Experimental vitreous and aqueous replacement with perfluorophenanthrene. Clinical, histologic, and electrophysiologic results.

Purpose: Anterior and posterior segment changes of experimental vitreous and aqueous substitution with Perfluorophenanthrene were evaluated.

Methods: In 28 rabbit eyes that underwent vitrectomy, tamponades of 1.2 cc Perfluorophenanthrene remained as long as 8 weeks under clinical and electrophysiologic control. Histologic examinations of the eyes were done 1, 2, 4, and 8 weeks after insertion of the tamponade. In an additional 15 rabbit eyes, Perfluorophenanthrene was injected into the anterior chamber, and in some cases it was removed after 2 and 4 weeks, respectively. Follow-up examinations, which were done no later than 12 weeks after injection, included clinical appearance, endothelial cell counts, corneal pachymetry, tonometry, and histopathology.

Results: Histologically we found narrowing of the outer plexiform layer and single macrophages in the inferior retina after 2 weeks. Cell loss in the outer nuclear layer and wrinkling of the outer retinal layers were observed after 4 weeks, which lead to the development of irregularities of all layers inferiorly after 8 weeks. Electroretinograms showed unchanged b-wave amplitudes after maximal light stimulation at each examination, but separate interpretation of low light intensity responses showed a significant decrease in b-wave amplitudes 4 weeks after surgery. Anterior segment intolerance started with stromal edema on the second day after surgery; corneal vascularization and scar formation occurred subsequently. Inferior endothelial cell density decreased to about 50%. Histologically inflammatory reactions, vacuolization of the inferior trabecular meshwork, and closure of the chamber angle between 5 and 7 o'clock were observed.

Conclusions: Perfluorophenanthrene is only suitable for very short-term vitreous replacement unless prolapsing into the anterior chamber. Damages to the retina were observed 2 weeks after surgery.