Observations of the bleb’s appearance, size, and vascularity and the anterior chamber’s depth were graded and documented as described. Width and length were measured by using calipers to delineate the margins of the bleb, and height was graded semiquantitatively by slit lamp examination (0, flat; 1, shallow/formed <1 mm; 2, elevated <2 mm; 3, high >2 mm). These measurements in millimeters were used as a guide to the grading of the blebs. Bleb vascularity was graded (0, avascular; 1, normal vascularity; 2, hyperemic; 3, very hyperemic) and its locality noted (top, nasal, temporal). Anterior chamber inflammation was assessed by slit lamp examination (0, no inflammation; 1, cells present; 2, fibrin formation; 3, hypopyon present), and anterior chamber depth was recorded as deep, shallow, or flat. Failure of IOP was defined as an indefinite return to baseline or an increase over baseline IOP.
Only the animals in the initial experiment killed on day 30 (n = 22) were used to analyze survival. The animals in the subsequent experiment, killed at earlier time points (n = 18), were used to complete the histologic profile.