Adult onset unilateral high myopia in a female patient: A case report.

purposeWe report a rare case of unilateral progressive adult-onset myopia in a healthy 27 year old female patient. OBSERVATIONS: The patient presented to our clinic in 2014 with gradual decrease in vision in the right eye since one and a half years. Her uncorrected visual acuity (UCVA) in the right eye was 0.05, improving to 1.0 with -2.25 Diopter Sphere (DS). The left eye uncorrected visual acuity was 1.0 partial improving to 1.0 with -0.50 Diopter Cylinder (DC) at 10°. The myopia in her right eye continued to increase steadily until her last detailed ophthalmic examination in November 2018, at the age of 31 years, showed a refractive error of -6.75 Diopter Sphere with -0.5 Diopter Cylinder at 170°. Ocular biometry readings showed an axial length (AL) of 25.79mm in the right eye compared to 25.05mm in 2015. The ocular examination of both eyes including clinical examination of anterior and posterior segment, corneal topography, lens densitometry, ultrasound B scan all were within normal limits. Over the last two years she has gradually developed moderate constant esotropia in the right eye, currently +30 Prism Diopters. A short visit to the clinic in December 2019, showed a refraction of -6.75DS with -0.5DC at 170° in the right eye and -0.50DC at 10° in the left eye. CONCLUSIONS AND IMPORTANCE: The abrupt onset of myopia in one eye in a healthy individual in this case, the degree of myopia, the nature and rate of progression, absence of risk factors, and otherwise normal ocular examination except for progressive increase in axial length is unusual. Our case brings us to conjecture the role of powerful local factors in the intrinsic regulation of eyeball growth going askew. We believe more and more reporting of myopia cases deviating from natural history and their study might provide clues in a new direction about myopia pathogenesis and our understanding and tackling of one of the oldest eye disease with an ever increasing prevalence.