Role of Refractive Errors in Inducing Asthenopic Symptoms Among Spectacle Corrected Ammetropes

Abstract

Refractive errors are a major cause of asthenopic symptoms in young age group.Aim and objectives -This study tries to ascertain the prevalence of refractive errors in a cohort of subjects with spectacle corrected ammetropia and to elucidate the relation between the type, severity and subcategories of refractive errors in such a group.Design – Descriptive cross sectional studyMethods – This is a prospective analysis of cases with asthenopia and coexistant significant refractive errors warranting use of spectacles. Best corrected visual acuity of 20/20 was ensured. Retinoscopy readings after complete cycloplegia were noted. Spherical equivalent was calculated from the absolute retinoscopy reading. Ammetropia not fully corrected with spectacles, history of migraine, headache not related to constant near work, symptoms less than three months duration, associated accomodation-convergence anomalies and latent squints were excluded.Results - The study group included thirty five patients. The mean age was 23.48 years; SD 6.97.  There were 15 males and 20 females.  Twenty seven patients had bilateral symptoms (77.14%). Thirty six subjects (58.08%) had a spherical equivalent between 0.25D to 0.75 D. The refractive errors included myopia (n-10), hypermetropia (n-26) and astigmatism (n-26). Near work associated headache was observed in 39 patients (62.86%). 46.15% of the cases with near work related headache had uncorrected astigmatism.Conclusion – Asthenopic symptoms are frequent and significant among spectacle corrected ammetropes. Lower degrees of refractive errors are more symptomatic. Hypermetropia and astigmatism constitute the major causative factors.