National Registry for the Blind in Israel: Estimation of prevalence and incidence rates and causes of blindness

Sight impairment registration in Trinidad: trend in causes and population coverage in comparison to the National Eye Survey of Trinidad and Tobago

BACKGROUND

Little was known about the population coverage and causes of sight impairment (SI) registration within the Caribbean, or the extent to which register studies offer insights into population eye health.

METHODS

We compared causes of SI registration in the Trinidad and Tobago Blind Welfare Association (TTBWA) register with findings from the 2014 National Eye Survey of Trinidad and Tobago (NESTT), and estimated registration coverage. Cross-sectional validation studies of registered clients included interviews, visual function and cause ascertainment in July 2013, and interviews and visual function in July 2016.

RESULTS

The TTBWA register included 863 people (all ages, 48.1%(n = 415) male) registered between 1951 and 2015. The NESTT identified 1.1%(75/7158) people aged ≥5years eligible for partial or severe SI registration, of whom 49.3%(n = 37) were male. Registration coverage was approximately 7% of the eligible population of Trinidad. Nevertheless, there was close agreement in the causes of SI comparing the register and population-representative survey. Glaucoma was the leading cause in both the register (26.1%,n = 225) and population-based survey (26.1%, 18/69 adults), followed by cataract and diabetic retinopathy. In the validation studies combined, 62.6%(93/151) clients had severe SI, 28.5%(43/151) had partial SI and 9.9%(15/151) did not meet SI eligibility criteria. SI was potentially avoidable in at least 58%(n = 36/62) adults and 50%(n = 7/14) children.

CONCLUSION

We report very low register coverage of the SI population, but close agreement in causes of SI to a contemporaneous national population-based eye survey, half of which resulted from preventable or treatable eye disease.

Childhood visual impairment and blindness: 5-year data from a tertiary low vision center in Israel

BACKGROUND

To assess the main causes leading to childhood visual impairment/blindness in a center for low vision in Israel and to analyze the literature on pediatric blinding diseases in developed countries.

METHODS

Retrospective study based on observational case series. Data were obtained from medical records of visually impaired children, seen at a national referral low vision center. Children were divided into two groups: moderate visual impairment (6/18 to 6/60) and severe visual impairment (SVI)/blindness (<6/60). Inherited eye diseases (IED) were grouped together for analysis. Data from the Israeli blind registry from the same period of time were analyzed for comparison. A review of literature on childhood blindness in developed countries since 2000 was conducted.

RESULTS

A total of 1393 children aged 0-18 years were included in the study. Moderate visual impairment was seen in 1025 (73.6%) and SVI/blindness in 368 (26.4%) of the studied children. Among blind children, IED accounted for at least 51% of all diagnoses, including mainly albinism and retinal dystrophies. IED prevalence was equally high in both main ethnic groups (Jewish and Arab Muslims). Non-IED (22.6%) included mainly patients with cerebral visual impairment and retinopathy of prematurity.

CONCLUSIONS

The leading cause of childhood visual impairment and blindness in our patient cohort was IED. Analyses of the literature from the last two decades show that IED are a major cause for SVI/childhood blindness in other developed countries as well. Updated patterns of global childhood blindness may suggest a need for new approach for screening programs and modern tactics for prevention.

Time Trends of Etiologies of Blindness in Israel 2009-2020:Have Methods to Decrease Leading Causes of Blindness Been Exhausted?

PURPOSE

To perform a nationwide analysis of trends in the incidence of etiologies for legal blindness in Israel during 2009-2020, and to compare the results with those of the previous decade.

DESIGN

Descriptive, retrospective population-based trend study.

METHODS

Data were retrieved from the Israeli National Registry of the Blind during 2009-2020. Data obtained included demographics, years of registration, and causes. Primary and secondary outcomes were the incidence of new certified blindness cases and its comparison with that of the previous decade, respectively.

RESULTS

The age-standardized incidence rate of blindness in Israel decreased from 15.76 per 100,000 residents in 2009 to 11.83 in 2020, a 24.9% drop. The mean annual decline was evident until 2013 (P < .001, 6.15%), but subsequently flattened (P = .71, 0.42%). Age-related macular degeneration (AMD), glaucoma, optic atrophy, and cataract decreased until 2014, and reached a plateau that was maintained until the end of the study period. Diabetic retinopathy (DR) incidence rates diminished throughout the decade (P < .001, 9.2%), with attenuation of the rate of decline after 2014.

