Global Trends in Blindness and Vision Impairment Resulting from Corneal Opacity 1984-2020: A Meta-analysis.

TOPIC: We provide global estimates of the prevalence of corneal blindness and vision impairment in adults 40 years of age and older and examine the burden by age, sex, and geographic region from 1984 through 2020. CLINICAL RELEVANCE: Corneal opacities (COs) are among the top 5 causes of blindness worldwide, yet the global prevalence, regional differences, and risk factors are unclear. METHODS: Abstracted data from the published literature and surveys were obtained from the Global Burden of Disease Vision Loss Expert Group. We supplemented this by an independent systematic literature search of several databases. Studies that provided CO vision impairment data based on population-based surveys for those 40 years of age or older were included, for a total of 244. For each of the 4 outcomes of blindness and moderate to severe vision impairment (MSVI) caused by trachomatous and nontrachomatous CO (NTCO), time trends and differences in prevalence by region, age, and sex were evaluated using a Poisson log-linear model with a generalized estimating equation method. Age-standardized estimates of global prevalence of blindness and MSVI were calculated using the 2015 United Nations standard populations. RESULTS: The global prevalence of blindness resulting from NTCO in those 40 years and older was 0.081% (95% confidence interval [CI], 0.049%-0.315%); that of MSVI was 0.130% (95% CI, 0.087%-0.372%). A significant increase with age was found (prevalence rate ratio, 2.15; 95% CI, 1.99-2.32). Latin America and Europe showed the lowest rates, with 2- to 8-fold higher rates of blindness or MSVI in other regions. The global prevalence of blindness resulting from trachomatous CO in those 50 years and older was 0.0094% (95% CI, 0%-0.0693%); that from MSVI was 0.012% (95% CI, 0%-0.0761%). Blindness resulting from trachomatous CO and MSVI increased with age and female sex, and rates were significantly higher in the African regions. A decrease in trachomatous blindness rates over time was found (prevalence rate ratio, 0.91; 95% CI, 0.86-0.96). DISCUSSION: An estimated 5.5 million people worldwide are bilaterally blind or have MSVI resulting from CO, with an additional 6.2 million unilaterally blind. Blindness resulting from trachomatous CO is declining over time, likely because of the massive scaleup of the global trachoma elimination program and overall socioeconomic development. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Clinicopathologic Features and Treatment Characteristics of Congenital Corneal Opacity Infants and Children Aged 3 Years or Less: A Retrospective Single Institution Analysis.

OBJECTIVE: In this retrospective single institution study, we investigated the clinicopathologic features and treatment characteristics of 90 patients with congenital corneal opacities (CCO) (117 eyes) who were 3 years and younger and treated at our hospital. SUBJECT AND METHODS: We reviewed the clinical data of patients with CCO who presented for the first time for treatment at our hospital between January 1, 2017, and December 31, 2017. CCO were classified using the "STUMPED" (Sclerocornea, Tears in Descement's membrane, Metabolic, Peters, Endothelial dystrophy and Dermoid) method and confirmed by pathological examination. -Results: Seventy percent of the patients had unilateral CCO. Iridocorneal adhesions (61 eyes, 52.1%) and cataracts (22 eyes, 18.8%) were the 2 most common ocular abnormalities. Systemic abnormalities were present in 5 patients (5.6%), including growth retardation (4 patients) and congenital brain defects (1 patient). Eighty-five eyes (72.6%) underwent penetrating keratoplasty (PK), and lamellar keratoplasty (LK) was performed in 30 (25.6%) eyes. Forty-seven (95.9%) eyes with Peters anomaly and all 16 eyes with sclerocornea received PK, and all 24 eyes with dermoids were treated with LK. CONCLUSION: Our study demonstrates that CCO has varied manifestations in infants and young children in China. A thorough medical history, careful clinical examination, and the use of accessory examinations such as ultrasound biomicroscopy are critical for the accurate diagnosis and classification of CCO and to provide guidance on therapeutic choices.

