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Abstract #15987 Published in IGR 2-3
Digital photography and blurred image processing of the retinal nerve fiber layer in glaucoma
Xu L; Chen Y; Yang HChinese Journal of Ophthalmology 2000; 36: 410
OBJECTIVE: Red-free photographs are effective in detecting the retinal nerve fiber layer (RNFL). The reasons why they are not used by most clinics are the laborious developing and blurred image evaluation. To account for getting real-time image and blurred image evaluation, digital photography and computerized image processing were used. METHODS: RNFL photographs were taken with a Nikon fundus camera connected to a high resolution digital camera (Kodak) and a green filter. It is necessary to see the texture of the RNFL to evaluate its image, but blurred images due to media opacities greatly lose their resolution. The authors used no focus to see the texture of the RNFL, but to evaluate the distribution pattern of the RNFL. RNFL images have more white reflex in the temporal superior, temporal inferior, nasal superior, and nasal inferior sections around the optic disc, according to the thickness of the RNFL. Threshold segmentation was used by shifting a threshold bar into position until the nasal or temporal section around the optic disc is black, by means of the software Photoshop. RESULTS: In normal RNFL images, the white reflex had a butterfly pattern, i.e., the temporal superior and temporal inferior sections around the optic disc were white. In cases with glaucoma, the characteristic early damage of the optic nerve was seen as the loss of the RNFL at the temporal superior and temporal inferior part of the retina, and thus the normal butterfly pattern had changed, and the temporal superior and/or temporal inferior sections were black. With this method, the RNFL can be evaluated more effectively. However, in cases with a faintly colored retinal pigment epithelium, and in cases with choroidal defects, it is still difficult to evaluate distribution of the RNFL. CONCLUSIONS: Digital photography and RNFL pattern evaluation is an easy and effective way to detect glaucomatous damage.LA: Chinese
Dr. L. Xu, Beijing Institute of Ophthalmology, Capital University of Medical Science, Beijing 100005, China
Classification:
2.13 Retina and retinal nerve fibre layer (Part of: 2 Anatomical structures in glaucoma)
6.8.2 Posterior segment (Part of: 6 Clinical examination methods > 6.8 Photography)
