Impact of pterygium on central corneal thickness measured by optical coherence tomography in older adults.

PURPOSE: To measure the central corneal thickness (CCT) using anterior segment optical coherence tomography (AS-OCT) in older adults with and without pterygium from the Brazilian Amazon Region Eye Survey (BARES). METHODS: BARES is a population-based epidemiological cross-sectional study conducted in Parintins city. Participants were residents ≥45 years of age identified through a door-to-door interview. Eligible participants were invited for a comprehensive eye exam. Pterygium occurrence and severity were assessed by ophthalmologists through slit-lamp examination considering its location (nasal or/and temporal) and severity (lesion with extension <3 mm, ≥3 mm not reaching the pupillary margin or ≥3 mm reaching the pupillary margin). CCTs were obtained and measurements from the more severely affected eye were included. Images were analyzed offline by masked observers. RESULTS: A total of 671 subjects, 533 (79.4%) with pterygium in at least one eye and 138 (20.6%) without pterygium in either eye, were examined. The mean CCT evaluated by multiple linear regression and adjusted for demographic variables and pterygium severity was 521 ± 34 µm (median = 521; range = 304-665). Decreased CCT was significantly associated with age and pterygium severity. Individuals aged 65-74 years had CCT 7 µm thinner than those aged 45-54 years (p = 0.044), individuals aged 75 years and older had CCT 15 µm thinner than those aged 45-54 years (p = 0.001), and eyes with severe pterygium had CCT 33 µm thinner than eyes without pterygium (p < 0.001). CONCLUSIONS: The CCT analysis in this population-based sample shows that a thinner cornea is associated with pterygium severity and older age.

Population-Based Cataract Surgery Complications and Their Impact on Visual Status in the Brazilian Amazon Region.

PURPOSE: To investigate cataract surgery prevalence, complications, visual outcomes, and coverage in a population of older adults from the Brazilian Amazon region. DESIGN: Population-based cross-sectional study. METHODS: Individuals ≥45 years of age from urban and rural areas of Parintins City, Brazil, were identified by cluster random sampling. Participants underwent ophthalmic examination, including uncorrected visual acuity, acuity with presenting correction (APC), and best-corrected visual acuity (BCVA) from each eye. In those with previous cataract surgery, surgical technique and complications including its contribution to vision impairment were noted. The association of surgical complications and surgical coverage with sociodemographic variables was assessed by multiple logistic regression. RESULTS: A total of 2,384 persons were determined to be eligible, and 2,041 (85.6%) were examined. Overall, prevalence of cataract surgery was 8.6%, with 11.3% urban and 5.0% rural. Surgical complications were associated with males, older age, and urban residency and were found in 60.4%, with posterior capsule opacification in 29.6% and posterior capsule rupture in 16.3%. Among the 270 eyes having cataract surgery, APC ≥20/32 was found in 44.4%, APC 20/40 to 20/63 in 20.8%, APC <20/63 to 20/200 in 14.4%, APC <20/200 to 20/400 in 2.6%, and APC <20/400 in 17.8%. Low surgical coverage was found with 57.9% of those with visual impairment due to cataract not being treated surgically. CONCLUSIONS: Although a reasonable prevalence of cataract surgery was found, a high complication rate, poor visual outcomes, and low cataract surgery coverage indicated that actions to improve quality and appropriate postsurgical management should be planned and implemented by public health authorities.

Presbyopia and Ocular Conditions Causing Near Vision Impairment in Older Adults From the Brazilian Amazon Region.

PURPOSE: To investigate the prevalence and causes of near vision impairment (NVI) in a population of older adults from the Brazilian Amazon Region. DESIGN: Population-based cross-sectional study. METHODS: Cluster sampling was used in randomly selecting subjects 45 years of age and older from urban and rural areas of Parintins city, Brazil. Participants underwent ophthalmic examination, including uncorrected (UCNVA), presenting (PNVA), and best-corrected near visual acuity (BCNVA) from each eye; biomicroscopy; funduscopy; and subjective refraction, including testing with additional lenses for near vision optical correction. A principal cause for NVI was assigned by the ophthalmologist and presbyopia was defined as UCNVA ≤ 20/40 changing to > 20/40 with BCNVA. Free-of-charge glasses were provided for those in need. RESULTS: A total of 2384 subjects were enumerated and 2025 had reliable NVA measurements from both eyes. The prevalence of NVI in the better-seeing eye was 96.5% with UCNVA, decreasing to 81.1% with PNVA and to 20.5% with BCNVA. Presbyopia was the principal cause of NVI in 71.8%, followed by cataract (16.5%) and pterygium (2.5%), and was associated with younger age and high schooling. Glasses for near vision were prescribed and provided to 1414 (69.8%) participants. CONCLUSIONS: A high prevalence of NVI was detected even in those wearing glasses for near. Prescription and provision of low-cost reading glasses should be considered by Brazilian health authorities to address this easily and promptly correctable form of vision impairment.

Mansonella ozzardi corneal lesions in the Amazon: a cross-sectional study.

OBJECTIVES: To characterise and confirm the presence of Mansonella ozzardi microfilariae in the cornea by biomicroscopy and corneal confocal microscopy. DESIGN: Cross-sectional study. SETTINGS: Clinical practice study in patients from rural communities in Coari city on the Solimões river, Amazonas state, Brazil. PARTICIPANTS: The eyes of 212 consecutive volunteer patients were examined using a flash light and their blood checked for the presence of microfilariae by an expert microscopist. Patients with suspicious corneal lesions (characterised as nummular keratitis) were submitted to biomicroscopy, fundoscopy and corneal confocal microscopy evaluation (CCME). In two patients, a biopsy of the limbal conjunctiva adjacent to the nummular keratitis was carried out and blood collected from the surgical wound for microfilariae investigation by thick blood film examination. PRIMARY AND SECONDARY OUTCOME MEASURES: Positive correlation between corneal biomicroscopic and confocal lesions and M ozzardi microfilaremia. RESULTS: Of the 212 patients, 56 (26.4%) were positive for microfilaremia. 22 patients with nummular keratitis identified under flash light examination underwent biomicroscopy and CCME. Corneal lesions were positively correlated to microfilaremia (p=0.0001). At biomicroscopy, lesions were classified as quiescent or active. At CCME, lesions were categorised as circular or filiform. The associations between corneal lesions, CCME findings and microfilaremia are shown. CONCLUSIONS: We describe M ozzardi microfilariae in the cornea and the associated eye pathology. Further studies using ocular tissue PCR and other imaging techniques would be helpful.