Youngrok Lee

Relationship between Visual Field Sensitivity and Macular Ganglion Cell Complex Thickness as Measured by Spectral-Domain Optical Coherence Tomography

PURPOSE To evaluate the strength and pattern of the relationship between visual field (VF) mean sensitivity (MS), assessed by standard automated perimetry (SAP), and macular ganglion cell complex thickness (GCCT), measured with spectral-domain optical coherence tomography (SD-OCT). METHODS Ninety-seven glaucoma patients were enrolled. GCCT, determined by ganglion cell complex (GCC) scanning, and two peripapillary retinal nerve fiber layer thickness (pRNFLT) measurements, using the NHM4 (RNFL1) and RNFL 3.45 (RNFL2) modes, were recorded. MS was recorded on the decibel (dB) and 1/L scales. The relationship between function (MS) and structure (GCC, pRNFLT) was sought. RESULTS The association of MS (in decibels) with GCC global (r = 0.445) and sectoral (superior, r = 0.528; inferior, r = 0.370) thicknesses was not significantly different from that of MS to global (RNFL1, r = 0.505; RNFL2, r = 0.498) and sectoral (RNFL 1 superior, r = 0.559; inferior, r = 0.440; RNFL 2 superior, r = 0.535; inferior, r = 0.443) pRNFLT, on linear regression analysis. The relationship pattern was curvilinear on the dB scale against GCCT and RNFLT. Logarithmic regression of MS (using both the dB and 1/L scales) against GCCT and RNFLT was better than linear regression in describing the pattern of association. CONCLUSIONS GCCT, determined by SD-OCT, showed correlation to MS of a strength similar to that demonstrated between MS and pRNFLT.

Characteristics of visual field progression in medically treated normal-tension glaucoma patients with unstable ocular perfusion pressure.

PURPOSE To investigate the characteristics of visual field (VF) progression in medically treated normal-tension glaucoma (NTG) patients (Koreans) with unstable ocular perfusion pressure (OPP). METHODS One hundred one eyes of 101 NTG patients followed up for more than 4 years (mean follow-up, 6.2 years ± 12.1 months) were included. Modified Anderson criteria (MC) and linear regression analysis (LA) of VF mean deviation (MD) within the central 10° and 10° to 24° area were assessed for determining VF progression in groups with lowest (LMF) and highest (HMF) 24-hour mean OPP [MOPP = 2/3;(mean arterial pressure - IOP)] fluctuation. Kaplan-Meier analyses were used to compare the elapsed time of confirmed VF progression in the two groups. Hazard ratios (HRs) for the association between clinical risk factors including 24-hour MOPP and central VF progression were obtained by using Cox proportional hazards models. RESULTS Three of 33 eyes in the LMF progressed, whereas 12 of 34 eyes in the HMF progressed within the central 10° according to the MC; the between-group difference was significant (P = 0.010). By LA within the central 10°, two eyes from the LMF and nine from the HMF groups showed progression (P = 0.025). The HMF showed a greater cumulative probability of central VF progression than the LMF, by both LA and MC (Kaplan-Meier analysis, P = 0.003, 0.015, log-rank test). In multivariate analysis, only 24-hour MOPP fluctuation was significantly associated with central VF progression (P = 0.014). CONCLUSIONS The 24-hour MOPP fluctuation was the most consistent prognostic factor among various IOP, blood pressure, and clinical factors for central VF glaucomatous progression in our series of NTG eyes.

Glaucoma diagnostic capabilities of optic nerve head parameters as determined by Cirrus HD optical coherence tomography.

