sign in sign up
<<
Home , Retinal detachment

Review Article Subhadra Jalali MS TRD are diabetes, Eales’s disease, Consultant sickle cell and trauma. Smt Kannuri Santhamma 3. Exudative and serous retinal detach- Vitreous Centre ments occur due to abnormalities in L V Prasad Institute water transport across the bed of the L V Prasad marg, Banjara Hills retina (retinal pigment epithelium) or in Hyderabad – 500 034 its blood supply. India Tractional and exudative/serous retinal etachment of the retina is a serious detachments are less common and will not event, which may result in complete be discussed in this paper. Fig. 2 Shallow retinal detachment with D traumatic dialysis misdiagnosed as serous blindness. The outer segments of the macular detachment due to central serous photoreceptors receive oxygen and nutri- Symptoms and Signs retinopathy – can be managed by simple tion from the . If the retina scleral buckling is detached from the choroid, the photo- The commonest presenting symptom of Photo: Subhadra Jalali receptors will fail. The fovea has no retinal RD is sudden, painless loss of vision or blurring of vision in the affected eye. Some can be seen with stereoscopic visualisation blood vessels and depends wholly on the of the retinal vessels that cast a shadow on choroid for its oxygen, so detachment of patients with partial RD notice field loss, i.e., loss of vision in only one part of the the underlying retinal pigment epithelium the macula leads to permanent damage to (Figure 2). the cones and rods at the posterior pole, and describe this as a veil or It is important to assess the state of the and loss of vision. If the macula is not shadow in one area of their vision. Flashes macula. If the macula is still attached, this detached, then good vision can be retained and may occur in the affected eye a is a medical emergency, and the patient if the retina is re-attached promptly. few days or weeks before the loss of vision. This is due to vitreous degeneration and its should have surgery within 24 hours in traction on the retina. Inferior retinal order to prevent macular detachment and Types of Retinal Detachment detachments can often be silent and slowly permanent loss of vision. If the macula is Retinal detachment (RD) is broadly classi- progressive so that the onset of RD goes already detached, then surgery should be fied into three types based on the clinical unnoticed until it reaches the posterior carried out within a week or two. appearance and underlying aetiology. pole. Sometimes RD is accompanied by In with opaque media, ocular B- mild discomfort and redness due to associ- scan ultrasonography is useful for diagnos- 1. Rhegmatogenous retinal detachment ated and hypotony, and this may be ing RD and associated pathology, like pro- (RRD) where the RD develops due to a mistakenly diagnosed as idiopathic anteri- liferative vitreoretinopathy (PVR), intraoc- retinal break (‘rhegma’, meaning a rent or uveitis. In children and young adults, ular foreign bodies, etc. Ultrasonography or a fissure) (Figure 1). Fluid, from the RD may be initially and is also rules out many lesions associated with vitreous cavity, passes through the reti- diagnosed only after the affected eye exudative retinal detachments such as nal break into the potential space under develops squint, or redness, or a white tumours, posterior , etc. the retina, leading to separation of the pupillary reflex due to rapid progression of retina from the underlying choroid. This . Predisposing Causes requires surgical treatment. In developing countries, retinal detach- Although RD can occur in any eye, certain 2. Tractional retinal detachment (TRD) ment frequently presents late, and this eyes are predisposed to develop detach- which occurs due to pre-retinal mem- means that the macula is detached in ment. The risk factors are given in Table 1. brane formation and scarring that pulls approximately 90% of eyes at presentation. All eyes that are predisposed to RD should the retina from its attachment. This may Patients are more likely to have scarring undergo periodical, dilated retinal exami- require surgery depending on the extent and fibrosis of the retina, and other prob- nation (including the retinal periphery by of the RD. The commonest causes of lems associated with long-standing retinal detachment. Because the abnormalities that scleral depression), to detect any retinal caused the detachment are often bilateral, breaks/areas of , that up to a third of patients may be blind in can predispose to RD. Early detection of their other eye at presentation – often some of these conditions can give an because of untreated retinal detachment.1 opportunity for prophylactic treatment. Management Diagnosis of Retinal Detachment Most retinal detachments progress to total The best method of diagnosing RD is by retinal detachments and complete loss of binocular indirect with vision. If the retina is not re-attached scleral indentation. An obvious RD is promptly (usually less than a week after recognised by loss of the red fundus macular detachment), then visual recovery reflex and marked elevation of the retina is progressively affected. Also, long-stand- (Figure 1). The retina appears grey, and ing retinal detachments start to develop Fig 1: Recent subtotal rhegmatogenous retinal detachment shows folds and undulations. Shallow scarring, called ‘proliferative vitreo- Photo: Subhadra Jalali detachments are difficult to diagnose but retinopathy’ (PVR) that can prevent re-