Prevalence and causes of corneal blindness.

BACKGROUND: The study aimed to assess the prevalence and causes of corneal blindness in a rural northern Chinese population. DESIGN: Cross-sectional study. PARTICIPANTS OR SAMPLES: The cluster random sampling method was used to select the sample. METHODS: This population-based study included 11 787 participants of all ages in rural Heilongjiang Province, China. These participants underwent a detailed interview and eye examination that included the measurement of visual acuity, slit-lamp biomicroscopy and direct ophthalmoscopy. An eye was considered to have corneal blindness if the visual acuity was <9/18 because of corneal diseases. MAIN OUTCOME MEASURES: The main outcome measure was prevalence rates of corneal blindness and low vision. RESULTS: Among the 10 384 people enrolled in the study, the prevalence of corneal blindness is 0.3% (95% confidence interval 0.2-0.4%). The leading cause was keratitis in childhood (40.0%), followed by ocular trauma (33.3%) and keratitis in adulthood (20.0%). Age and illiteracy were found to be associated with an increased prevalence of corneal blindness. CONCLUSION: Blindness because of corneal diseases in rural areas of Northern China is a significant public health problem that needs to be given more attention.

Prevalence and associated factors of corneal opacity among adults in Kolladiba town, Northwest Ethiopia: a cross-sectional study.

OBJECTIVE: This study aimed to assess the prevalence and associated factors of corneal opacity among adults in Kolladiba town, Northwest Ethiopia. METHODS AND ANALYSIS: A community-based cross-sectional study was conducted using a systematic random sampling technique. A total of 846 adult individuals were recruited for the study. Ethical approval was obtained from the University of Gondar School of Medicine Ethical Review Committee. A standardised, semistructured questionnaire plus an ocular examination were used to collect the data. The data were entered into Epi Info V.7 and cleaned and analysed using SPSS V.26. Binary and multivariable logistic regression analyses were performed to select candidate variables and identify statistically significant factors. Variables with a p value of less than 0.05 according to the multivariable logistic regression analysis were considered to be statistically significant. RESULTS AND CONCLUSION: The prevalence of corneal opacity among the study participants was 27.2% (95% CI 24.4% to 30.4%). In this study, age 49-60 years (adjusted OR (AOR): 1.90; 95% CI 1.03 to 3.32), age ≥61 years (AOR=2.12; 95% CI 1.17 to 3.87), inability to read and write (AOR=2.65; 95% CI 1.68 to 4.16), middle-income level (AOR=2.12; 95% CI 1.30 to 3.47) and poor income level (AOR=4.96; 95% CI 3.04 to 8.09) were factors that were significantly associated with corneal opacity.In this study, the prevalence of corneal opacity was considerably high. Being poor and unable to read and write were the primary factors significantly associated with corneal opacity. Hence, concerned stakeholders should strive to reverse the effects of corneal opacity on the quality of life of the study and causal studies should be considered in the future.

Population-based study on the prevalence, clinical characteristics and vision-related quality of life in patients with corneal opacity resulting from infectious keratitis: results from the Corneal Opacity Rural Epidemiological study.

