Shortening of interpupillary distance after topical prostaglandin analog eye drop application in an ophthalmic surgeon: A case report.

Purpose: This study reports a case of interpupillary distance (IPD) shortening after instillation of topical prostaglandin analog (PGA) eye drops. Observations: The patient was a 36-year-old ophthalmic vitreoretinal surgeon from Tochigi, Japan, with primary open-angle glaucoma and bilaterally instilled PGA eye drops to decrease intraocular pressure. His IPD had been recorded closely based on surgical microscope settings. The patient had a stable IPD for over five years before the use of PGA drops. The patient noticed IPD shortening associated with latanoprost usage since four years. The IPD shortened further twice with temporal switching to bimatoprost. However, the IPD partially recovered both the times on discontinuing the medication over the course of several months. Conclusions and Importance: Fluctuations in IPD with visible cosmetic changes occur in association with the use of topical PGA eye drops. There might be effects of PGA drops on binocular vision, which are possibly unaddressed and warrant further study.

Shortening of Interpupillary Distance after Instillation of Topical Prostaglandin Analog Eye Drops.

PURPOSE: To investigate changes in the interpupillary distance (IPD) after continual instillation of topical prostaglandin analogs (PGAs) in glaucoma patients as an objective indicator of prostaglandin-associated periorbitopathy (PAP). DESIGN: Retrospective, comparative case series. METHODS: A total of 152 institutional patients with glaucoma were enrolled in this study. Inclusion criteria were visual acuities exceeding 10/20 bilaterally and no intraocular surgery during observation. Intervention/observation procedures: First-time bilateral instillation of bimatoprost, travoprost, latanoprost, or tafluprost and IPDs measured by automatic refractometry. IPDs, intraocular pressures (IOPs), and refractive errors were measured before and after continual drug administration (treatment, 2-24 months). MAIN OUTCOME MEASUREMENTS: Post-treatment changes in IPDs. A total of 61 untreated patients served as controls. RESULTS: The IPDs shortened significantly (P < 0.001) after treatment (-0.80 ± 2.1 mm); the IPDs of control subjects remained unchanged (0.05 ± 0.96 mm; P = 0.69). The IPD change after bimatoprost instillation (-2.20 ± 0.97 mm) was significantly (P < 0.001) greater than with other PGAs (-0.65 ± 2.09 mm). The IOPs decreased significantly (P < 0.001) (-3.7 ± 4.3 mm Hg); the refractive errors did not change significantly (P < 0.099) (-0.07 ± 0.69 diopter) post-treatment. The percentages of subjects with 2-mm or greater decreases in IPD after bimatoprost, travoprost, latanoprost, or tafluprost were 85.7%, 20.0%, 18.2%, and 17.2%, respectively, and with 3-mm or greater decreases in IPD 35.7%, 12.0%, 14.5%, and 12.1%, respectively. The specificities were 93.4% and 100% in the control group, respectively, with IPD threshold changes of 2 and 3 mm or more, respectively. CONCLUSIONS: The IPD decreased significantly after topical PGAs within 24 months. The effect was significantly greater with bimatoprost than with other PGAs. The noninvasive, immediate automatic refractometry measurement may be an objective numerical indicator of PAP.

Developing an Item Bank to Measure Quality of Life in Individuals With Glaucoma, and the Results of the Interview With Patients: The Effect of Visual Function, Visual Field Progression Rate, Medical, and Surgical Treatments on Quality of Life.

PURPOSE: To construct a new item bank to measure quality of life (QOL) in glaucoma patients and to evaluate glaucoma patients' QOL using the item bank. METHODS: An item bank of questions was generated through a literature review of QOL instruments useful for glaucoma patients. Using this item bank, a cognitive survey was performed on 203 patients with glaucoma (112 males and 91 females, 61.9±11.9 y old; mean±SD). The results were then analyzed using the Rasch analysis, and the Rasch-derived disability scores were predicted using linear modelling and the following clinical parameters: age, mean total deviation (mTD) in superior and inferior visual field (mTDsup/mTDinf), mTD progression rate, better visual acuity, worse visual acuity, number of eye drops administered per day, number of trabeculectomy procedures experienced in both eyes. RESULTS: A total of 23 questionnaires of QOL in glaucoma patients were identified resulting in an item bank of 187 questions related to the following tasks: reading/writing, walking, going out, eating and driving (direct disability) as well as questions concerned with worry/anxiety, social participation, and physical symptoms (indirect disability). In the optimal model for direct disability, age and mTDinf were identified as significant predictors, whereas number of eye drops administered per day and number of trabeculectomy experienced were included in the optimal model for indirect disability. CONCLUSIONS: A new item bank to measure QOL in glaucoma patients was developed and evaluated. Age and mTDinf were found to be related to direct disability while medical and surgical treatments were related to indirect disability.

