Prevalence of keratoconus in refractive surgery practice population in North Macedonia.

PURPOSE: To determine the prevalence of keratoconus (KC) in relation to ethnicity in a group of people who consulted an ophthalmological care institution seeking for refractive surgery in N. Macedonia. METHODS: This was a cross-sectional, interventional retrospective study. Chart reviews were performed for all new patients attending between January 2016 and January 2020 at the Sistina Ophthalmology Hospital in Skopje. All patients were screened; KC diagnosis and classification were based on the corneal topography. Ethnicity and gender classifications were according to patients' self-opinions. RESULTS: A total of 2812 patients charts reviewed. The mean age was 31.71 years (SD ± 9.73), and 1209 (43%) were male. A total of 2050 (72.9%) declared themselves as Macedonians, 649 (23.1%) Albanians, 76 (2.7%) Turks and 37 (1.3%) in other ethnicities. Differences in age between the ethnic groups were statistically significant (x2 = 90.225, p < 0.001). KC was diagnosed in 343 patients (12.2%), while 9 (0.7%) were KC suspects and 6(0.21%) presented pellucid marginal degeneration. KC was more frequent in males (n = 246, 71.7% of total) and skewed toward younger patients. Increasing patients' age decreased the odds of KC diagnosis by 3.7% (95% CI 1.8%-4.4%) per annum. Males were four times more likely to be diagnosed with KC (AOR = 4.01; 95% CI 3.12-5.16). In comparison with Macedonian patients, Turks were more likely to be diagnosed with KC (AOR = 4.09; 95% CI 2.47-6.78). There was no difference between Macedonians and Albanians (p = 0.08). CONCLUSION: The prevalence of KC at a refractive surgery practice in N. Macedonia is much higher compared with general population (6.8/100,000) and similar to the prevalence in Middle East Asia. Nationwide screening programs are needed to diagnose the disease earlier.

First Experiences with Implantation of Phakic Lenses in Correction of Myopia in R. N. Macedonia.

Objective: Analysis of visual acuity parameters in patients with moderate to high myopia and myopic astigmatism 1 year after treatment with phakic intraocular lenses. Material and methods: This was a retrospective study on 35 patients (52 eyes) with moderate to high myopia who were implanted with the Visian V4c phakic implantable Collamer lens (Staar Surgical, Nidau, Switzerland). Examined parameters were: uncorrected distance visual acuity (UDVA) and best corrected visual acuity (CDVA), manifest and cycloplegic refraction, intraocular pressure, and endothelial cell count. The investigated parameters were measured preoperatively, 1, 3, 6 and 12 months postoperatively. Results: In 17 patients, phakic lenses were implanted binocularly and in 18 patients monocularly. Preoperatively 34.62% of patients had CDVA from 0.9 to 1.0. One year after the surgery 48.08% of patients had UDVA from 0.9 to 1.0. Preoperatively 80.77% of patients had diopter range from -6.00 Dsph to -10.00 Dsph. At 1 year postoperatively 78.85% of patients were within 0.00 Dsph to -1.00 Dsph. Preoperatively, in patients with astigmatism -4 Dcyl to -2 Dcyl dominated, as opposed to significant improvement postoperatively when 94.23% had astigmatism ranging from -1.0 Dcyl to 0 Dcyl. Conclusion: The implantation of phakic lenses demonstrated a successful postoperative outcome in the treatment of myopia and myopic astigmatism. Visual acuity and refraction show a gradual and significant improvement in visual function parameters within 1 year of lens implantation.