Rate Of Post-Lasik And Post-Prk Keratoectasia In An Eye Specialist Hospital In Riyadh, Saudi Arabia; A Retrospective Study.

To determine the rate and clinical characteristics of post refractive ectasia among patient underwent laser in situ keratomileusis (LASIK) vs. photorefractive keratectomy (PRK).

 At a single eye institute, King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia

patients were diagnosed with post-refractive ectasia post LASIK and post PRK from the year 2014 to 2020 were reviewed retrospectively.Evaluation of age, gender, spherical equivalent refraction, intraocular pressure (IOP), pachymetry, topographic data, type of refractive surgery, presence of flap, and time to the onset of ectasia. Data were managed and coded and the demographic outcomes presented as percentages and frequencies for categorical outcomes and in means and standard deviation (SD) for Continuous variables. A (P-value) less than 0.05 will be considered statistically significant.

A total of 704 charts of ectasia were reviewed; of which 127 eyes were identified as post LASIK/PRK ectasia. Ectasia occurred after LASIK in 114 cases while 13 cases were after PRK (p-value >0.0001). Fifty-five ectasia cases were found in patients who underwent LASIK or PRK before or at the age of 30 years.  LASIK group presented with a higher average k max of 54.04 compared to 51.58 in the PRK group. Mean central corneal thickness was 399 µm (ranges from 295-498) and 430 µm (ranges from 225-536) after LASIK and PRK, respectively (P-value 0.004).

Post-PRK ectasia is significantly lower than post-PRK with a lenient clinical outcome compared to LASIK patients. Young age and male gender cindered a risk factor.