Purpose: To evaluate the tolerability and efficacy of carboxyfluorescein ester (BCECF - AM) as adjunctive antifibrotic agent in a rabbit model of filtration surgery.
Methods: 20 pigmented rabbits 3-6 months old were used. It were divided into two groups, 10
}; rabbits each. Surgical procedure: sclerectomy & iridectomy were done for both eyes. Rt eye was operated after application of the photosensitizer as one single dose of BCECF-AM (80 μg). It was given subconjunctivally in the sclerectomy site 5.0 mm from the limbus 10 minutes before operation. Episclera and Tenons were irradiated for 8 minutes using the blue light, fixed at 2 cm from the target. Group I followed for 2 weeks and group II for 4 weeks. At the end of that period, rabbits were killed, enucleation was done and histopathological examination was performed.
Results: All eyes showed early hyperaemia of conjunctiva and hazy cornea. lOP was lowered and built up after 5 days .in left eyes, while right eyes continued till 14 days, then built up gradually to preoperative level in the 3rd and 4th week (P< 0.001). Histopathology: the irradiated eyes showed minimal fibrosis, low vascularization of conjunctiva. At 4 weeks there was excess pigmentation of ciliary processes, destruction of periphery of the retina, thickening of choroid. Left eyes showed excessive fibrosis and vascularization of conjunctiva, no other changes.
Conclusion: PDT seems to be an antifibrotic agent which increase the efficacy and prolong the function of the filtering operation. Further studies are needed to standardize the different parameters like drug dose,