8.2  Clinical Decision Making

A retinal detachment may occur when vitreous traction causes a break in the retina, allowing liquid vitreous passage to enter the subretinal space. If the rate of collection of subretinal fluid exceeds the retinal pigment epithelium’s ability to pump this out, a retinal detachment forms. Repair of a retinal detachment may include any of the following mechanisms:

  1. Closure of the break(s) with an endotamponade
  2. Repair of the break(s) with retinal pexy
  3. Re-apposition of the retina to the retinal pigment epithelium
  4. Relief of vitreous and/or retinal traction

The decision on how to treat a retinal detachment remains highly debatable. The options available include: pneumatic retinopexy, scleral buckling, vitrectomy, or a combination of these techniques. Although often more than one of these techniques will yield a favorable result, there are cases when a particular technique is preferred over others by certain surgeons. For this reason, each of these procedures needs to be mastered by the training vitreo-retinal surgeon.

The reasons for controversy in deciding how to treat a retinal detachment are complex. In addition to the ocular condition, patient factors (for example, need for plane travel in the post-operative period); surgeon factors (skill set) and environmental factors (accessibility to the operating room, equipment, and economics) can influence clinical decision-making. The best option should provide the highest anatomical and functional success with the lowest morbidity, complications and number of procedures. Determining this is difficult. Each retinal detachment is unique. Techniques of approaching the “same” operation are not only highly variable but constantly progressing. Designing studies of this heterogeneous population is fraught with difficulty. Many studies on retinal detachment are of small case series, are outdated and have different inclusion/exclusion criteria and definitions of success. Complication rates depend on surgical technique and skill. Ultimately each surgeon will have their own opinion, based on the available evidence and surgical experience. The following discussion provides a guideline for those learning the art and science of retinal detachment repair.

Pneumatic Retinopexy

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).

Chan CK et. al. Pneumatic Retinopexy for the Repair of Retinal Detachments: A Comprehensive Review (1986-2007). Surv Ophthalmol. 2008;53(443-478).

Chan CK et. al. Pneumatic Retinopexy for the Repair of Retinal Detachments: A Comprehensive Review (1986-2007). Surv Ophthalmol. 2008;53(443-478).

Tornambe PE, Hilton GF. Pneumatic retinopexy. A multicenter randomized controlled clinical trial comparing pneumatic retinopexy with scleral buckling. The Retinal Detachment Study Group. Ophthalmology 1989; 96(12)1181-2.

Ross WH, Lavina A. Pneumatic retinopexy, scleral buckling, and vitrectomy surgery in the management of pseudophakic retinal detachments. Canadian Journal of Ophthalmology. 2008; 43(1):65-72.

Scleral Buckle Versus Vitrectomy Alone

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]

Campo RV, Sipperley JO, Sneed SR, Park DW, Dugel PU, Jacobsen J, Flindall RJ. Pars plana vitrectomy without scleral buckle for pseudophakic retinal detachments. Ophthalmology. 1999 Sep;106(9):1811-5; discussion 1816.

Cowley M, et. al. Clinical risk factors for proliferative vitreoretinopathy. Arch Ophthalmol. 1989;107 (8):1147-1151.

Hiemann H et. al. Scleral buckling versus primary vitrectomy in rhegmatogenous retinal detachment (SPR Study): Design issues and implications. SPR Study Report No. 1. Graefe’s Arch Clin Exp Ophthalmol 2001; 239:567–574.

Chong DY, Fuller DG. The Declining Use of Scleral Buckling With Vitrectomy for Primary Retinal Detachments. Arch Ophthalmol. 2010;128(9):1206-8.

Vitrectomy Versus Combined Vitrectomy and Scleral Buckle

In some patients who either require vitrectomy (for instance, the presence of significant vitreous haemorrhage or PVR) or when this procedure has been chosen, the addition of a scleral buckle may be advantageous.[5] Firstly, this may enhance removal of peripheral vitreous (particularly in phakic patients and those with media opacity such as dense peripheral vitreous haemorrhage, cortical cataract or posterior capsular opacification).[13] Secondly, the scleral buckle provides additional support for the peripheral retina and may reduce the risk of re-detachment, especially if PVR is present or develops[5] or the breaks are inferior and fail to be covered by gas or silicone oil endotamponade.[14,15] Other indications for combined scleral buckling include the presence of significant anterior loop traction and retinal redetachment after vitrectomy with significant PVR (especially inferior).

Opponents of combined vitrectomy and scleral buckling surgery believe that the direct relief of vitreous traction by vitrectomy makes additional scleral buckling redundant. Some studies in pseudophakic eyes have shown statistically equivalent anatomical and visual outcomes with vitrectomy alone compared with combined surgery.[16,17,18] Others have shown equivalent success rates with vitrectomy alone when comparing superior and inferior breaks[19] or no benefit with the addition of a scleral buckle to vitrectomy for inferior breaks.[20]

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