Pterygium in adults from the Brazilian Amazon Region: prevalence, visual status and refractive errors

Abstract

AimsTo determine prevalence of pterygium, its role as main cause of unilateral and bilateral visual impairment and blindness and its impact on refractive errors from adults living in a high ultraviolet exposure area in the Brazilian Amazon Region.MethodsCluster sampling was used in randomly selecting subjects ≥45 years of age from urban and rural areas of Parintins city. Eligible subjects were enumerated through a door-to-door household survey and invited for an eye exam including refraction. Pterygium was assessed considering location (nasal, temporal or both) and size (<3 mm or ≥3 mm reaching or not pupillary margin).ResultsA total of 2384 persons were enumerated and 2041 (85.6%) were examined. Prevalence of pterygium was 58.8% (95% CI 53.8% to 63.7%) and associated with male gender (OR=1.63; 95% CI 1.37 to 1.94; p=0.001), while higher education was a protective factor (OR=0.63; 95% CI 0.44 to 0.92; p=0.018). Older age and rural residence were associated with pterygium ≥3 mm reaching or not pupillary margin, while higher education was a protective factor for pterygium ≥3 mm reaching pupillary margin. Prevalence of pterygium as cause of visual impairment and blindness was 14.3% and 3.9%, respectively. Significantly higher hyperopic refractive errors were found in eyes with pterygium ≥3 mm reaching or not pupillary margin.ConclusionsPterygium was highly prevalent and the second cause of visual impairment and blindness after provision of refractive correction. Risk factors for pterygium were male gender, advanced age, lower education and rural residency. Strategies to provide pterygium early detection and proper management should be considered by healthcare authorities in this population.

Comprehensive Analysis of the Transcriptome-Wide m6A Methylome in Pterygium by MeRIP Sequencing

“…Pterygium is a triangular fibrovascular tissue that grows from the bulbar conjunctiva of the palpebral fissure to the cornea, and it often occurs on the side of the nose (Chen et al, 2014). According to the latest epidemiological survey, the prevalence of pterygium in Asia is 7% (Ang et al, 2012;Chen et al, 2015;Khanna et al, 2020), while in Africa and South America, it is higher (Nemesure et al, 2008;Fernandes et al, 2020). Therefore, it is necessary to explore the specific mechanism of pterygium.…”

Histopathological Variability and Concomitant Lesions in Pterygium in a Large Case Series

“…Its ability to grow blood vessels and invade adjacent corneal tissue is closely resembling neoplastic processes. Notwithstanding that recurrence rate is highly variable and may reach up to 78% in some instances [ 2 – 4 ], yet, these lesions are still often approached as stromal degenerative disorders and treated conservatively. With growing evidence pointing towards a preneoplastic process, a shift in the clinical management of pterygia is foreseeable.…”

“…Its etiology is unknown; however, its prevalence in populations living near the equator suggests a link to ultraviolet exposure. The term “pterygium belt” was coined to describe regions saddling both sides of the equator where pterygium is highly prevalent, affecting up to half of the population in some areas [ 2 ].…”

Association among pterygium, cataracts, and cumulative ocular ultraviolet exposure: A cross-sectional study in Han people in China and Taiwan

“…Wang et al reported that the overall prevalence of pterygium in 1,910 Han and 741 Mongolian people was 6.4% and that pterygium was significantly correlated with age, outdoor occupation, and time spent in rural areas [ 43 ]. In the Brazilian Amazon, a region with high UV exposure, randomly selected adults had a 58.8% prevalence of pterygium; the prevalence was higher for the male sex, older age, lower education, and rural residence, and it was lower for higher education [ 55 ]. The prevalence of pterygium in that study was similar to that of Sanya (58.8%) in our study.…”