PurposeTo compare the glaucoma diagnostic capabilities of optic nerve head (ONH) parameters with retinal nerve fiber layer thickness (RNFLT) using Cirrus spectral-domain optical coherence tomography (Carl Zeiss Meditec Inc, Dublin, CA; version 5.0.0.326). MethodsTwo hundred twenty-nine glaucomatous patients, 405 preperimetric glaucoma patients, and 109 healthy individuals were imaged by Cirrus optical coherence tomography optic disc cube mode. Correlations were sought between RNFLT and ONH parameters (disc and rim area, average and vertical cup-to-disc ratio, and cup volume). Areas under receiver operating characteristic curves (AUCs) of average RNFLT were compared with those of ONH parameters with respect to discrimination between glaucomatous patients and healthy individuals. Subgroup analysis was performed in early, moderate-to-advanced glaucomatous groups, glaucoma patients with a small disc area and a large disc area. ResultsRim area showed the strongest correlation with average RNFLT (r=0.663) and the highest AUC (0.871). The overall AUC for discrimination between healthy individuals and glaucomatous patients was higher for average RNFLT than for rim area (0.957 vs. 0.871, P<0.001). In the early and small disc area subgroup, the AUC of average RNFLT was significantly greater than those of all ONH parameters. In moderate-to-advanced glaucomatous groups’ patients, the AUCs of average RNFLT and rim area, in large disc area group patients, the AUC of average RNFLT and vertical cup-to-disc ratio, did not differ significantly. ConclusionsRNFLT was better than any tested ONH parameter when used for glaucoma discrimination, especially in patients with early-stage glaucoma and in glaucomatous patients with small optic discs.

Structure-function relationship of the macular visual field sensitivity and the ganglion cell complex thickness in glaucoma.

PURPOSE We attempted to understand better the relationship between the macular visual field (VF) mean sensitivity (MS) assessed by standard automated perimetry (SAP) and the ganglion cell complex thickness (GCCT), and macular peripapillary retinal nerve fiber layer thickness (mpRNFLT) assessed by spectral domain optical coherence tomography (SD-OCT, RTVue-100) in open-angle glaucoma (OAG) patients. METHODS We enrolled in the study 217 OAG patients with baseline intraocular pressure (IOP) in the statistically normal range. GCCT and mpRNFLT measurements, using the ganglion cell complex (GCC) and the optic nerve head (ONH) modes of RTVue-100 OCT, were obtained for analysis. Macular VF sensitivity was recorded in the dB and 1/L scales. The relationship of the function (MS) and structure (GCCT, mpRNFLT) was sought globally and in two VF sectors (superior and inferior). RESULTS The relationship of the macular VF sensitivity (dB) to the GCC, and mpRNFL global (R(2) = 0.111, 0.127) and sectoral (superior R(2) = 0.358, 0.171; inferior R(2) = 0.227, 0.263) thicknesses were statistically significant (all P < 0.05). The relationship of the macular VF sensitivity to the GCCT differed significantly from that of the macular VF sensitivity to the mpRNFL in the superior VF sector (R(2) = 0.358 vs. 0.171, P < 0.05). CONCLUSIONS GCCT determined by SD-OCT (RTVue-100) showed a statistically significant structure-function association with macular VF, and the strength of the association was greater than that of the mpRNFL with macular VF in the superior central VF area.

Macular and retinal nerve fiber layer thickness: which is more helpful in the diagnosis of glaucoma?

PURPOSE To explore factors affecting the glaucoma diagnostic capability of macular thickness and circumpapillary retinal nerve fiber layer (cRNFL) thickness as determined by spectral domain-optical coherence tomography. METHODS Area under the curve (AUC) of the receiver operating characteristics (ROC) discriminating healthy from glaucomatous eyes was determined using 10 macular thickness and 16 cRNFL thickness parameters. Glaucomatous eyes were categorized into two groups using four criteria according to whether cRNFL thickness or macular thickness measurement was better for glaucoma detection (cRNFL better group [RBG], macula better group [MBG], respectively). The clinical characteristics were compared between RBG and MBG. ROC regression analysis was conducted to identify variables affecting diagnostic capability using either macular thickness or cRNFL thickness measurements. RESULTS Four hundred twenty-four glaucomatous patients and 297 healthy subjects were analyzed. Of all cRNFL parameters, average thickness showed the largest AUC (0.958). Of macular parameters, the inferior outer sector showed the largest AUC (0.880). More eyes were placed into the RBG than the MBG, making use of all four criteria (90 vs. 24, 143 vs. 46, 76 vs. 18, and 103 vs. 36, respectively). RBG patients had a smaller optic disc area than did MBG patients in 3 of the 4 criteria. Signal strength affected the diagnostic performance of cRNFL thickness measurement (P = 0.043), whereas that of macular thickness was not affected by any covariate analyzed. CONCLUSIONS Overall, cRNFL thickness measurements were generally superior to those of macular thickness when used to diagnose glaucoma. Macular thickness parameters were of greater value in eyes with larger optic discs.

