The influence of laser fluence on IOP
L was evaluated in three experimental groups and in a control group. RB was applied to the walls of the incisions, made as shown in
Figure 1 , in the eyes to be treated with PKD. The incisions in both PKD and control group corneas were then closed using three interrupted sutures to approximate the incision surfaces. Three PKD groups were treated with laser fluences of 115, 153, or 192 J/ cm
2 delivered over 180, 240, and 300 seconds, respectively, at a constant irradiance of 0.64 W/cm
2. Incisions in the control group were sutured but were not treated with RB or laser irradiation, as our prior studies had shown that neither light nor dye treatment alone produces significant bonding.
12 Each treated group contained three to six eyes, and the untreated group contained eight eyes. The sutures were removed from the experimental corneas immediately after the PKD treatment and from the control corneas, and the IOP
L was measured. The results are shown in
Figure 3 . The IOP
L was greater in all PKD-treated corneas than in the control (
P < 0.005). The IOP
L increased with laser fluence, reaching 230 ± 95 at 115 J/cm
2 and 370 ± 125 at 153 J/cm
2. The IOP
L was greater than 500 mm Hg (the maximum pressure measurable) for eyes treated with 192 J/cm
2. No signs of thermal damage, such as tissue shrinkage, were observed under the irradiation conditions used.