Improvements in Test-Retest Variability of Static Automated Perimetry by Censoring Results With Low Sensitivity in Retinitis Pigmentosa.

Purpose: We evaluated whether omitting (censoring) points in more severely damaged visual field areas can reduce test-retest variability of static automated perimetry (SAP) in retinitis pigmentosa (RP), as variability creates a significant challenge when monitoring for changes. Methods: Cohort 1 included 27 eyes in 16 RP subjects with visual acuity (VA) ranging from 20/20 to 20/70 who completed Humphrey 10-2 size III SAP, once per visit at three visits. Cohort 2 included 15 eyes in nine RP subjects with VA ≤ 20/60 who completed Humphrey 30-2 size V SAP, twice per visit at three visits. Variability was assessed using 95% coefficient of repeatability (CR) calculations for uncensored (all threshold values and data points included) and censored data. Results: In cohort 1, the uncensored between-visit 95% CR was 11.6 decibels (dB); censoring locations with threshold values of <8 to 20 dB resulted in 31% to 53% reductions in the 95% CR. For cohort 2, uncensored 95% CRs were 8.7 and 8.0 dB for within- and between-visit variability, respectively; censoring <8 to 17 dB resulted in 15% to 41% and 15% to 43% reductions in within-visit and between-visit 95% CRs, respectively. For both cohorts, censoring at higher values yielded slightly less variability, at the expense of discarding data from a greater number of eyes and test locations. Conclusions: For 20/20 to 20/70 VA tested with size III stimuli, censoring lower sensitivity values results in substantially lower test-retest variability, which may help detect true changes for locations without severe baseline loss. Translational Relevance: A rule of thumb for clinical practices using SAP to monitor RP is that longitudinal losses of >9 dB for individual test locations with initial values ≥ 9 dB are likely to be real and meaningful, as they exceed typical variability.

Optimizing the use of frequency doubling technology perimetry in community vision screenings.

PURPOSE: In recent years, Frequency Doubling Technology perimetry (FDT) has been added to traditional ocular health testing in screening for glaucoma. This study examines a number of strategies to employ FDT in an effort to determine its optimal use in large community screenings. METHODS: In Part I, 1253 persons participated in a free, community vision screening in a large metropolitan area. FDT testing was limited to those in a high-risk group, defined as individuals over age 45 and either black or having a family history of glaucoma that passed the eye health part of the screening. In Part II, a simulated screening performed at the same location examined four different strategies for utilizing FDT: (1) FDT limited to the high risk group passing eye health testing; (2) FDT on all persons passing eye health testing; (3) FDT and eye health testing on all persons; and (4) FDT on all persons, without eye health testing. RESULTS: In the community screening, 1043 persons (83.2%) passed the eye health testing. 159 (15.2%) of the 1043 were in the high risk group and were tested with FDT. 19 (1.5%) of these tests resulted in failure. There were few unreliable tests (5.0%). For the simulated screening, specificity and sensitivity with 95% confidence intervals for strategies one through four were, respectively, 83.3% (64.5 to 93.7) and 77.8% (51.9 to 92.6); 80.0% (60.9 to 91.6) and 88.9% (63.9 to 98.1); 76.7% (57.3 to 89.4) and 94.4% (70.6 to 99.7); 90.0% (72.3 to 97.4) and 38.9% (18.3 to 63.9). CONCLUSION: In the community screening, FDT performed reliably and identified abnormalities in a significant number of persons in the high-risk group passing the eye health part of the screening. However, with the exception of the poor sensitivity shown by strategy 4, results from the simulated screening did not support the usefulness of one strategy over another.