CONCLUSIONS

The impact of efforts to reduce the incidence of preventable causes of blindness may have nearly reached saturation for most of the leading causes of blindness in Israel, namely, AMD, glaucoma and cataract. The incidence of DR has been maintained; however, attenuation has been observed. New modalities to detect and treat these causes may have to emerge before a resurgence of improvement can occur.

Global Prevalence and Causes of Visual Impairment and Blindness in Children: A Systematic Review and Meta-Analysis

Purpose:

To determine the global prevalence and common causes of visual impairment (VI) and blindness in children.

Methods:

In this meta-analysis, a structured search strategy was applied to search electronic databases including PubMed, Scopus, and Web of Science, as well as the list of references in the selected articles to identify all population-based cross-sectional studies that concerned the prevalence of VI and blindness in populations under 20 years of age up to January 2018, regardless of the publication date and language, gender, region of residence, or race. VI was reported based on presenting visual acuity (PVA), uncorrected visual acuity (UCVA), and best corrected visual acuity (BCVA) of equal to 20/60 or worse in the better eye. Blindness was reported as visual acuity worse than 20/400 in the better eye.

Results:

In the present study, 5711 articles were identified, and the final analyses were done on 80 articles including 769,720 people from twenty-eight different countries. The prevalence of VI based on UCVA was 7.26% (95% confidence interval [CI]: 4.34%–10.19%), PVA was 3.82% (95% CI: 2.06%–5.57%), BCVA was 1.67% (95% CI 0.97%–2.37%), and blindness was 0.17% (95% CI: 0.13%–0.21%). Refractive errors were the most common cause of VI in the subjects of selected articles (77.20% [95% CI: 73.40%–81.00%]). The prevalence of amblyopia was 7.60% (95% CI: 05.60%–09.10%) and congenital cataract was 0.60% (95% CI: 0.3%–0.9%).

Conclusion:

Despite differences in the definition of VI and blindness, based on PVA, 3.82%, and based on BCVA, 1.67% of the examined samples suffer from VI.

Incidence and Risk Factors for Blindness in Adults With Diabetes: The Israeli National Diabetes Registry (INDR)

PURPOSE

To estimate the 3-year incidence of blindness among diabetes patients aged ≥18 years; to compare blindness incidence rates of persons with and without diabetes; and to investigate risk factors associated with diabetic retinopathy (DR), age-related macular degeneration (ARMD), glaucoma, and cataract-related blindness.

DESIGN

Cohort study.

METHODS

The Israeli National Diabetes Registry for 2012 was cross-linked with the database of blindness certifications obtained from the National Registry of the Blind. Blindness was defined as the receipt of an official certificate of blindness (a visual acuity of 3/60 or worse, or a visual field loss of <20 degrees in the better eye.) Incidence rates of blindness, overall and by main cause of blindness, were calculated for the years 2013-2015. Standardized morbidity ratios (SMRs) for 2013 were calculated, using the nondiabetic population as a reference. A multinomial logistic model was used to identify covariates associated with the incidence of blindness by main cause of blindness.

RESULTS

The 3-year incidence rates were 31.0 and 8.4 per 10 000 for overall and DR-related blindness, respectively. The SMR for overall blindness in people with diabetes was significantly higher than in the general nondiabetic population (1.39; 95% confidence interval: 1.27-1.53); however, the SMRs for ARMD, glaucoma, and cataract were not statistically significant. Poor metabolic control, insulin treatment, long diabetes duration, and chronic kidney disease were associated with DR-related blindness. Low socioeconomic status (SES) was associated with both cataract and DR-related blindness.

CONCLUSIONS

Optimum metabolic control of diabetes is important for prevention of DR-related blindness. SES-related disparities in blindness risk should be explored and reduced by directing efforts to provide appropriate treatment for all diabetic patients in order to prevent unnecessary blindness.

