Retinal Detachment Surgery

The Dilemma Between Personal Experience and Clinical Trials

Peter Walter

Disclosures

Expert Rev Ophthalmol. 2012;7(5):441-447. 

In This Article

The Three Major Standard Treatment Possibilities: PR, SB & Vitrectomy

Gas Injection: PR

PR was introduced by Hilton and Grizzard,[4] and extensively investigated by Tornambe.[5] PR was originally recommended in detachments with breaks in the superior 8 clock hours. Later, modified PR techniques were applied in detachments with inferior breaks.[6]

Tornambe published experiences in 302 eyes, in which he found a single injection attachment rate of 68% and a final attachment rate after reoperations of 95%, with a minimum follow-up of 6 months. He found that the extent of retinal detachment, the number of breaks and the lens status affects the rate of attachment. In a subgroup where less than 25% of the retina is detached with a single small hole and clear media and no PVR, the reattachment rate was 98% when he used 360° retinopexy.[5]

Recently, Ellakwa evaluated long-term data after PR in a prospective interventional case series of 40 patients and found a stable reattachment of the retina in 60% after a single injection.[7] In a recently published retrospective chart analysis of 213 patients receiving PR, Davis et al. found a single injection success rate of 64% with a follow-up of at least 6 months. They found that vitreous hemorrhage and large detachments (>4.5 clock hours) are indicators for a high risk of failure.[8] Single injection success rates are different between phakic and nonphakic eyes. In phakic eyes, success rates are reported to be between 71 and 84% and in nonphakic eyes the success rates are between 41 and 67%. The final anatomical success rate after additional procedures was reported as 96.1%, additional breaks were found in 11.7% and PVR occurred in 5.2% according to a review by Chan et al..[9]

Complications of PR were new retinal breaks (7–33%), cystoid macular edema (0–8%), subretinal gas (0–4%), PVR (3–13%), cataract formation (1–20%) and epiretinal membranes (2–11%).[10,11]

PR can be performed as an office-based procedure and it is often advocated that the economic burden for the patient and/or insurance companies is lower than using the other techniques even when the reoperations are taking into account.

Scleral Buckling

In SB, episcleral elements were used to indent the wall of the eye in a way that the vitreous is compressed in the direction of the retinal break. Thereby traction is released from the hole and the hole is pressed in the direction of the condensed vitreous which possibly helps to close the hole. Fluid is displaced from underneath the retina and the distance between the retinal pigment epithelium and the retina is reduced which facilitates reabsorption of subretinal fluid by the retinal pigment epithelium. The curvature of the eye is also changed so that tractional forces cannot pull the retina inwards. Moreover, fluid movements are reduced in the eye helping to reduce flow into the break and underneath the retina. However, the hole needs coagulation either by transscleral cryopexy or by laser photocoagulation. The laser can be applied transsclerally or transpupillary.

SB with episcleral elements was described by Custodis[12] in Germany, by Schepens et al.[13] and Lincoff et al. in the USA,[14] and others. Large case series were published demonstrating the success of SB in uncomplicated cases yielding single surgery reattachment rates of between 81 and 88%.[15–20]

The risk profile includes the failure of the procedure, infection of the episcleral device,[21] a change in the patients refraction,[22–25] a conjunctival erosion, an extrusion or intrusion of the implant,[26–28] as well as motility problems and double vision,[29,30] as well as retinal folds.[31]

Primary Pars Plana Vitrectomy

With the introduction of pars plana vitrectomy (ppV) by Machemer et al. this technique was also used in the repair of retinal detachments.[32] The use of ppV for retinal detachment surgery is increasing as vitrectomy is regarded as a very safe technique. It was first applied in complicated retinal detachments such as PVR cases, giant retinal tears or trauma.[33–35] The introduction of heavier than water liquids[36] to drain subretinal fluid internally and the availability of wide-angle viewing systems made ppV more and more attractive for surgeons to use it also for more simple cases of retinal detachments.