AIM: To estimate prevalence and characterise clinical features and vision-related quality of life (VR-QoL) of corneal opacities (COs) resulting from infectious keratitis in a rural North Indian population. METHODS: The Corneal Opacity Rural Epidemiological study was a cross-sectional study conducted in 25 randomly selected clusters of rural Gurgaon, Haryana, India to determine prevalence of corneal disease across all age groups. During house-to-house visits, sociodemographic details, presence, type and clinical characteristics of corneal disease, laterality and resultant visual impairment (VI) was noted. Subgroup analysis of data was performed to understand the prevalence, clinical characteristics, VR-QoL in patients with CO due to infectious keratitis. VR-QoL scores were compared with healthy controls. RESULTS: Overall, 65 of 12 113 participants had evidence of infectious keratitis-related CO with a mean age of 63.3 (±14.7 SD) years. Prevalence of infectious keratitis-related CO, including both bilateral (12/65) and unilateral (53/65) cases was 0.54% (95% CI 0.41 to 0.66) seen in a total of 77 eyes of 65 participants. Mean visual acuity was 1.18±0.80 with 30/77 (38.9%) eyes having a presenting visual acuity <3/60. Most of the CO due to infectious keratitis was <3 mm in size (61.03%; 47/77), nebular (42.85%; 33/77) and central (49.35%; 38/77) in location. These participants had significantly higher VR-QoL scores and hence poorer VR-QoL across all three domains of vision function (scores of 28 vs 22, 7.5 vs 5 and 15.5 vs 9, respectively; p<0.0001) when compared with healthy controls. CONCLUSION: The data from this study give an insight into the burden and clinical characteristics of COs resulting from infectious keratitis. VR-QoL is significantly impaired in patients with CO resulting from infectious keratitis, both in bilateral and unilateral cases.

The frequency of severe corneal opacities in premature infants.

PURPOSE: To study the frequency and possible causes of severe corneal opacities in premature infants undergoing retinopathy of prematurity (ROP) screening in the neonatal intensive care unit (NICU) at a single institution. METHODS: The medical records of all infants screened for ROP in the NICU between January 2015 and March 2019 were reviewed retrospectively. Criteria for screening were gestational age (GA) of <32 weeks or birth weight (BW) <1501 g. Characteristics of premature infants with severe corneal opacities were extracted from the record. RESULTS: A total of 445 premature infants were screened during the 51-month period. The prevalence of severe corneal opacities was 1.4% (6 infants). The median GA of the affected infants was 24.5 weeks (range, 23-32), and the mean BW was 624 g (range, 500-860 g). Two infants had lagophthalmos; their corneal opacity was unilateral. All the infants were under continuous positive airway pressure (CPAP) for a prolonged period. All 4 infants with bilateral corneal opacities required treatment for severe ROP-laser (n =1), bevacizumab injection (n = 1), or both (n = 2). CONCLUSIONS: Severe corneal opacities in premature infants are rare but potentially sight threatening, because they can hinder the retinal examination. Lagophthalmos-related exposure keratopathy is an obvious risk factor. CPAP therapy may be another risk factor leading to the development of severe corneal opacities. Identification of infants at risk and prompt commencement of lubricants is necessary to avoid long-term corneal opacities.

Prevalence and associations of blinding trachoma in indigenous Australians within central Australia: the Central Australian Ocular Health Study.

PURPOSE: To determine the prevalence and associations of blinding trachoma within the indigenous Australian population living in central Australia. METHODS: A total of 1884 individuals aged 20 years or older, living among 30 remote communities within the statistical local area of 'Central Australia', were recruited for this study. This equated to 36% of those aged 20 years or older and 67% of those aged 40 years or older within this district. Participants were recruited as they presented to the eye clinic at each remote community. Anterior segment examination was performed and the rates of trachomatous trichiasis (TT) and trachomatous corneal opacification (CO) were documented. The prevalence of TT and CO in one or both eyes was presented. RESULTS: There were 6.1% (95% CI 5.0-7.2) (8.3% of those aged 40 years or older) who had TT and 3.3% (95% CI 2.5-4.1) (4.4% of those aged 40 years or older) who had CO. Both TT and CO were associated with advancing age and female sex. Prevalence varied widely between communities, from 0% to 33% for TT and 0% to 27% for CO. CONCLUSION: Our study has shown that blinding trachoma remains endemic among indigenous Australians in central Australia. However, compared with previous estimates, the prevalence of TT and CO appears to be decreasing.