Applying "Lasso" Regression to Predict Future Glaucomatous Visual Field Progression in the Central 10 Degrees.

PURPOSE OF THE STUDY: We recently reported that it is beneficial to apply least absolute shrinkage and selection operator (Lasso) regression to predict future 24-2 visual field (VF) progression. The purpose of the current study was to investigate the usefulness of Lasso regression to predict VF progression in the central 10 degrees (10-2) in glaucoma patients. METHODS: Series of 10 VFs (Humphrey Field Analyzer 10-2 SITA-standard) from each of 149 eyes in 110 open angle glaucoma patients, obtained over 5.7±1.4 years (mean±SD) were investigated. Mean deviation values of the 10th VF were predicted using varying numbers of VFs (ranging from the first to third VFs to the first to ninth VFs), applying ordinary least square regression (OLSLR) and Lasso regression. Absolute prediction errors were then compared. RESULTS: With OLSLR, prediction error varied between 5.4±5.0 (using first to third VFs) and 1.1±1.6 dB (using first to ninth VFs). Significantly smaller prediction errors were obtained with Lasso regression, in particular with small numbers of VFs (from 2.1±2.8: first to third VFs, to 1.0±1.6 dB: first to ninth VFs). A large λ value, which is an index showing the degree of penalty in Lasso regression, was observed when a small number of VFs were used for prediction. CONCLUSION: Mean deviation prediction using OLSLR with a small number of VFs resulted in large prediction errors. It was useful to apply Lasso regression when predicting future progression of the central 10 degrees, compared to OLSLR.

Estimating the Binocular Visual Field of Glaucoma Patients With an Adjustment for Ocular Dominance.

PURPOSE: To investigate whether it is possible to improve estimation of the binocular visual field (VF) using monocular sensitivities on a linear scale adjusted for ocular dominance. METHODS: Monocular and binocular VF measurements were evaluated using the Humphrey Field Analyzer (HFA; 24-2 Swedish Interactive Threshold Algorithm standard program) in 60 eyes of 30 patients with open angle glaucoma. Ocular dominance was measured twice in each patient and the average value was used. Measured binocular sensitivity was then predicted based on monocular measurements using the "better sensitivity" integrated visual field (IVF) method, monocular sensitivity summation methods on the dB scale, linear scale (1/Lambert), and finally monocular sensitivity summation methods on the linear scale adjusted for the ocular dominance. RESULTS: The absolute prediction error with the linear scale summation method (mean ± SD: 3.11 ± 4.00) was significantly smaller than the IVF method (3.15 ± 4.09; P = 0.014). Further, the absolute prediction error for the ocular dominance adjusted method (3.10 ± 3.99) was significantly smaller than the nonadjusted linear scale summation method (P = 0.014). The absolute prediction error associated with the dB scale summation method was significantly larger than any other method (8.15 ± 5.06; P < 0.0001). CONCLUSIONS: The most accurate estimation of binocular sensitivity was achieved using the linear monocular sensitivity summation model adjusted for ocular dominance.

Outcomes of Late-Onset Bleb-Related Endophthalmitis Treated with Pars Plana Vitrectomy.

