Off-Label Application Of Combined Cross-Linking (Cxl) With Transepithelial Photorefractive Keratectomy (Transprk) Octavius Topography Optimised Treatment In Treating Corneal Ectasias

OCTAVIUS is Bausch and Lomb’s proprietary topography optimised treatment, licensed for use with the Teneo Model 2 excimer laser in treating refractive errors in normal corneas. OCTAVIUS uses corneal elevation data to generate a customised ablation profile to both correct refractive errors and regularise corneas with detected elevation abnormalities. Combined cross-linking and topography-guided TransPRK (CXL-Plus) is established as an off-label treatment option for corneal ectasia. The purpose of this study was to determine whether OCTAVIUS could similarly be used off-label to treat corneal ectasias.

This was a retrospective study of three patients with corneal ectasia treated with OCTAVIUS TransPRK and CXL.Two patients with keratoconus and one patient with post-LASIK ectasia received TransPRK with OCTAVIUS combined with CXL in the worse eye.

At baseline, patient one (P1, keratoconus) had Kmax of 55 dioptres (D) and central 2mm inferior-superior (I-S) asymmetry of 6D, patient two (P2, post LASIK ectasia) had Kmax of 48D and asymmetry of 3.8D and patient three (P3, keratoconus) had Kmax of 58D and asymmetry of 16D. Epithelial thickness and corneal maps were obtained with optical coherence tomography (OCT) and the ACE diagnostic platform (Bausch & Lomb) and imported to the Teneo. Correction of the refractive cylinder was prioritised, with OCTAVIUS simulating flattening of the steepest, most elevated areas. TransPRK was followed by full-fluence CXL (5.4J). No mitomycin C (MMC) was used. A bandage lens was placed for a week and antibiotic/steroid drops applied for a month.

At baseline, patient one (P1, keratoconus) had Kmax of 55 dioptres (D), anterior elevation of 18µm and central 2mm inferior-superior (I-S) asymmetry of 6D, patient two (P2, post LASIK ectasia) had Kmax of 48D, anterior elevation of 12µm and I-S asymmetry of 3.8D and patient three (P3, keratoconus) had Kmax of 58D, anterior elevation of 55µm and I-S asymmetry of 16D.

At 3 months, selective flattening of the steepest, highest locations had occurred, together with steepening of adjacent flat areas. Patients had a mean reduction in Kmax, I-S asymmetry and anterior elevation of 3.6D,5D and 13µm. There was a mean reduction in higher order aberration (HOA) of 0.88µm and a mean increase in corrected distance visual acuity (CDVA) of 0.18 logMAR.

The results indicate that TransPRK with OCTAVIUS can reduce topographic irregularity by selectively flattening steep areas and steepening adjacent flat areas. When combined in a CXL-Plus procedure, this improved topography may be ‘locked-in’ to improve both long-term wavefront and CDVA.

This potential improvement in wavefront and CDVA may be affected by corneal remodelling and haze from CXL. This is less of a concern in correcting abnormal topography where CXL is not necessary, for example, in corneal scars and decentred ablations

Corneal complications from simultaneous procedures notwithstanding, OCTAVIUS’s ability to improve irregular topography may make it a crucial tool in the armamentarium of refractive surgeons.