Global prevalence of visual impairment associated with myopic macular degeneration and temporal trends from 2000 through 2050: systematic review, meta-analysis and modelling

Purpose

We used systematic review and meta-analysis to identify and assimilate evidence quantifying blindness and visual impairment (VI) associated with myopic macular degeneration (MMD), then derived models to predict global patterns. The models were used to estimate the global prevalence of blindness and VI associated with MMD from 2000 to 2050.

Methods

The systematic review identified 17 papers with prevalence data for MMD VI fitting our inclusion criteria. Data from six papers with age-specific data were scaled to relative age-dependent risk and meta-analysed at VI and blindness levels. We analysed variance in all MMD VI and blindness data as a proportion of high myopia against variables from the place and year of data collection, with a model based on health expenditure providing the best correlation. We used this model to estimate the prevalence and number of people with MMD VI in each country in each decade.

Results

We included data from 17 studies comprising 137 514 participants. We estimated 10.0 million people had VI from MMD in 2015 (prevalence 0.13%, 95% CI 5.5 to 23.7 million, 0.07% to 0.34%), 3.3 million of whom were blind (0.04%, 1.8 to 7.8 million, 0.03% to 0.10%). We estimate that by 2050, without changing current interventions, VI from MMD will grow to 55.7 million people (0.57%, 29.0 to 119.7 million, 0.33% to 1.11%), 18.5 million of whom will be blind (0.19%, 9.6 to 39.7 million, 0.11% to 0.37%).

Conclusion

The burden of MMD blindness and VI will rise significantly without efforts to reduce the development and progression of myopia and improve the management of MMD.

Trends in Blind and Low Vision Registrations in Taipei City

Purpose

To determine the overall reported incidence and causes of registrable blindness and low vision in Taipei, Taiwan, that have occurred in the previous 10 years.

Methods

Study data were obtained from disability identification registration forms completed between January 1995 and December 2004. Definitions of low vision and blindness were defined by WHO criteria: low vision included visual acuity worse than 6/18 (20/60) to a lower limit of 3/60 (20/400). Blindness was defined as visual acuity worse than 3/60 (20/400) in the better eye with best possible correction.

Results

There were 3151 registrations for visual impairment during the study period. A total of 239 registrations were excluded due to insufficient data. Of the remaining 2912 (1518 males and 1394 females), 640 males and 647 females were legally blind (44.20%). A total of 878 males and 747 females were partially sighted. The six leading causes of low vision and blindness, in decreasing frequency, were glaucoma, optic neuropathy, diabetic retinopathy, retinitis pigmentosa, age-related macular degeneration, and myopic macular degeneration.

Conclusions

The proportions of new registrations owing to glaucoma, diabetic retinopathy, age-related macular degeneration, and myopic macular degeneration have changed significantly since 2000; the proportion due to diabetic retinopathy has increased.

Health Service Use and Mortality of the Elderly Blind

PURPOSE

To determine whether blindness in older people is associated with increased health service use and mortality.

DESIGN

Retrospective matched cohort study from July 1, 1999, through June 30, 2010.

PARTICIPANTS

A blind cohort 65 years of age and older from a volunteer blind register and a cohort of age- and gender-matched controls selected randomly from the Western Australian electoral roll.

METHODS

Person-level linked hospital, emergency department (ED), mental health, and death records for the blind and control cohorts were used. Generalized estimating equations assuming a negative binomial distribution were used to estimate relative rates of hospital admissions, lengths of stay, and mortality after adjusting for sociodemographic variables and comorbidity. Emergency department and mental health service visits also were quantified.

MAIN OUTCOME MEASURES

Relative rates of hospital admissions, lengths of stay, and mortality, as well as crude proportions of ED and mental health service visits.

RESULTS

The blind cohort comprised 1726 individuals alongside 1726 matched controls; 39% were men, and the mean age was 83 years. Combined, the cohorts accumulated a total of 34 130 hospital admissions amounting to 201 867 bed-days. After adjusting for the principal reason for hospital admission and comorbidity, the blind cohort was admitted to the hospital 11% (95% confidence interval [CI], 6%-17%) more often than the control cohort. The blind cohort also stayed in the hospital longer than the controls, but this effect varied by age. Blind participants 65 to 69 years of age spent 88% more days (95% CI, 27%-178%) in the hospital compared with age-matched controls, whereas there was no difference in length of stay between the cohorts by 80 years of age (rate ratio, 1.10; 95% CI, 0.97-1.25). A larger proportion of the blind cohort visited a hospital ED and accessed mental health services compared with the control cohort.

