Complex diabetic tractional retinal detachment comprises a minor proportion of diabetic eye disease treated by most retina specialists, but given the prevalence of diabetic retinopathy, the advanced techniques required for repair of tractional retinal detachment will remain a staple of the retina surgeon’s skill set.

A number of factors must be considered in deciding whether to proceed with surgery for tractional retinal detachment. When vitreoretinal traction involves the macula, inducing a reduction in visual acuity, the decision to proceed is generally straightforward. Spectral domain OCT is invaluable in assessing macular distortion and detachment as well as progression from prior examinations. In some cases of macula-threatening detachment, surgical intervention is warranted, particularly if there has been objective evidence of progression.¹ In addition, the status of the fellow eye, with particular attention to rapidly progressive tractional retinal detachment, is an important consideration in the decision to proceed. The occurrence of subhyaloid hemorrhage in the setting of a completely attached posterior hyaloid, particularly when hemorrhage obscures the macula in a young patient, may prompt early intervention. Like any surgical procedure, surgery for diabetic tractional retinal detachment is not without risk.^2,3 Stringent attention to the risk-benefit ratio must be exercised, in particular for functionally monocular patients and those for whom fellow eye surgery yielded limited results.

While many surgeons favor deferring surgical intervention until the macula becomes involved, prolonged perturbation of macular anatomy, and in some cases even transient tractional detachment of the macula, may result in permanently impaired visual function. A subset of tractional retinal detachments will progress to combined tractional-rhegmatogenous retinal detachment, which is associated with reduced surgical success rates and visual outcomes.⁴

Key Components of the Surgical Strategy

Although specific tactics may differ, most surgeons agree on the strategic approach to diabetic tractional retinal detachment surgery. The most critical element of success is detaching the posterior hyaloid. In general, the technical complexity of the procedure correlates with the extent of hyaloid adherence.² Removal of the hyaloid in complex cases generally requires a combination of delamination alternating with segmentation of adherent vitreous and epiretinal proliferative tissue (Figure 1). Avoiding iatrogenic retinal breaks, which often necessitate a more aggressive surgical approach and may carry a worse final prognosis, is paramount in these cases.^3,4 In order to maintain hemostasis throughout the procedure, attention should be given to any foci of perfused retinal neovascularization or bleeding from retinal vasculature. Successful intraoperative (and postoperative) hemostasis cannot be overemphasized, particularly in patients requiring endo-tamponade at the conclusion of surgery. Once the hyaloid has been removed, careful attention may be turned to the macula for delamination of residual epiretinal tissue that is causing macular distortion.

Complete posterior vitreous detachment should be achieved if possible. In cases with preexisting or iatrogenic retinal breaks and significant residual epiretinal tissue, it is crucial to remove all traction associated with the breaks. Residual postoperative traction is associated with increased risk for recurrent detachment. Combined tractional and rhegmatogenous retinal detachment is often associated with rapidly progressive proliferative vitreoretinopathy (PVR), and subretinal PVR frequently develops. In the most severe cases of tractional retinal detachment, it may not be possible to isolate epiretinal proliferative tissue from inseparable underlying retinal tissue, and focal retinectomy may be required to achieve reattachment.

Finally, scatter panretinal photocoagulation (PRP) should be performed in order to retard or prevent further complications from proliferative diabetic retinopathy. Some surgeons elect to perform scatter PRP in a separate session, either before or after incisional surgery,³ in an effort to reduce postoperative inflammation. I prefer to perform some laser photocoagulation prior to the incisional surgery in some cases, because it may confer some degree of regression of retinal neovascularization, which aids in intraoperative hemostasis.

My Techniques and Tools

Careful preoperative ophthalmic and medical assessment aids in achieving the surgical goals. The presence of cataracts or other opacities of the anterior media must be considered in order to ensure adequate intraoperative visualization for the duration of the procedure. Also, perioperative control of systemic hypertension may aid in intraoperative hemostasis and should be addressed, together with glycemic control, in cooperation with the patient’s general medical physician. Consideration of preoperative laser photocoagulation or administration of a pharmacologic to address retinal neovascularization is warranted.

