New surgical approaches to the management of keratoconus and post-LASIK ectasia

The objective of this study is to describe the authors' results with intrastromal corneal ring segments (Intacs) and a new variation of lamellar keratoplasty, termed intralamellar keratoplasty (ILK), for the treatment of keratoconus (KCN) and post-laser-assisted in situ keratomileusis (LASIK) ectasia.

A retrospective review of contact lens-intolerant KCN and post-LASIK ectasia cases that had surgery with either Intacs or ILK was performed. The end points were mean uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical equivalent (SE), manifest and topographic cylinder, and restoration of contact lens tolerance.

Intacs were implanted in 13 keratoconic or post-LASIK ectasia eyes of 11 subjects. Mean UCVA improved by 1 line (range, -5 to +8); mean BCVA improved by 1 line (range, -1 to +4). Mean manifest SE was essentially unchanged. Mean manifest cylinder was reduced by 2.77 diopters (D), mean topographic cylinder was decreased by 2.29 D, and 12 of 13 eyes were successfully able to wear contact lenses. Four eyes with advanced KCN underwent ILK. Mean UCVA improved by 1 line (range, 0 to 12); mean BCVA improved by 4 lines (range, 1 to 10). Mean SE was lessened by 1.13 D. Mean manifest cylinder was reduced by 1.82 D and mean topographic cylinder by 1.14 D. Half the subjects were successfully fit with contact lenses.

Both Intacs and ILK improved mean UCVA, BCVA, and manifest and topographic astigmatism. In most cases, good contact lens fit was achieved with visual rehabilitation to levels that obviated penetrating keratoplasty.