The fishmouth phenomenon in retinal detachment: old concepts revisited.

Abstract

SUMMARY The 'fishmouth phenomenon' seen in some previously treated retinal detachments is associated with large horseshoe tears and scleral buckling techniques. A method of treating patients with this complication is described in which scleral buckling with implant or explant is not used. The technique utilises intravitreal air tamponade with cryopexy and gives good results. The incidence of patients developing the fishmouth phenomenon as a complication of primary simple retinal detachment surgery is much lower when an intravitreal air technique is used than the expected incidence following a primary scleral buckling operation.The objective of this paper is to describe the management of difficult large posterior horseshoe-tear retinal detachments which develop the aptly named 'fishmouth phenomenon', in which a second surgical procedure is required following a failure of scleral buckling with scleral silicone implant or explant and/or encircling silicone tape.The prognosis for reattachment of the retina in routine retinal detachment surgery for primary rhegmatogenous detachments, by different surgical techniques, is now well documented. The results from different series indicate reattachment in 90 to 95 % of patients (Kreiger et al., 1971;Chignell, 1977;and Curtin, 1976). The reduced chance of a successful first surgical procedure in more complicated detachments, for example, detachments due to macular holes (Leaver and Cleary, 1975) and in secondary detachments is also recognised.Results of operations for detachment where the primary process of detachment involves retinal lesions with large posterior tears suggest that the larger the tear the worse the prognosis (Lincoff et al., 1977). At the worst a giant tear may extend through almost 3600 and is virtually unmanageable with present surgical techniques. Difficulties are encountered in routine scleral buckling procedures with large horseshoe tears when the buckle causes the operculum of the tear to elevate as the rolled edges of the tear come closer together. This compromising effect is greater with circumferential buckles than with radial buckles. If further tightening of an encircling tape is attempted at this time, it

Scleral buckling—a brief historical overview and current indications

“…Circumferential buckles should generally be avoided for horseshoe tears unless the tears are very small (Fig. 14) as they can cause 'fish-mouthing' over the buckle [78,88] resulting in inadequate break closure (Fig. 15).…”

Development of a New Scleral Depressor for Determining the Location of a Buckle during Scleral Buckling Surgery

“…If a break occurs up to the midpoint of a buckle, the fishmouth phenomenon can occur [28]. This occurred when using the new device on the first patient in this study so intravitreal gas was injected after the surgery (Fig.…”