Description
A retinal detachment occurs when the sensory retina lifts and separates from the retinal pigment epithelium (RPE). Tractional retinal detachment (TRD) refers to a detachment caused by fibrotic or fibrovascular strands of vitreous creating traction on the retina. TRD is a sequel to previous hemorrhage, trauma, surgery, infection or inflammation. Specific causes may include:
(a) proliferative retinopathy e.g. diabetes, sickle cell, prematurity, venous occlusions
(b) intraocular inflammation e.g. toxacariasis
(c) penetrating ocular trauma
Histologically, the tractional membranes may include components such as RPE cells, astrocytes, fibrocytes and collagen fibrils. Unlike a rhegmatogenous retinal detachment, TRD has a primary mechanical etiology rather than being due to a break in the sensory retina.
Symptoms
Tractional retinal detachment may be asymptomatic if the macula is not involved. Otherwise, the patient may report visual loss, a shadow in the visual field, photopsia or floaters.
Signs
The elevated retina is usually taut or dome shaped, due to traction from the associated vitreous fibrovascular proliferation. The affected retina may appear smooth, or show signs of traction with retinal folds or striae, or be necrotic and difficult to distinguish from the associated vitreous membranes. Unlike an exudative retinal detachment, a TRD is immobile and does not usually shift with eye or head movements. It is usually localized and rarely extends to the ora serrata. A mild relative afferent pupillary defect may be present.
Prevalence
Rare (approximately 1/10,000). Overall, TRD is less common than RRD, although more common in association with certain conditions, particularly proliferative retinopathies.
Significance
TRD can cause devastating damage to vision or blindness if untreated.
Differential Diagnosis
Retinoschisis- Acquired Degenerative, Retinoschisis – Juvenile X-Linked, Choroidal detachment, Retinal detachment – Exudative, Retinal detachment – Rhegmatogenous
See Also
Retinal detachment – classification, Vitreous hemorrhage, Vitreomacular Traction Syndrome, Epiretinal membrane, Macular hole
Management
Urgent
A retinal detachment in which the macular is not yet involved is an ocular emergency needing treatment within 24 hours. If the macular has already detached, then treatment is still urgent, 48-96 hours. Bed rest is indicated until surgery is performed for acute RD threatening the fovea.
Additional Investigations
Ocular coherence tomography (OCT) may be of assistance in assessing pre-retinal proliferation and tractional effects. B-scan ultrasound may be used dynamically to assess the mobility of the retina and vitreous and show traction from fibrovascular proliferation.
Incisional Surgery
TRD may progress and threaten the macula, necessitating treatment. Appropriate treatment depends on the type, severity and location of the detachment; however, surgical treatment often involves pars plana vitrectomy to relieve retinal traction. Other treatment options include laser photocoagulation, cryotherapy, pneumatic retinopexy and scleral buckle.
Advice
Prevention of TRD is the best treatment. Pan-retinal photocoagulation for proliferative retinopathy is proven to reduce possible sequelae of progressive retinal ischemia, including TRD. Also consider regular reminders to the patient of the benefits of good control of glycemic, hypertensive and lipid status. Patients at risk of retinal detachment in their other eye are advised to attend immediately if they notice any visual symptoms. Patients should conduct monocular checks of their vision (alternate covering of each eye)
Prognosis
Chronic retinal detachment with detachment of the macula leads to progressive loss of retinal function that will not recover even after successful surgery.
Figure 1
Chronic tractional retinal detachment which has been reattached. The scar tissue is the vertically orientated white lesion overlying the optic disc at the lower left of the image. There is pigment migration and straightening of the retinal vessels.