CONCLUSIONS

Health service use is increased for the elderly blind compared with age-matched controls after accounting for comorbidity. The elderly blind have more hospital admissions, ED visits, and mental health-related visits. The younger elderly blind stay longer in hospital. However, there was no evidence of worse mortality outcomes after adjusting for comorbidity.

Trends in the incidence and causes of severe visual impairment and blindness in children from Israel

PURPOSE

To describe trends in the incidence and causes of legal childhood blindness in Israel, one of the few countries worldwide that maintain a national registry of the blind.

METHODS

We performed a historical cohort study of annual reports of the National Registry of the Blind (NRB) between 1999 and 2013. All data regarding demographic information, year of registration and cause of blindness of children 0-18 years of age registered for blind certification were obtained from the annual reports of the NRB. Causes of legal blindness analyzed were optic atrophy, retinitis pigmentosa, retinopathy of prematurity (ROP), albinism, other retinal disorders, cataract, and glaucoma. The main outcome measure was the incidence of new cases of certified legal blindness.

RESULTS

The incidence of newly registered legally blind children in Israel almost halved from 7.7 per 100,000 in 1999 to 3.1 per 100,000 in 2013. The decline was mainly attributable to a decreased incidence of blindness resulting from retinitis pigmentosa and ROP. The incidence of registered cases due to cerebral visual impairment increased.

CONCLUSIONS

During the past decade the incidence of severe childhood visual impairment and blindness declined in Israel. A continuous decline in consanguineous marriages among the Jewish and Arab populations in Israel may have contributed to the decrease in the rate of vision loss due to retinitis pigmentosa in children.

Blindness Registers as Epidemiological Tools for Public Health Planning: A Case Study in Belize

For public eye health programs, blindness registers can be an important tool for informing service planning. This study examines how the Belize Council for the Visually Impaired (BCVI) used its blindness register data to drive several public health interventions. Cross-sectional analysis was performed for all active registrants (n=1194) to determine the distribution of causes of registration according to age, sex, and geographical district. Cataract was the leading cause of registration (39.6%), followed by glaucoma (20.8%), diabetic retinopathy (10.2%), and childhood blindness (9.4%). The distribution of the causes of registration was fairly similar between men and women and across the various districts. However, in Stann Creek, whose population is largely of African descent, glaucoma exceeded cataract. For most causes, the majority of registrants were registered at age 50 or older. Follow-up was conducted four years later. Several interventions had been initiated, most notably bolstering cataract surgical services and creating screening programs for glaucoma and diabetic retinopathy. The register itself was also improved to maximize its utility for future use. While standardized surveys may be the most appropriate method of estimating population-based measures such as prevalence or incidence, the blindness register is still a valuable source of data for public health planning.

A preliminary descriptive analysis of Corneal Transplant Registry of National Eye Bank in India

PURPOSE

To describe and analyze the Corneal Transplant Registry of National Eye Bank and also evaluate graft outcomes in India.

METHODS

All patients who underwent corneal transplant at our center within six months of setting up of Corneal Transplant Registry and installation of database at National Eye Bank were included in the study. The established database was analyzed for utilization, donor and recipient details and graft outcomes. Outcome was assessed at the end of one year follow up. The influence of various donor and recipient factors affecting outcome were evaluated. Visual outcome was analyzed in terms of shift in visual handicap category. Statistical tests like analysis of variance, Kruskal-Wallis test and Chi square tests were applied for determination of clinical significance wherever required.

RESULTS

326 corneas were received from 168 donors; of these, 234 (71.7%) were utilized for transplantation. Out of 177 patients with adequate (one year) follow up (75.6% patients), optical corneal replacement was performed in106 patients and therapeutic keratoplasty in71. 78% (82/106) patients in the optical group retained clear grafts at the end of follow up. 59.7% (49 of 82) of patients who attained clear grafts belonged to visual disability category 3 or worse pre-operatively. 59.1% of these achieved BCVA of ≥6/60 at the end of follow up; thus shifting up their visual handicap category. Primary graft failure was found to be associated with full thickness keratoplasty and not with lamellar procedures (p<0.05) and occurred in 4.2% patients (5) with optical corneal replacement whereas 7.5% patients (8) developed secondary graft failure. Age of donor (p=0.54), death enucleation time (p>0.05), cause of donor death (p=0.15), type of surgical procedures (p=0.538) and indication for surgery did not have any significant effect on outcome. 76% patients who underwent therapeutic graft achieved elimination of corneal infection.

