Visual Field Pattern Standard Deviation Research Articles

Progression Pattern of Initial Parafoveal Scotomas in Glaucoma

To characterize the progression pattern of initial parafoveal scotomas (IPFSs) using cross-sectional and longitudinal 10-2 visual field (VF) data. Retrospective, observational study. Glaucoma patients with an IPFS in either hemifield based on 2 reliable 24-2 Swedish interactive threshold algorithm standard VFs (≥3 adjacent points with P<0.05 within the central 10° of fixation, 1 point or more with P<0.01 lying at the innermost paracentral points, and no scotoma outside the central 10°) and at least 2 10-2 VFs (first and last VFs 1 year or more apart). To simulate a cohort with an extended follow-up, eyes with an IPFS were divided into subgroups based on the severity of glaucoma using their 10-2 VF pattern standard deviation (PSD). Cross-sectional data were used to create an average pattern deviation map that was generated by averaging pattern deviation map values of 10-2 VF point-by-point within each subgroup. Longitudinal data (eyes with 5 or more 10-2 VFs) was used to perform pointwise linear regression analysis of pattern deviation values. Patterns of IPFS progression were identified from these cross-sectional and longitudinal assessments. Average pattern deviation maps (cross-sectional) and maps of progression rates (longitudinal) in different disease severity subgroups. Eighty eyes (80 patients) and 40 eyes (40 patients) with an IPFS were included for cross-sectional and longitudinal analyses, respectively. The mean age ± standard deviation, 24-2 VF mean deviation, and 24-2 VF PSD for all eyes were 63±10 years, -3.27±2.18 dB, and 5.46±2.40 dB, respectively. Based on maps generated in both cross-sectional and longitudinal analyses, IPFS in the superior hemifield had an arcuate pattern initially that later deepened approximately 3° to 5° above fixation. The scotoma then elongated toward the physiologic blind spot and spread toward the nasal periphery, sparing the area corresponding to the papillomacular bundle. The IPFS in the inferior hemifield had a similar pattern, but was slightly farther from fixation. Superior and inferior IPFS have a similar characteristic pattern of progression, although the latter tend to be farther from fixation. Understanding these patterns should help in the management of such patients and in improving VF testing algorithms.

Glaucoma Progression in Eyes with a History of Refractive Corneal Surgery

To evaluate the glaucoma progression in patients with a history of refractive corneal surgery (RCS). A total of 313 eyes of 313 glaucoma patients (RCS group, 34 eyes; non-RCS group, 279 eyes) with a mean follow-up period of 2.7 years were included. Glaucoma progression was determined either by experts' stereoscopic optic disc/retinal nerve fiber layer (RNFL) photographs or by serial visual field (VF) data. Uni- and multivariate Cox's proportional hazards models were used to determine associations between potential risk factors including a history of RCS and glaucoma progression. Among 313 eyes, 87 (27.8%) eyes showed progression either by optic disc/RNFL photographs or VF assessment during the follow-up period. Ten (29.4%) of eyes in the RCS group and 77 (27.6%) of eyes in the non-RCS group showed glaucoma progression; however, prevalence of progression did not differ between the two groups (P = 0.482). Among all participants, baseline age and VF pattern standard deviation (PSD; hazard ratios of 1.013 and 1.119; P = 0.026 and P < 0.001, respectively) were significant risk factors for progression. In both the RCS and the non-RCS group, only VF PSD was a significant risk factor for progression according to multivariate Cox proportional hazards (1.193, 1.099, P < 0.001, P < 0.001, respectively). Baseline VF PSD and age substantially affected glaucoma progression in all study participants, although their RCS history was not a significant risk factor for glaucoma progression.

Retinal nerve fiber layer thickness in subgroups of multiple sclerosis, measured by optical coherence tomography and scanning laser polarimetry