Purpose. To investigate clinical results on bleb-related endophthalmitis (BRE) after trabeculectomy treated with pars plana vitrectomy (PPV) and to evaluate influence factors for visual prognosis. Methods. Investigating medical records retrospectively, BRE was defined as an endophthalmitis induced by bleb infection. A total of 2018 eyes of 1225 patients who had trabeculectomy between December 2000 and July 2013 were included in this study. Eleven eyes of 11 patients with BRE were performed with PPV. Results. The mean age was 56.6 years. The mean period between trabeculectomy and BRE onset was 7.4 years. The mean period from starting symptom to initiation of treatment for endophthalmitis (PSITE) was 2.3 days. Bleb leakages were observed in 7 eyes (64%). On culture examinations, highly pathogenic bacteria (HPB) were identified in 6 cases (55%). HPB infection was influence factors on visual disturbance (P = .0337). Number of HPB infections is significantly higher in poor visual outcome than without poor visual outcome (P = .0310). Conclusion. Visual prognosis of BRE treated by PPV is significantly better when the pathogenic bacteria are not HPB. Severe visual loss occurred with HPB infection even though patients had appropriate treatments. Physicians need to have careful consideration to prevent bleb infection after trabeculectomy with MMC.

Diagnosis of Early-Stage Glaucoma by Grid-Wise Macular Inner Retinal Layer Thickness Measurement and Effect of Compensation of Disc-Fovea Inclination.

PURPOSE: To evaluate grid-wise analyses of macular inner retinal layer thicknesses and effect of compensation of disc-fovea inclination for diagnosing early-stage glaucoma. METHODS: Spectral-domain optical coherence tomography measurements over a 6.0 × 6.0-mm macular area were prospectively obtained in 104 eyes of 104 patients with early-stage glaucoma with a mean deviation of -1.8 ± 1.9 dB and 104 eyes of 104 age- and refraction-matched normal subjects. Macular retinal nerve fiber layer (mRNFL), ganglion cell-inner plexiform layer (GCIPL) combined, and ganglion cell complex (GCC) thickness of the entire area and each subdivided macular grid were determined to compare diagnostic capability for glaucoma using receiver operating characteristic curves and various normal cutoff values for each layer thickness and number of grids flagged as abnormal. Diagnostic capability was then compared with that of circumpapillary RNFL (cpRNFL) measurements. Effects of compensation of inclination of disc-fovea line by reconfiguration of the macular grid were also studied. RESULTS: Macular inner retinal layer analyses using 8 × 8 grids generally yielded higher diagnostic capability. Only the 8 × 8 grid GCC analyses using the various normal cutoff values yielded a sensitivity ≥ 0.90 with specificity ≥ 0.95 under several conditions in discriminating the glaucoma eyes. In glaucoma and normal eyes with both reliable cpRNFL and macular measurements, the best sensitivity/specificity were 0.98/0.95 for the 8 × 8 grid-mRNFL analysis and 0.93/0.96 for the 8 × 8 grid GCC analysis using various normal cutoff values, which were better than that (0.78/0.95) for clock-hour cpRNFL analysis (P = 0.001). Compensation of the disc-fovea inclination did not improve the diagnostic capability. CONCLUSIONS: Grid-wise analysis of macular GCC--especially using 8 × 8 grids and normative data-based cutoff values--was very useful for diagnosing early-stage glaucoma, though compensation of the disc-fovea inclination had little effect.

How Many Visual Fields Are Required to Precisely Predict Future Test Results in Glaucoma Patients When Using Different Trend Analyses?

PURPOSE: To evaluate the minimum number of visual field (VF) tests required to precisely predict future VF results using ordinary least squares linear regression (OLSLR), quadratic regression, exponential regression, logistic regression, and M-estimator robust regression model. METHODS: Series of 15 VFs (Humphrey Field Analyzer 24-2 SITA standard) were analyzed from 247 eyes of 155 open-angle glaucoma patients. Future point-wise (PW) VF results and mean VF sensitivities were predicted with varying numbers of VFs in each regression method. RESULTS: In PW-OLSLR, as expected, the minimum absolute prediction error was obtained using the maximum number of VFs in the regression (14 VFs); mean absolute prediction error was equal to 2.4 ± 0.9 dB. Ten VFs were required to reach the 95% confidence interval (CI) of the minimum absolute prediction error. Prediction errors associated with the exponential and quadratic regression models were significantly larger than those from PW-OLSLR, whereas errors from logistic regression were not significantly smaller than those from PW-OLSLR; however, the absolute prediction error from the M-estimator robust regression model was significantly smaller than those associated with PW-OLSLR (P < 0.01, paired Wilcoxon test). Like PW-OLSLR, 10 VFs were needed to obtain the minimum absolute prediction error of mean VF sensitivity, but there were no significant differences in errors using the different regression methods. CONCLUSIONS: Approximately 10 VFs, are needed to achieve an accurate prediction of PW VF sensitivity and mean sensitivity. Prediction error of PW VF sensitivity can be significantly minimized using the M-estimator robust regression model compared with conventional OLSLR.

