The mean (±SD) duration of an APAC episode was 13.8 ± 10.6 hours (range, 3–40). Patient characteristics are shown in
Table 1 . The IOP measurements at presentation in the affected eyes were stratified (according to the maximum marker in Perkins applanation tonometry) as follows: 51 to 60 mm Hg (
n = 3) and >60 mm Hg (
n = 14).
In terms of RNFL thickness in the affected eyes, significant differences were demonstrated comparing 1 and 4 and 1 and 12 weeks for the average and four-quadrant RNFL thicknesses; however, no such differences were demonstrated between 4 and 12 weeks
(Table 2) .
Analogous longitudinal comparison of the RNFL thickness in the fellow eyes did not yield significant differences for the average (P = 0.44), superior (P = 0.20), nasal (P = 0.82), inferior (P = 0.16) or temporal quadrants (P = 0.97) at 1, 4, and 12 weeks.
The superior (
P < 0.001,
R 2 = 0.45), nasal (
P < 0.001,
R 2 = 0.50), inferior (
P < 0.001,
R 2 = 0.46), and temporal quadrant (
P < 0.001,
R 2 = 0.34) and average RNFL thicknesses for the affected eyes were correlated with post-APAC follow-up interval by inverse regression analysis
(Fig. 1) . Average RNFL thickness in the affected eyes was associated with duration of APAC episode at 4 (
P < 0.001,
r = −0.69) and 12 weeks (
P < 0.001,
r = −0.92), but not at 1 week (
P = 0.26,
r = 0.20) from linear regression analysis and Pearson correlation.
Controlling for duration of APAC episode with multivariate regression, the follow-up interval remained statistically significant for average RNFL thickness reduction (P < 0.001, r = −0.69).
Four of the affected eyes had repeatable glaucomatous VF defects, and five had a generalized reduction of sensitivity, with VF normal in the remaining eight and all the fellow eyes. Average RNFL thickness in the affected eyes correlated with MD and PSD at 12 weeks (P < 0.001, r = 0 0.91 and P = 0.004, r = −0.67, respectively), but not at 1 week (P = 0.78, r = −0.074 and P = 0.50, r = −0.18, respectively) or 4 weeks (P = 0.05, r = 0.48 and P = 0.18, r = −0.34, respectively). One of the eight affected eyes with normal VF had abnormal average RNFL thickness (outside 95% confidence intervals, as determined by OCT software) at 12 weeks.
In terms of the intereye difference, the RNFL thicknesses (average and four quadrants) in the affected eyes were significantly greater than were the analogous thicknesses in the fellow eyes at 1 week after the APAC episode. In contrast, the inferior and superior quadrant RNFL thicknesses in the affected eyes were lower at 4 and 12 weeks, whereas the analogous average and nasal-quadrant RNFL dimensions were lower only at 12 weeks compared with the fellow eyes
(Table 3) .
Figure 2shows a typical example of OCT findings and the optic disc photographs for an affected eye at 1, 4, and 12 weeks after APAC.