Topography-Guided Corneal Collagen Crosslinking Combined With Transepithelial (No-Touch) Prk In Moderate Keratoconus

To evaluate the clinical outcomes of combined topography-guided corneal collagen cross-linking (CXL) with transepithelial (no-touch) photorefractive keratectomy (PRK) in patients with moderate keratoconus.

Prospective interventional study conducted at a single university-affiliated ophthalmology clinic.

30 eyes of 15 patients diagnosed with moderate-stage keratoconus were included in the study. The mean age was 28.2 ± 1.7 years.

The diagnosis of keratoconus was established based on clinical findings, measurements obtained using a rotating Scheimpflug camera of corneal thickness, keratometry, and visual acuity assessment. Patients were divided into two groups: 

• Group 1 (control) – early-stage (15 eyes - 1 eye of each patient)

• Group 2 (moderate stage): 9 eyes (60%) with stage 2 and 6 eyes (40%) with stage 3. Postoperative follow-up examinations were performed at 1 month, 3 months, 6 months, and at subsequent visits.

Crosslinking was performed in 15 moderate-stage eyes of 15 patients (1 eye of each patient).

Combined PRK No-Touch treatment was applied in 4 eyes with stage 2 and 1 eye with stage 3 keratoconus. Visual acuity before treatment was 0.16±0.04; after treatment 0.21±0.04 at 1 month,0.23±0.05 at 3 months,0.24 ± 0.05 at 6 months. 

No statistically significant difference was detected between the first and last months of follow-up in visual acuity (p >0.05),and pre-treatment corneal curvature values (K1:47.88±1.37 and K2:52.71±1.33 D) and 6 months after treatment (K1:47.78±1.37 and K2:51.37± 1.44 D). Before treatment, central corneal thickness showed a statistically significant difference between control stage (482±12 µm) and stage 2 (433±17 µm) (p< 0.05).After treatment, values were 423±16 µm at 1;432±14 µm at 3,and 441±16 µm at 6 months.

In short-term follow-up, crosslinking treatment was observed to halt disease progression in moderate-stage keratoconus eyes. The follow-up period of our study regarding the combined approach was less than 72 months. Patients were followed biannually. Our literature review results indicate that refractive surgery procedures show positive outcomes in terms of visual acuity and aberrations.

Ultimately, in keratoconus treatment involving refractive surgery, long-term investigations regarding corneal biomechanics and randomized studies are needed; with individualized application of these combined treatments, more promising results are expected.