Transient but significant visual field defects after robot-assisted laparoscopic radical prostatectomy in deep tRendelenburg position.

BACKGROUND: Robot-assisted laparoscopic radical prostatectomy (RALP) is a minimally invasive surgical procedure for prostate cancer. During RALP, the patient must be in a steep Trendelenburg (head-down) position, which leads to a significant increase in intraocular pressure (IOP). The association of RALP with visual field sensitivity, however, has not been prospectively studied. The purpose of this study was to evaluate prospectively the visual field, retinal nerve fiber layer (RNFL) thickness, and optic disc morphology in 50 normal eyes of 25 male patients that underwent RALP. METHODS: The subjects were 25 males among 33 consecutive patients who underwent uneventful RALP under general anesthesia in our hospital. Visual field tests using the Humphrey visual field analyzer 30-2 SITA-standard program were performed before, 7 days after, and 1-3 months after RALP. IOP was measured before, during, and after RALP; and ophthalmologic examinations, including slit-lamp, fundus examination, and optical coherence tomography (OCT), were scheduled before and 7 days after surgery. RESULTS: IOP was significantly increased during RALP up to 29.4 mmHg (P<0.01). Postoperative local visual field defects were detected in 7 eyes of 7 subjects dominantly in the lower hemifield without abnormal findings in the optic nerve head or retina, and the visual field recovered to normal within 3 months after surgery. General factors associated with RALP, IOP, RNFL thickness, or optic disc parameters did not differ significantly between eyes with and without postoperative visual field defects, and parameters of OCT measurements were not altered after surgery. CONCLUSION: Transient but significant unilateral visual field defects were found in 28% of the subjects examined. The probable cause are the increased IOP and altered perfusion during surgery and ophthalmologic examinations are therefore suggested before and after RALP.

Do pattern deviation values accurately estimate glaucomatous visual field damage in eyes with glaucoma and cataract?

BACKGROUND/AIMS: To study the efficacy of pattern deviation (PD) values in the estimation of visual field compensating the influence of cataract in eyes with glaucoma. METHODS: The study subjects comprised of 48 eyes of 37 glaucoma patients. Mean total deviation value (mTDs) on Humphrey Field Analyzer after cataract surgery was compared with mean PD (mPD) before the surgery. Visual field measurements were carried out ≤6 months before (VF(pre)) and following (VF(post)) successful cataract surgery. The difference between the mPD or mTD values in the VF(pre) and mTD values in the VF(post) (denoted as εmPD/ΔmTD) was calculated, and the influence of the extent of 'true' glaucomatous visual field damage or cataract (as represented by εmPD and ΔmTD, respectively) on this difference was also investigated. RESULTS: There was a significant difference between mTD in the VF(pre) and mTD in the VF(post) (p<0.001, repeated measures analysis of variance). There was not a significant difference between mPD in the VF(pre) and mTD in the VF(post) (p=0.06); however, εmPD was significantly correlated with the mTD in VF(post) and also ΔmTD (R(2)=0.56 and 0.27, p<0.001, Pearson's correlation). The accurate prediction of the mTD in the VF(post) can be achieved using the pattern standard deviation (PSD), mTD and also visual acuity before surgery. CONCLUSIONS: Clinicians should be very careful when reviewing the VF of a patient with glaucoma and cataract since PD values may underestimate glaucomatous VF damage in patients with advanced disease and also overestimate glaucomatous VF damage in patients with early to moderate cataract.

Applying "Lasso" Regression to Predict Future Visual Field Progression in Glaucoma Patients.

