Background: Surgical implantation of the intraocular sustained-release ganciclovir device is a safe and effective treatment for cytomegalovirus (CMV) retinitis. Previous histopathologic studies on eyes containing such implants have been limited by the necessity of removing the device before processing. Microtome sectioning of hard plastics within paraffin-embedded blocks is infeasible, and the anatomic relations of implant to eye are destroyed.
Methods: The authors studied four eyes from three patients who had undergone implant insertion. Globes with implants in place were fixed in neutral 10% formation, embedded in methylmethacrylate, sectioned on a special microtome, and stained with hematoxylin-eosin.
Results: After methacrylate embedding, the precise anatomic relations of the implant to the neighboring uveoscleral coats were preserved. In two eyes, the suture tab of the implant protruded through the sclera, exiting subconjunctivally. In two eyes, the implant was totally intravitreal. In all patients, the device was supported by fibrous tissue which emanated from a surgical coloboma of the pars plana ciliaris. Focal granulomatous inflammation adjoined suture and implant materials but no other inflammation or deleterious effects on the ocular structures were noted.
Conclusion: This report is the first to document the intraocular histopathology of the ganciclovir implant. The subconjunctival location, enhancing the potential for endophthalmitis, may be avoided by trimming of the suture tab close to the anchoring suture and not tying it too tightly. Methylmethacrylate embedding is a useful technique for preserving the microanatomy of intraocular implants.