Therapeutic Topography-Guided Photorefractive Keratectomy (Tg-Prk) Combined With Corneal Collagen Crosslinking (Cxl) In Keratoconus Patients

Keratoconus is a progressive ectatic disorder of the cornea which often presents with fluctuating refraction and high irregular astigmatism and traditionally has been a contraindication for traditional refractive laser treatments.  Topography-guided photorefractive keratectomy (Tg-PRK) is a customized laser ablation, enabling specific targeting of corneal irregularity which can help regularise the cornea resulting in improved corrected distance visual acuity (CDVA) and uncorrected distance visual acuity (UDVA).

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Retrospective consecutive series of 54 keratoconic eyes undergoing TG-PRK followed by collogen crosslinking (CXL) Schwind Amaris 1050. Images were captured with the Schwind Sirius and CXL was perfomed as per the Athens protocol.  Mitomycin  0.02% was used in all cases. Preoperative and post-operative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction (MR) and topographic cylinder were analyzed. All Cases with sufficient data at 24 months follow-up were included.

54 patients had sufficient data at 24 months for analysis as per our methodology. 50% of patients (27/54) had a UDVA ≥20/40 . 42% (22/54) CDVA improved ≥ 1 line. 26% (14/54) CDVA improved ≥ 2 lines. 13.2% (7/54) lost ≥2 lines. Mean astigmatism reduced from 3.14±1.56D to 2.18±1.74D (p<0.0001). Mean spherical equivalent reduced from -2.51±3.48D to -0.69±2.24D (p<0.0001).

TG-PRK CXL shows efficacy and safety for eyes with keratoconus, with half of patients achieving 20/40 UDVA or better. 42% had improved CDVA with more than a quarter improving 2 or more lines providing an alternative to contact lens intolerant keratoconus patients.