Tolentino, Refojo en Schepens, 'A hydrophilic acrylate implant for scleral buckling: technique and clinical experience' (Retina 1981; 1(4):281-6)

In 1981 verscheen een lovend artikel van Tolentino, Refojo en Schepens, 'A hydrophilic acrylate implant for scleral buckling: technique and clinical experience' (Retina 1981; 1(4):281-6)   over de nieuwe hydrogel ‘Refojo implant’ (of MAI), die - na eerst langdurig bij konijnen te zijn getest - bij 51 patiënten was toegepast, zowel intrascleraal als episcleraal. 

Abstract: 
A new hydrophilic acrylate implant developed for scleral buckling was used in 51 patients: as an accessory meridional piece under a solid silicone buckle in 25 and as a main buckling element in 26 (intrasclerally in 15 and episclerally in 11). Clinical observations six to 18 months aller implantation showed the implants to be well tolerated in all cases. There was no infection, rejection, extrusion of the implant, or erosion of the eye coats. In two patients who had reoperations, smooth fibrous tissue encapsulating the implant including the scleral bed was present. Our observations indicate that this new material has all the characteristics of an ideal implant for scleral buckling.

Refojo and co-workers developed and described a new scleral buckling material made of methyl acrylate and 2-hydroxyethyl .acrylate. 12 Laboratory studies in rabbits ,showed this material, called the Refojo implant (or MAI), to be inert and well tolerated in the anterior chamber, vitreous cavity, and orbit. ¹ Long-term observations in rabbits · (F.I. Tolentino, MD, M.F. Refojo, DSc, M. Lahav, MD, and LH.S. Liu, MD, unpublished observations) show that the Refojo implant is an effective intrascleral or episcleral buckling material.
We report herein our experience with the Refojo implant in human eyes.

Patients, Materials, and Methods
The experimental use of the Refojo implant in human eyes was approved by the Subcommittee on Human Studies of the Massachusetts Eye and Ear Infirmary. All patients gave their informed consent. The Refojo implant was used only in uncomplicated cases of rhegmatogenous retinal detachment. Patients with glaucoma or serious systemic disorders and those over 75 years old were excluded. Patients who had follow-up examinations less than six months after implantation were excluded from this report. The longest follow-up period was 18 months. (...)
In 25 cases, the implant was used as an accessory meridional implant placed beneath the solid silicone material that had been previously implanted as an equatorial buckle. In most instances, the objective of adding a meridional implant was to augment the height of the buckle because the retina! break had developed a fishmouth. In some cases, the aim was to extend the buckling effect posteriorly to cover a retinal break located behind a previously placed buckle. In 26 cases, the implant was used as the main scleral buckling element, either intrasclerally or episclerally (Table 1).

Het doel van het onderzoek was om na te gaan of de Refojo implant goed te verdragen was door het menselijk oog. Het nieuwe materiaal bleek ideaal voor netvliesoperaties.

Discussion
The goal of this study was not to compare the Refojo implant with other available materials for scleral buckling but rather to determine whether it was tolerated by human ocular tissue. This study shows that the implant is well tolerated in human eyes; thus confirming earlier observations in laborafory animals. ¹ 
This new material appears to have the features of an ideal scleral buckling material. First, it is soft and elastic, properties that help to prevent erosion of the sclera or conjunctiva when the material is implanted intrasclerally or episclerally. It may be an ideal material for scleral buckling in children. Second, it is devoid of dead spaces, which reduces the risk of its harboring pathogenie organisms. This allows its safe use as an intrascleral implant. Third, when it is soaked in antibiotic, the implant absorbs and retains it, which further reduces the risk of infection.¹ Fourth, the material produces a fibrous capsule over the scleral bed as early as four weeks after implantation. This capsule strengthens the scleral bed and could make reoperation in cases of recurrent retinal detachment easy and safe.
Although the implants used in this study were pilot samples, they could be used in a wide range of applications as a scleral buckling material: intrasclerally or episclerally, with or without an encircling band, equatorially or radially. Although long-term observatföns in more cases are required, we feel that continued use of this new implant for scleral buckling is justified, based on our present observations. The clinical application of this hydrophilic acrylate material is presently limited to scleral buckling. As more clinical experience is gained, we foresee wider clinical applications of the material not only iri ophthalmic surgery but also in other surgical specialties.

References
1. Refojo M F, Natchiar G, Liu HS, et al: New hydrophilic implant for scleral buckling. Ann Ophthalmol 12:88-92, 1980.
2. RefoJo M F, Leong F-L: .A poly(methyl acrylate-co-hydroxyethyl 'acrylate) hydrogel implant material of strength and softness. J Biomed Mater Res 15:497-508, 1981.
3. Schepens CL, Okamura ID, Brockhurst RJ: The scleral buckling procedures. 1. Surgical techniques and management. Arch 0phthalmol 58:797-811, 1957.
4. Okamura ID, Schepens CL, Brockhurst RJ: The scleral buckling procedures. IV. Reoperations following scleral buckling. Arch Ophthalmol 62:445-458, 1959.
5. Schepens CL, Okamura ID, Brockhurst RJ, Regan CDJ: Scleral buckling procedures. V. Synthetic sutures and silicone implants. Arch Ophthalmol 64:868-881, 1960.
6. Okamura ID, Schepens CL, Brockhurst RJ, et al: The scleral buckling procedures. VII. Silicone implants in reoperations. Arch .Opthalmol 72:297-308, 1964.
7. Regan CDJ, Schepens CL, Okamura ID, et al: The scleral buckling procedures. VI. Further notes on silicone in primary operations. Arch Ophthal111ol 68:313-328, 1962.
8. Custodis E: Die Behandlung der Netzhautablösung durch umschriebene Diathcrmiekoagulation und einer mittels Plombenaufnähung erzeugten Eindellung der Sklera im Bereich des Risses. Klin Monatsbl Augenheilkd 129:476-495, 1956.
9. Lincoff HA, Baras 1, McLean J: Modifications to the Custodis procedure for retina! detachment. Arch Ophthalmol 73:160..: 163, 1965.
10. McPherson A, Moura R: Full-thickness scleral buckling with cryoapplication and silicone sponge in retina! detachment surgery: A review of 447 cases. In: Pruett RC, Regan CDJ, eds. Retina Congress. New York, Appleton-Century-Crofts, 1972, pp 325-353.

12-6-2024