[Comparison of four MICS intraocular lenses regarding their rates of neodymium:YAG laser capsulotomy]. / Vergleich von 4 MICS-Intraokularlinsen im Hinblick auf ihre Neodym:YAG-Laser-Kapsulotomieraten.

BACKGROUND: The aim of this study was to evaluate the incidence of posterior capsule opacification up to 50 months following 1.7-mm bimanual MICS-cataract surgery. METHODS: Bimanual MICS cataract surgery was performed in 197 eyes (135 patients) via two 1.7-mm corneal incisions. Four MICS acrylic foldable IOLs were implanted: AcriSmart 48S-5, n = 54 (Acritec GmbH, Hennigsdorf, now AT.Smart 48S Carl-Zeiss-Meditec, AG, Jena, Germany), ThinLens UltraChoice 1.0, n = 53 (Technomed GmbH, Baesweiler, Germany), AcriFlex 46, n = 41 und AcriFlex 48 CSE, n = 7 (Acrimed GmbH, Berlin, now: Lentis L-303, Oculentis GmbH, Berlin, Germany) and CareFlex, n = 43 (w2o Medizintechnik AG, Bruchsal, Germany). Statistical analysis was performed using the Kaplan-Meier technique. RESULTS: High levels of completeness of follow-up rates were: ThinLens 96%, CareFlex 100%, AcriSmart 93%, AcriFlex 92%. The capsulotomy rate was 43.13% for ThinLens within a mean/max. follow-up period of 801/1131 days, 34.88% for CareFlex (565/872 days), 40% for AcriSmart (988/1506 days) and 15.91% for AcriFlex (728/975 days). By limiting the follow-up period to a comparable maximum of 850 days for all four IOLs, our capsulotomy rates were as follows: ThinLens 33.33%, CareFlex 32.56 %, AcriSmart 20.0% and AcriFlex 11.36%. MICS IOLs have higher capsulotomy rates than hydrophobic acrylic lenses and sharp-edged silicone lenses. In literature comparisons MICS-IOLs do not exceed the variance levels of capsulotomy rates of PMMA, hydrophilic acrylic and silicone lenses without sharp edges. Cases of decentration or luxation of MICS-IOLs following Neodym:YAG laser capsulotomy were not detected. Capsulotomy frequency with the CareFlex was statistically significantly higher in comparison to the AcriSmart (Log Rank Mantel Cox Test, p = 0.007) and AcriFlex (log rank Mantel Cox test, p = 0.002). CONCLUSIONS: Capsulotomy rates observed varied for the four MICS-IOL-types tested. The posterior capsule opacification frequency of the two best MICS-IOLs (AcriFlex, AcriSmart) did not exceed the higher variance levels of posterior capsule opacification rates of the round-edged "conventional" non-MICS IOLs of PMMA, silicone or hydrophilic acryl material. Sharp-edged silicone or hydrophobic acrylic "conventional" lenses have shown lower posterior capsule opacification rates.

Corneal blindness in Plato's cave: the acting forces to prevent and revert corneal opacity. Part I: epidemiology and new physiopathological concepts.

The burden of corneal blindness and visual deficiency can be felt worldwide. Its association with several endemic diseases such as childhood blindness, trauma, infectious keratitis (including variants caused by herpes, hanseniasis, and fungi), vitamin A deficiency, diabetes mellitus, and other dry eye syndromes reflects its poorly understood underlying mechanisms and suggests that the actual frequency of the disease is underestimated. The low effectiveness of preventive and therapeutic strategies against corneal scarring or deformity predicts a high frequency of patients with corneal blindness in the future. Corneal blindness is associated with environmental factors and socioeconomic limitations that restrain health assistance and maintain a modest efficiency of the current therapeutic strategies for resolving corneal diseases in large-scale programs. We present here a critical review of the concepts associated with corneal blindness that need to be considered when planning strategies to prevent and treat corneal blindness worldwide (to be able to leave Plato's cave, where corneal blindness is encaged.

