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.

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.

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.

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.

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.

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.

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.

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.

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'.

Visual impairment attributable to uncorrected refractive error and other causes in the Ghanaian youth: The University of Cape Coast Survey.

PURPOSE: To determine the prevalence of visual impairment attributable to refractive error and other causes in a youthful Ghanaian population. METHODS: A prospective survey of all consecutive visits by first-year tertiary students to the Optometry clinic between August, 2013 and April, 2014. Of the 4378 first-year students aged 16-39 years enumerated, 3437 (78.5%) underwent the eye examination. The examination protocol included presenting visual acuity (PVA), ocular motility, and slit-lamp examination of the external eye, anterior segment and media, and non-dilated fundus examination. Pinhole acuity and fundus examination were performed when the PVA≤6/12 in one or both eyes to determine the principal cause of the vision loss. RESULTS: The mean age of participants was 21.86 years (95% CI: 21.72-21.99). The prevalence of bilateral visual impairment (BVI; PVA in the better eye ≤6/12) and unilateral visual impairment UVI; PVA in the worse eye ≤6/12) were 3.08% (95% CI: 2.56-3.72) and 0.79% (95% CI: 0.54-1.14), respectively. Among 106 participants with BVI, refractive error (96.2%) and corneal opacity (3.8%) were the causes. Of the 27 participants with UVI, refractive error (44.4%), maculopathy (18.5%) and retinal disease (14.8%) were the major causes. There was unequal distribution of BVI in the different age groups, with those above 20 years having a lesser burden. CONCLUSION: Eye screening and provision of affordable spectacle correction to the youth could be timely to eliminate visual impairment.

A Community-based Eye Care Intervention in Southern Egypt: Impact on Trachomatous Trichiasis Surgical Coverage.

PURPOSE: The purpose of this study was to measure the impact of a community-based intervention on uptake of trichiasis surgery in Southern Egypt. METHODS: Four villages where trachoma is endemic were randomly selected in the Samalout district, Egypt. Two villages were selected for intervention (intervention villages) and two matched villages for nonintervention (nonintervention villages). The intervention model provided community information sessions, door-to-door health education, screening, and improvements in the clinical capacity of eye care providers. The intervention was evaluated through two pre- and post-intervention community-based surveys that included the prevalence of trachoma and the utilization of eye care services at local hospitals. All patients with trichiasis answered a questionnaire regarding surgical utilization and barriers. RESULTS: In the baseline survey, the trachomatous trichiasis (TT) surgical coverage was 22.7% (38.9% males, 16.7% females) in all villages. Following the intervention, the TT surgical coverage increased to 68% in villages that received the intervention (81.5% males, 60% females). Nonintervention villages had a TT surgical coverage of 26.1% (37.5% males, 20% females). In the intervention villages, the prevalence of TT significantly decreased from 9.4% (5.7% males, 11.8% females) to 3.8% (1.9% males, 5.1% females) (P = 0.013), in 2008. In nonintervention villages, there was a slight, but insignificant decrease in TT from 10.1% (3.1% males, 14.4% females) to 8.2% (3% males, 11.5% females) (P = 0.580). The major barriers to uptake of TT surgical services were: "Feeling no problem" (17.3%), "fear of surgery" (12.7%) and "cost" (12.7%). CONCLUSION: A community-based eye health education program with door-to-door screening significantly increased the uptake of TT surgical services. Although improvements to the delivery of surgical service are essential, they did not lead to any significant improvements in the nonintervention villages.

The frequency of occurrence of certain corneal conditions by age and sex in Iranian adults.

