Rhegmatogenous Retinal Detachment: Management, Part 2

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Last month, Ophthalmic Pearls discussed risk factors, features, and examination of rhegmatoge­nous retinal detachments (RRD). This month, the authors continue with a discussion of RRD management.

After Dx: How to Proceed

RRDs with superior breaks that threaten the macula require urgent vitreoretinal intervention. While awaiting definitive management, patients should maintain a posture that prevents the subretinal fluid from detaching the macula.

Definitive management of RRD includes barrier laser retinopexy in select situations, pneumatic retinopexy, pri­mary scleral buckle, primary pars plana vitrectomy (PPV) with intraocular tamponade or combined scleral buckle and vitrectomy.

Barrier laser retinopexy. This procedure is indicated for localized detachments such as subclinical retinal detachment. This is usually performed with the patient under topical anesthe­sia. Patients must be forewarned that, despite this treatment, the RRD may progress and require additional inter­vention, including surgery.

Pneumatic retinopexy. Pneumatic retinopexy is indicated for specific RRD cases, including those with break(s) confined to the superior 8 clock hours, with all breaks being confined within 2 clock hours. Contraindications include large (giant) retinal tears, proliferative vitreoretinop­athy (PVR), advanced glau­coma, poor compliance with head posturing, individuals who need to travel by air, and, in some cases, pseu­dophakia.

The procedure, which is performed with the patient under regional anesthesia, entails transconjunctival in­travitreal injection of an ex­pansile gas bubble, plus reti­nopexy to the retinal breaks. In general, retinopexy is done using cryotherapy or laser photocoagulation. Transconjunctival cryopexy usually is performed before gas injection, during a single outpatient visit. For laser retinopexy, gas injection is performed initially, followed by laser photocoagulation several days later. The expansile intraocular gases include 100% sulfur hexafluoride (SF₆, 0.6 mL), perfluoroethane (C₂F₆, 0.4 mL), and perfluoropropane (C₃F₈, 0.3 mL).

Reattachment can be achieved with a single pneumatic retinopexy procedure in 80% of cases and with ≥1 procedure in 98%.¹

Although pneumatic retinopexy is minimally invasive, the risk of new or missed retinal breaks is greater with this procedure than with more invasive surgery such as vitrectomy or scleral buckle.² Other possible complications include gas migration into the sub­retinal space, central retinal artery occlusion from elevated IOP, vitreous incarceration at the wound, accelerated cataract formation, and endophthal­mitis.

Scleral buckle and pars plana vit­rectomy. All breaks must be located, then treated with cryotherapy or laser retinopexy. Vitreoretinal traction must be relieved by either scleral buckling or vitrectomy. In most cases, the subretinal fluid is drained internally (via the reti­nal hole during vitrectomy) or exter­nally (by scleral cut-down in primary scleral buckle surgery), if needed.

Scleral buckle surgery. This extra­ocular procedure should be considered for young, phakic patients with tear(s) anterior to the equator. It is not suitable for patients with a giant retinal tear or PVR.

Transscleral cryotherapy is per­formed around the retinal break, and the external scleral indentation from the buckle helps to support the break. The buckle-induced indentation aids in adhesion between the neurosensory retina and the retinal pigment epitheli­um, while relieving vitreous traction on the retina.³ Several types of scleral buckling material are available, including encirclage and segmental and radial buckles. The procedure is usually per­formed in the operating room while the patient is under regional anesthesia or, rarely, general anesthesia.

Surgical steps are as follows:

• 360-degree conjunctival peritomy
• Slinging recti muscles
• Localizing the break with binocular indirect ophthalmoscopy (BIO)
• Cryotherapy with or without exter­nal drainage of subretinal fluid
• Inserting the segmental and/or encircling scleral buckle
• Suturing and tightening of the buckle
• Checking of central retinal artery perfusion to determine need for anterior chamber paracentesis
• Antibiotic wash around the buckle
• Closing the conjunctiva
• Subconjunctival antibiotic and steroid injections

Intraoperative complications include scleral perforation and recti muscle trauma/slip. In cases requiring subreti­nal fluid drainage, the surgeon must be aware of risk for suprachoroidal hem­orrhage, hypotony, and retinal incarcer­ation at the drainage site. Postoperative complications include PVR formation, re-detachment, buckle migration/extrusion, buckle-related infections, refractive changes, ocular motility dis­orders, anterior segment ischemia, and glaucoma (from vortex vein or ciliary body compression).

Among suitable cases, reattachment can be achieved with a single primary scleral buckle procedure in 80% to 90%.⁴

Pars plana vitrectomy. PPV may be indicated for posterior retinal break, multiple breaks in different meridians, giant retinal tear, concurrent PVR, and dense vitreous hemorrhage obscuring the retinal break(s). PPV is performed in the operating room while the patient is under regional anesthesia or, rarely, general anesthesia.