Prior to undergoing surgery, it is imperative that the patient have a clear and realistic understanding of the goals of the procedure and the likely short- and long-term vision outcomes. In spite of a technically successful surgery and reattachment of the retina, postoperative visual acuity outcomes are often limited as a result of preexisting retinal ischemia and damage. The importance of early and ongoing postoperative care in achieving durable success should be discussed in the setting of severe diabetic eye disease.

I use 25- and 27-gauge micro-incisional vitrectomy instrumentation (MIVI) in all cases of diabetic tractional retinal detachment repair. Following the core vitrectomy and removal of vitreous hemorrhage if present, I initiate separation of the posterior hyaloid. I favor an inside-out approach, beginning at the optic nerve head and working toward the periphery. Even in severe cases where placoid tissue is obscuring the optic disc and retina within the arcades, I generally begin proximal to the optic nerve head; I find that the shear force dynamics of inside-out dissection are favorable with regard to minimizing iatrogenic retinal breaks. The hyaloid is tightly adherent to foci of fibrovascular proliferation (FVP), with the most stringent points of attachment often occurring in association with the larger retinal vessels. I alternate delamination of the posterior hyaloid with segmentation of tightly adherent foci of FVP, and generally excise the foci of FVP following isolation from the posterior hyaloid.

Employing MIVI greatly facilitates the tactics required for delamination of epiretinal FVP and placoid tissue. I employ the MIVI small-gauge probe as a multifunctional tool. Utilizing preset parameters (Figure 2) in the Constellation Vision System (Alcon) for modulation of cut rate, fluidics, and duty cycle, the vitrectomy probe allows for aspiration, hyaloid and membrane delamination, vertical scissors, horizontal scissors, and blunt pick functionality (Figure 3). Contemporary wide-angle viewing systems also facilitate surgery for tractional retinal detachment, allowing for excellent visualization. The current generation of chandelier endo-illuminators confers excellent visualization during bimanual dissection techniques. Use of a curved illuminated endolaser facilitates photocoagulation of the peripheral retina during surgical repair.

In cases that require endotamponade for retinal breaks, I try to avoid using silicone oil whenever possible. Postoperative hemorrhage, and perhaps elaboration of other soluble mediators in severe diabetic retinopathy, may contribute to rapidly progressive fibrosis under silicone oil.⁵

Follow-Up Care

Durable reattachment of the retina should be achievable in the vast majority of tractional retinal detachment cases (Figure 4), although visual acuity outcomes are highly variable. They generally correlate with the extent and severity of preoperative pathology, including the degree of retinal ischemia, severity and duration of macular distortion and detachment, presence of preexisting rhegmatogenous detachment affecting the macula, and other ocular morbidities, such as glaucomatous optic neuropathy and neovascular glaucoma, among others.

In addition to the standard postoperative considerations, postoperative examinations should include assessment for postoperative hemorrhage, proliferation of epiretinal tissue exerting traction, subretinal fluid with occurrence of rhegmatogenous retinal detachment, neovascularization of the anterior or posterior segments, elevated intraocular pressure, and diabetic macular edema. ■

References

1. Packer AJ. Vitrectomy for progressive macular traction associated with proliferative diabetic retinopathy. Arch Ophthalmol. 1987;105(12):1679-1682.
2. Eliott D, Hemeida T. Diabetic traction retinal detachment. Int Ophthalmol Clin. 2009;49(2):153-165.
3. Thompson JT, de Bustros S, Michels RG, Rice TA. Results and prognostic factors in vitrectomy for diabetic traction retinal detachment of the macula. Arch Ophthalmol. 1987;105(4):497-502.
4. Thompson JT, de Bustros S, Michels RG, Rice TA. Results and prognostic factors in vitrectomy for diabetic traction-rhegmatogenous retinal detachment. Arch Ophthalmol. 1987;105(4):503-507.
5. Messmer E, Bornfeld N, Oehlschlager U, Heinrich T, Foerster MH, Wessing A. Epiretinal membrane formation after pars plana vitrectomy in proliferative diabetic retinopathy. Klin Monbl Augenheilkd. 1992;200(4):267-272.

Dr. Leiderman is an assistant professor of ophthalmology and director of the Vitreoretinal Microsurgery Laboratory at the University of Illinois College of Medicine’s Illinois Eye and Ear Infirmary in Chicago.