CONCLUSIONS

The development of corneal graft registry established an effective means to evaluate our corneal transplantation services. Outcomes of sight restoring corneal transplants performed were comparable to results of graft registries from developed nations.

Blindness and visual impairment in Germany: a slight fall in prevalence

BACKGROUND

Some 70% of all cases of blindness in Germany are due to diseases of old age. As the population at large is aging, the prevalence of blindness and visual impairment would be expected to rise. To assess this, we studied prevalence trends in Germany over the past three decades.

METHODS

We calculated the age- and sex-standardized prevalence of blindness in Germany using data from the archive of the blind registry of the Rhineland Regional Council (Landschaftsverband Rheinland, LVR) for the years 1978 to 2006. We then validated the findings with the aid of data on blindness and visual impairment from the Statistics on Severe Disability (Schwerbehindertenstatistik, SBS) that are published periodically by the German Federal Statistical Office.

RESULTS

The number of registered blind persons in the Rhineland increased from 10,665 in 1978 to 12,706 in 1987 and 15,766 in 1997, but it changed little thereafter, remaining at 15,725 in 2006. There was a corresponding trend in the prevalence of blindness in the Rhineland, which rose from 116.8 to 165.6 per 100,000 persons from 1978 to 1997 but was roughly the same, at 163.1 per 100,000 persons, in 2006. The SBS data on blindness and visual impairment reveal a decline in prevalence from 392 to 372 per 100,000 persons between 1987 and 2005. The standardized prevalence rates for blindness and visual impairment in Germany have been declining slowly since about 1997.

DISCUSSION

Blindness and visual impairment have become slightly less common in Germany, even though the population is aging. This may be due, at least in part, to better eye health care.

Time trends in the incidence and causes of blindness in Israel

PURPOSE

To evaluate time trends in the incidence and causes of new cases of blindness in Israel between 1999 and 2008.

DESIGN

Descriptive, retrospective population-based study.

METHODS

During the decade of the study, 19 862 inhabitants of Israel were newly registered as legally blind. Data were retrieved from the 1999 to 2008 annual reports of the National Registry of the Blind in Israel and were reviewed retrospectively. Specific rates by age, gender, calendar year, and cause of blindness were calculated. Total and cause-specific annual age-standardized rates were calculated as well. Findings were evaluated by the use of Poisson regression models.

RESULTS

The age-standardized rate of incidence of newly registered legal blindness at the end of the studied decade was half of that at the beginning, declining from 33.8 per 100 000 in 1999 to 16.6 per 100 000 in 2008. The decline mainly was attributable to a decreased incidence of blindness resulting from age-related macular degeneration, glaucoma, diabetic retinopathy, and cataract.

CONCLUSIONS

Contemporary interventions in ophthalmology combined with widely available universal free access to healthcare seem to be effective in causing a major reduction in the incidence of blindness.

Trends in Registered Blindness and its Causes over 19 Years in Western Australia

PURPOSE

To estimate the population-based incidence rates of blindness registration and their trends over time in Western Australia.

METHODS

A retrospective review was performed on all cases of bilateral blindness registered with the Association for the Blind of Western Australia between 1984 and 2002. The causes and mean age at blindness registration were ascertained and incidence rates of blindness due to various causes were calculated.

RESULTS

A total of 3852 blind certificates were examined. From 1984 to 1994, the annual incidence of registered bilateral blindness decreased significantly at an average rate of 9.4% per year (p < 0.0001), but then rose at a mean rate of 4.1% per year (p < 0.0001). ARMD blindness similarly fell by 8.9% per year (p < 0.0001), but then rose after 1994 by 4.5% per year (p < 0.0001). The incidence due to glaucoma decreased at an average rate of 10.3% per year (p < 0.0001) until 1994 and then rose at 7.4% per year at borderline significance (p = 0.025).