Population-based assessment of visual impairment and pattern of corneal disease: results from the CORE (Corneal Opacity Rural Epidemiological) study.

OBJECTIVE: To characterise types of corneal diseases and resulting visual impairment (VI) in a rural North Indian population. DESIGN: Cross-sectional, population-based study. METHODS: The Corneal Opacity Rural Epidemiological study included 12 899 participants from 25 random clusters of rural Gurgaon, Haryana, India to determine the prevalence of the corneal disease in the general population. Sociodemographic details, presence and type of corneal morbidity, laterality, VI (presenting visual acuity (PVA) <6/18 in the better eye) and characteristics of corneal opacities were noted. RESULTS: Overall, 12 113 participants of all ages underwent detailed ophthalmic examination and prevalence of corneal opacity was found to be 3.7% (n=452) with bilateral involvement in 140 participants (31%) during the house-to-house visits. Of the total 571 eyes of 435 patients presenting with corneal opacity at the central clinic, PVA was <3/60 in 166 (29.1%), 3/60 to <6/60 in 14 (2.5%), 6/60 to <6/18 in 164 (28.7%), 6/18 to ≤6/12 in 85 (14.9%) and 6/9 to 6/6 in 142 eyes (24.9%), respectively. Further, there were a total of 115 eyes (20.1%) with nebular corneal opacity, 263 (46.1%) with macular, 162 (28.4%) with leucomatous and 31 (5.4%) with an adherent leucoma. The odds of having VI due to corneal disease were greater for the illiterate (OR:4.26; 95% CI: 2.88 to 6.31; p<0.001) and elderly (OR:11.05; 95% CI: 7.76 to 15.74; p<0.001). CONCLUSION: The data from this study give an insight into the characteristics of various corneal pathologies and resulting VI in the general population. This is a pioneer study involving all age groups on the burden of VI due to corneal diseases.

Findings from a Rapid Assessment of Avoidable Blindness (RAAB) in the Southwest Region of Kyrgyzstan.

Purpose: Reliable data on eye care needs in Kyrgyzstan are not readily available. The purpose of this study was to determine the prevalence and causes of blindness and visual impairment in persons aged 50 and above in the southwest of Kyrgyzstan and to support the Ministry of Health (MoH) in the planning of eye care in the region.Methods: A population-based survey was conducted in three states (Oblast) in the southwest region of Kyrgyzstan. Sixty clusters of 50 people aged 50 years and older were selected by probability proportionate to size sampling. Ethical approval was obtained from the MoH, consent was obtained from each participant.Results: A total number of 3,000 persons aged 50 and older were sampled. Among these 2,897 (95.9%) were examined. The prevalence of bilateral blindness was 1.7% [95%CI: 1.1-2.4]. Cataract (43.3%) was the main cause of blindness, followed by glaucoma (30%), age-related macular degeneration (ARMD) (8.3%), other posterior segment diseases (6.7%) and non-trachomatous corneal opacities (5%). The prevalence of blindness and visual impairment increased strongly with age. The cataract surgical coverage in blind persons was 59%.Conclusion: Cataract and glaucoma were the major causes of blindness and visual impairment in persons 50 and above. The majority of the causes (85%) were avoidable, with 45% (cataract and uncorrected aphakia) treatable, 6.7% (corneal opacity and phthisis) preventable by primary health care/eye care services and 33.3% (cataract surgical complications, glaucoma) preventable by specialized ophthalmic services. The data suggest that an expansion of eye care services to reduce avoidable blindness is needed, as ageing will lead to an increase in older people at risk and a higher demand for eye care in the future.

Assessment of trachoma in suspected endemic areas within 16 provinces in mainland China.

