Structural evaluation of preperimetric and perimetric glaucoma

Purpose: To evaluate diagnostic ability of macular ganglion cell layer–inner plexiform layer (GCL-IPL) for detection of preperimetric glaucoma (PPG) and perimetric glaucoma and comparison with peripapillary RNFL. Methods: Three hundred and thirty seven eyes of 190 patients were enrolled (127 normals, 70 PPG, 140 perimetric glaucoma). Each patient underwent detailed ocular evaluation, standard automated perimetry, and spectral domain optical coherence tomography. Diagnostic abilities of GCL-IPL and RNFL parameters were determined. Data were compared using one-way analysis of variance, Pearson's Chi-square test, and area under the curve (AUC). Results: After adjusting for age, gender, and signal strength, all GCL-IPL and RNFL parameters except mean thickness and disc area differed significantly. Among GCL-IPL thicknesses, inferotemporal had the highest AUC (0.865) for classifying perimetric glaucoma from normals, inferior (0.746) for PPG from normals, and inferotemporal (0.750) for perimetric glaucoma from PPG. When using RNFL, inferior thickness had the highest AUC (0.922) in discriminating POAG from normal, while the same parameter had lower AUC (0.813) in discriminating PPG from normal. The average thickness had maximum AUC (0.775) for discriminating POAG from PPG. For discriminating perimetric glaucoma and normals, inferotemporal GCL-IPL had the highest strength (sensitivity 81.43% and specificity 77.96%), slightly lower than inferior RNFL thickness (sensitivity 87.85% and specificity 84.26%). The same parameters were sensitive in discriminating perimetric glaucoma from PPG (87.14% and 92.85%, respectively). However, their specificities were poor (56.43% both). Conclusion: RNFL had better diagnostic ability, when compared with GCL-IPL for detecting PPG and perimetric glaucoma. However, difference was small and may not be clinically relevant.

Evaluation of macular ganglion cell analysis compared to retinal nerve fiber layer thickness for preperimetric glaucoma diagnosis

Purpose: To compare the diagnostic ability of the ganglion cell analysis (GCA) and retinal nerve fiber layer (RNFL) protocol on optical coherence tomography (OCT), to diagnose preperimetric glaucoma. Methods: A prospective, cross-sectional study of 275 adult patients including 47 early glaucoma (mean deviation better than -6.0 D), 150 glaucoma suspects (106 with suspicious discs and 44 ocular hypertensive (OHT), and 78 normal controls was done. Eligible participants were scanned with the spectral domain CirrusTM OCT (Carl Zeiss Meditec, Dublin, CA). Average peripapillary RNFL thickness and GCA measurements were obtained. Area under receiver operating characteristic (AROC) curves were used to evaluate discriminant value of both protocols to diagnose likely preperimetric glaucoma among glaucoma suspects. Results: Average RNFL and GCA were significantly thinner in glaucoma patients compared to glaucoma suspects and normal controls (P < 0.001). The RNFL was 92.26 ± 8.8 ? in normal controls, 87.9 ± 12.12 ? in glaucoma suspects and significantly thinner in POAG (70.29 ± 10.18 ?; P < 0.001). The GCA was 81.94 ± 6.17 ? in normal controls, 77.69 ± 9.03 ? in glaucoma suspects, and significantly thinner in POAG (69.36 ± 11.06 ?; P < 0.001). AROCs for discriminating glaucoma suspects from normal were modest, with no difference in AROC of average RNFL or GCA measurements (DeLong; P = 0.93). Average RNFL thickness had significantly greater AROC values than average GCA for discriminating glaucoma suspects (both suspicious discs and OHT) from glaucoma (P = 0.03 and 0.05, respectively. AROC for diagnosing glaucoma was significantly better (P = 0.02) for RNFL (0.88 ± 0.03) than GCA (0.77 ± 0.04). Conclusion: In the present time, GCA measurements, as provided by the SD-OCT, do not appear to outperform RNFL measurements in the diagnosis of preperimetric glaucoma.

Diagnostic Ability of Spectral Domain OCT: Comparision between Preperimetric Glaucoma and Large Physiologic Cupping

PURPOSE: To assess the distinction ability for differentiating glaucoma patients based on optic disc, retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) measured using spectral domain optical coherence tomography (SD-OCT). Additionally, the diagnostic ability of these parameters was evaluated by comparing preperimetic glaucoma patients who frequently visited the clinic and normal patients with and without a large physiologic cup/disc (C/D) ratio. METHODS: Using SD-OCT, the optic disc, RNFL and GCIPL of preperimetic glaucoma patients were compared with normal people with and without a large C/D ratio from March, 2011 to December, 2014 at Department of Ophthalmology, Inha University Hospital. Preperimetic glaucoma was defined using the normal standard automated perimetry for glaucomatous optic nerve changes such as asymmetry of vertical C/D ratio, rim thinning, notching, excavation and RNFL defect. RESULTS: When comparing preperimetic glaucoma patients to normal people without large disc cupping, the most reliable parameter for optic disc parameters, vertical C/D ratio (0.89), showed more reliable diagnostic ability than the most reliable parameter for retinal nerve fiber, inferior RNFL thickness (0.79) and superonasal and inferonasal GCIPL thickness were the most reliable GCIPL parameters (p = 0.005 and 0.002, respectively). When comparing preperimetic glaucoma patients to normal people having a large physiologic disc cupping, average C/D ratio among optic nerve parameters, inferior RNFL thickness among RNFL thickness parameters and inferior GCIPL thickness among GCIPL parameters showed highly reliable diagnostic abilities. These 3 parameters were not statistically different (all p > 0.05) and had lower distinction ability than reported in previous studies. CONCLUSIONS: Diagnostic abilities of SD-OCT for distinguishing preperimetric glaucoma from normal people having large physiologic disc cupping were similar for optic disc, RNFL and GCIPL and showed low diagnostic ability than compared to normal people without large disc cupping.