CONCLUSIONS

There has been a nonlinear decrease in the incidence of registered blindness, in particular glaucoma-related blindness, in Western Australia. Rates of total registered blindness and that due to ARMD fell from 1984 to 1994, but have risen since.

Registered Blindness and Low Vision in Kuwait

AIM

To estimate the incidence rates and major causes of registered blindness and low vision in Kuwait.

METHODS

Data on age, gender and cause of blindness and low vision were collected from the Visual Disability Committee while evaluating Kuwaiti citizens applying for a blindness allowance from January 2000 to December 2004. Criteria for legal blindness in Kuwait are visual acuity 6/60 or less in the better eye with best possible correction or a visual field less than 20 degrees around the central fixation point. Incidence rates per 100,000 person years of observation were calculated for both genders in four age subgroups and four severity categories. The causes of registered blindness were classified according to the International Classification of Diseases, 10th edition.

RESULTS

412 persons were registered as blind, 272 males (66.01%) and 140 females (33.98%), mean age 28.7 +/-25.2 years, 39.32% below 20 years of age, 31.79% 21-40 years, 18.68% 41-60 years, and 9.95% 61 years and over . Male gender was prevalent for all age subgroups. The overall incidence rate was 9.97 per 100,000 person years of observation, 13.33 for the male and 6.69 for the female patients. The incidence rates rose from 7.35 for those 20 years and younger to 14.80 for the age subgroup 41-60 and 23.16 for those 61 years and above. The rates of severe visual impairment classified in categories 4 and 5 were higher than the rates for categories 2 and 3. Retinitis pigmentosa was the leading cause of blindness, followed by congenital anomalies and optic atrophy. In the subgroup below 20 the rate of optic atrophy was highest, followed by congenital malformations, retinitis pigmentosa and retinopathy of prematurity. In the next age subgroup (21-40 years), the rate of retinitis pigmentosa was three times as high as in the younger subgroup, followed by optic atrophy, congenital malformations and albinism. In the subgroup 41-60 the incidence rate for phthisis bulbi was twice as high as the rates for retinitis pigmentosa and optic atrophy. For those 61 years and older, the incidence rate of phthisis bulbi was almost five times as high as that for optic atrophy. The incidence rates for the male patients were higher for the major causes of disability in all age subgroups.

CONCLUSIONS

The overall incidence rate of registered blindness for Kuwait is less than in many other national registries. The marked prevalence of the male gender in all age subgroups is specific for Kuwait. The rates of the leading causes of registered blindness reflect the prevalence of the younger subgroups in our registry. Additional data on co-morbidity and dedicated efforts to reveal unrecognized and unregistered blindness, particularly among females, will overcome the limitations of the registry, and will serve to outline the tendencies in avoidable vision loss and monitor the efficacy of the prevention programs in the future.

[Humanistic burden and health resource utilization among neovascular age-related macular degeneration patients in France]

OBJECTIVE

To assess the impact of bilateral neovascular age-related macula degeneration (NV-AMD) on function and health resource utilization (HRU) in France.

PATIENTS AND METHODS

Cross-sectional study including 401 NV-AMD patients and 471 controls conducted in five countries in 2006. In both groups, demographic and clinical data were collected and the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25), the EuroQoL (EQ-5D), the Hospital Anxiety and Depression Scale (HADS), and questionnaires on HRU were administered.

RESULTS

Eighty-seven NV-AMD patients and 92 controls were recruited in France. The mean age of the NV-AMD patients was 79 (range, 65-95), and 64% were female. After adjusting for age, gender, and co-morbidities, compared to controls, NV-AMD patients reported substantially worse vision-related quality of life on the NEI-VFQ (adjusted mean, 44.4 [36.2-52.7] versus 91.8 [86.2-97.5], p<0.0001). HADS anxiety and depression scores were significantly worse in NV-AMD patients (anxiety score, 8.5 [6.3-10.8] versus 5.1 [3.5-6.7] p=0.0005; depression score: 7.1 [5.1-9.1] versus 2.9 [1.5-4.4] p<0.0001). Per patient yearly cost analysis showed significantly higher direct medical costs: 3396 euro versus 85 euro (p<0.0001), and indirect nonmedical-related costs (mainly for assistance with activities of daily living): 2985 euro versus 494 euro (p=0.014).