Community Eye Health Vol 16 No. 46 2003 25 Retinal Detachment

Table 1: Risk Factors for Rhegmatogenous Retinal Detachment* 1. Axial . 2. Post (/pseudophakia) especially if the posterior capsule is ruptured during surgery and/or there is vitreous loss. 3. Yag laser . 4. Lattice degeneration of the retina. 5. Symptomatic (flashes/floaters) retinal tears. 6. Ocular trauma. 7. RD in one eye. 8. Family history of RD. 9. Certain genetic disorders such as Marfan’s syndrome, Stickler’s syndrome. 10. Pre-existing retinal diseases like choroid, . 11. Following acute retinal infections as in syndrome (ARN) or CMV . Fig. 3b: Same eye after re-attachment surgery with and silicone oil * Excludes causes that result in combined rhegmatogenous and tractional retinal injection detachment Photo: Subhadra Jalali attachment. Besides PVR changes, chronic countries. However, vitrectomy techniques 2. Lattice degeneration with or without retinal detachments can develop other have revolutionised retinal detachment holes and with or without vitreous trac- complications such as hypotony, pigmen- surgery, giving a higher rate of successful tion (risk of progression uncertain). tary , new vessels, cataract re-attachment than previously. and uveitis, which can compromise visual To ‘treat or not to treat’ depends on other outcome. Rarely, the detachment does not Results of Treatment factors that predispose to a high risk of ret- progress, either due to spontaneous closure inal detachment (Table 1) and on theknown of the retinal break or by development of RD is no longer an incurable condition. complications of prophylactic treatment. demarcation lines. Surgical results have improved consider- Methods of prophylactic treatment in c l u d e 2,3 The principle of retinal re-attachment ably in the last two decades. In develop- , laser photocoagulation and, surgery is to close all the retinal breaks and ing countries, the final re-attachment very rarely, prophylactic scleral buckling. create strong chorioretinal adhesions so rates vary from 77–87% with the use of 1 that these breaks do not open and new modern technology. The anatomical suc- Conclusion breaks do not occur. cess depends on a variety of factors includ- Two approaches are established to ing the type of retinal detachment, age Retinal detachment is a vision threatening achieve this objective. One is an external of patient and surgical expertise. Unfortu- condition that requires early surgery. It can approach using scleral indentation with sil- nately, visual results do not always match be diagnosed best by retinal examination icone material called ‘scleral buckling’. the anatomical success. If the macula has using indirect ophthalmoscopy. Treatment This approach needs minimal instrumenta- been detached for a long time, central outcomes have improved with modern sur- tion and materials, and is widely available. vision will not be regained, however, the gical techniques, but the key to successful It is suitable for uncomplicated forms of patient will usually obtain useful naviga- re-attachment is early detection and prompt retinal detachment, with a high success tional vision. In India, 80% of successfully referral by primary eye care workers. More rate. However, this surgery is not appropri- re-attached obtained a vision of widespread availability of trained human 1 ate for complicated retinal detachments 6/60 or better. resources and equipment is essential to such as those with PVR (Figures 3a, 3b), manage and prevent retinal detachments giant retinal tears, coloboma choroid, pene- Prophylaxis that can cause unilateral and, not uncom- monly, bilateral permanent blindness. trating ocular trauma, etc. It is important to prevent RD, since 5–15% In these situations, an internal approach of retinal re-attachment operations are References called `vitrectomy’ is used. This requires unsuccessful and only 55–60% eyes with expensive and complex equipment and is re-attached retinas get good visual out- 1 Yorston D, Jalali S. Retinal detachment in devel- available in few centres in developing comes.3,4 Also RD surgery is more expen- oping countries. Eye 2002; 16: 353–358. 2 Thompson J A, Snead M P, Billington B M, sive than prophylactic treatment and can be Barrie T, Thompson J R, Sparrow J M. National associated with serious complications. audit of the outcomes of primary surgery for Most rhegmatogenous RDs are due to rhegmatogenous retinal detachment. Eye 2002; 16: 771–777. retinal tears that occur from vitreoretinal 3 Johnson Z, Ramsay A, Cottrell D, Mitchell K, traction in areas of abnormally firm vitreo- Stannard K. Triple cycle audit of primary retinal retinal adhesions. Exceptions are post- detachment surgery. Eye 2002; 16(3): 513–518. traumatic tears and round holes in areas of 4 Wilkinson CP, Rice TA. Prevention of retinal detachment. In: Michel’s Retinal Detachment, lattice degeneration in myopic eyes of 2nd edition. 1997; pages 1128–1133. young patients. Prophylactic treatment 5 Hilton GF, McLean EB, Chuang EL. Retinal aims to create strong chorioretinal adhe- Detachment. monograph, th sions in areas of retinal tears or areas of American Academy of Ophthalmology, 5 edi- tion. 1989; pages 89–95. strong vitreoretinal traction. Visible lesions that could be considered for prophylactic ✩ ✩ ✩ treatment include: 4,5 Fig. 3a: Chronic retinal detachment with advanced PVR and large horse-shoe tear 1. Horseshoe tears (high risk of progres- Photo: Subhadra Jalali sion to RD without treatment). 26 Community Eye Health Vol 16 No. 46 2003