Histologic study of healing after ab interno laser sclerostomy

We examined the histologic characteristics of healing after ab interno laser sclerostomy in a human eye. A KTP 532 green laser coupled to a 300-microns quartz fiberoptic probe was used to create an ab interno sclerostomy in a terminally ill patient with pigmentary glaucoma. The intraocular pressure increased five days postoperatively and did not respond to medical treatment. The patient died six weeks postoperatively of metastatic lung cancer. Histopathologic analysis showed a patent 150-microns scleral lumen from the anterior chamber to the episclera, surrounded by a 300-microns zone of acellular thermal damage. There was no healing of the lumen. The subconjunctival end of the lumen was capped with a thick episcleral scar, which caused the failure of the operation.