ABSTRACT
PURPOSE: To establish a grading system that helps identify high-risk individuals who may experience corneal ectasia after LASIK. DESIGN: Retrospective, comparative, interventional case series. PARTICIPANTS: One hundred forty-eight consecutive patients (148 eyes) were included in this study. Thirty-seven patients who underwent LASIK at other refractive centers experienced corneal ectasia in 1 eye after LASIK. One hundred eleven eyes of 111 patients who underwent successful LASIK during the same period were age and gender matched and served as controls. INTERVENTION: All patients underwent preoperative and postoperative topographic analysis of the cornea. The follow-up period in both groups of patients ranged from 2 to 5 years, with a mean follow-up of 3.6 years. All patients underwent LASIK for myopia (spherical equivalent, -4.00 to -8.00 diopters). MAIN OUTCOME MEASURES: Corneal keratometry, oblique cylinder, pachymetry, posterior surface elevation, difference between the inferior and superior corneal diopteric power, and posterior best sphere fit (BSF) over anterior BSF were given a grade of 1 to 3 each. An ectasia grading system was established, and the cumulative risk score was assessed. RESULTS: Patients who had a grade of 7 or less showed no evidence of corneal ectasia, whereas 16 (59%) of 27 patients who had a grade of 8 to 12 had corneal ectasia. Twenty-one (100%) of 21 patients with a grade of more than 12 had corneal ectasia after LASIK (P<0.0001). CONCLUSIONS: A risk score may help in the prediction of patients who are at risk of experiencing corneal ectasia after LASIK. A prospective clinical study is needed to assess the validity of these risk factors.
Subject(s)
Cornea/pathology , Corneal Diseases/etiology , Keratomileusis, Laser In Situ/adverse effects , Postoperative Complications , Corneal Diseases/classification , Corneal Topography , Dilatation, Pathologic/classification , Dilatation, Pathologic/etiology , Humans , Retrospective Studies , Risk Factors , Visual AcuityABSTRACT
PURPOSE: To determine the major causes of eye diseases leading to visual loss and blindness among children attending a school for the blind in Riyadh, Saudi Arabia. METHODS: A total of 217 school children with visual disabilities attending a school for the blind in Riyadh were included. All children were brought to The Eye Center, Riyadh, and had complete ophthalmologic examinations including visual acuity testing, biomicroscopy, ophthalmoscopy, tonometry and laboratory investigations. In addition, some patients were subjected to electroretinography (ERG), electrooculography (EOG), measurement of visual evoked potentials (VEP), and laboratory work-up for congenital disorders. RESULTS: There were 117 male students with an age range of 6-19 years and a mean age of 16 years. In addition, there were 100 females with an age range of 6-18 years and a mean age of 12 years. Of the 217 children, 194 (89%) were blind from genetically determined diseases or congenital disorders and 23 (11%) were blind from acquired diseases. The major causes of bilateral blindness in children were retinal degeneration, congenital glaucoma, and optic atrophy. The most common acquired causes of childhood blindness were infections and trauma. CONCLUSION: The etiological pattern of childhood blindness in Saudi Arabia has changed from microbial keratitis to genetically determined diseases of the retina and optic nerve. Currently, the most common causes of childhood blindness are genetically determined causes. Consanguineous marriages may account for the autosomal recessive disorders. Public education programs should include information for the prevention of trauma and genetic counseling. Eye examinations for preschool and school children are mandatory for the prevention and cure of blinding disorders.
Subject(s)
Blindness/epidemiology , Schools/statistics & numerical data , Adolescent , Adult , Age Distribution , Age of Onset , Blindness/diagnosis , Blindness/etiology , Child , Electrooculography , Electroretinography , Female , Fluorescein Angiography , Fundus Oculi , Humans , Incidence , Male , Optic Nerve Diseases/complications , Retinal Diseases/complications , Risk Factors , Saudi Arabia/epidemiology , Sex Distribution , Visual AcuityABSTRACT
PURPOSE: To assess the corneal tissue absorption of azithromycin in desiccated and normal eyes of rabbits. METHODS: A total of 25 New Zealand Albino rabbits weighing 2-3 kg each were included. One eye of each rabbit was desiccated. The other eye was left as control. Azithromycin 1.5% topical eyedrops were instilled in both eyes. Five rabbits were sacrificed at each of the following time points: 30 min, 3 hr, 6 hr, and 12 hr. Corneal tissues specimens were subjected to high-performance liquid chromatography mass spectrometry. A paired t test was used to evaluate the statistical difference in corneal tissue absorptions of azithromycin at each time point. RESULTS: The mean corneal tissue levels of azithromycin in dry eyes were 66.3 microg/ml, 92.6 microg/ml, 117.5 microg/ml, and 179.9 microg/ml, and the mean corneal tissue levels of azithromycin in normal eyes were 42.0 microg/ml, 43.4 microg/ml, 43.3 microg/ml, and 80.0 microg/ml at 30 min, 3 hr, 6 hr, and 12 hr respectively. Both groups showed increase in corneal tissue absorption overtime (p < 0.0001). Significantly higher levels of azithromycin were noted in dry eyes at each time point except at the 30-min time point. CONCLUSIONS: This study demonstrated that corneas exposed to desiccation showed statistically significant increase in azithromycin level compared to normal eyes.
