Battling The Bulge - Tackling Extreme Corneal Ectasia

To describe a unique approach of "Annular Tuck in lamellar keratoplasty" performed for advanced bilateral Terriens Marginal Corneal degeneration 

A tertiary care hospital in South Asia 

A 34 year old lady hailing from the Middle East presented with gradually progressing diminution of vision in both eyes. A detailed examination including slit lamp evaluation, refraction and corneal tomography revealed severe corneal ectasia with circumferential thinning in the periphery suggestive of advanced Terriens marginal corneal degeneration. Amongst the options for visual rehabilitation, she had very poor improvement with spectacles and was unable to tolerate contact lenses. Surgical options like a full thickess or lamellar keraroplasty would necessitate a very large graft with increased risk of rejection and infection. We performed a unique modification of a lamellar keratoplasty aimed at reducing the central corneal curvature and providing tectonic support while improving vision called a "Annular tuck in lamellar keratoplasty". The host bed was prepared by performing a careful ring shaped peripheral lamellar dissection. The donor was then prepared in a doughnut shaped partial thickness corneal scleral graft with the central 8 mm trephined out. The ring shaped graft was then sutured to the host with two rounds of interrupted sutures on the corneal and scleral side. Serial follow ups with anterior segment OCT and tomography showed good appostion and reduction of the corneal curvature with significant improvement of vision. Sutures were removed and glasses were prescribed at the end of 6 months follow up. 

A Annular tuck in lamellar keratoplasty is a viable option to tackle extreme corneal ectasias like advanced Terriens marginal corneal degeneration in contrast to a traditional large diameter full or partial thickness keratoplasty. Good tectonic support and adequate reduction of the corneal curvature are achieved in turn improving visual acuity. In this report, we wish to demonstrate this technique as a viable alternative in Terriens marginal degeneration  hence overcoming the complications of traditional large diameter transplants.