Diagnostic and therapeutic challenges.
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Anti-Infective Agents↗
Biomedical subjects
Clement K Chan
Publications and source records attributed to Clement K Chan.
Ocular features of west nile virus infection in North America: a study of 14 eyes.
PURPOSE: To present a case series of ocular findings of West Nile virus infection (WNVI) in North America. DESIGN: Retrospective, noncomparative, observational case series. PARTICIPANTS: All patients were referred to the authors for WNVI with ocular involvement between the years 2002 and 2005. METHODS: Chart review was performed on all participants. All participants underwent complete ophthalmic evaluation during each examination, including best-corrected Snellen visual acuity measurement, tonometry, slit-lamp biomicroscopy of the anterior and posterior segments, and dilated fundus examination with indirect ophthalmoscopy. Fundus photography and fluorescein angiography were also performed on all eyes. Relevant ocular findings associated with WNVI were recorded and tabulated. MAIN OUTCOME MEASURES: The authors studied the characteristics, frequency, and locations of ocular lesions found in participants' eyes. RESULTS: There were 14 eyes (7 patients) with ocular West Nile virus lesions from 2002 to 2005. Average patient age was 58.4 years (range, 32-85 years). Ocular findings in descending order of frequency included multifocal chorioretinal target lesions in 12 eyes (85.7%), retinal hemorrhages in 7 eyes (50.0%), vitritis in 6 eyes (42.9%), chorioretinal linear streaks in 4 eyes (28.6%), perivascular sheathing and vasculitis in 4 eyes (28.6%), narrowed retinal vessels in 4 eyes (28.6%), disc edema in 4 eyes (28.6%), optic atrophy in 2 eyes (14.3%), vascular occlusion in 2 eyes (14.3%), and VIth nerve palsy in 1 eye (7.1%). Peripheral fundus lesions were found in all 14 eyes (100%), whereas posterior fundus lesions were found in 8 eyes (57.1%). Five patients (71.4%) were diabetic. Diabetic retinopathy was present in 7 eyes (70%). CONCLUSIONS: Multifocal choroiditis is the most common ocular manifestation associated with WNVI, with a typically benign clinical course. Less frequent ocular lesions, including optic neuritis and occlusive vasculitis, frequently induce persistent and likely permanent visual deficit. Diabetic patients and those older than 50 years of age are more vulnerable to the more severe features of WNVI, including more serious ocular lesions.
Adult↗
Full-thickness macular hole after LASIK for the correction of myopia.
PURPOSE: To describe 19 patients (20 eyes) who developed a macular hole (MH) after undergoing bilateral LASIK for the correction of myopia. DESIGN: Noncomparative, interventional, retrospective, multicenter case series. PARTICIPANTS: Nineteen patients (20 eyes) who developed an MH after bilateral LASIK for the correction of myopia at 10 institutions in Venezuela, Colombia, Puerto Rico, Spain, and the United States. METHODS: Chart review. MAIN OUTCOME MEASURE: Macular hole development. RESULTS: The MH formed between 1 to 83 months after LASIK (mean, 12.1). In 60% of cases, the MH developed < or =6 months after LASIK, and in 30% of cases it developed > or =1 year after LASIK. Eighteen of 19 (94.7%) patients were female. Mean age was 46 years (range, 25-65). All eyes were myopic (range, -0.50 to -19.75 diopters [mean, -8.9]). Posterior vitreous detachment was not present before and was documented after LASIK in 55% of eyes. A vitrectomy closed the MH on the 14 eyes that underwent surgical management, with an improvement of final best-corrected visual acuity in 13 of 14 (92.8%) patients. Our 20 eyes with a full-thickness MH after LASIK reflect an incidence of approximately 0.02% (20/83938). CONCLUSION: An MH may infrequently develop after LASIK for the correction of myopia. Our study shows that vitreoretinal surgery can be successful in restoring vision for most myopic eyes with an MH after LASIK. Vitreoretinal interface changes may play a role in MH formation after LASIK for the correction of myopia.
Adult↗
Characteristics of sixty myopic eyes with pre-laser in situ keratomileusis retinal examination and post-laser in situ keratomileusis retinal lesions.
PURPOSE: A survey of eyes with pre-laser in situ keratomileusis (LASIK) retinal examinations and characteristics of post-LASIK retinal breaks and retinal detachments (RDs). METHODS: A survey of worldwide vitreoretinal surgeons (424 physicians). Surveyed information included demographics, best-corrected visual acuity, degree of myopia, pre- and post-LASIK retinal findings, follow-up time, and treatment outcome. RESULTS: Sixty eyes with pre-LASIK retinal examinations developed post-LASIK retinal breaks and RDs. There was an average of 2.3 breaks per eye, yielding a total of 140 breaks in the 60 eyes. Forty eyes also had RDs besides the retinal breaks. Large percentages of eyes had substantial myopia (mean myopia, -9.5 +/- 5.8 diopters [D]) and complex vitreoretinal complications. Forty percent developed vitreoretinal complications within 6 months after LASIK. The 20 eyes that developed more extensive RDs (>3 clock hours) had a significantly higher mean myopia than did the 6 eyes that developed limited RD (< or = 3 clock hours) within 12 months after LASIK (-8.92 +/- 6.82 D versus -3.50 +/- 1.97 D, P = 0.03). There were significant statistical differences in distribution of retinal breaks and tears between the temporal and nasal quadrants (P < 0.001, P < 0.001, respectively, chi2, but not between the superior and inferior quadrants. CONCLUSION: Distributions of retinal breaks in this study were comparable with results found in non-LASIK eyes in young myopes. Treatment for post-LASIK vitreoretinal complications was highly successful. The vulnerability of such highly myopic eyes for vitreoretinal complications warrants their close monitoring.
Adolescent↗
Acute exudative polymorphous vitelliform maculopathy syndrome.
PURPOSE: The authors describe clinical characteristics of acute exudative polymorphous vitelliform maculopathy syndrome, also termed polymorphous maculopathy syndrome (PMS), an unusual tapetoretinal disorder first reported by Gass. METHODS: Detailed ophthalmoscopy, fluorescein angiography, electrophysiology, and optical coherence tomography (OCT) were performed on a patient with PMS. RESULTS: Numerous small, yellowish lesions arranged in a honeycombed pattern at the level of the retinal pigment epithelium (RPE) around the disk and the macula, a shallow macular detachment (documented by OCT), and a perifoveolar yellow ring appeared in both eyes. Initial fluorescein angiography revealed mild early hyperfluorescence and late staining of the perifoveolar rings and the multifocal yellow lesions. Gradually, subretinal yellowish deposits gravitated as a meniscus below the macula with subsequent further changes. Electrophysiology showed reduced amplitudes of the electroretinogram and electrooculogram and abnormal dark adaptometry. A rhegmatogenous retinal detachment in the left eye was successfully repaired, with a visual acuity of 20/30. Antecedent upper respiratory infection and headaches and positive serology for the coxsackie virus suggest the possibility of a virus-induced disorder. Genetic studies of this patient showed normal DNA sequences for the bestrophin and peripherin/RDS genes. CONCLUSION: This is the first report of PMS with the following characteristics: occurrence in a woman, development of a rhegmatogenous retinal detachment, and electroretinogram, visual-evoked response, color vision, and OCT findings. PMS has features similar to but also different from those of Harada disease and Best disease. Further studies are necessary to determine its relationship to other acquired conditions, such as virus-induced disorders, and genetic defects unrelated to abnormalities of the bestrophin and peripherin/RDS genes.
Acute Disease↗