Normal range values of ocular axial length in adult Sudanese population

Abstract

Background: The axial length is one of the essential ocular biometric parameters which is to be done prior to any cataract surgery based on ultrasound. These ocular axial length (OAL) values can be influenced by sex, age, race, ethnicity, genetics, and refractive errors. Objectives: The aim of this study is to determine the normal ranges values of OAL in adult Sudanese population and to define the effects of age, gender, and tribal ethnicity on axial length. Materials and Methods: This is descriptive multi-center hospital-based study, carried out over a period of 6 months from January 2015 to June 2015. The study takes place in five study areas: Three in Khartoum and two in Omdorman. These centers are Khartoum Eye Hospital, Makkah Eye Complex, Alwalidain Eye Hospital, and Omdurman Military Hospital and Sudan Eye Center. The study population was recruited from patients presenting to the mentioned five Hospitals Biometric Departments or volunteers who accepted to be enrolled in the study. One thousand Sudanese adults participants (n = 1000), 507 female and 493 male, with ages ranging from 18 to 105 years were included. Patients with vitreoretinal diseases, intraocular surgery, recent trauma and staphyloma were excluded. All participants underwent systematic OAL measurements by A-scan ultrasonography. Effect of age, gender, and tribal ethnicity on OAL was analyzed. Results: The study showed that the average axial length was 23.09 mm ranging from 18.13 mm to 29.09 mm. It was longer in males (average 23.29), ranging from 20.31 mm to 28.48 mm and shorter in females (average 22.81), ranging from 18.31 mm to 29.09 mm. In the four main Sudanese tribes, the Nubian group had the longest axial length (23.23 mm), followed by the African group (23.15 mm), and then the Arab group (23.09 mm). Bejja group had the shortest axial length (22.85 mm). Conclusion: OAL in Sudanese adults was within the international standard but with a wider range (18.13–29.09 mm). Males' OAL was longer than the OAL of females. No significant age OAL variations, but the tribal ethnicity factor was clear, so tribal ethnicity had a major influence on Sudanese OAL.