PURPOSE: We evaluated the usefulness of various regression models, including least absolute shrinkage and selection operator (Lasso) regression, to predict future visual field (VF) progression in glaucoma patients. METHODS: Series of 10 VFs (Humphrey Field Analyzer 24-2 SITA-standard) from each of 513 eyes in 324 open-angle glaucoma patients, obtained in 4.9 ± 1.3 years (mean ± SD), were investigated. For each patient, the mean of all total deviation values (mTD) in the 10th VF was predicted using varying numbers of prior VFs (ranging from the first three VFs to all previous VFs) by applying ordinary least squares linear regression (OLSLR), M-estimator robust regression (M-robust), MM-estimator robust regression (MM-robust), skipped regression (Skipped), deepest regression (Deepest), and Lasso regression. Absolute prediction errors then were compared. RESULTS: With OLSLR, prediction error varied between 5.7 ± 6.1 (using the first three VFs) and 1.2 ± 1.1 dB (using all nine previous VFs). Prediction accuracy was not significantly improved with M-robust, MM-robust, Skipped, or Deepest regression in almost all VF series; however, a significantly smaller prediction error was obtained with Lasso regression even with a small number of VFs (using first 3 VFs, 2.0 ± 2.2; using all nine previous VFs, 1.2 ± 1.1 dB). CONCLUSIONS: Prediction errors using OLSLR are large when only a small number of VFs are included in the regression. Lasso regression offers much more accurate predictions, especially in short VF series.

Diagnostic performance and reproducibility of circumpapillary retinal nerve fiber layer thickness measurement in 10-degree sectors in early stage glaucoma.

PURPOSE: To study the circumpapillary retinal nerve fiber layer thickness (cpRNFLT) in a 10°-wide sector using spectral-domain optical coherence tomography for diagnostic ability in early stage open-angle glaucoma (OAG). METHODS: cpRNFLT measurements (3.4-mm diameter centered on the disc) were obtained from 89 eyes with early stage OAG (mean deviation, -2.5 ± 1.8 decibels) and 89 age-matched normal eyes. The ability of 180°-, 90°-, 30°-, and 10°-wide cpRNFLT sectors in discriminating early stage OAG eyes was evaluated by calculating the area under the receiver-operating characteristic curves (AUCs) and sensitivity/specificity per diagnostic criteria with varying sector widths, normative data-based cpRNFLT cutoff levels and numbers of abnormal sectors. The intra- and inter-visit reproducibilities of the cpRNFLT 10°-sector measurements were studied in a separate group of eyes with normal and early stage OAG. RESULTS: The greatest AUC obtained using the cpRNFLT 10° sector, 0.924 (confidence interval, 0.875-0.958), did not differ significantly from those obtained with the 180°, 90°, and 30° sectors. Only calculations using the 10° sectors had sensitivities and specificities of 0.90 or higher with the best performance of the sensitivity/specificity of 0.92/0.94. These values tended to be better (P = 0.070) than with the 30° sectors, 0.85/0.94, which were also selected with several combinations of various cutoff levels and the number of abnormal sectors. The coefficients of variation for the intra- and inter-visit reproducibility of the 10°-sector measurements were 10 % or less in 32 and 24 of the 36 sectors. CONCLUSION: The cpRNFLT 10°-sector measurements showed reasonable reproducibility and identified eyes with early stage OAG with a sensitivity and specificity of 0.92/0.94.

An objective evaluation of gaze tracking in Humphrey perimetry and the relation with the reproducibility of visual fields: a pilot study in glaucoma.

PURPOSE: To develop a novel method to evaluate gaze tracking (GT) results and to examine their relationship with test-retest reproducibility of visual field (VF) measurements. METHODS: Subjects comprised of 42 eyes of 42 glaucoma patients. Vision fixation during VF tests with the Humphrey Field Analyzer was evaluated using the gaze fixation line chart at the bottom of the VF printout. We defined some GT parameters as follows: average tracking failure frequency per stimulus (TFF), average frequency of eye movements between 1° and 2°, 3° and 5°, and more than 6°. Humphrey VFs (24-2 and 10-2 Swedish Interactive Threshold Algorithm [SITA] standard) were prospectively examined twice within a period of 3 months in 42 glaucoma patients. Mean absolute variability of total deviation (TD) values in the test-retest VFs was measured and its relationship to fixation losses (FLs), false positives (FPs), false negatives (FNs), mean deviation (MD), and pattern standard deviation (PSD) was investigated using the corrected Akaike Information Criterion (AICc) from linear modeling. RESULTS: The best model to predict test-retest variability in the 24-2 VF included PSD, TFF, and FNs as dependent variables, while the best model for the 10-2 VF included PSD and average frequency of eye movements between 3° and 5° (P < 0.05 for all coefficients). CONCLUSIONS: Gaze tracking parameters are closely related to the reproducibility of VF results, and it would be beneficial to objectively use these parameters when estimating the reliability of VF tests.

