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Retinal nerve fibre layer thickness in a general population in Iran
Author(s) -
Hashemi Hassan,
Khabazkhoob Mehdi,
Nabovati Payam,
Yekta Abbasali,
Emamian Mohammad Hassan,
Fotouhi Akbar
Publication year - 2017
Publication title -
clinical and experimental ophthalmology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.3
H-Index - 74
eISSN - 1442-9071
pISSN - 1442-6404
DOI - 10.1111/ceo.12849
Subject(s) - medicine , ophthalmology , confidence interval , retinal , dioptre , visual acuity , ophthalmoscopy , population , fundus (uterus) , glaucoma , refractive error , optometry , environmental health
Abstract Background To determine retinal nerve fibre layer (RNFL) thickness distribution and its related factors in a general population of 45 to 69 year olds in Iran. Design Population‐based cross‐sectional study. Participants Of the 5190 participants of phase one of Shahroud Eye Cohort Study, 4737 participated in Phase two (participation rate = 91.3%). Methods All study participants underwent visual acuity measurement, refraction tests, slit lamp examination and ophthalmoscopic fundus exam. Tests also included imaging with Cirrus HD‐OCT 4000 and its RNFL thickness data were used in this study. Main Outcome Measures The overall RNFL thickness and the average RNFL thickness in different quadrants. Results Mean RNFL thickness in the superior, inferior, nasal and temporal quadrants were 92.47 µm [95% confidence interval (CI): 92.14–92.80], 111.22 µm (95% CI: 110.7–111.73), 118.93 µm (95% CI: 118.31–119.55), 74.83 µm (95% CI: 74.07–75.59) and 65.48 µm (95% CI: 65.06–65.90). Multiple linear regression models indicated that RNFL thickness in all quadrants decreased with ageing, was lower in females (coefficient:–0.87 and P = 0.015), decreased by 1.42 µm ( P < 0.001) for each millimetre increase in axial length and decreased by 0.41 µm ( P = 0.041) for each diopter decrease in spherical equivalent refraction of myopia. Conclusion RNFL thickness in the 45 to 69‐year‐old Iranian population is lower compared to other studies. This difference should be noted in making disease diagnoses, particularly glaucoma. Also, there is a significant relationship between ageing and RNFL thinning in all quadrants. Longer axial length, myopia and male gender are associated with reduced RNFL thickness.