A Combined Procedure of Intrastromal Corneal Rings Explantation and Penetrating Keratoplasty in a Patient With Keratoconus: A Case Report.

Keratoconus is a non-inflammatory and degenerative corneal ectasia that determinate progressive steepening of paracentral cornea with development of irregular astigmatism and visual function deterioration. According to the stage of the pathology, different methods of correction can be used: rigid contact lenses may be used to alter corneal shape and partially correct astigmatism, corneal collagen cross-linking (CXL) and intrastromal corneal ring segment (ICRS) implantation can reinforce corneal stroma to slow disease progression. Late-stage treatment comprehend anterior lamellar keratoplasty or penetrating keratoplasty. We evaluated a 31-year-old patient who was subjected to bilateral ICRS implantation combined with CXL due to keratoconus. This led, after 9 months, to ring extrusion in his left eye, corneal thinning and microperforation into the aqueous chamber with residual irregular astigmatism of 4.50 D. cyl. 10°. The patient underwent ICRS explantation and PKP during the same surgical session. After 15 months of follow-up, the BCVA was 0.2 LogMAR with a residual astigmatism of 6.3 dpt.