Comparison of Total Deviation of Standard Automated Perimetry and Matrix FDT in Preperimetric Glaucoma Patients

PURPOSE: To compare the results of total deviation (TD) as measured by standard automated perimetry (SAP) and measured with of Matrix Frequency-doubling Technology (FDT) in patients with preperimetric glaucoma. METHODS: Fifty-two eyes of 52 patients with preperimetric glaucoma were included. Subjects were examined with Matrix FDT and Stratus optical coherence tomography (OCT), and the results of each examination were analyzed. The proportions of abnormal results in SAP TD, Matrix TD, and Matrix pattern deviation (PD) were calculated. Among the results of tests, the following correlations were evaluated: SAP TD and Matrix, and visual fields and OCT. In addition, the differences in peripapillary retinal nerve fiber layer thickness (RNFL) according to the result of SAP TD in preperimetric patients with abnormal Matrix PD were analyzed. RESULTS: A abnormalities in SAP TD, Matrix TD and Matrix PD were found in 22 (42.3%), 34 (65.4%), 41 (78.9%) eyes, respectively. There was marginal correlation between SAP TD and Matrix PD (p=0.07). No significant correlation was found between SAP TD and OCT, although Matrix PD and OCT did show significant correlation (p<0.05). In preperimetric patients with abnormal Matrix PD, RNFL thickness was significantly lower in the abnormal SAP TD group than in the normal SAP TD group on average, in the superior quadrant, and at the 12 o'clock and 5 o'clock positions (p<0.05). CONCLUSIONS: In patients with preperimetric glaucoma, 42.3% and 78.9% had glaucomatous VF defects in SAP TD and Matrix PD, respectively. These results were higher than expected, especially those of SAP TD.

Interpretation of Frequency Doubling Technology Perimeter in Diagnosis of Glaucoma and Glaucoma Suspect

PURPOSE: To find applicable parameters of the frequency doubling technology perimeter (FDP), which is known to be useful in detecting early visual field loss. METHODS: The subjects were 65 eyes of normal individuals, 58 eyes of glaucoma suspects, and 37 eyes of glaucoma patients. FDP (MD, PSD), SAP (MD, PSD, CPSD), and 5 parameters of OCT were analyzed. The receiver operating characteristic (ROC) curve, sensitivity, and specificity of each parameter were evaluated, and the comparison of FDP parameters by Pearson's chi-square was made between the glaucoma suspect group and the normal group. The same comparison was made among the normal+glaucoma suspect and glaucoma group. RESULTS: In discriminating between the normal and glaucoma suspect groups, the FDP-PSD revealed an AUC of 0.745 (cutoff: 3.17dB), which was significantly larger than that of SAP-PSD with an AUC of 0.660 (cutoff: 1.73dB). In comparing FDP, PSD by Anderson criteria was most reliable with a hit ratio of 0.732. On the other hand, in discriminating among the normal+glaucoma suspect group and glaucoma group, the SAP-PSD showed an AUC 0.971 (cutoff: 2.92dB), much larger than the FDP-PSD with an AUC of 0.863 (cutoff: 3.78dB). In addition, in comparing the parameters of FDP by Pearson chi-square, PSD 1% was the most reliable with a hit ratio of 0.813. CONCLUSIONS: FDP is a valuable screening tool in detecting early visual field loss. PSD by Anderson criteria can be a reliable parameter for the diagnosis of pre-perimetric glaucoma, and PSD 1% can be used in the discrimination of perimetric glaucoma.

Stratus OCT, SWAP, Matrix FDT in Preperimetric Glaucoma

PURPOSE: To evaluate the peripapillary retinal nerve fiber layer (RNFL) thickness with optical coherence tomography (OCT) in normal subjects and preperimetric glaucoma patients, as well as compare the results of OCT, short wavelength automated perimetry (SWAP), frequency doubling technology perimetry (FDT) in preperimetric glaucoma patients. METHODS: Thirty-six eyes of 36 preperimetric glaucoma patients who have definitive localized RNFL defects in disc photograph and normal standard visual field, as well as 35 eyes of 35 normal subjects, were enrolled in this study. We compared the peripapillary RNFL thickness between the two groups using Stratus OCT. Stratus OCT, FDT, and SWAP results in preperimetric glaucoma group were also compared. RESULTS: Compared with normal controls, peripapillary RNFL thickness, including the average, superior, and inferior quadrant, was significantly low (P<0.05) in the preperimetric glaucoma group, 93.40+/-11.16 micrometer, 118.33+/-21.17 micrometer, and 108.72+/-16.76 micrometer respectively. In preperimetric glaucoma group, functional and structural abnormalities were found in 55.6% with Stratus OCT, 31.4% with SWAP, and 79.4% with Matrix FDT. CONCLUSIONS: Statistically significant reduction of RNFL thickness was revealed in the preperimetric glaucoma group, and Matrix FDT was the most sensitive test for detecting early glaucomatous change, followed by Stratus OCT, and SWAP.