effect of external drainage operations on the scleral rigidity

Eighty eyes with chronic simple glaucoma were operated upon by trabeculectomy, Scheie's modified and iris inclusion operations. The scleral rigidity was measured, before operation and along a period of 30 months postoperatively. The mean coefficient of scleral rigidity was reduced from 0.0251 to 0.0231 in the eyes controlled with operation, from 0.0261 to 0.0240 in the eyes controlled with operation and miotics, and from 00255 to 0.0242 in the uncontrolled eyes with operation and miotics. The cause of reduction in the coefficient of scleral rigidity was the reduction in intra-ocular pressure and the addition of miotics in uncontrolled eyes with operation even with higher pressure