Detection of macular and circumpapillary structural loss in normal hemifield areas of glaucomatous eyes with localized visual field defects using spectral-domain optical coherence tomography

BackgroundTo investigate thickness of the macular ganglion cell complex (mGCC) and circumpapillary retinal nerve fiber layer (cRNFL) in retinal segments without visual field (VF) loss in glaucomatous eyes in which localized VF defects were confined to a single hemifield, using spectral-domain optical coherence tomography (SD-OCT).MethodsSeventy-one Asian glaucomatous patients and 64 normal subjects underwent mGCC and cRNFL imaging employing RTVue-100 SD-OCT. We compared both thickness parameters in retinal segments without VF defects with those in segments in which such defects were evident, and in matched segments of normal controls. Linear regression analysis was used to investigate the relationship between mGCC and cRNFL thickness parameters of segments with or without VF defects, and glaucoma status based on Humphrey field analyzer (HFA) indices.ResultsMean mGCC thickness in the hemiretinae of glaucomatous eyes without VF defects was 87.2 ± 9.3 μm, significantly lower than in matched control hemiretinae (96.2 ± 5.0 μm; p < 0.001), but significantly higher than in glaucomatous hemiretinae with VF defects (76.4 ± 9.9 μm; p < 0.001). A similar trend was also noted with mean cRNFL thickness. There were significant associations between both thickness parameters in glaucomatous hemiretinae with or without VF loss and degree of VF damage at initial presentation.ConclusionsPerimetrically normal hemifields of glaucomatous eyes had significantly lower mGCC and cRNFL thicknesses than did the corresponding retinal regions of healthy eyes. SD-OCT may be a useful ancillary diagnostic tool for evaluation of early macular and circumpapillary structural changes in glaucomatous eyes with localized VF defects.

Retinal Nerve Fiber Layer Normative Classification by Optical Coherence Tomography for Prediction of Future Visual Field Loss

PURPOSE To evaluate the utility of baseline Stratus optical coherence tomography (OCT; Carl Zeiss Meditec, Dublin, CA) retinal nerve fiber layer (RNFL) normative classification in the prediction of future visual field (VF) loss. METHODS Eighty-eight eyes with suspected glaucoma with abnormal RNFL classification by Stratus OCT were followed up for more than 4 years. VF conversion in three consecutive tests was assessed after baseline Stratus OCT and VF examination. Baseline intraocular pressure, VF global indices, OCT RNFL thickness, and number of abnormal OCT sectors were compared between VF converters (CG) and nonconverters (NCG). Positive and negative predictive values (PPV, NPV) of OCT sectors with abnormal classifications were calculated with respect to VF conversion. Hazard ratios (HRs) of various risk factors, including abnormal OCT classification, with respect to future VF conversion, were determined by use of the Cox proportional hazard model. RESULTS Twenty-one (23.9%) eyes showed VF conversion during follow-up. Baseline OCT RNFL thickness was significantly lower and the number of abnormal OCT RNFL sectors significantly greater in CG than in NCG patients (P = 0.022 for both). The PPV and NPV of normative OCT RNFL classification was highest in the inferior quadrant (50%, 87.1%, respectively). Baseline VF mean deviation (MD) and the number of abnormal OCT RNFL sectors were both associated with future VF conversion (HR, 0.788 and 1.290, respectively). CONCLUSIONS In patients with suspected glaucoma, an abnormal RNFL classification in the inferior area of the optic disc or an elevated number of abnormal RNFL sectors, as determined by Stratus OCT, were both associated with future VF conversion.

