Comparison and Correlation of Retinal Sensitivity Between Microperimetry and Standard Automated Perimetry in Low-tension Glaucoma

Precis: Our study demonstrated that in low-tension glaucoma (LTG) patients, Microperimeter-3 (MP-3)-derived and Humphrey Field Analyzer (HFA)-derived retinal sensitivities were similar and strongly correlated, allowing the respective data to be interrelated. Purpose: To compare and correlate retinal sensitivities obtained by Nidek MP-3 with those obtained from the HFA in eyes with LTG. Materials and Methods: In this prospective comparative study, 45 eyes of 24 LTG patients underwent retinal sensitivity assessments using the MP-3 (Nidek Technologies) and the HFA (Carl Zeiss Meditec) at the UCLA-Doheny Eye Center. Global and pointwise retinal sensitivity measurements were compared and correlated between the 2 devices. Results: No statistically significant differences (P=0.85) were noted between the mean retinal sensitivities determined by each device (MP-3: 26.33 +/- 4.31 dB; range, 13.05 to 31.60 vs. HFA: 26.42 +/- 3.98 dB; range, 17.17 to 30.96), and a strong correlation (r=0.66,P<0.001) was noted for retinal sensitivity measurements. In addition, moderate to strong correlations were observed between the mean retinal sensitivity derived by MP-3 versus HFA-derived mean deviation (r=0.57,P<0.001), as well as, the pattern standard deviation (r=0.67,P<0.001). The intraclass correlation coefficient was excellent (ICC=0.80, 95% confidence interval, 0.63-0.89), while the Bland-Altman analysis showed good agreement between the 2 devices with respect to retinal sensitivity. Conclusion: Retinal sensitivity measurements obtained by the MP-3 microperimetry instrument and the standard automated HFA perimeter were similar and highly correlated in patients with LTG. Given the potential benefits of microperimetry technology such as auto-eye-tracking and potentially more precise structure-function correlations, the use of microperimetry to monitor visual function in glaucoma management warrants further consideration.