Experimental Studies on the Retinal Responses to Intravitreal Perfluorocabon Liquids

Perfluorocarbon liquids (PFCLs) are useful tools during vitreous surgery for complicated retinal detachments. Generally, these liquids are used as short-term vitreous replacement without retinal toxicities. But long-term tolerance of intraocular fluorochemicals is not established. We evaluated long-term tolerances to intraocular perfluorophenanthrene(Vitreon) or perfluorodecalin(DK-line) in the rabbit retina for a period of up to 3 months. Three days after C3F8 gas-compression of the vitreous, 1.2ml of highly purified PFCLs were injected into 26 rabbit eyes. Control eyes received same volumes of balanced salt solution. Eyes were examined by indirect ophthalmoscopy and light and electron microscopy. Clinically PFCLs were emulsified and dispersed into small bubbles after 2-3 weeks. Mild posterior subcapsular cataracts and vitreous opacities were observed after long-term retention of PFCLs. Histopathologically, at 1 week after surgery, several epiretinal macrophages were present in both groups. Focal disarrangements of photoreceptors were observed in perfluorodecalintreated group. At I month after surgery, protrusion of Muller cell, dropdown of photoreceptor nuclei, loss of photoreceptors, outer and inner segments and retinal pigment epithelial hypertrophy were observed. In perfluorodecalin-treated group, atrophy in outer nuclear layer and thinning of all the retinal layers occurred. At 3 months after surgery, small oil-like droplets were scattered throughout the retinal layers and retinal pigment epithelium in perfluorodecalin-treated group. These findings were almost totally confined to the lower part of retina that has been long-term contact with the liquids. Our findings suggest that perfluorodecalin is more toxic to the retina than perfluorophenanthrene. Both liquids are not adequate for long-term vitreous replacement, but may be useful for short-term intraoperative use.

A Clinical Comparison between Intraoperative and Postoperative Extended Period: Tamponade with Perfluorophenanthrene(C14, F24)Liquid in the Vitreoretinal Surgery

Perfluorocarbon liquids have been used as vitreous substitutes for the complicated vitreoretinal surgery. Some authors have reported that perfluorophenanthrene(C14, F24) liquid could be left in the eye for extended term without ocular toxicity. We reviewed 37 eyes that had undergone surgery using perfluorophe-nanthrene(C14, F24) liquid at our hospital since June, 1991 to March, 1996. It was used as intraoperative tool in 20 eyes(Group I), and as postoperative tamponade material in 17 eyes for variable period from 24 hours to 45 days(Group II). Group III includes 11 anatomically successful eyes among group II. Follow up periods were from 111 to 1763(mean 341) days. The rate of anatomical success was 100, 64.7% in group I and II, and the rate of functional success was 70, 70.6, 90.9% in group I, II, III, respectively. Postoperatively, proliferative vitreoretinopathy, recurrent retinal detachment, and elevation of intraocular pressure were observed in both group I and II. According to the above results, it would be better that perflourophenanthrene liquid be used as an intraoperative tool than as a postoprative extended period tamponade.

Intraoperative Perfluorophenanthrene Use in Complicated Retinal Detachment

23 eyes of 23 patients who underwent conventional vitreoretinal surgery with high specific gravity perfluorocarbon liquid, perfluorophenanthrene, for complicated retinal detachment were evaluated retrospectively. Preoperative vitreoretinal findings showed grade C2 PVR in 4 eyes and C3 in 1 eye and C4 in 10 eyes and C5 in 8 eyes. As a result, 17 eyes(74%) showed anatomical success, completely reattached in 15 eyes, partially reattached in 2 eyes, and 12 eyes(52%) showed functional success (corrected visual acuity 5/200 or better). Follow-up period was over 6 months in all cases. Postoperative complications includes keratopathy in 6 eyes, hypotony in 5 eyes, cataract in 2 eyes, transient vitreous hemorrhage in 1 eye, acute increased IOP in 1 eye, posterior synechiae in 1 eye, cystoid macular edema in 1 eye, and pupillary membrane in 1 eye. Consequently, perfluorophenanthrene can be used beneficially in yield of surgical field and mechanical stabilization of retina in complicated retinal detachment surgery.

