How the tophic problems and the rubbing eye behavior may aggravate the presence of keratoconus in trisomy 21

Abstract

PurposeDown syndrome is a congenital anomaly caused by non‐dislocation of chromosome 21. Ocular features in trisomy 21 patients, such as changes in corneal collagen composition as well as thinning predisposing to keratoconus are well appreciated. We present a case of unilateral acute corneal hydrops in a young adult with trisomy 21, and the management to prevent corneal perforation yielding a successful visual outcome.MethodA 20‐year‐old man presented in our emergency department due to sudden visual loss and severe left ocular pain. Visual acuity was 20/200 in the right eye, and finger counting in the left. Anterior segment examination revealed pigmented endothelial cells and endothelial cell count reduced to 2583 CD/mm2 in the right eye, as well as a very large central corneal leukoma and corneal ectasia in the right eye. Corneal topography confirmed the presence of an acute corneal hydrops in the left eye as well as milder keratoconus in the right.ResultsApart from topical steroid drops, oral acetazolamide and timolol drops were used to reduce the intraocular pressure on a decompensated cornea with reduced endothelial cell count. Penetrating keratoplasty was eventually necessary. Due to intolerance and insufficient patient ability to use form‐stable contact lenses, a cross‐linking procedure was performed to stabilize the right eye. Both surgeries lead to best‐corrected acuity of 20/50 OU without a need for additional contact lens correction. Surface issues related to trisomy 21 were addressed using topical lubricants.ConclusionIn the presented case, preexisting keratoconus, worsened by frequent eye rubbing of abnormal collagen composition corneas, permits transmission of mechanical forces to thinner exposed tissue, leading to acute hydrops. The extensive corneal tissue damage that occurred with stromal scarring left necessitates keratoplasty to successfully restore vision. This case highlights the need for preventive ophthalmic examinations in patients of trisomy 21 to rule out the presence of keratoconus. The timely application of lubricants, as well as anti‐histamines and mast cell stabilizers could reduce the eye rubbing behavior that aggravates corneal anomalies in such mentally handicapped individuals. This may reduce progression and eventual need for surgical interventions.