Factors Associated with the Signal Strengths Obtained by Spectral Domain Optical Coherence Tomography

Purpose The aim of this study was to investigate factors associated with the signal strengths (SS, image quality scores) of optic disc and macular images obtained using Cirrus spectral domain optical coherence tomography (OCT). Methods Ninety-two glaucomatous eyes were imaged using the Cirrus OCT macular and optic disc cube modes after pupil dilation. The influences of patient age, spherical equivalent, cataract presence, and cataract and glaucoma severity (visual field mean deviation), on the SS of images obtained using the two cube modes were compared between patients whose images showed high SS (SS ≥7) and low SS (SS <7). Results The signal strength was significantly higher in images obtained using the macular cube compared to the optic disc cube mode (7.8 ± 1.3 vs. 6.9 ± 1.1, respectively; p = 0.001). Age and visual acuity of patients differed significantly between the high- and low-SS groups when data acquired using the optic disc (p = 0.027 and 0.012, respectively) and macular cube modes (p = 0.046 and 0.014, respectively) were analyzed. When the optic disc cube mode was employed, the extent of cataracts was significantly related to SS, whereas when the macular cube mode was used, none of the factors analyzed was significantly associated with SS. Conclusions Age, visual acuity, and the extent of cataracts were significantly associated with images of higher SS when the Cirrus OCT optic disc cube mode was employed.

Characterization of peripapillary atrophy using spectral domain optical coherence tomography.

Purpose To characterize the features of peripapillary atrophy (PPA), as imaged by spectral-domain optical coherence tomography (SD-OCT). Methods SD-OCT imaging of the optic disc was performed on healthy eyes, eyes suspected of having glaucoma, and eyes diagnosed with glaucoma. From the peripheral β-zone, the retinal nerve fiber layer (RNFL), the junction of the inner and outer segments (IS/OS) of the photoreceptor layer, and the Bruchs membrane/retinal pigment epithelium complex layer (BRL) were visualized. Results Nineteen consecutive eyes of 10 subjects were imaged. The RNFL was observed in the PPA β-zone of all eyes, and no eye showed an IS/OS complex in the β-zone. The BRL was absent in the β-zone of two eyes. The BRL was incomplete or showed posterior bowing in the β-zone of five eyes. Conclusions The common findings in the PPA β-zone were that the RNFL was present, but the photoreceptor layer was absent. Presence of the BRL was variable in the β-zone areas.

The glaucoma detection capability of spectral-domain OCT and GDx-VCC deviation maps in early glaucoma patients with localized visual field defects

PurposeTo evaluate and compare the glaucoma detection capabilities afforded by retinal nerve fiber layer (RNFL) thickness and deviation maps obtained using Cirrus spectral domain optical coherence tomography (Cirrus OCT), and GDx employing variable corneal compensation (GDx-VCC) in glaucoma patients with early, localized visual field (VF) loss.MethodsThis prospective controlled, comparative study was performed on 42 eyes with localized VF defects, and 42 age/refractive error-matched healthy eyes. All participants were imaged by both imaging devices at the same visit. The area of the RNFL defect in each deviation map, corresponding to a VF defect, was analyzed by direct counting of color-coded superpixels in each device. Receiver operating characteristic (ROC) curves were constructed and compared between Cirrus OCT and GDx-VCC.ResultsThe areas under the ROCs (AUCs) of RNFL quadrant thicknesses in hemifields with visual field (VF) defects did not differ significantly (Cirrus OCT; 0.961, GDx-VCC; 0.919, P = 0.07). However, Cirrus OCT afforded a better diagnostic ability, by deviation map analysis, than did GDx-VCC (0.972 vs 0.887, P = 0.02).ConclusionsThe RNFL thicknesses assessed by either Cirrus OCT or GDx-VCC were comparable in terms of early glaucoma diagnostic capability. However, when areas containing RNFL defects were analyzed via deviation mapping, Cirrus OCT was better than GDx-VCC.