Optical coherence tomography (OCT) and scanning laser polarimetry (GDx ECC) are non-invasive methods used to assess retinal nerve fiber layer (RNFL) thickness, which may be a reliable tool used to monitor axonal loss in multiple sclerosis (MS). The objectives of this study are (1) to compare OCT with the GDx ECC; (2) to assess and compare the RNFL thickness in subgroups of MS. Ophthalmologic examination and RNFL assessment by OCT and GDx were performed in 65 MS patients (26 relapsing-remitting (RRMS), ten secondary-progressive (SPMS), 29 primary-progressive (PPMS)). Twenty-eight patients (43%) had a history of optic neuritis (ON). Adjustments were made for age and disease duration. RNFL thickness was reduced in eyes with previous ON (p < 0.01). No differences were found between PPMS and relapse-onset MS. OCT and GDx ECC measurements were moderately correlated (rho = 0.73, p < 0.01). Visual field-mean deviation (MD) values correlated with OCT means (r = 0.44, p < 0.01) and GDx ECC TSNIT average (r = 0.41, p < 0.01). In patients without previous ON, EDSS correlated with MD (r = −0.36, p < 0.01), visual field-pattern standard deviation (PSD) (r = 0.30, p < 0.05), OCT means (r = −0.31–0.30, p < 0.05) and macular volume (r = −0.37, p < 0.01). For MSIS-29 physical impact score, significant correlations were found with MD (r = −0.48, p < 0.01) and PSD (r = 0.48, p < 0.01). Conclusions: No differences between PPMS and relapse-onset MS subgroups were found. RNFL thickness was reduced in eyes with previous ON. Although OCT and GDx ECC findings were moderately correlated and showed significant correlations with measures of visual function in patients without previous ON, EDSS correlated significantly with visual and OCT measures, but not with GDx ECC.

Diurnal Intraocular Pressure Fluctuation and Associated Risk Factors in Eyes with Angle Closure

To investigate diurnal intraocular pressure (IOP) fluctuation in eyes with angle closure in comparison with normal subjects and to look for associated risk factors for IOP fluctuation. Prospective, cross-sectional study. Ninety-eight eyes of 98 Asian subjects with angle closure (consisting of 32 primary angle-closure suspects [PACS], 34 subjects with primary angle closure [PAC], and 32 subjects with primary angle-closure glaucoma [PACG]) and 21 eyes of 21 normal control subjects. All angle-closure subjects were enrolled after laser peripheral iridotomy but before commencement of any medical or surgical treatment. Ophthalmic examination, including dynamic gonioscopy and automated perimetry, were performed, and diurnal IOP measurements were obtained using noncontact air-puff tonometry at hourly intervals between 8:00 am and 5:00 pm. Mean diurnal IOP, peak diurnal IOP, trough IOP, and IOP fluctuation (peak IOP-trough IOP) were compared between groups. Multiple linear regression analysis was performed to study the association of IOP fluctuation with clinical variables such as age, extent of peripheral anterior synechiae (PAS), central corneal thickness, vertical cup-to-disc ratio, and pattern standard deviation (PSD) on automated perimetry. Mean diurnal IOP, peak IOP, and IOP fluctuation. Most subjects were Chinese (89.1%) and female (61.3%). Intraocular pressure fluctuation was significantly higher in PACG (5.4+/-2.4 mmHg) and PAC (4.5+/-2.3 mmHg) subjects compared with PACS subjects (3.7+/-1.2 mmHg) and normal controls (3.8+/-1.1 mmHg; P = 0.005), with highest IOP found in the early morning. The combined PACG and PAC group had more than twice the risk (odds ratio, 2.38; 95% confidence interval, 1.1-5.1; P = 0.025) of having IOP fluctuation of more than 3 mmHg compared with the combined PACS and normal group. Extent of PAS (Pearson's correlation coefficient, r = 0.37; P = 0.0001) and visual field PSD (r = 0.34; P = 0.0002) were found to be associated with greater IOP fluctuation. The PACG and PAC eyes showed diurnal IOP fluctuation of 4 to 5 mmHg, and this fluctuation was higher than in PACS subjects and normal controls. The degree of PAS and visual field loss were associated with IOP fluctuation in PAC and PACG eyes.

Risk Factors for Normal-Tension Glaucoma Among Subgroups of Patients

To identify risk factors for normal-tension glaucoma among subgroups of patients. In 93 patients with unilateral normal-tension glaucoma, intereye comparison of baseline spherical equivalent, central corneal thickness, untreated intraocular pressure, disc area, and zone beta variables was performed among the following 4 subgroups classified according to age and visual field pattern standard deviation of the eye with glaucoma: subgroup 1 (age < or = 50 years and visual field pattern standard deviation < or = 8 dB), subgroup 2 (< or = 50 years and >8 dB), subgroup 3 (>50 years and < or = 8 dB), and subgroup 4 (>50 years and >8 dB). Fourteen, 27, 30, and 22 patients were included in subgroups 1, 2, 3, and 4, respectively. The untreated intraocular pressure in subgroup 1 (P = .005), the zone beta variables in subgroup 2 (P < .001), and both the untreated intraocular pressure (P = .010 and P = .034, respectively) and the zone beta variables (P < or = .008 and P < or = .006, respectively) in subgroups 3 and 4 were significantly greater in the eyes with glaucoma than in the normal contralateral eyes (by paired t test or Wilcoxon signed rank test). The other variables showed no significant difference between the eyes in any subgroup. The zone beta variables (and not the untreated intraocular pressure) may represent significant risk factors in young patients having normal-tension glaucoma with moderate to severe visual field loss.

