Dataset Information

Estimation of retinal ganglion cell loss in glaucomatous eyes with a relative afferent pupillary defect.

ABSTRACT: To estimate retinal ganglion cell (RGC) losses associated with a relative afferent pupillary defect (RAPD) in glaucoma.A cross-sectional study was conducted including both eyes of 103 participants from the Diagnostic Innovations in Glaucoma Study. A total of 77 subjects had glaucoma in at least one eye and 26 were healthy. Pupil responses were assessed using an automated pupillometer that records the magnitude of RAPD as an "RAPD score." Standard automated perimetry (SAP) and optical coherence tomography (OCT) also were performed. Retinal ganglion cell counts were estimated using empirical formulas that combine estimates from SAP and OCT. The estimated percentage RGC loss was calculated using the combined structure function index (CSFI).There was good correlation between RAPD magnitude and intereye differences in estimated RGCs (R(2) = 0.492, P < 0.001), mean deviation (R(2) = 0.546, P < 0.001), retinal nerve fiber layer thickness (R(2) = 0.362, P < 0.001), and CSFI (R(2) = 0.484, P < 0.001). Therefore, a high RAPD score is likely to indicate large asymmetric RGC losses. The relationship between intereye difference in RGC counts and RAPD score was described best by the formula; RGC difference = 21,896 + 353,272 * RAPD score. No healthy subjects had an absolute RAPD score > 0.3, which was associated with asymmetry of 105,982 cells (or 12%).Good correlation between the magnitude of RAPD and intereye differences in mean deviation and estimated RGC counts suggests pupillometry may be useful for quantifying asymmetric damage in glaucoma. (ClinicalTrials.gov number, NCT00221897.).

SUBMITTER: Tatham AJ

PROVIDER: S-EPMC3907131 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Estimation of retinal ganglion cell loss in glaucomatous eyes with a relative afferent pupillary defect.

Tatham Andrew J AJ Meira-Freitas Daniel D Weinreb Robert N RN Marvasti Amir H AH Zangwill Linda M LM Medeiros Felipe A FA

Investigative ophthalmology & visual science 20140129 1

<h4>Purpose</h4>To estimate retinal ganglion cell (RGC) losses associated with a relative afferent pupillary defect (RAPD) in glaucoma.<h4>Methods</h4>A cross-sectional study was conducted including both eyes of 103 participants from the Diagnostic Innovations in Glaucoma Study. A total of 77 subjects had glaucoma in at least one eye and 26 were healthy. Pupil responses were assessed using an automated pupillometer that records the magnitude of RAPD as an "RAPD score." Standard automated perimet ...[more]

PMID: 24282221

Similar Datasets

Project description:To examine the hypotheses that in glaucomatous eyes with single-hemifield damage, retinal blood flow (RBF) is significantly reduced in the retinal hemisphere corresponding with the abnormal visual hemifield and that there are significant associations among reduced retinal sensitivity (RS) in the abnormal hemifield, RBF, and structural measurements in the corresponding hemisphere.Prospective, nonrandomized, case-control study.Thirty eyes of 30 patients with glaucoma with visual field loss confined to a single hemifield and 27 eyes of 27 controls.Normal and glaucomatous eyes underwent spectral-domain optical coherence tomography (SD-OCT) and standard automated perimetry. Doppler SD-OCT with a double-circle scanning pattern was used to measure RBF. The RBF was derived from the recorded Doppler frequency shift and the measured angle between the beam and the vessel. Total and hemispheric RBF, retinal nerve fiber layer (RNFL), and ganglion cell complex (GCC) values were calculated. The RS values were converted to 1/Lambert. Analysis of variance and regression analyses were performed.Total and hemispheric RS, RBF, RNFL, and GCC values.The total RBF (34.6±12.2 ?l/minute) and venous cross-sectional area (0.039 ± 0.009 mm(2)) were reduced (P<0.001) in those with glaucoma compared with controls (46.5 ± 10.6 ?l/minute; 0.052 ± 0.012 mm(2)). Mean RBF was reduced in the abnormal hemisphere compared with the opposite hemisphere (15.3 ± 5.4 vs. 19.3 ± 8.4 ?l/minute; P = 0.004). The RNFL and GCC were thinner in the corresponding abnormal hemisphere compared with the opposite hemisphere (87.0 ± 20.2 vs. 103.7 ± 20.6 ?m, P = 0.002; 77.6 ± 12.1 vs. 83.6 ± 10.1 ?m, P = 0.04). The RBF was correlated with RNFL (r = 0.41; P = 0.02) and GCC (r = 0.43; P = 0.02) but not the RS (r = 0.31; P = 0.09) in the abnormal hemisphere. The RBF (19.3 ± 8.4 ?l/minute), RNFL (103.7 ± 20.6 ?m), and GCC (83.6 ± 10.1 ?m) were reduced (P<0.05) in the hemisphere with apparently normal visual field in glaucomatous eyes compared with the mean hemispheric values of the normal eyes (23.2 ± 5.3 ?l/minute, 124.8 ± 9.6 ?m, and 96.1 ± 5.7 ?m, respectively).In glaucomatous eyes with single-hemifield damage, the RBF is significantly reduced in the hemisphere associated with the abnormal hemifield. Reduced RBF is associated with thinner RNFL and GCC in the corresponding abnormal hemisphere. Reduced RBF and RNFL and GCC loss also are observed in the perimetrically normal hemisphere of glaucomatous eyes.

Project description:PurposeTo compare prospectively detection of progressive retinal nerve fiber layer thickness (RNFL) atrophy identified using time-domain optical coherence tomography with visual field progression using standard automated perimetry in glaucoma suspect and preperimetric glaucoma patients or perimetric glaucoma patients.DesignProspective, longitudinal clinical trial.MethodsEligible eyes with 2 years or more of follow-up underwent time-domain optical coherence tomography and standard automated perimetry every 6 months. The occurrence of visual field progression was defined as the first follow-up visit reaching a significant (P < .05) negative visual field index slope over time. RNFL progression or improvement was defined as a significant negative or positive slope over time, respectively. Specificity was defined as the number of eyes with neither progression nor improvement, divided by the number of eyes without progression. Cox proportional hazard ratios were calculated using univariate and multivariate models with RNFL loss as a time-dependent covariate.ResultsThree hundred ten glaucoma suspect and preperimetric glaucoma eyes and 177 perimetric glaucoma eyes were included. Eighty-nine eyes showed visual field progression and 101 eyes showed RNFL progression. The average time to detect visual field progression in those 89 eyes was 35 ± 13 months, and the average time to detect RNFL progression in those 101 eyes was 36 ± 13 months. In multivariate Cox models, average and superior RNFL losses were associated with subsequent visual field index loss in the entire cohort (every 10-μm loss; hazard ratio, 1.38; P = .03; hazard ratio, 1.20; P = .01; respectively). Among the entire cohort of 487 eyes, 42 had significant visual field index improvement and 55 had significant RNFL improvement (specificity, 91.4% and 88.7%, respectively).ConclusionsStructural progression is associated with functional progression in glaucoma suspect and glaucomatous eyes. Average and superior RNFL thickness may predict subsequent standard automated perimetry loss.

Dataset Information

Estimation of retinal ganglion cell loss in glaucomatous eyes with a relative afferent pupillary defect.

Publications

Estimation of retinal ganglion cell loss in glaucomatous eyes with a relative afferent pupillary defect.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets