13.8  Sickle Cell Detachment

Intraoperative analgesia, oxygenation, and hydration are essential during surgery for sickle cell disease patients. General anesthesia is preferred over local anesthesia in these patients and, if general anesthesia is contraindicated, sub-Tenons block is preferred over retrobulbar block due to theoretical increased risk of orbital compartment syndrome from sickling events associated with a retrobulbar block. Topical or systemic acetazolamide should be avoided.

The goals of surgery in PSR retinal detachment repair are similar to any other retinal detachment repair – to clear media opacity, relieve vitreoretinal traction, and treat all breaks. Preoperative intravitreal bevacizumab (days to weeks prior to surgery) can be a useful adjunct to decrease the likelihood of intraoperative bleeding and to facilitate dissection of sea fan membranes.[6]

Patients with PSR tend to be younger, phakic, and have a formed vitreous. The use of encircling scleral buckle was previously discouraged, citing risk of anterior segment ischemia.[7] However, with modern surgical techniques and care taken to avoid placing a high and broad buckle, encircling scleral buckle elements can adequately support the vitreous base without compromising perfusion of the anterior choroid and ciliary body.[8]

Relieving vitreoretinal traction associated with neovascular membranes can be accomplished via either segmentation and/or delamination techniques. Bi-manual approach with a chandelier light or lighted pick can greatly facilitate dissection. Segmentation involves the vertical cutting of fibrovascular tissue into small segments to relieve anterior-posterior traction, whereas, delamination involves removal of membranes through horizontal dissection in the plane between retina and fibrous tissue to remove tangential traction. Some surgeons advocate for segmentation over delamination since delamination carries a higher risk of iatrogenic breaks in the already thin, atrophic peripheral retina. The sea fan neovascular complexes are also usually firmly adherent to underlying retina and removing them by delamination can be challenging.[9] Endolaser is performed to treat all retinal breaks, to surround and barricade neovascular complexes, and may be added to peripheral non-perfused retina to ablate ischemic retina, in efforts to decrease further vascular endothelial growth factor drive. Care must be taken to prevent intraocular pressure elevation during surgery, and also at the close of surgery with placement of gas or silicone oil tamponade. Eyes with SCR are prone to vitreoschisis and prudent use of dilute Kenalog is advised to ensure that a full posterior vitreous detachment is induced. PFO can be used to stabilize bullous retina and to aid in elevation of sticky peripheral hyaloid. Occasionally, removal of the crystalline lens may be needed to accomplish goals in the periphery.

The surgical outcomes in PSR are generally good when surgery is performed for vitreous hemorrhage or epiretinal membrane. In a case series of 15 patients with PSR, 6 patients with vitreous hemorrhage and 1 with ERM, underwent PPV and all had improved vision postoperatively.[8] The prognosis for PSR-related retinal detachment is more guarded. In the same case series, 4 of 8 patients with retinal detachment developed recurrent detachment (50% primary reattachment rate). In a separate retrospective case series that included 38 eyes with retinal detachment, the primary reattachment rate was 79%. Both studies highlight the complexity of treating retinal detachment in patients with proliferative sickle retinopathy.[10]