The Accuracy and Clinical Application of Predictive Models for Primary Open-Angle Glaucoma in Ocular Hypertensive Individuals

This report compares the accuracy of 3 prediction models for the development of primary open-angle glaucoma (POAG). The models differ primarily in their handling of these eye-specific variables: intraocular pressure (IOP), central corneal thickness (CCT), vertical cup-to-disc ratio (VCD), and visual field pattern standard deviation (PSD). The "means" model includes age and the means of right and left eyes; the "means plus asymmetry" model includes age, the means of right and left eyes as well as the absolute difference between eyes for eye-specific variables; and the "worse" eye model includes age and values from the eye at higher risk for developing POAG. This report uses data from the observation group of the Ocular Hypertension Treatment Study (OHTS) and the placebo group of the European Glaucoma Prevention Study (EGPS) who have complete data on both eyes at baseline. Performance of the prediction models is assessed using the c-statistic, calibration chi-square, and Pearson correlation coefficient. The OHTS observation group (n = 717; 6.7 years median follow-up) and the EGPS placebo group (n = 324; 4.9 years median follow-up). Baseline data included demographic characteristics, medical history, ocular examination, visual fields, and optic disc photographs. Development of reproducible visual field abnormality or optic disc deterioration as determined by masked readers and attributed to POAG by a masked end point committee. Baseline factors that were statistically significant in all predictive models were age, IOP, CCT, VCD, and PSD. Also, statistically significant were baseline asymmetry in IOP and asymmetry in VCD. The c-statistics for the "means" model, "means plus asymmetry" model, and "worse" eye model were 0.74, 0.77, and 0.75, respectively. The calibration chi-square values were 7.32, 11.19, and 1.81, respectively. Correlation coefficients between risk estimates calculated by different models ranged from 0.94 to 0.98. The high agreement between the risk estimates from 3 different predictive models for the development of POAG suggests little difference in their statistical or clinical performance. The predictive model that uses the means of both eyes for eye-specific variables is the simplest to use and the most robust to measurement variability and error.

Agreement Between Stereophotographic and Confocal Scanning Laser Ophthalmoscopy Measurements of Cup/Disc Ratio: Effect on a Predictive Model for Glaucoma Development

To evaluate risk estimates obtained by incorporating confocal scanning laser ophthalmoscopy measurements of cup/disc (C/D) ratio into a previously described and validated predictive model to estimate the risk of glaucoma development in ocular hypertension. These risk estimates were compared with those obtained by the original model in which vertical C/D ratio was estimated from stereophotographs. Cross-sectional study. The study included 118 eyes of 59 patients with normal optic discs, normal visual fields, and high intraocular pressure. The original predictive model contained information on 6 baseline factors: age, intraocular pressure, central corneal thickness, vertical C/D ratio, visual field pattern standard deviation, and presence of diabetes. Information regarding these baseline factors was collected for each patient. For the original model, vertical C/D ratio was estimated from stereophotographs. The Heidelberg Retina Tomograph (HRT) model used an identical model, except that the parameter linear C/D ratio was used to provide C/D ratio estimates. All patients underwent confocal scanning laser ophthalmoscopy imaging HRT II within 6 months of stereophotographs. The agreement between stereophotograph and HRT II risk estimates was evaluated by Bland-Altman plots. The difference between HRT II and stereophotograph estimates of C/D ratio was within 0.2 in 95% of the patients. When incorporated into the predictive model, estimates of risk using the HRT II parameter linear C/D ratio were highly correlated to those obtained using stereophotographs (rho=0.954; P<0.001). The 95% limits of agreement were -4.57% to 4.65%. HRT II and stereophotograph estimates of C/D ratio can be used interchangeably when incorporated into a predictive model to estimate the risk of conversion from ocular hypertension to glaucoma.