Comparison of Standard Automated Perimetry Thresholds to Thresholds Obtained With Two Different Microperimetry Devices

Abstract

Purpose: : Microperimetry has been used in the past few years to evaluate macular sensitivity in different eye diseases. However, little is known about its correspondence with the standard automated perimetry (SAP). In this study, we investigated the relationships of threshold measures between SAP and two microperimetry devices: the Nidek Microperimeter-1 (MP1) and the Opko OCT/SLO Microperimeter (SLO).

Methods: : Subjects presenting best corrected visual acuity ≥ 20/20 and no history of eye disease were recruited. All subjects underwent SAP (SITA algorithm; Humphrey Field Analyzer, Carl Zeiss Meditec, Dublin, CA), MP1 (4-2 algorithm; Nidek, Fremont, CA) and SLO (4-2 algorithm; OPKO/OTI, Toronto, Canada) using the 10-2 array of test locations. For each of the instruments, duration of the stimulus was set at 200 msec and target sizes were Goldman I and III. Subjects repeated each test once and the mean value of each point was used for analysis. Also microperimetry threshold values (dB) were converted to equivalent SAP values (dB) using the stated (MP1) or measured (SLO/OCT) luminance at each nominal dB level.

Results: : Five subjects (5 right eyes; mean age, 32.2 ± 3.5 yrs) were enrolled. For Goldman III target size, linear regression analysis revealed significant correlations (p<0.001) between thresholds of SLO and SAP (r=0.48), MP1 and SAP (r=0.25), and MP1 and SLO (r=0.34). These same correlations remained significant when considering Goldmann I target size (p<0.001, r=0.43, r=0.61 and r=0.56, respectively).

Conclusions: : Threshold values of the two microperimetry devices correlated with SAP thresholds independently of the target size. This finding should be considered while using these additional tools for evaluation of macular function.

Keywords: perimetry • visual fields • imaging/image analysis: clinical