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Abstract #3419 Published in IGR 4-2
The effect of laser-assisted in situ keratomileusis on retinal nerve fiber layer measurements obtained with scanning laser polarimetry
Roberts TV; Lawless MA; Rogers CM; Sutton GL; Domniz YJournal of Glaucoma 2002; 11: 173-176
PURPOSE: Scanning laser polarimetry provides indirect measurements of retinal nerve fiber layer thickness by measuring the retardation of polarized laser light as it passes through the retinal nerve fiber layer. Laser-assisted in situ keratomileusis is a refractive technique by which corneal stromal photoablation is achieved by the structural and refractive changes induced by the excimer laser. Both techniques are becoming widely performed and there is some evidence that scanning laser polarimetry measurements are significantly changed after laser-assisted in situ keratomileusis. The authors performed a larger study to determine whether laser-assisted in situ keratomileusis induces predictable and consistent alterations in the measurement of retinal nerve fiber layer thickness. METHODS: Retinal nerve fiber layer thickness measurements using scanning laser polarimetry were performed one week before and one week after laser-assisted in situ keratomileusis in 30 consecutive eyes (16 patients) undergoing the procedure. RESULTS: Mean ± SD preoperative spherical equivalent refraction was -4.66 ± 2.40 D, mean ablation depth was 73.0 ± 36.23 μm, and mean patient age was 40.6 ± 8.7 years. Six of 12 retinal nerve fiber layer thickness measurements showed significant change (p < 0.05) after laser-assisted in situ keratomileusis. There was no correlation with corneal ablation depth (p > 0.05) for all parameters. CONCLUSIONS: Laser-assisted in situ keratomileusis significantly affects retinal nerve fiber layer thickness measurements obtained by scanning laser polarimetry. Sequential images should be interpreted with caution and new postoperative baseline images should be obtained.
Dr. T. Roberts, The Eye Institute, 270 Victoria Avenue, Chatswood, NSW, 2067, Australia. troberts@theeyeinstitute.com.au
Classification:
2.13 Retina and retinal nerve fibre layer (Part of: 2 Anatomical structures in glaucoma)
6.9.1 Laser scanning (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis)
