEASURES

Visual impairment and blindness were defined by both presenting and corrected visual acuity according to World Health Organization criteria: better eye < 6/18 and < 3/60, respectively.

RESULTS

Comprehensive examinations, including Snellen visual acuity, were performed on 2073 participants (83.6%) The prevalence estimate of presenting visual impairment was 40.4% (95% confidence interval [CI], 36.1-44.7) and of presenting blindness was 8.1% (95% CI, 6.5-9.9). After pinhole correction, the corresponding prevalences were 26.8% (95% CI, 23.5-30.1) and 5.3% (95% CI, 4.0-6.6). Cataract, uncorrected refractive error, and glaucoma were the most common causes of visual impairment.

CONCLUSIONS

Visual impairment and blindness remain major public health problems in rural Myanmar. Specific programs directed toward reducing the cataract burden need to be implemented.