Purpose: To investigate the validity and reliability of retinoscopy in screening for keratoconus using the rotating Pentacam Scheimpflug camera as the gold standard comparison. Methods: Patients between the ages of 10 and 30 years who were referred to the outpatient clinic with keratoconus, keratoconus suspect, reduced vision, eye discomfort or frequent change of glasses, or for refraction or refractive surgery, were screened by two independent and masked retinoscopists for the presence of scissoring reflex. Patients then underwent vision testing, slit lamp examination, and Pentacam imaging. A diagnosis of keratoconus by Pentacam was made if the final D index in the Belin and Ambrósio Display was ≥2.69. The results of retinoscopy and Pentacam examinations were compared to assess the validity and reliability of the test. Results: A total of 123 patients (67 male patients and 45 female patients) with a mean age of 21 years ±5.6 (range 10–30 years) comprising 245 eyes were included. There were 87 eyes with keratoconus, and using the Amsler–Krumeich classification, 67.8%, 26.4%, 2.3%, and 3.4% of the eyes had stage I, II, III, and IV, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of retinoscopy were 97.7%, 79.9%, 70.8%, and 98.4%, respectively. The area under the curve was 0.88 (95% confidence interval, 0.83–0.92). There was excellent agreement between the 2 retinoscopists (Cohen's kappa value 0.84). Conclusions: Retinoscopy appears to be a very sensitive and reliable test for detecting keratoconus including early disease. Such a test may be implemented in population-based screening programs for keratoconus.

OBJECTIVE:To determine the demographics and associated clinical features of Omani keratoconus patients presenting to the Ministry of Defence Hospital (MODH) in Muscat.METHODS:This is a retrospective, descriptive study whereby the electronic medical records of all Omani keratoconus patients presenting to the MODH between January 2011 and December 2015 were reviewed. Demographic details, corrected distance visual acuity, refraction, corneal topography, pachymetry, and treatment received were all documented.RESULTS:There were 458 new keratoconus patients (257 males, 201 females) comprising a total of 893 eyes with a mean age of 20 years ± 5.6 (standard deviation) (range 6–46 years). On their first visit, 35% of eyes had spectacle-corrected distance visual acuity <0.5 logarithm of the minimum angle of resolution (LogMAR), 38% had central corneal thickness <450 um, and 25% had a mean keratometry more than 53 Diopter (D). According to the Amsler-Krumeich classification, 37%, 30%, 18%, and 16% of eyes classified into stages I, II, III, and IV, respectively. The severity of keratoconus did not correlate with the age of patients (rs = −0.13, P < 0.05). Over the 5-year period of the study, 502 eyes were fitted with rigid gas permeable lenses with 91% achieving the vision of 0.1 LogMAR or better, 22% of eyes underwent collagen cross linking, 3% underwent intracorneal ring segments implantation, and 4% underwent corneal grafting.CONCLUSION:A significant proportion of Omani keratoconus patients seen in the MODH showed advanced disease on their first visit. There was no correlation between severity and age suggesting that keratoconus can progress quickly in our pediatric group. Population-based studies are an important next step. Meanwhile, early detection and timely interventions to limit the burden of the disease are crucial.

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