This paper describes the 10-year outcomes of patients with progressive keratoconus who were treated with topography-guided partial-refraction PRK combined with corneal cross-linking (CXL), known as the Athens protocol.
Study design
Researchers retrospectively examined records from 144 adults with progressive keratoconus and corneal thickness of at least 400 microns. Patients were excluded if they had underlying systemic disease, previous eye surgery or corneal scarring, chemical injury or delayed epithelial healing, a history of herpetic keratitis, severe dry eye, current infection, pregnancy or were breastfeeding. The authors evaluated safety and efficacy data from 1 and 10 years after surgery.
Outcomes
Overall, UDVA and CDVA increased significantly at 1 year and remained stable at 10 years, with UDVA showing a trend toward continued improvement at 10 years. About 45% and 38% of patients showed an increase of at least 2 lines of UDVA and CDVA, respectively. No eyes lost more than 1 line of distance vision.
Over the 10-year follow-up period, 136 eyes showed no progression, 3 eyes showed minimal progression with no thinning and 4 eyes showed a progressive hyperopic shift or overcorrection. There was slight corneal thinning from the initial excimer ablation but no additional corneal thinning over time.
Limitations
This was a retrospective study completed by a single surgeon. Patient age and severity of keratoconus were not reported, and these factors may impact the potential for clinical improvement. The cause of the vision loss was not discussed, and the authors did not discuss possible complications.
Clinical significance
Combined same-day topography guided PRK, phototherapeutic keratectomy and CXL provide a safe long-term alternative to CXL alone in treating both the progressive ectasia. The use of the Athens protocol may improve visual function in patients with contact lens intolerance and prevent the need for corneal transplant.