Evaluation of spectral domain optical coherence tomography parameters in discriminating preperimetric glaucoma from high myopia

AIM: To evaluate the diagnostic ability of macular ganglion cell-inner plexiform layer(GCIPL) thickness o b t a i n e d b y s p e c t r a l-d o m a i n o p t i c a l c o h e r e n c e tomography(SD-OCT) in discriminating non-highly myopic eyes with preperimetric glaucoma(PPG) from highly myopic healthy eyes. METHODS: A total of 254 eyes, including 76 normal controls(NC), 116 eyes with high myopia(HM) and 62 non-highly myopic eyes with PPG were enrolled. The diagnostic ability of OCT parameters was accessed by the areas under the receiver operating characteristic(AUROC) curve in two distinguishing groups: PPG eyes with nonglaucomatous eyes including NC and HM(Group 1), and PPG eyes with HM eyes(Group 2). Differences in diagnostic performance between GCIPL and RNFL parameters were evaluated. RESULTS: The minimum(AUROC curve of 0.782), inferotemporal(0.758) and inferior(0.705) GCIPL thickness were the top three GCIPL parameters in discriminating PPG from non-glaucomatous eyes, all of which had statistically significant lower diagnostic ability than average RNFL thickness(0.847). In discriminating PPG from HM, the best GCIPL parameter was minimum(0.689), statistically significant lower in diagnostic ability than average RNFL thickness(0.789) and three other RNFL thickness parameters of temporal and inferotemporal clock-hour sectors. CONCLUSION: The minimum GCIPL thickness is the best GCIPL parameter to detect non-highly myopic PPG from highly myopic eyes, whose diagnostic ability is inferiorto that of average RNFL thickness and RNFL thickness of several temporal and inferotemporal clock-hour sectors. The average RNFL thickness is recommended for discriminating PPG from highly myopic healthy eyes in current clinical practice in a Chinese population.

Optical Coherence Tomography Parameters in Preperimetric Open-Angle Glaucoma

Purpose: To evaluate the measurements of the peripapillary retinal neurofiber layers (RNFL) and the ganglion cells complex (GCC) obtained by Optical Coherence Tomography (OCT) in eyes with preperimetric open-angle glaucoma. Methods: One hundred and forty eyes of 75 patients (21 male and 54 female), 80 eyes with preperimetric glaucoma (PPG) (45 patients) and 60 normal eyes (30 subjects) were included in this study. Automated visual field examination was done to all participants using Humphrey field analyzer, program 30-2. The GCC thickness and peripapillary RNFL thickness were measured using RTVue-100 (Optivue, Inc., Fremont, CA). The areas under ROC (receiver operating characteristic)—curves (AUCs) were defined for all examined GCC and RNFL parameters. Results: GCC of the eyes with PPG was significantly thinner than GCC of the normal eyes: (89.58 vs 97.82 microns, P < 0.001). There was no significant difference between upper and lower GCC halves in both study groups. We found a reduction of RNFL thickness in glaucomatous eyes (P < 0.001) compared with normals. AUCs for GCC parameters in eyes with PPG were larger than AUCs for RNFL parameters. Conclusion: Our study showed that the peripapillary RNFL and GCC thickness are lower in preperimetric glaucoma than in normal eyes. Despite the fact that GCC measurements (especially GLV) show better AUC than peripapillary measurements, we suggest that two scans (GCC and ONH) put together are superior in detecting early structural glaucomatous damage. Several diagnostic parameters should be considered in the clinical diagnosis of preperimetric glaucoma.

Diagnostic evaluation of optical coherence tomography parameters in normal, preperimetric and perimetric glaucoma patients

AIM: To compare the diagnostic ability of glaucoma parameters measured by the optical coherence tomography(OCT) in normal, preperimetric glaucoma(PPG) and perimetric glaucoma(PG) patients. METHODS: This cross-sectional observational study includes 127 eyes of 127 subjects. Patients were divided into PPG(51 eyes), PG(46 eyes), and normal controls(30 eyes) based on clinical optic disc assessment and Humphrey visual field changes. The Heidelberg Spectralis OCT machine using Glaucoma Module Premium Edition software was used to measure the retinal nerve fiber layer(RNFL) and Bruch’s membrane opening-minimum rim width(BMO-MRW) to assess the optic nerve head and ganglion cell layer(GCL) thickness in the macula. RESULTS: RNFL, MRW, and GCL thickness were all significantly thinner in PG compared to PPG and the normal group. The BMO-MRW parameters showed better specificity(>70%) at 90% specificity compared to both RNFL and GCL parameters to discriminate normal, PPG, and PG patients. All BMO-MRW parameters showed higher area under curves(AUC) compared to RNFL and GCL parameters with the highest AUC observed in the superotemporal sector of the BMO-MRW(AUC=0.819 and and 0.897 between normal and PPG and PG groups respectively).CONCLUSION: While the BMO-MRW best discriminates PPG and PG against normal eyes, GCL parameters poorly differentiate the three groups.