Clustering visual field test points based on rates of progression to improve the prediction of future damage.

PURPOSE: To develop new visual field (VF) sectors based on pointwise rates of glaucomatous VF progression ("progression regions") and to evaluate their usefulness for predicting future progression. METHODS: A training dataset consisting of 10 VFs from each of 412 eyes in 412 open-angle glaucoma patients and a validation dataset consisting of 15 VFs from each of 71 eyes in 45 patients were investigated. First, using the training dataset, the VF was divided into small regions, according to the rates of progression of all 52 test points in the VF. Then, using the initial four VFs of the validation dataset, total deviation (TD) values in the 10th VF were predicted by applying linear regression analysis in derived regions and the absolute prediction error was calculated. The analysis was iterated, predicting TD values of the 10th VF, but each time including an additional VF in the regression (from five to nine VFs). Absolute prediction errors were then compared with conventional pointwise linear regression (PLR) and regression based on Nouri-Mahdavi (NM) sectors. RESULTS: Twenty-three progression regions were derived. In general, absolute prediction errors were significantly smaller for regression based on these regions compared with PLR and NM sectors. CONCLUSIONS: Predictions of VF progression can be improved by dividing the VF into small regions based on clusters of test points with similar progression rates.

Establishment of an experimental ferret ocular hypertension model for the analysis of central visual pathway damage.

Glaucoma optic neuropathy (GON) is a condition where pathogenic intraocular pressure (IOP) results in axonal damage following retinal ganglion cell (RGC) death, and further results in secondary damage of the lateral geniculate nucleus (LGN). Therapeutic targets for glaucoma thus focus on both the LGN and RGC. However, the temporal and spatial patterns of degeneration and the mechanism of LGN damage have not been fully elucidated. Suitable and convenient ocular hypertension (OH) animal models with binocular vision comparable to that of monkeys are strongly needed. The ferret is relatively small mammal with binocular vision like humans - here we report on its suitability for investigating LGN. We developed a new method to elevate IOP by injection of cultured conjunctival cells into the anterior chamber to obstruct aqueous outflow. Histologically, cultured conjunctival cells successfully proliferated to occlude the angle, and IOP was elevated for 13 weeks after injection. Macroscopically, the size of the eye gradually expanded. Subsequent enlargement of optic nerve head cupping and atrophic damage of LGN projected from the OH eye were clearly observed by anterograde staining with cholera toxin B. We believe the ferret may be a promising OH model to investigate secondary degeneration of central nervous system including LGN.

Focal relationship between structure and function within the central 10 degrees in glaucoma.

PURPOSE: To investigate which measurements of inner macular thickness are the most useful for evaluating the focal relationship with visual sensitivity within the central 10° in glaucoma and which layers require correction for retinal ganglion cell (RGC) displacement. METHODS: Sixty eyes of 60 subjects with glaucoma were included. Sensitivity of each test point of 10-2 standard automated perimetry was compared with the thickness of the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), GCL+ inner plexiform layer (IPL), and RNFL+GCL+IPL (GCC), with and without RGC displacement, using Spearman's rank correlation coefficients. Visual sensitivity was evaluated by unlogged 1/Lambert (1/L) values. RESULTS: Retinal nerve fiber layer thickness correlated significantly with the sensitivities of all test points except for some in the papillomacular bundle region when adjusting for RGC displacement (rs = 0.287-0.767, P < 0.05). In the central 5.8°, the GCL and (GCL+IPL) thickness correlated significantly with the sensitivities of all test points when adjusting for RGC displacement (GCL: rs = 0.363-0.729, P < 0.01; (GCL+IPL): rs = 0.359-0.715, P < 0.01). The GCC thickness correlated significantly with the sensitivities of all 68 test points when adjusting for RGC displacement (rs = 0.359-0.767, P < 0.01). RGC displacement improved the correlation between sensitivity and GCL, (GCL+IPL), and GCC in the central 4 points (GCL: rs = from 0.270-0.470 to 0.421-0.540; (GCL+IPL): rs = from 0.195-0.450 to 0.381-0.549; GCC: rs = from 0.132-0.449 to 0.359-0.562). CONCLUSIONS: The GCC is the most useful parameter to evaluate structure and function within the central 10° in glaucoma. Adjusting for RGC displacement is essential to evaluate the relationship between structure of the GCL-related layer and function at the central macula.

