Detection of retinal blood vessels based on nonlinear projections

10.1007/s11265-008-0179-5Journal of Signal Processing Systems551-3103-11

Diagnostic Specificities of Retinal Nerve Fiber Layer, Optic Nerve Head, and Macular Ganglion Cell-Inner Plexiform Layer Measurements in Myopic Eyes

PURPOSE: To evaluate and compare the diagnostic specificities of peripapillary retinal nerve fiber layer (RNFL) thickness, macular ganglion cell-inner plexiform layer (GC-IPL) thickness, and optic nerve head (ONH) measurements in non-glaucomatous myopic individuals. METHODS: In a prospective, cross-sectional study, participants underwent a complete ophthalmic examination, a screening automated visual field test, and axial length measurement. The study eye then underwent optic nerve and macular scanning using spectral-domain optical coherence tomography (OCT) instrumentation to determine RNFL thickness, GC-IPL thickness, and ONH measurements. False positive rates for each of the OCT-derived parameters, using pre-defined criteria for an abnormal test, were calculated. Comparative analysis was performed using the McNemar test. RESULTS: Data from 43 eligible subjects were analyzed. The mean age was 30 ± 6.8 years (range: 22 to 50) with average axial length of 25.26 ± 1.21 mm (range: 23.06 to 29.07) and mean spherical equivalent of −4.50 ± 1.93 diopters (range: −1.00 to −9.00). The false positive rate was higher when using RNFL parameters compared to both ONH (47% vs. 7%, respectively; P < 0.001) and GC-IPL (47% vs. 26%, respectively; P = 0.049) parameters. The false positive rate was higher when using GC-IPL parameters, compared to ONH parameters (26% vs. 7%, respectively; P = 0.039). CONCLUSIONS: Caution should be exercised when relying on OCT-derived RNFL and GC-IPL thickness values to diagnose glaucoma in myopic individuals. OCT-derived ONH parameters perform better than RNFL and GC-IPL parameters and may increase diagnostic specificity in this population

Peripheral and posterior pole retinal lesions in association with high myopia: A cross-sectional community-based study in Hong Kong

Purpose: To evaluate the prevalence and factors associated with posterior pole and peripheral retinal lesions in Chinese subjects with high myopia. Methods: Three hundred and thirty-seven asymptomatic adults with high myopia of refractive error ≤-6D were examined in a cross-sectional community-based study. All subjects underwent cycloplegic refraction, ultrasound biometry and dilated fundal examination. Statistical analysis was performed to assess factors associated with the presence of posterior pole and peripheral retinal lesions. Results: The mean age of the 337 subjects was 36.0 years and the mean spherical equivalent refractive error was -10.2D. Thirty-eight eyes (11.3%, 95% CI=8.1-15.2%) were found to have one or more posterior pole lesions and subjects with posterior pole lesion had significantly older age, longer axial length and higher degree of myopia (all P<0.001) compared with subjects without posterior pole lesion. After controlling for axial length, both the severity of refractive error and older age were significantly associated with the presence of posterior pole lesion (both P<0.001). For peripheral retinal lesions, 189 eyes (56.1%, 95% CI=50.6-61.5%) were found to have one or more peripheral retinal lesions. The presence of peripheral retinal lesion was associated with younger age and higher degree of refractive error (P=0.046 and 0.002, respectively). Conclusion: Posterior pole and peripheral retinal degenerative lesions were found in a considerable proportion of subjects with high myopia. As some of these retinal lesions might predispose to visual impairment, highly myopic individuals should be educated on the symptoms of various eye conditions and seek care immediately if symptoms arise.link_to_subscribed_fulltex

Effectiveness study of atropine for progressive myopia in Europeans

Contains fulltext : 167761.pdf (Publisher’s version ) (Open Access)PurposeRandomized controlled trials have shown the efficacy of atropine for progressive myopia, and this treatment has become the preferred pattern for this condition in Taiwan. This study explores the effectiveness of atropine 0.5% treatment for progressive high myopia and adherence to therapy in a non-Asian country.MethodsAn effectiveness study was performed in Rotterdam, the Netherlands. Overall 77 children (mean age 10.3 years+/-2.3), of European (n=53), Asian (n=18), and African (n=6) descent with progressive myopia were prescribed atropine 0.5% eye drops daily. Both parents and children filled in a questionnaire regarding adverse events and adherence to therapy. A standardized eye examination including cycloplegic refraction and axial length was performed at baseline and 1, 4, and 12 months after initiation of therapy.ResultsMean spherical equivalent at baseline was -6.6D (+/-3.3). The majority (60/77, 78%) of children adhered to atropine treatment for 12 months; 11 of the 17 children who discontinued therapy did so within 1 month after the start of therapy. The most prominent reported adverse events were photophobia (72%), followed by reading problems (38%), and headaches (22%). The progression rate of spherical equivalent before treatment (-1.0D/year+/-0.7) diminished substantially during treatment (-0.1D/year+/-0.7) compared to those who ceased therapy (-0.5D/year+/-0.6; P=0.03).ConclusionsDespite the relatively high occurrence of adverse events, our study shows that atropine can be an effective and sustainable treatment for progressive high myopia in Europeans