8.2  Clinical Decision Making

Pneumatic retinopexy provides the simplest approach to repairing retinal detachments. In addition, it has the advantage of being performed in the outpatient rather than operating room setting, and is more cost-effective. Suitable patients are those with a small single tear less than 1 - 2 clock hours within the superior 6 (or 8) clock hours, sufficient view for full peripheral retinal examination, no proliferative vitreoretinopathy and an ability to posture. When performed in the appropriate patient, it can yield excellent results (around 70-80% anatomical success in phakic eyes and 40-70% in pseudophakic eyes with a single procedure).[1] Although single-operation success is less than for scleral buckling or vitrectomy, final anatomical (98-100% re-attachment) and visual outcomes are not disadvantaged by initial pneumatic retinopexy.[1,2,3] Recent studies showed that the visual outcomes of pneumatic retinopexy may even be better than vitrectomy and that retinal integrity may be better after a pneumatic retinopexy than after vitrectomy (PIVOT trial).

In patients unsuitable for pneumatic retinopexy, the decision of whether to treat a retinal detachment with scleral buckling or vitrectomy remains controversial. Recently there has been a very strong movement towards pars plana vitrectomy in the management of retinal detachment, particularly in pseudophakic patients, with >90% vitrectomy rate in many centers. The reasons for this are complex, but may include: a requirement for greater mastery of indirect ophthalmoscopy, longer and technically more difficult operation, different complication profile (such as myopic shift and risk of diplopia) and lower reimbursement incentive with scleral buckling. Retinal breaks in pseudophakic patients are often small and anterior and are harder to identify with indirect ophthalmoscopy than wide-angle viewing during vitrectomy.[4] The persistence of sub- retinal fluid at the conclusion of scleral buckling when drainage has not been performed can make surgeons anxious, and failures are likely to be evident earlier following scleral buckling than vitrectomy. OCT imaging demonstrates residual subfoveal fluid in many patients treated with scleral buckle – this may be an uncommon finding for optometrists who will refer patients back to the surgeon.
In contrast, advancements in small gauge vitrectomy technology and techniques have made this procedure safer, faster and more efficacious. The decline in scleral buckling is likely to continue if knowledge of this technique fails to be passed onto training surgeons.

Despite this trend, the authors believe that scleral buckling holds an important place in the management of certain retinal detachments. In young patients (particularly myopes with lattice degeneration), a posterior vitreous detachment is often non-existent or incomplete. Failure to adequately elevate the posterior hyaloid (which may be difficult and lead to additional breaks) and perform sufficient vitrectomy risks future vitreous contraction and re-detachment.[5] In phakic patients, shaving of the peripheral vitreous and relief of traction by vitrectomy alone is limited by the presence of the lens. Development of cataract with vitrectomy but not scleral buckling is a major disadvantage. Inferior breaks are less well supported by traditional endotamponades that float, such as gas or silicone oil. In traumatic retinal dialyses the vitreous usually remains attached and excellent results can be achieved with scleral buckling alone. Some studies have found vitrectomy to be an independent risk factor for development of proliferative vitreoretinopathy [6]or epiretinal membrane formation.[7] In the appropriate patient, scleral buckling remains a highly efficacious, cost-effective treatment.[5]

The Scleral Buckling versus Primary Vitrectomy in Rhegmatogenous Retinal Detachment (SPR) study was a multi-centre, randomised controlled trial comparing scleral buckling with primary vitrectomy in the management of rhegmatogenous retinal detachment.[8] It is the largest such study of retinal detachment to date. Patients did not have greater than Grade A proliferative vitreoretinopathy (PVR) and were not suitable for a single meridional sponge. Best-corrected visual acuity was better with scleral buckling than pars plana vitrectomy in phakic patients, even after accounting for cataract.[9] This finding has been supported by data from other trials.[10,11] No difference in visual acuity was found in aphakic and pseudophakic patients. Single-operation anatomical success was 63% for each procedure in phakic patients, but statistically higher for vitrectomy (95%) than scleral buckling (71%) in aphakic / pseudophakic patients. Final anatomical success was statistically similar with each procedure in phakic (96%) and aphakic/pseudophakic patients (93-95%). The study has been criticised for its high rate of post-operative PVR.[12]