From the pathophysiological view vitrectomy seems to be a good method because it releases vitreous traction exactly where it leads to retinal breaks. Due to the considerably improved visibility of the whole fundus during vitrectomy, pathologies are no longer missed or overlooked. In general, the concept of vitrectomy for treating retinal detachments consists of removing as much of the vitreous as possible, drain the subretinal fluid internally and fill the vitreous cavity with gas or air after treating all breaks with laser or cryopexy. Many case series reported single surgery success rates between 64 and 100%.[37–41]

However, vitrectomy has a specific risk profile. In phakic eyes, cataract progression is very likely.[42,43] Iatrogenic holes,[44] remnants of perfluorcarbon liquids even underneath the retina,[45] overfill with gas with postoperative glaucoma,[46] positioning problems with intraocular lenses after cataract surgery,[47] and others have been reported.

Vitrectomy can be combined with episcleral elements to enhance the release of traction. This is usually done with an encircling element. The combination of both techniques may improve the chances for reattaching the retina but may also add the risk profile of SB to that of ppV. In a retrospective comparative case series Kinori et al. found a reattachment rate of 81.3% in patients treated with vitrectomy alone, whereas the reattachment rate after one surgery was 87.1% in patients where vitrectomy was combined with an encircling band. The difference was not statistically significant. There was also no difference in final visual acuity between the two groups. One may think that in cases with inferior breaks vitrectomy alone would be inferior to vitrectomy plus encircling band, but that was not the case in their investigation.[48] In that study all patients were included if they had either ppV or ppV and SB. Patients after trauma, with PVR C or worse, giant retinal tears, children under 16 years, patients with previous vitreoretinal procedures and patients with proliferative retinal diseases were excluded. By contrast, in another retrospective study by Mehta and coworkers, a significant difference in reattachment rates occurred in phakic patients; 83% in the vitrectomy alone group versus 97% in the vitrectomy and encircling band group. In pseudophakic patients no difference was found.[49]

In another study by Weichel et al., reattachment rates in pseudophakic retinal detachments were 92.6% in the vitrectomy alone group and 94% in the ppV and SB group, which was not significant. Also, the rate of complications was statistically not different in both groups in this retrospective comparative study.[50]

Wickham et al. found no difference in the reattachment rates between vitrectomy with or without a buckle in detachments caused by inferior breaks.[51]

Another debate is the use of transconjunctival techniques using 23, 25 or even 27 gauge instruments for vitrectomy. Undoubtedly, the patient comfort is better after small gauge vitrectomy than after standard 20-gauge vitrectomy, and some other issues may also be discussed, such as the costs and surgical time.[52,53] However, here, safety and retinal reattachment rates should be focused upon. Safety was an issue in the first years of transconjunctival vitrectomy. Reports were published showing an increase in endophthalmitis incidence after vitrectomy using the transconjunctival approach;[54,55] however, newer reports did not confirm these data. Currently, the small gauge transconjunctival techniques are regarded as being as safe as the standard 20-gauge vitrectomy technique.[56–58] Beside the endophthalmitis risk, success rates have to be considered. In a retrospective chart review, Mura et al. found a single success rate of 92.4% after 25-gauge vitrectomy.[59] These very good data were confirmed by Bourla et al. with single surgery success rates of 97.4% in a retrospective case series with a follow-up of 3 months.[60] Similar data were reported by Miller et al. (92.9%)[61] and Mendrinos et al. (92%).[62] However, only 74% were reported by Lai and coworkers.[63] For 23 gauge vitrectomy, good single surgery success rates were also reported. In Tsang et al.'s prospective case series, this rate was 91.7%.[64]

In a retrospective comparison between 25- and 20-gauge vitrectomy, von Fricken et al. reported single surgery success rates of 90.6% for 25-gauge vitrectomy and 91.8% for the 20-gauge group.[65] Colyer and coworkers compared success rates of transconjunctival 25-gauge vitrectomy with the standard 20-gauge approach. They found a single operation success rate after 25-gauge transconjunctival vitrectomy in 83.3% and in 89.6% after 20-gauge vitrectomy in pseudophakic eyes with inferior breaks, indicating no difference.[66]

processing....