CONCLUSIONS

NV-AMD patients in France reported substantially worse QoL and more anxiety and depression symptoms. The functional impact of blindness led to significantly higher health resource utilization in the AMD patients, resulting in higher total health costs compared to a similarly aged control group.

Trends in blind registration in the adult population of the Republic of Ireland 1996-2003

BACKGROUND/AIM

The Republic of Ireland has a centralised database of all registered, blind people in the country. The last study of the national blind register was undertaken in 1996. The current study sought, firstly, to investigate and identify any recent changes in the register composition. Secondly, there is concern that many eligible people are not appropriately registered. To examine this further, registration levels among patients attending an Irish outpatient ophthalmology clinic were determined.

METHODS

Criteria for blind registration in Ireland are (1) a best corrected visual acuity of 6/60 or less in the better eye, or (2) a visual field subtending an angle of 20 degrees or less. The National Council for the Blind in Ireland (NCBI) is the sole custodian of a national registration database recording all eligible, registered people. This computerised database was analysed to provide information on the demographics and blind registration condition of those on the register in 2003. This information was compared with the results of the 1996 study. To assess the accuracy of the current register, the registration status of eligible patients attending the outpatient clinic of a busy, tertiary referral ophthalmology department, over a 9 week period, was studied.

RESULTS

6862 adults were registered as blind on the NCBI register in Ireland in 2003, representing an increase of 37% since 1996. The leading causes of registration were age related macular degeneration (ARMD) (25%), glaucoma (12%), and retinitis pigmentosa (7%). Comparing the 1996 and 2003 data, dramatic increases in the numbers registered caused by ARMD (from 812 to 1729 people, a 113% increase) and diabetic retinopathy (DR) (from 147 people to 323 people, a 120% increase) were found. The numbers registered as a result of glaucoma were relatively stable (795 in 1996 and 811 in 2003). A substantial drop, of 53%, was noted in the number of people registered as a result of cataracts, from 561 people to 261. Of the 672 new cases registered in 2003, ARMD accounted for 44%, glaucoma 13%, and DR 7%. Over the 9 week study period 75 patients, out of a total 2320 patients who attended the outpatient department, fulfilled the blind registration criteria. It was found that 21% (16 of 75) of the eligible clinic outpatients had not been appropriately registered.

CONCLUSION

An overall increase in adult blind registration of 37% in the Republic of Ireland was found between 1996 and 2003. There were large increases in registered blindness as a result of ARMD (113%) and DR (120%). A notable decrease in registration as a result of cataracts was discovered. Vigilance by clinicians is necessary to ensure that eligible patients are registered.

The value of corneal transplantation in reducing blindness

PURPOSE

To analyse the role of keratoplasty in reducing world blindness due to corneal diseases.

METHODS

Review of published literature. We collected and analysed articles published in the English language literature related to the prevalence and causes of blindness in different parts of the world, causes of corneal blindness, and outcome of corneal transplantation for various corneal diseases.

RESULTS

A total of 80% of the world's blind live in developing countries. Retinal diseases are the most important causes of blindness (40-54%) in established economy nations while cataract (44-60%) and corneal diseases (8-25%) are the most common causes of blindness in countries with less developed economies. Keratitis during childhood, trauma, and keratitis during adulthood resulting in a vascularized corneal scar and adherent leucoma are the most frequent causes of corneal blindness in developing countries. Corneal diseases are responsible for 20% of childhood blindness. Nearly 80% of all corneal blindness is avoidable. The outcome of keratoplasty for vascularized corneal scar and adherent leucoma is unsatisfactory, necessitating repeat surgery in a high proportion of these cases. Other barriers for keratoplasty in these nations are suboptimal eye banking, lack of trained human resources, and infrastructure.

CONCLUSIONS

Since the developing world carries most of the load of corneal blindness and the major causes of corneal blindness are corneal scar and active keratitis, development of corneal transplantation services need a comprehensive approach encompassing medical standards in eye banking, training of cornea specialists and eye banking personnel and exposure of ophthalmologists to care of corneal transplants for better follow-up care. However, concerted efforts should be made to develop and implement prevention strategies since most corneal blindness is preventable.