BACKGROUND: China used to be among the countries with a high prevalence of trachoma. At the launch of The Global Elimination of Trachoma (GET) 2020 campaign by the World Health Organization (WHO) in 1996, China was placed on the list of countries endemic for trachoma based on historical data. However, empirical observation and routinely collected eye care data were suggesting that trachoma was no longer a public health problem. To determine whether the GET 2020 goals had been met in P. R. China, we conducted a targeted assessment with national scope. METHODOLOGY/PRINCIPAL FINDING: Province assessment teams, trained in WHO Trachoma Rapid Assessment (TRA) methodology and in WHO simplified trachoma grading system, carried out assessments in 16 provinces (among them, 2 provinces conducted pilot assessment). Based on the published literature, including national and international reports, suspected trachoma-endemic areas within each province were identified. Within these areas, trachomatous inflammation- follicular (TF) assessments were carried out in at least 50 grade-one children in primary schools serving villages with the lowest socio-economic development. Trachomatous trichiasis (TT) and corneal opacity (CO) assessments were conducted among persons aged 15 and over in villages within the catchment area of the selected schools. Of 8,259 children examined in 128 primary schools in 97 suspected trachoma endemic areas, only 16 cases of conjunctivitis were graded as TF. 38 cases with TT were found among the 339,013 examined residents in villages surrounding the schools. Among these 97 suspected trachoma endemic areas in only three was the prevalence of TT more than 0.2%. CONCLUSIONS/SIGNIFICANCE: This large study suggested that trachoma was not a public health problem in 16 provinces that had been previously suspected to be endemic. These findings will facilitate planning for elimination of trachoma from PR China.

Comparison of 5468 retreatments after laser in situ keratomileusis by lifting the flap or performing photorefractive keratectomy on the flap. / Comparación de 5.468 retratamientos tras láser in situ queratomileusis levantando el lentículo o mediante queratectomía fotorrefractiva sobre el lentículo.

PURPOSE: To assess visual outcomes of retreatment after laser in situ keratomileusis (LASIK) by lifting the flap or performing photorefractive keratectomy (PRK) on the flap, as well as to establish whether there was an increased risk of epithelial ingrowth (EIG) when LASIK and lifting of the flap are separated by a long time interval and to determine the incidence of corneal haze after PRK. METHODS: Retrospective study of 4077 patients (5468 eyes) who underwent LASIK and subsequent retreatment were reviewed in order to study their visual results and identify cases of EIG and corneal haze. RESULTS: Enhancements included 5196 eyes from 3876 patients that were retreated by lifting the flap, and 272 eyes from 201 patients that were retreated by PRK on the flap. No statistically significant differences were found between the retreatments in terms of predictability, efficacy, and safety. A total of 704 cases of EIG were found after lifting the flap, for which surgical cleansing was necessary in 70. Surgical cleansing decreased the efficacy index when compared with patients with EIG who did not need cleansing (P=.01). Differences in terms of safety and predictability were not statistically significant. The incidence of corneal haze after ablation of the surface of the previous flap was 14.34%, although none of these cases were clinically relevant. CONCLUSIONS: Visual outcomes were similar between patients who were retreated by lifting the flap and those who underwent PRK. The incidence of EIG when the flap was lifted was 13.55%. The incidence of EIG increases with the time elapsed between the primary procedure and retreatment.

The Prevalence of Corneal Opacity in Rural Areas in Iran: A Population-based Study.

