No abstract

PurposeTo evaluate the prevalence of pterygium and its determinants in the underserved, rural population of Iran.MethodsIn this cross-sectional study of 3851 selected individuals, 86.5% participated in the study, and the prevalence of pterygium was evaluated in 3312 participants. A number of villages were selected from the north and south of Iran using multistage cluster sampling. Pterygium was diagnosed by the ophthalmologist using slit-lamp examination.ResultsThe mean age of the study participants was 37.3 ± 21.4 years (2–93 years), and 56.3% (n = 1865) of them were women. The prevalence of pterygium was 13.11% [95%confidence interval (CI):11.75–14.47]. The prevalence of pterygium was 14.99 (95%CI:12.79–17.19) in men and 12.07 (95%CI:10.3–13.84) in women. Pterygium was not seen in children below the age of 5 years. The prevalence of pterygium increased linearly with age; the lowest and highest prevalence of pterygium was observed in the age group 5–20 years (0.19%) and 61–70 years (28.57%). Evaluation of the relationship between pterygium with age, sex, educational level, and place of living using a multiple model showed that age, living in the south of Iran, and low educational level were correlated with pterygium.ConclusionThe prevalence of pterygium was significantly higher in Iranian villages when compared with the results of previous studies. This finding may represent the effect of a rural lifestyle and its risk factors.

No abstract

Purpose: To provide a comprehensive review on different characteristics of abnormal head postures (AHPs) due to different ocular causes, its measurement, and its effect on facial appearance. Methods: In this review article, PubMed, Scopus, and Google Scholar search engines were searched for the scientific articles and books published between 1975 and September 2020 based on the keywords of this article. The selected articles were collected, summarized, classified, evaluated, and finally concluded. Results: AHP can be caused by various ocular or nonocular diseases. The prevalence of ocular causes of AHP was reported to be 18%–25%. 1.1% of patients presenting to ophthalmology clinics has AHP. The first step in evaluating a patient with AHP is a correct differential diagnosis between nonocular and ocular sources by performing comprehensive eye examinations and ruling out other causes of orthopedic and neurological AHP. Ocular AHP occurs for a variety of reasons, the most important of which include nystagmus, superior oblique palsy, and Duane's retraction syndrome. AHP may be an essential clinical sign for an underlying disease, which can only be appropriately treated by the accurate determination of the cause. Long-standing AHP may lead to facial asymmetry and secondary muscular and skeletal changes. Conclusion: In conclusion, a proper differential diagnosis between nonocular and ocular causes, knowledge of the different forms of AHP and their measurement methods, accurate diagnosis of the cause, and proper and timely treatment of ocular AHP can prevent facial asymmetry and secondary muscular and skeletal changes in the patients.

Purpose: To determine the effect of different types of Rigid Gas Permeable (RGP) contact lenses on ocular aberrations in patients with keratoconus. Methods: Eighteen eyes of young patients with mild to moderate keratoconus were selected. General ocular examinations such as refraction, visual acuity, and ocular aberrations were performed. Three types of RGP contact lenses, i.e., Boston, Senso Select and Wohlk, were fitted using the cross over method. Repeated measures analysis of variance and Mauchly's test of sphericity were used to compare the average of residual high order aberrations and visual acuity after fitting each type of lens. Results: Vertical coma was -0.271 ± 0.37 µm before fitting and decreased to 0.081 ± 0.08 µm with Boston, 0.098 ± 0.08 µm with Senso Select and 0.124 ± 0.08 µm with Wohlk contact lens (P-value < 0.0001). The mean RMS (root mean square) for high order aberrations decreased from 0.526 ± 0.43 µm before fitting to 0.256 ± 0.09 µm with Boston, 0.263 ± 0.12 µm with Senso Select, and 0.304 ± 0.10 µm with Wohlk contact lens (P-value= 0.001). The mean RMS for low order aberrations decreased from 1.480 ± 0.78 µm before fitting to 0.703 ± 0.43 µm with Boston, 0.802 ± 0.39 µm with Senso Select, and 0.760 ± 0.45µm with Wohlk (P-value < 0.0001). Conclusion: Despite achieving optimal fit and good visual acuity with these different RGP lenses, in keratoconus patients, their performance is different in reducing ocular aberrations.