Discriminating between glaucoma and normal eyes using optical coherence tomography and the 'Random Forests' classifier.

PURPOSE: To diagnose glaucoma based on spectral domain optical coherence tomography (SD-OCT) measurements using the 'Random Forests' method. METHODS: SD-OCT was conducted in 126 eyes of 126 open angle glaucoma (OAG) patients and 84 eyes of 84 normal subjects. The Random Forests method was then applied to discriminate between glaucoma and normal eyes using 151 OCT parameters including thickness measurements of circumpapillary retinal nerve fiber layer (cpRNFL), the macular RNFL (mRNFL) and the ganglion cell layer-inner plexiform layer combined (GCIPL). The area under the receiver operating characteristic curve (AROC) was calculated using the Random Forests method adopting leave-one-out cross validation. For comparison, AROCs were calculated based on each one of the 151 OCT parameters. RESULTS: The AROC obtained with the Random Forests method was 98.5% [95% Confidence interval (CI): 97.1-99.9%], which was significantly larger than the AROCs derived from any single OCT parameter (maxima were: 92.8 [CI: 89.4-96.2] %, 94.3 [CI: 91.1-97.6] % and 91.8 [CI: 88.2-95.4] % for cpRNFL-, mRNFL- and GCIPL-related parameters, respectively; P<0.05, DeLong's method with Holm's correction for multiple comparisons). The partial AROC above specificity of 80%, for the Random Forests method was equal to 18.5 [CI: 16.8-19.6] %, which was also significantly larger than the AROCs of any single OCT parameter (P<0.05, Bootstrap method with Holm's correction for multiple comparisons). CONCLUSIONS: The Random Forests method, analyzing multiple SD-OCT parameters concurrently, significantly improves the diagnosis of glaucoma compared with using any single SD-OCT measurement.

Validating the sumi quality of life questionnaire with rasch analysis.

PURPOSE: To validate the Sumi Visual Disability Questionnaire (Sumi VDQ) to estimate visual disability in glaucoma patients using Rasch analysis. METHODS: A total of 162 glaucoma patients underwent visual field (VF) testing in both eyes (Humphrey 24-2 Swedish Interactive Threshold Algorithm [SITA] standard program). The binocular VF was then calculated using the integrated VF (IVF) method. Visual disability was scored using the Sumi VDQ, which was originally written in Japanese and contains 30 items (questions). Response scale analysis, targeting, and infit statistics associated with Rasch analysis were evaluated. Unidimensionality was analyzed using principal component analysis (PCA). In addition, the correlation between the person parameter obtained with Rasch analysis and the mean of total deviation values (mTD) in the IVF was compared with the correlation between the arithmetic sum of visual disability score and mTD of the IVF. RESULTS: All 30 items in the Sumi VDQ showed productive infit values (0.61-1.46). The person parameters distributed between -4.50 and 3.62, while the item difficulty targeting parameters distributed between -0.88 and 2.06. None of the PCA components had eigenvalues whose lower limit of 95% confidence interval (CI) exceeded 2 (0-1.5). There was a significant relationship between person parameter and mTD of IVF (r = -0.78, P < 0.001), which was significantly stronger (Meng-Rosenthal-Rubin method, P = 0.002) than that between arithmetic sum of visual disability score and mTD of IVF (r = -0.61, P < 0.001). CONCLUSIONS: The Sumi VDQ has constructive psychometric properties. In particular, the Rasch analysis-derived person parameter appears to be clinically more meaningful than the arithmetic sum of visual disability score.