Adaptive optics scanning laser ophthalmoscopy may support early diagnosis of glaucoma

Purpose: To compare image characteristics of retinal nerve fiber layer (RNFL) between glaucoma patients and healthy controls using adaptive optics scanning laser ophthalmoscopy (AOSLO). Methods: This was a cross-sectional pilot study with two groups: a glaucoma group with patients with moderate or severe glaucoma as per the Hodapp–Parrish–Anderson classification system and a control group with healthy individuals. The optic nerve damage in moderate glaucoma was predominantly located in only one hemisphere; the other hemisphere was un- or minimally affected on optical coherence tomography and automated perimetry and is referred to as early glaucoma. The structure of RNFL bundles and gain (%) in RNFL images with mean pixel values between 15 and 35 were analyzed. Imaging was performed one degree away from the optic disc margin at two and four cardinal clock positions in the glaucoma and control groups, respectively. The field of view was 1.3° at 2.3 ? resolution. We studied one eye per participant. Results: There were 11 glaucoma patients and 7 healthy controls. Imaging was successful at 88% of the locations in controls and early glaucoma; the reflectivity differed significantly (0.51 and 0.56, respectively, P < 0.001) but not the structure of RNFL bundles (Cohen’s Kappa 0.11) between them. In patients with moderate and severe glaucoma, imaging was successful only at 46% of the locations; RNFL bundles were not discernible, and RNFL reflectivity did not differ from those with early glaucoma (P < 0.11). Conclusion: The recorded gain (%) of RNFL images obtained using AOSLO could be an objective indicator of early glaucoma

Discriminating Ability of Scanning Laser Polarimetry with Variable Corneal Compensation in Normal and Glaucomatous Eyes

PURPOSE: We investigated the diagnostic ability of scanning laser polarimetry with variable corneal compensation (GDx VCC) parameters to distinguish glaucomatous eyes with different degrees of visual field abnormality from normal eyes. METHODS: Subjects were divided into a control group (n=47) and an early to moderate glaucoma group (n=100). The latter included 53 early glaucoma patients (mean deviation > -6dB with a Humphrey Field Analyzer). Using a receiver operating characteristic (ROC) curve, the diagnostic power of GDx VCC parameters was analyzed and the correlations between those parameters and Humphrey Field Analyzer (HFA) indices were statistically analyzed. RESULTS: Nerve fiber indicator (NFI) provided the best discriminating ability with the highest area under the ROC curve (AUROC) value for detecting eyes with early to moderate perimetric glaucoma. TSNIT average showed the highest AUROC value for detecting eyes with early perimetric glaucoma. The optimal NFI cut-off value to discriminate between the control group and early to moderate group was 22, offering the best combination of sensitivity (88.0%) and specificity (83.0%). The optimal TSNIT average cut-off value to discriminate between the control group and early glaucoma group was 53.49 micrometer, providing the best combination of sensitivity (84.9%) and specificity (85.1%). Most of the thickness parameters showed higher AUROC values than those of the ratio or modulation parameters. A statistically significant correlation was found between the GDx VCC parameters and HFA indices. CONCLUSIONS: Measurement of the retinal nerve fiber layer (RNFL) by scanning laser polarimetry with variable corneal compensation is useful in discriminating between normal and glaucomatous eyes.

Early Detection of Glaucoma with Retinal Nerve Fiber Layer Photograph

The purpose of this study was to evaluate the usefulness of retinal nerve fiber layer [RNFL] photography and Heidelberg Retina Tomograph [HRT, Heidelberg, Germany] in early detection of glaucoma. Among 2802 people who underwent routine health checkup at. Seoul National University Hospital from July I to Decernber 31, 1996, forty-nine persons were included whose IOP was above 21mmHg or cup/disc ratio was 0.5 or greater. RNFL photography, HRT and automated perimetry [Humphrey Field Analyzer, program C30-2] were performed. Twelve eyes were diagnosed as glaucoma and one sye as glaucoma suspect. Four eyes with glaucoma had RNFL defect with normal visual field and 7 eyes with glaucoma had both RNFL defect and glaucomatous visual field defect. Of 26 eyes suggested as glaucoma by FSM classification of HRT, only 8 eyes met the diagnostic cri-teria of glaucoma of this study. Among 21 eyes with decreased hump height in HRT only 7 eyes were diagnosed as glaucoma. RNFL photography increased the detection rate for glaucoma by 50% over that with visual field test. only. RNFL photography will be a valuable method for early detection of glaucorna while HRT may play a suppleinentary role.