Bilateral manifestations of Terrien’s marginal degeneration: a case report

A 35-year-old male patient attended our Outpatient Department with a complaint of diminution of vision in the left eye. He had a history of pterygium surgery in the left eye 20 days ago elsewhere. There was no improvement in visual acuity by best correction. Slit lamp examination showed bilateral peripheral corneal thinning with neovascularization and central macular grade corneal opacities in the left eye. Corneal topography showed ectatic areas on the anterior and posterior elevation maps and areas of high-risk corneal thinning on pachymetry in the left eye, high maximum keratometry values in both eyes despite normal corneal pachymetry in the right eye indicating progression of the disease in the right eye as well. Based on slit lamp examination, results of corneal topography, anterior segment optical coherence tomography, and lipid profile we diagnosed him as a case of bilateral Terrien’s marginal degeneration (TMD) involving the left eye more than the right eye. The patient was otherwise asymptomatic and was started on lubricants in both eyes with close follow up. We found a rare presentation of an early asymmetrical bilateral TMD associated with history of pterygium surgery. Corneal topography along with slit lamp examination and increased lipid profile levels helped in diagnosing the case as TMD while ruling out other close differentials of the disease like pellucid marginal degeneration and keratoconus.