PURPOSE: To determine the prevalence of corneal opacity in rural areas in Iran: a population-based study Methods: This was a cross-sectional population-based study using multi-stage cluster sampling from rural-dwellers of villages in the north and southwest of Iran. All participants underwent vision testing including measurement of visual acuity and refraction followed by slit lamp examination by an ophthalmologist through which the presence of corneal opacity was determined. RESULTS: The participants were 3314 people (response rate = 86.5%), and 56.3% were female. The prevalence of corneal opacity in at least one eye in the studied subjects was 1.68% (95% CI: 1.08-2.27%); 1.07% (95% CI: 0.04-3.43%) and 2.47% (95% CI: 1.49-3.43%) in women and men, respectively, and 1.45% (95% CI: 0.4-2.45%) and 1.97% (95% CI: 1.3-2.94%) in the southwest and north of the country, respectively. The prevalence of corneal opacity was related to male gender (OR = 2.06, 95% CI: 1.13-3.74) and age (OR = 1.06, 95% CI: 1.04- 1.09) but not with education level. The prevalence of visual impairment and blindness among cases with corneal opacity was 46.2% and 19.2%, respectively. CONCLUSION: Given the high prevalence of corneal opacity in rural areas in Iran, it is essential to prioritize rural areas for allocation of resources and facilities for the diagnosis, screening, and necessary treatment measures.

Prevalence of trachoma-related trichiasis and corneal opacity in rural Myanmar: the Meiktila Eye Study.

OBJECTIVE: To describe the prevalence of trachomatous trichiasis and corneal opacity (CO) within central Myanmar. DESIGN: Population-based cross-sectional ophthalmic survey. PARTICIPANTS: Random, stratified, cluster sampling of the inhabitants > or =40 years of age from villages in the Meiktila District was performed; 2481 eligible participants were identified and 2076 participated in the study. METHODS: Visual acuity was measured using an E Snellen chart at 6 meters. Lid, ocular surface, and anterior segment examinations were performed at the slit lamp. MAIN OUTCOME MEASURES: Trachoma was graded as trachomatous trichiasis (TT) or CO according to the World Health Organization grading system. RESULTS: The population prevalence of trachoma (TT and CO) was 2.6% (95% confidence interval [CI]. 1.67%-3.42%). For every 1-year increase in age, the odds of trachoma increased by 5.3% (95% CI, 4.9%-5.7%). There was no significant effect of gender on the prevalence of trachoma (P = 0.5). No formal schooling was a strong predictor of trachoma (odds ratio, [OR], 4.9; 95% CI, 3.9-6.1), and having <3 children in the house was protective (OR, 0.75; 95% CI, 0.61-0.93); however, neither occupation nor the number of people in a household had an effect on trachoma. CONCLUSIONS: The prevalence of blinding trachoma in central Myanmar remains relatively low. This is a tribute to the success of the Burma Trachoma Control Program and demonstrates the need for such a program to remain an integral part of public health care and community health services to further diminish the prevalence of this condition. This will be facilitated by a focus on trachoma risk factors and further research into the prevalence of inflammatory trachoma within the pediatric population.

Prevalence and causes of childhood blindness in camps for displaced persons in Khartoum: results of a household survey.

The prevalence and causes of visual impairment and blindness were determined in 29 048 children < 16 years in all households of 5 camps for internally displaced people in Khartoum State, Sudan. After house-to-house visits by trained health care workers, 916 children received further assessment, 2.7% of whom were found to be blind, 1.6% to be severely visually impaired and 5.5% to be visually impaired, according to World Health Organization criteria. The prevalence of blindness in children in the camps was estimated as 1.4 per 1000 children. The leading causes of blindness were found to be corneal opacities (40.0%), mainly due to vitamin A deficiency, followed by amblyopia (32.5%).

Corneal Breakthrough Haze After Photorefractive Keratectomy With Mitomycin C: Incidence and Risk Factors.

