Optimal Orientation of a Segmental Buckle

Because the retina is fixed at the ora serrata and at the disk, when detaching, it tends to form radial folds. A circumferentially oriented buckle will augment, or at least preserve, the radial folds because it shortens the circumference of the globe, causing redundant retina circumferentially. The resulting radial folds tend to aggravate and align with a retinal break, producing what is termed "fishmouthing" of the retinal break (Fig. 6.2). The fishmouthing, in turn, provides a path for vitreous fluid to enter the subretinal space, causing failure. The logical approach to filling the potential

Fig. 6.2. Optimal orientation of segmental buckle as tamponade of horseshoe tear. Left: Using a circumferential buckle, the horseshoe tear is not tamponaded adequately. The operculum, an area of future traction, is not on the ridge of the buckle, but on the descending slope. In addition, there is a risk of posterior radial folds ("fishmouthing") with subsequent leakage of the tear. Right: A short radial buckle provides an optimal tamponade for the horseshoe tear. The entire tear is placed on the ridge of the buckle, i.e., this counteracts posterior "fishmouthing" of the tear and provides an optimal support for the operculum, counteracting at the same time future anterior vitreous traction

Fig. 6.2. Optimal orientation of segmental buckle as tamponade of horseshoe tear. Left: Using a circumferential buckle, the horseshoe tear is not tamponaded adequately. The operculum, an area of future traction, is not on the ridge of the buckle, but on the descending slope. In addition, there is a risk of posterior radial folds ("fishmouthing") with subsequent leakage of the tear. Right: A short radial buckle provides an optimal tamponade for the horseshoe tear. The entire tear is placed on the ridge of the buckle, i.e., this counteracts posterior "fishmouthing" of the tear and provides an optimal support for the operculum, counteracting at the same time future anterior vitreous traction

Fig. 6.3. Limit of an optimal circumferential buckle. When applying a circumferential buckle, radial folds are less likely if the buckle is not longer than 90°. If the circumferential buckle is less than 90°, the induced radial folds, caused by the constriction of the globe, will be just compensated by the two sloping ends of the buckle

Fig. 6.3. Limit of an optimal circumferential buckle. When applying a circumferential buckle, radial folds are less likely if the buckle is not longer than 90°. If the circumferential buckle is less than 90°, the induced radial folds, caused by the constriction of the globe, will be just compensated by the two sloping ends of the buckle fold at the posterior edge of a horseshoe tear is a radial buckle. A radial buckle supports the operculum and, at the same time, closes the posterior edge of the break, avoiding fishmouthing [23]. Goldbaum et al. [24] calculated that when applying a circumferential buckle, radial folds are less likely if the buckle is not longer than 90° (Fig. 6.3). If the circumferential buckle is less than 90°, the induced radial folds, caused by constriction of the globe, will be compensated by the sloping ends of the buckle.

The radial buckle is advantageous because it: (1) places the entire break on the ridge of the buckle; (2) counteracts fishmouthing of the break and the risk of posterior leakage; and (3) provides optimal support for the operculum, counteracting future traction and the risk of anterior leakage. Therefore, whenever possible, the sponge should be oriented with its long axis in a radial direction of the break. Multiple radial buckles can be used if the breaks are separated by approximately 11/2 clock hours. When a circumferential buckle is necessary, the greater the length of the buckle, the more likely radial folds will result. Consequently, the shorter the circumferential buckle, the better it is.

Thus, minimal segmental buckling or so-called extraocular minimal surgery had evolved [25,26]. It is one of the four options today in use for treating a primary rhegmatogenous retinal detachment.

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