Steps include:

• Creating three sclerostomy ports (for the infusion cannula, illumination probe, and vitrectomy handpiece)
• Core vitrectomy, shaving the vitreous base, and relieving any traction over the retinal break
• Using perfluorocarbon liquid to flat­ten the retina and displace the subret­inal fluid via the original retinal break (optional step, depending on surgeon preference)
• Retinopexy around retinal breaks; laser is often used
• Fluid-air exchange
• Injecting vitreous substitute such as isoexpansive gas or silicone oil

Nonexpansile intraocular gas tam­ponade, such as SF₆ 20%, C₂F₆ 15%, or C₃F₈ 15%, will usually last two weeks, three weeks, and eight weeks (respec­tively) due to different rates of resorp­tion. Patients should be advised about the postoperative posturing necessary to allow the buoyant vitreous substitute to tamponade the break. This posturing is maintained until most of the gas bubble has been resorbed.

If silicone oil tamponade is used, it is typically removed three to six months after surgery; in some eyes, it is retained indefinitely.

The success rate of PPV for RRD ranges from 64% to 96%, depending on the complexity of the case.⁵

Intraoperative complications include trauma to intraocular structures (e.g., iatrogenic retinal breaks or iatrogenic cataracts) and vitreous/retina incarcer­ation at sclerotomy wounds. Postop­erative complications may include endophthalmitis, sympathetic ophthal­mia, glaucoma, and cataract.

Combined scleral buckle and pars plana vitrectomy. This combination is sometimes needed for simple RRD (Fig. 1). Although most comparative studies of scleral buckle, PPV, and the combination procedure showed no significant differences in success rates for single-session surgery, a few have demonstrated that PPV alone is supe­rior to scleral buckle alone for primary RRD.⁵ In a retrospective study at Singa­pore National Eye Centre, patients who received the combination procedure had better anatomic success rates than those who underwent PPV alone (90% vs. 80%, p < .001).⁶

In complicated RRD cases, combin­ing scleral buckle and PPV can improve visualization of breaks during PPV and provide better support of the peripheral retina.

AFTER COMBINATION SURGERY. Ultra-widefield fundus photograph of an eye that underwent scleral buckle and PPV with gas. The photograph was obtained several weeks postoperatively. A partially resorbed gas bubble is visible (left arrow), and the indent from the buckle can be seen supporting the peripheral retina (right arrow).

Timing of Intervention

The urgency to repair RRD depends on the status of the macula and other patient-specific characteristics. Even if the macula is on (fovea spared), urgent intervention may be necessary. When the fovea is already detached (macula-off), reattaching the retina may be less urgent. Some experts suggest that the number of days of foveal detachment may indicate the urgency of surgery. Thus, if the fovea has been detached for two days, surgery should be performed within two days.⁷

In a study of patients with macula-off retinal detachment, those who underwent surgery within three days of developing central vision loss had better visual outcomes postoperatively.⁸ However, the visual outcomes for cases in which surgical repair was delayed for 10 days did not differ significantly from outcomes for cases not surgically repaired until a month following the loss of central vision.⁸

Conclusion

The management of RRD requires a detailed assessment to ensure identi­fication of all breaks. This facilitates the planning and execution of surgical intervention. Surgical treatment entails locating and sealing all breaks as well as relieving vitreous traction. Prompt intervention may produce better visual outcomes. Care should be taken to select the most appropriate procedure or procedures, with consideration given to the timing of intervention.

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1 Hilton GF, Tornambe PE. Retina. 1991;11(3):285-294.

2 Chan CK et al. Surv Ophthalmol. 2008;53(5):443-478.

3 Sullivan P. Techniques of scleral buckle. Ryan’s Retina, Vol 3. 6th ed. Philadelphia: Elsevier; 2017:1889-1915.

4 Thelen U et al. Acta Ophthalmol. 2012;90(5):481-486.

5 Young HY et al. Primary vitrectomy in rheg­matogenous retinal detachment. Ryan’s Retina, Vol 3. 6th ed. Philadelphia: Elsevier; 2017:1933-1942.

6 Wong CW et al. Retina. 2014;34(4):684-692.

7 Hassan TS et al. Ophthalmology. 2002;109(1):146-152.

8 Frings A et al. Br J Ophthalmol. 2016;100(11):1466-1469.

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Dr. Chiam is an ophthalmology resident at Singa­pore National Eye Centre. Dr. Ting is the surgical retinal fellow at the Singapore National Eye Centre and an assistant professor at Duke-Na­tional University Singapore (Duke-NUS) Medical School. Dr. Lee is the senior consultant, deputy head of the Surgical Retinal Department of Sin­gapore National Eye Centre, and an adjunct asso­ciate professor at Duke-NUS. Dr. Ang is a senior consultant at the Surgical Retinal Department of Singapore National Eye Centre and a clinical pro­fessor at Duke-NUS. Financial disclosures: None.

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Acknowledgment: We thank the Ocular Imaging Department, Singapore National Eye Centre, for providing the retinal photographs in Parts 1 and 2 of this series.