Controlled encircling procedure for retinal detachment

Standardized scleral buckling approach in the management of noncomplex primary rhegmatogenous retinal detachment

PURPOSE

To analyze the anatomical and functional outcomes of a standardized scleral buckling approach in patients with noncomplex primary rhegmatogenous retinal detachment (RRD).

METHODS

Retrospective institutional case series of 135 eyes of 131 patients diagnosed with noncomplex primary RRD. All patients underwent scleral buckling surgery with the placement of an encircling 5 mm oval sponge at 15 ± 2 mm posteriorly from the limbus, cryopexy, subretinal fluid drainage, and air tamponade.

RESULTS

Final anatomical success at 12 months was achieved in all 135 eyes (100%). Primary anatomical surgical success was obtained in 127 out of 135 eyes (94%), while re-detachment occurred in eight out of 135 cases (6%). Primary anatomical success was significantly lower in pseudophakic eyes (p < 0.001). At the end of the follow-up period, no vision loss was observed in any patient and both sphere and cylinder refraction shift was mild. There was a low rate of postoperative complications. Nine out of 135 eyes (6.6%) developed full thickness macular hole, whether in 24 out of 135 eyes (17.8%) epiretinal membrane development was noticed.

CONCLUSION

A standardized scleral buckling approach for primary noncomplex RRD may be effective. The technique is reproducible, easier, and quicker to perform if compared to classic scleral buckling procedures, suggesting that it may represent a valuable surgical option. Special care is needed in the management of pseudophakic RRD due to higher risk of RRD recurrence.

Modified Controlled Encircling Scleral Buckle for Retinal Detachment

During encircling scleral buckle placement, the ends of the element are tightened to achieve a shortened radius of the eye. The determining factor of the final buckle height is subjective using usually a combination of the buckle height visualized with the degree of scleral indentation and can be difficult to be taught early on to trainees. Here, we describe a case series in which a modified controlled encircling scleral buckle technique that simplifies and standardizes the achievement of reproducible buckle height of about a 1 mm is objective and easy to be taught. This novel encircling scleral buckling technique successfully achieves a good postoperative scleral buckle height in a reproducible and standardized fashion using objective measurements and it is easier to be taught to trainees.

Reinforced episcleral cerclage in retinal detachment. A note on surgical technique

Episcleral silicone rods are used as encircling elements in retinal detachment surgery. In order to reinforce the encircling effect and form a stable effective buckle, the episcleral silicone rod is combined with an Arruga suture or a fairly rigid teflon band. The Arruga string (a 2-0 supramid suture) is sewn, in a longitudinal direction, into a solid silicone rod (2 mm in diameter) or into a silicone half-cylinder (diameter 3 or 4 mm). Soft sponge-like rods can also be reinforced with a 2 mm broad teflon band placed on the flat surface of the half-cylindrical silicone element. Drainage of subretinal fluid is usually performed in order to make room for the high circumferential buckle. Experience has shown that this modified encircling procedure is very useful in complicated cases of retinal detachment.

[Tension under controlled conditions in the encircling operation (author's transl)]

The complications, which occur in encircling-operations, such as String-Syndrome, scleral Nekrosis, glaucoma-development (due to narrowing the anterior chamber) as well as closure of the central artery most frequently happen, when the globe has been tightened too much. From the calculations we have make using the cerclage element in reducing the circumference and volume (Fig. 2) we have shown that an identation of the sclera more than 3 mm deep is not advisable. The Silicon-Cerclage-Materials, which we use, are tested by the tension-testing machine, which determines the modulus of elasticity. The stress, that is force per sectional area, is determined in relation to the amount of elongation in the material (Fig. 3). A round silicon rod with a diameter of 2 mm and a modulus of elasticity between 150 and 200 p/mm2 proved most effective. In addition, we have conducted experiments with the Cerclage-rods on enucleated human eyes (Fig. 4). In one experiment the intraocular pressure was determined in relation to the pull of the weight upon the globe (Fig. 5). In a second experiment the reduction of the circumference was related to the height of the intraocular pressure (Fig. 6). The elastic Cerlage-rod has the advantage of creeping, when tensed, it tries to regain its original length. However, the globe, owing to the pressure within it, works against the creeping. With the help of the stress-strain diagram (Fig. 7) and the experiments on the human eye we can determine more accurately the degree of the creeping. In index 1 we can see how much the circumference has been finally reduced including the creeping in relation to the height of the intraocular pressure. The intraocular pressure should not be increased above 35 mm Hg. Otherwise: 1. the circumference of the globe will be considerably more reduced; 2. the intraocular pressure will rise much more slowly when compared to results at the lower eye-tension and 3. the volume reducing-effect will diminish markedly. It is important to measure the intraocular pressure before the end of the operation in order to avoid the above mentioned complications.