PURPOSE: To determine the prevalence of posterior embryotoxon, corneal opacity, pigment on endothelium, corneal dystrophy, and corneal vascularization in a middle-aged Iranian population, and their association with age and sex. METHODS: In a cross-sectional study with multistage cluster sampling, subjects were chosen from 40 to 64-year-old residents of Shahroud in northern Iran. Participants had ophthalmic examinations before and after pupil dilation. Corneal abnormalities were diagnosed by an ophthalmologist using a slit lamp. RESULTS: Of the 6311 invitees, 5190 people (82.2%) participated; 58.6% (n=3040) were female. The prevalence of posterior embryotoxon, corneal opacity, and pigment on endothelium were 14.7% (95% CI: 13.4-16.0), 4.1% (95% CI: 3.4-4.7) and 1.2% (95% CI: 0.9-1.5), respectively, and corneal dystrophy and corneal vascularization were seen in 0.3% (95% CI: 0.2-0.5) and 3.7% (95% CI: 3.0-4.3), respectively. Unlike posterior embryotoxon, the prevalence of all studied abnormalities increased with age after adjusting for sex. The prevalence of posterior embryotoxon (p=0.023) and corneal dystrophy (p=0.038) was significantly higher in women, and the prevalence of corneal opacity (p<0.001) was significantly higher in men. After adjusting for age, sex, and cataract, cases with corneal opacity and corneal vascularization demonstrated significantly worse uncorrected and corrected visual acuity (p<0.001). CONCLUSION: This report is the first to explore the prevalence of a variety of corneal conditions in a Middle-Eastern population. The findings indicate that one out of five people may have some sort of corneal conditions, and some can impact corrected visual acuity.

Prevalence of corneal diseases in the rural Indian population: the Corneal Opacity Rural Epidemiological (CORE) study.

OBJECTIVE: The present population-based study was undertaken to estimate the prevalence, determinants and causes of corneal morbidity and blindness in a rural North Indian population. DESIGN: Population-based study in India with 12 899 participants of all ages. METHODS: Participants were recruited from 25 village clusters of district Gurgaon, Haryana, India using random cluster sampling strategy. All individuals were examined in detail with a portable slit lamp for evidence of any corneal disease during the door-to-door examination. Comprehensive ocular examination including logMar visual acuity, slit lamp biomicroscopy, non-contact tonometry and dilated retinal evaluation was performed at a central clinic site in the respective villages. RESULTS: Overall, 12 113 of 12 899 people (93.9% response rate) were examined during the household visits. Prevalence of corneal disease was 3.7% (95% CI 3.4% to 4.1%) and that of corneal blindness was 0.12% (95% CI 0.05% to 0.17%). Multivariable analysis demonstrated that corneal disease was significantly higher in the elderly (p<0.0001) and illiterates (p<0.0001). Common causes of corneal opacity in the study population were pterygium (34.5%), ocular trauma (22.3%) and infectious keratitis (14.9%). Corneal diseases contributing to blindness were post-surgical bullous keratopathy (46.2%) and corneal degenerations (23.1%). CONCLUSIONS: The study findings demonstrate that currently ocular trauma, infectious keratitis, post-surgical bullous keratopathy, and corneal degenerations are responsible for the major burden of corneal blindness and morbidity in the Indian population. The prevalence of corneal morbidity due to vitamin A deficiency and trachoma was low in this rural population.

A retrospective survey of ocular abnormalities in pugs: 130 cases.

OBJECTIVES: To determine the types and frequency of ophthalmic findings in pugs. MATERIALS AND METHODS: Retrospective analysis of case records of pugs presented to an ophthalmology unit between 2001 and 2012. Ophthalmological findings were correlated with age, gender, presenting signs and time of onset of disease. RESULTS: In total, 130 pugs (258 eyes) with a mean (±sd) age of 2 · 8 (±2 · 87) years were examined. Ocular abnormalities identified included keratoconjunctivitis sicca (n = 39 eyes), macroblepharon (n = 258 eyes), entropion (n = 258 eyes), distichiasis (n = 56 eyes), ectopic cilia (n = 8 eyes), conjunctivitis (n = 88 eyes), corneal pigmentation (n = 101 eyes), opacity (n = 63 eyes), ulceration (n = 46 eyes), vascularisation (n = 35 eyes), iris-to-iris persistent pupillary membranes (n = 21 eyes) and cataract (n = 18). Keratoconjunctivitis sicca was significantly associated with the presence of corneal pigmentation (P = 0 · 007 for left eyes; P = 0 · 043 for right eyes). However corneal pigmentation was also identified in pugs (n = 61) without keratoconjunctivitis sicca. There was a significant influence of ectopic cilia on corneal ulceration (P < 0 · 001). Younger dogs (mean age, 1 · 28 (±0 · 45) years) were significantly more affected by distichiasis. CLINICAL SIGNIFICANCE: The high number of cases of corneal pigmentation without keratoconjunctivitis sicca suggests that there may be additional yet undetermined factors involved in the development of corneal pigmentation in pugs.