Experimental Studies on the Retinal Responses to Subretinal Perfluorocarbon Liquids

Perfluorocarbon liquids are frequently used intraoperatively in repair of complicated retinal detachments. One complication of their use is prfluorocarbon liquids entering the subretinal space via a retinal break or an iatrogenic retmotomy since these liquids are much heavier than water, We evaluated the response to subretinal perfluorophenanthrene (VitreonR) on the rabbit retina ophthalmoscopically and microscopically. Twenty eight rabbit eyes underwent subretinal injection of 50-100 ml of perfluorophenanthrene via the vitreous space. The same volume of balanced salt solution was injected into control eyes. Eyes were monitored by indirect ophthalmoscopy and examined by light and electron microscopy. Progressive retinal detachments with newly formed retinal breaks in the inferior quadrants developed in 24 of 28 eyes. In the remaining 4 eyes, small retinal bleb, from 0.5 to 3DD size, occurred in inferior peripheral retina. The photoreceptor outer and inner segments were lost and receptor cell nuclei began to deplete within 1-3 days. In addition, marked vacuole formation in the retinal fiber layers as well as in inner and outer nuclear layers were seen. The photoreceptor outer and inner segments had a1most dlsappeared and the number of nuclei in irulei and outer nuclear layers was markedly decreased from 1 to 3 months. The control eyes reattached and healed spontaneously within 3-5 days. Our findings suggest that all subretinal perfluorophenanthrene should be carefully removed from the eyes at the end of the surgery.

Experimental Studies on the Retinal Responses to Subretinal Perfluorocarbon Liquids

Perfluorocarbon liquids are frequently used intraoperatively in repair of complicated retinal detachments. One complication of their use is prfluorocarbon liquids entering the subretinal space via a retinal break or an iatrogenic retmotomy since these liquids are much heavier than water, We evaluated the response to subretinal perfluorophenanthrene (VitreonR) on the rabbit retina ophthalmoscopically and microscopically. Twenty eight rabbit eyes underwent subretinal injection of 50-100 ml of perfluorophenanthrene via the vitreous space. The same volume of balanced salt solution was injected into control eyes. Eyes were monitored by indirect ophthalmoscopy and examined by light and electron microscopy. Progressive retinal detachments with newly formed retinal breaks in the inferior quadrants developed in 24 of 28 eyes. In the remaining 4 eyes, small retinal bleb, from 0.5 to 3DD size, occurred in inferior peripheral retina. The photoreceptor outer and inner segments were lost and receptor cell nuclei began to deplete within 1-3 days. In addition, marked vacuole formation in the retinal fiber layers as well as in inner and outer nuclear layers were seen. The photoreceptor outer and inner segments had a1most dlsappeared and the number of nuclei in irulei and outer nuclear layers was markedly decreased from 1 to 3 months. The control eyes reattached and healed spontaneously within 3-5 days. Our findings suggest that all subretinal perfluorophenanthrene should be carefully removed from the eyes at the end of the surgery.

Treatment of Complicated Retinal Detachments by Intraoperative Use of Perfluorphenantenanthrene Liquid

We have applied the intraoperative use of Perfluorophenanthrene (C14F24) liquid in 19 eyes of complicated retinal detachment surgery in 19 patients since November 1990 to October 1991. The vast majority of case of retinal detachment was trauma (9 eyes) and uveitis including pars planitis (6 eyes) remainders were juvenile retinoschisis, cataract surgery, myopIa, diabetes one eye each. The grade-D of proliferative change was found in 9 eyes (D1 3 eyes, D2 3 eyes, D3 3 eyes) and 8 eyes belong to over grade-C2 (C2 4 eyes, C3 4 eyes). Multiple anterior retinal tears were found in two. Giant retinal tear was noticed in 5 eyes and the other one was made on therapeutic purpose. Intraoperative reattachment was obtained in all eyes. The follow-up periods were 6 or more (mean 9.1) months. At last follow-up, the retina was attached in 12 eyes (63%), partially attached in 2 (10%) and redetached in 5 (26%). Visual acuity was improved or same in 12 eyes (63%), became worse in 7(37%). Visual acuity of 0.02 or better was obtained in 12(63%) eyes and 3(16%) saw 0.1 or better. Perfluorophenanthrene liquid was thought as non-toxic, heavy biomaterial and effective to treat the complicated retinal detachments.

The Effect of Topical Perfluorophenanthrene on Corneal Neovascularization in the Rats

The effect of topical perfluorophenanthrene on corneal neovascularization was studied at chemically induced corneal burn on the rats. A central corneal burn was produced with 10% NaOH. Right eye was treated with perfluorophenanthrene and gentamicin eye drops four times a day for five days, the left with balanced salt solution and gentamicin eye drops as control. After five days treatment the rats were sacrified, and the tissue slide were prepared for microscopIc examination. Using slide projector the tissue slide were projected and magnified on the screen. The number of corneal new vessels, the distance of new vessel from the limbus, and the degree of increased corneal thickness were calculated in both groups. As the result there were no statistical difference between two groups. Analysis using ANOVA program showed the fact that statistically significant correlationship between the degree of corneal thickness and the number of the new vessels and the distance from the limbus were found. The result could confirm the mechanism of corneal neovascularization that disarrangement of the compact corneal tissue could allow the formation of the new vessels.