PURPOSE: To identify preoperative and intraoperative factors affecting breakthrough corneal haze incidence after photorefractive keratectomy (PRK) with mitomycin C (MMC). METHODS: In this retrospective study of PRK performed at the Care Vision Refractive Laser Center, Tel Aviv, Israel, a total of 7535 eyes (n = 3854 patients; mean age ± SD, 26 ± 6 years; 55% men) underwent PRK with intraoperative MMC application. Patients with histories of corneal pathology or surgery were excluded. Incidence, time of onset, and corneal haze severity were documented on follow-up of 118 ± 110 days. Eyes were grouped by preoperative refraction [low (≤-3D), moderate (-3D to -6D), or high (>-6D) myopia; low (≤3D) or high (>3D) astigmatism; low or high hyperopia]; by intraoperative time (above or below 40 seconds); and by MMC application time (above or below 40 seconds). The main outcome measures were incidence, onset time, and severity of corneal haze. RESULTS: The haze incidence was 2.1% in eyes with high myopia versus 1.1% in those with low to moderate myopia (P = 0.002), and 3.5 times higher in eyes with high than with low astigmatism (P < 0.05). The overall incidence was higher in eyes treated for hyperopia (10.8%) than for myopia (1.3%) (P = 0.0001). In eyes with moderate myopia, the haze incidence was lower in MMC application time ≥40 seconds (0%) than in <40 seconds (1.3%) (P = 0.03). After surgery, a mild early haze incidence peaked at 68.8 ± 6 days and severe late haze at 115 ± 17 days (P = 0.02). CONCLUSIONS: Hyperopic and large myopic or astigmatic corrections carry higher risk of haze. Longer MMC application might have beneficial haze prevention.

Epidemiology of blindness in children.

An estimated 1.4 million of the world's children are blind. A blind child is more likely to live in socioeconomic deprivation, to be more frequently hospitalised during childhood and to die in childhood than a child not living with blindness. This update of a previous review on childhood visual impairment focuses on emerging therapies for children with severe visual disability (severe visual impairment and blindness or SVI/BL).For children in higher income countries, cerebral visual impairment and optic nerve anomalies remain the most common causes of SVI/BL, while retinopathy of prematurity (ROP) and cataract are now the most common avoidable causes. The constellation of causes of childhood blindness in lower income settings is shifting from infective and nutritional corneal opacities and congenital anomalies to more resemble the patterns seen in higher income settings. Improvements in maternal and neonatal health and investment in and maintenance of national ophthalmic care infrastructure are the key to reducing the burden of avoidable blindness. New therapeutic targets are emerging for childhood visual disorders, although the safety and efficacy of novel therapies for diseases such as ROP or retinal dystrophies are not yet clear. Population-based epidemiological research, particularly on cerebral visual impairment and optic nerve hypoplasia, is needed in order to improve understanding of risk factors and to inform and support the development of novel therapies for disorders currently considered 'untreatable'.

The long-term natural history of trachomatous trichiasis in the Gambia.

PURPOSE: Trachoma is the leading infectious cause of blindness. However, there are few data on the natural history of trachomatous trichiasis to guide program planning or that investigate its pathogenesis. METHODS: A cohort of Gambians with trichiasis in one or both eyes who had declined surgery was observed. Clinical examinations were performed at baseline and 4 years later. Conjunctival swab samples were collected for Chlamydia trachomatis PCR and bacteriology. RESULTS: One hundred fifty-four people were examined at baseline and 4 years later (241 nonsurgical eyes). At baseline 124 (52%) eyes had major trichiasis (5+ lashes), 75 (31%) minor trichiasis (1-4 lashes), and 42 (17%) no trichiasis. By 4 years, trichiasis had developed in 12 (29%) of 42 previously unaffected eyes. Minor trichiasis progressed to major in 28 (37%) of 75 eyes. New corneal opacification more commonly developed in eyes that had major (10%) compared to minor (5%) trichiasis at baseline. Bacterial infection was common (23%), becoming more frequent with increasing trichiasis. C. trachomatis infection was rare (1%). Conjunctival inflammation was common (29%) and was associated with progressive trichiasis and corneal opacification. CONCLUSIONS: Trichiasis progressed in the long-term in this environment, despite a low prevalence of C. trachomatis. Blinding corneal opacification develops infrequently, unless major trichiasis is present. Epilation and early surgery need to be formally compared for the management of minor trichiasis. The pathologic correlates and promoters of conjunctival inflammation need to be investigated.