The increasing use of vitrectomy for the primary management of retinal detachment was studied at one hospital that compared the characteristics of the surgical procedures used in 1979-1980 with their cases 20 years later (in 1999) [6]. Of 124 eyes managed in 1979-1980, only one had vitrectomy as the primary mode of treatment. In 1999,79 of 126 (63%) were managed with vitrectomy. The severity of cases did also differ, however, with more complex cases, such as pseudophakic retinal detachments, giant retinal tears, and proliferative vitreoretinopathy cases managed in 1999.

The rates of retinal reattachment after vitrectomy vary from 64% to 100% after a single operation [7-11]. When all the cases are combined, the retina was reattached in 87.7% (421 of 480 eyes) of eyes after one operation and 96.7% after multiple operations. The surgical techniques did vary and might explain some of the differences in anatomic outcomes. In some series, concomitant scleral buckling was done [10], but in others, a scleral buckle was not used in any of the eyes [9]. Also, vitrectomy was done only in pseudo-phakic eyes, compared with other series that were operated without regard to the lens status. The most common causes of failure of the primary operation were missed retinal breaks or the development of PVR. In a series of 25 failed cases analyzed for the cause of failure, missed retinal breaks were responsible for 64.3% of failures [12]. These cases were managed with vitrectomy revision with or without scleral buckling. The visual acuity outcomes are not stated in many of these reports, and it is not possible to determine if the outcomes are more favorable than in eyes treated with scleral buckling alone. Some retrospective reviews and randomized clinical studies comparing the anatomic outcomes between vitrectomy and scleral buckling as the primary operation have been reported [13-15]. In general, they report similar anatomic and visual outcomes and probably have too small a number of eyes to have sufficient power to detect a difference. A large prospective randomized study with matched retinal detachments would be required to find if there is a difference in visual acuity outcomes. Such a study would probably require hundreds of patients, since the anatomic reattachment rates are high both with scleral buckling and with vitrectomy and is currently in progress in Germany (SPR Study) [16].

There are several advantages to the use of vitrectomy in the primary management of retinal detachment. Intraocular visualization is much improved, reducing the possibility of missing retinal breaks. In one prospective study of 51 eyes undergoing vitrectomy, 7 (13.7%) eyes were found to have previously undetected retinal breaks, and additional holes were found in 21 (41%) eyes [17]. The traction on the tear is removed with vitrectomy with any vitreous debris or hemorrhage. Thus, the patient rarely sees "floaters" post-operatively. The retina is almost completely flattened at the time of surgery with the help of perfluorocarbon liquids, and there is almost no persistent subretinal fluid involving the macula. Thus, the recovery of macular function starts immediately postoperatively. Choroidal detachment is rarely seen in vitrectomized eyes. Endo-laser photocoagulation is more comfortable for the patient and may cause less surgically-induced inflammation compared with cryotherapy. If a scleral buckle is used in conjunction with vitrectomy, it tends to be a smaller buckling element, especially with large posterior retinal tears. In pseudophakic eyes, there is less change in postoperative refractive error when no scleral buckle is used.

The complications of vitrectomy may affect the visual and anatomic outcome. The possibility of iatrogenic retinal breaks as a result of cutting near mobile retina or from vitreous incarceration at sclerotomy sites increases the risk of failure. A large gas bubble may be associated with glaucoma or with iris capture of an intraocular lens. Unexplained visual field defects may also occur after vitrectomy. Rarely, a retinal fold that involves the macula is seen postoperatively. The patient complains of marked distortion. Endophthalmitis is a rare but devastating complication. In phakic eyes, the postoperative progression of nuclear cataract may be the single reason that vitrectomy is not recommended routinely for every retinal detachment. In a young patient with a clear lens in the fellow eye, the loss of accommodation resulting from pseudopha-kia can be quite disabling. Thus, whenever possible, it is preferable to use an operation that will not increase the rate of cataract progression.

There are also economic considerations that may play a role in the choice between vitrectomy and scleral buckling as the primary treatment for retinal detachment. The cost of supplies for a scleral buckling procedure is significantly less than that of a vitrectomy. If cataract surgery is also required later, the cost difference is multiplied. The rehabilitation time is increased after vitrectomy compared with scleral buckling. In general, most of my patients are able to return to work 1 week after scleral buckling. After vitrectomy, most patients are incapacitated for 2-4 weeks because of head positioning and inability to drive. There is a prolonged recovery time, with lengthened disability. While these factors might seem small for the individual case, it is estimated that up to 30,000-50,000 retinal detachments are treated annually in the United States.

Further data will be required to define the role of vitrectomy for the management of uncomplicated retinal detachments. In particular, these studies should provide strong clinical evidence for situations where the benefits from vitrectomy are superior to scleral buckling. At the present time, the main limitation for vitrectomy in phakic eyes is the progression of nuclear cataract. Until there are better treatments developed to prevent this complication, scleral buckling remains the main treatment modality for most retinal detachments with vitrectomy as an adjunct for more complex cases.

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