Table 1.

Regression of ETDRS Visual Acuity on Retinal Thickness in Patients with Retinitis Pigmentosa and Macular Cysts

Retinal Location	Cases/Eyes with Cysts*	Slope (letters/100 µm)†	P-value‡
Foveal Center	89/141	−1.7 ± 0.8	0.032
Central Area (1 mm diameter)	88/137	−1.7 ± 1.1	0.105
Inner Ring (1 mm ID - 3 mm OD)	89/139	−4.4 ± 2.4	0.067
Outer Ring (3 mm ID - 6 mm OD)	89/139	−7.6 ± 2.7	0.006

^*The variation in the number of cases or eyes with cysts reflects instances where retinal thickness could not be correctly quantified by the software at a given location.

^†Estimates of mean slope ± standard error by PROC MIXED of SAS.

^‡The two-tailed significance level with respect to zero slope.