Biomedical subjects
Barbara S M Tam
Publications and source records attributed to Barbara S M Tam.
Prevalence and characteristics of peripheral retinal degeneration in Chinese adults with high myopia: a cross-sectional prevalence survey.
PURPOSE: The purpose of this study was to study the prevalence of peripheral retinal findings in adult Chinese patients with high myopia (refraction < or = -6.00 D) and to investigate the correlation between the retinal lesions and the severity of myopia or axial length. METHODS: A cross-sectional prevalence survey screening was conducted in high ethnic Chinese myopes with refractions equal to or less than -6.00 D. The examinations included cycloplegic refraction, A and B scan ultrasonography, and retinal examinations by indirect ophthalmoscopy with scleral indentation and Goldmann three-mirror contact lens examination. RESULTS: Two hundred thirteen eyes in 213 patients with a mean refraction of -10.10 +/- 4.23 D (range = -6.00 to -27.00 D) were examined. The mean axial length was 26.69 +/- 1.68 mm (range = 25.18-33.62 mm) and the mean age was 33.5 +/- 10.6 years (range = 18-73 years). The most common peripheral retinal finding was pigmentary degeneration (51.2%), followed by lattice degeneration in 12.2% and retinal holes in 7.5% of eyes. A positive correlation was noted between axial length and the lesions of pigmentary degeneration and pavingstone degeneration. The prevalence of retinal holes was 6.4% and 30.0% in eyes with axial length of < 30 mm and > or = 30 mm, respectively (chi-squared test, p = 0.006). CONCLUSION: A high prevalence of peripheral retinal degenerations was found in adult Chinese high myopes. The presence of retinal holes was positively correlated with very high myopia of an axial length of > or = 30 mm.
Needle tap in the diagnosis of inflammation.
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Sutureless vitrectomy surgery.
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Photodynamic therapy with verteporfin for subfoveal idiopathic choroidal neovascularization: one-year results from a prospective case series.
OBJECTIVE: To study the safety and efficacy of photodynamic therapy (PDT) with verteporfin in treating subfoveal choroidal neovascularization (CNV) of idiopathic cause. DESIGN: A prospective, noncomparative, consecutive, open-label, two-center, interventional case series. PARTICIPANTS: Patients aged 50 years or younger with the diagnosis of idiopathic CNV by exclusion of other related causes together with the CNV extending under the geometric center of the foveal avascular zone. METHODS: Seventeen eyes from 17 patients received PDT with verteporfin according to a standardized protocol. Retreatment was considered if fluorescein leakage from the CNV was shown in fluorescein angiography at every 3-month follow-up. The visual, clinical, and angiographic responses were observed. Complications from treatment were monitored and documented. MAIN OUTCOMES MEASURES: The changes in the best-corrected visual acuity (BCVA) at the 1-year follow-up. The proportion of patients with improved (gained 2 lines or more), stable, and dropped (lost 2 lines or more) vision and the mean number of treatments required during the 1-year interval were measured. Complications were monitored and tabulated. RESULTS: Seventeen eyes with complete 1-year follow-up were analyzed. The mean logarithm of the minimum angle of resolution BCVA improved from 0.64 to 0.41 (Wilcoxon signed-ranks test, P = 0.007). Sixteen eyes (94%) had stable or improved vision. Only one patient (6%) had moderate loss of vision. The mean number of PDT treatment was 1.8 per eye over the 1-year period. Patients with smaller lesion size or active vascular CNV on presentation were more likely to have a final BCVA of 20/100 or better (Fisher's exact test, P = 0.006 and P = 0.015, respectively). No serious local or systemic complications were encountered. CONCLUSIONS: PDT seems to be a promising treatment strategy in achieving a stable or improved vision for subfoveal idiopathic CNV. The treatment was well tolerated. Further studies and longer follow-up are warranted to assess the long-term safety and efficacy of PDT compared with observation or other treatment modalities.
Macular hole surgery with or without indocyanine green stained internal limiting membrane peeling.
BACKGROUND: To compare the anatomical and visual outcome in primary idiopathic macular hole surgery with or without indocyanine green (ICG) stained internal limiting membrane (ILM) peeling. METHODS: The medical records of the last 40 consecutive eyes receiving primary idiopathic macular hole surgery with gas as internal tamponade performed by a single surgeon were retrospectively reviewed and analysed. All eyes had a follow-up period of at least 6 months. In the initial 22 consecutive eyes, no ILM peeling was performed (non-ILM peeling group). The subsequent 18 eyes underwent surgery with ICG-stained ILM peeling (ILM peeling group). RESULTS: The primary anatomical closure rates were 88.9% and 59.1% in the ILM peeling group and non-ILM peeling group, respectively. The difference was statistically significant (Fisher's exact test, P = 0.038). Improvement in visual acuity was more marked in the ILM peeling group than in the non-ILM peeling group, with a mean improvement of 3.6 and 1.3 lines, respectively (two-tailed t-test, P = 0.036). There were significantly more cases with improvement of two or more lines of visual acuity after surgery, with 66.7% in the ILM peeling group and 31.8% non-ILM peeling group (Chi-square test P = 0.028). However, there was no significant difference in the final postoperative logMAR best-corrected visual acuity between the two groups (two-tailed t-test, P = 0.073). CONCLUSIONS: Based on this study, ICG-stained ILM peeling seems to improve the anatomical and visual outcome in primary idiopathic macular hole surgery. Further studies in this aspect are warranted.