Retinoscopy as a Screening Tool for Keratoconus.

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.

Clinical Profile of Omani Keratoconus Patients: An Experience from a tertiary referral centre in Muscat.

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.

Oman's progress towards reaching "Ultimate Intervention Goals" for the surgery "S" component of SAFE strategy for the elimination of blinding trachoma in 2008.

BACKGROUND: A community based survey for Trachomatous Trichiasis (TT) was conducted in the high (TT >5% in 1997) and meso endemic areas (TT 1% to 5% in 1997) of Oman during 2008-09. METHODS: Investigators examined Omanis 40 age years and older from randomly selected villages. Eyes were examined for TT and vision. The medical history of surgery and advice given for TT surgery were recorded. The TT cases that were unadvised by health staff were defined as un-approached cases. Cluster adjusted prevalence of TT and risk of TT by gender were estimated. RESULT: We examined 4,951 of 5,268 persons in high-endemic areas and 965 of 993 (97.2%) persons in meso-endemic areas. The cluster adjusted prevalence of TT in the high and meso endemic areas were 7.54% (95% Confidence Interval [CI] 6.78-8.30) and 1.69% (95% CI 0.88-2.50) respectively. There were 5 TT patients in high endemic areas and none in meso-endemic areas who were not approached or managed in the past. The prevalence of TT across all ages was less than 1 per 1,000 of the population in all wilayats of Oman. Females had a significantly higher risk of cluster adjusted TT compared to males (Odds Ratio = 1.87 [95% CI 1.85-1.89]). The prevalence of blindness was 0.5% among TT cases in high endemic areas. CONCLUSION: Oman seems to have reached the Ultimate Intervention Goals (UIGs) of the "S" (Surgery) component in 2008 in high and meso-endemic areas. The efforts of existing eye services could be better evaluated if un-approached TT cases are used to calculate the TT prevalence. Oman needs to focus more on females with TT to reach the UIGs.

Assessment of visual gain following cataract surgeries in oman: a hospital-based cohort study.

OBJECTIVES: The post-operative vision is used as benchmark to determine the quality of cataract surgery. However, late presentation and co-morbidities influence the visual gain and they should also be considered while auditing cataract surgeries. The authors present method of analysis of cataract surgeries for older than 30 years of aged patients performed by ophthalmologists in Oman during 2003. METHODS: Ophthalmologists evaluated visual and ocular status of eyes with cataract. Cataract was operated using operative microscope and lens was implanted in the eye. The vision was recorded six weeks after surgery and visual gain was grouped from postoperative vision in relation to the preoperative vision. Presence of co-morbidities like glaucoma, corneal opacities, macular degenerations and others were considered while evaluating visual outcomes. RESULTS: 3,485 eyes operated were included in our study. 3,003 (86.2%) of them were operated by extra-capsular cataract extraction and lens implantation. Following surgery, 960 (27.5%) eyes had vision ³6/18. 1,483 (42.6%) eyes had vision between 6/60 and 6/18. 233 (6.8%) eyes had vision <3/60. Excellent grade of vision gain in relation to preoperative visual status was found in 2,250 (64.6%) eyes, 'good' visual gain was in 422 (12.1%) eyes and 'poor' visual gain was in 335 (9.6%) eyes. Postoperative visual status was significantly associated to the co-morbidities. (p<0.001). Nearly 14% of persons were lost to the follow up. CONCLUSION: In countries like Oman with high prevalence of trachoma, glaucoma and diabetes, the proposed grading of visual gain that accounts for the preoperative vision and the presence of co-morbidity could be better option for auditing the cataract surgery.

Contact Lens Induced Corneal Ulcer Management in a Tertiary Eye Unit in Oman - A descriptive study.

OBJECTIVES: The corneal disease is a priority problem in Oman. We present patients with contact lens (CL) induced severe keratitis, admitted in the corneal unit of Al Nahdha Hospital in Oman. METHODS: The study was conducted in 2005-2006. Ophthalmologists examined the eyes using slit lamp bio-microscope. Visual acuity was noted using Snellen's distance vision chart. Specimens of corneal scraping and CLs were sent for culture and sensitivity tests. Patients with severe keratitis were admitted and treated with medicines. Corneal and visual statuses were noted at the time of discharge from hospital and after six weeks. Numbers, percentages and their 95% confidence intervals were calculated. Pre- and post-treatment vision were compared using a scattergram. RESULTS: The 52 eyes of 15 males and 37 female patients with corneal ulcers were examined. Thirty-two patients were between 20 to 30 years of age. Only 13 (25%) patients had visited an ophthalmologist within 24 hours of developing severe keratitis. Seventeen (33%) had central ulcers and six (11.5%) had ulcer ≥5 mm in size. Pseudomonas was found in 29 (55.8%) of CL and corneal material scraped from the eyes of 15 (28.8%) patients. Vision was <6/60 (legally blind) in 12 (23.1%) eyes before and in five (9.6%) eyes after treatment. Twenty-six (50%) patients were lost to follow up. CONCLUSION: CL related severe keratitis causes visual disabilities. Prevention and proper records are essential. Treatment improves vision and hence facilities for management should be strengthened.

Compliance of spectacle wear and its determinants among schoolchildren of Dhakhiliya region of Oman: A descriptive study.

OBJECTIVE: To determine the degree of compliance of spectacle wear and some of its determinants among school children of Dhakhiliya region of Oman. METHODS: This was a cross-sectional descriptive study of a sample of 663 students who had been prescribed spectacles for constant wear. After one year, experienced field staff conducted a follow-up visit where 571 of these students were examined. Information on age, gender, type and severity of refractive error was collected from the school health records and refractionist's report and analyzed to associate them to the compliance of spectacle wear. RESULTS: The majority (71.6%) of students were using spectacles at the time of follow up. The compliance rate was 65.1% in boys and 78.3% in girls. Agewise, it was 66.7% in 6-7-year-olds, 66.7% in 12-13-year-olds and 79.1% in 16-17-year olds. The rate was 72.5% among students with myopia and 67.9% among those with hypermetropia. The compliance of spectacle wear was significantly higher among students with myopic refractive error of 2.5 D or more compared to those with less than 2.5 D. The difference in the compliance rates among students with hypermetropia of different grades was not significant. CONCLUSIONS: The study identifies the factors of high-risk of non compliance as (a) male gender, (b) younger age, and (c) low myopic refractory error. The eye health care program of Oman should focus on these high risk groups to further improve the compliance for visual aids.