Delhi Journal of Ophthalmology

High Myopia: A Hospital-Based Study of The Clinical Profile and Visual Impairment

Rejitha Chinnu Varghese, Uma Kulkarni
Department of Opthalmology, Yenepoya Medical College, Mangalore, India

Editor-in-Chief, Delhi Journal of Ophthalmology, Dr R.P.Centre, AIIMS.

Corresponding Author:

Uma Kulkarni
Professor, Ophthalmology
Yenepoya Medical College, Mangalore 
Mailing id: “Lakshmi Keshava, 4th cross, Shivabagh, Mangalore India.

Received: 27-JAN-2020 Accepted: 20-MAY-2020 Published Online: 20-DEC-2020

Introduction:  High axial myopia is an increasingly common refractive error leading to retinal degeneration and visual impairment.

Objective: To study the clinical profile and visual impairment in high myopia presenting to a teaching hospital. 

Material and methods: This study was a descriptive observational study of high myopia and included unilateral, and bilateral cases of all age groups. The study was conducted after ethical clearance and a written informed consent. Clinical history, best corrected visual acuity, ocular fundus findings, axial length and refraction were determined. The results were analyzed using descriptive statistics, and chi square test. 

Results: The mean age in high myopia was 36.28 ± 15.46 years and was significantly higher in males than females (p=0.006828). There was no significant difference in the age and gender distribution of unilateral (10.66%) and bilateral high myopia (89.33%). 76.05% of the eyes had SE between 6-12 D of which, 9 eyes were corrected to <6D of myopia following cataract surgery. The mean SE was -9.57 ± 4.4D; the mean axial length was 27.39 ± 1.62 mm and the distribution of SE and axial length in males and females was statistically comparable The most common fundus finding was temporal or annular crescent (73.94%) followed by tessellated fundus (41.54%). Severe visual impairment was seen in 14.78% and blindness was seen in 14.08% of the eyes and the distribution did not increase with increasing age (p=0.1350), but were significantly more in males than females (p=0.0110) and in eyes with myopic maculopathy than those without (p <0.00001). The most common cause of blindness was myopic maculopathy (25.35%) comprising chorioretinal atrophy at the macula (12.69%), posterior staphyloma (11.79%) and choroidal neovascular membrane (6.33%) and was significantly more in eyes with longer axial lengths (p <0.00001). Other causes of visual impairment included posterior sub-capsular cataract (19.01%), glaucomatous cupping (11.7%), optic disc pallor (2.8%), retinitis pigmentosa (1.4%). Lattice and other peripheral retinal degenerations were seen in 15.48% cases.

Conclusion: High myopia causes significant visual impairment affecting 28.87% of the eyes. The most common cause being myopic maculopathy. The visual impairment tends to be more with longer axial lengths, higher SE, and in males more than females. 

Keywords :High Myopia, Blindness, Visual Impairment, Myopic Maculopathy, Posterior Staphyloma