CHAPTER 7

Other Retinal Vascular Diseases

Sickle Cell Retinopathy

The sickle cell hemoglobinopathies of greatest ocular importance are those in which mutant hemoglobins S, C, or both are inherited instead of normal hemoglobin A (see BCSC Section 2, Fundamentals and Principles of Ophthalmology). Sickle cell hemoglobinopathies are most prevalent in the black population. In the US African American population, sickle cell trait (Hb AS) affects 8%; sickle cell disease (Hb SS), 0.4%; and hemoglobin SC disease, 0.2% (Table 7-1). Thalassemia, in which the α- or β-polypeptide chain is defective, is rare but frequently causes retinopathy. Although sickling and solubility tests (sickle cell preparations) are reliable indicators of the presence of hemoglobin S and are therefore excellent for screening, they do not distinguish between heterozygous and homozygous states. Hemoglobin electrophoresis testing should be performed for patients testing positive on sickle cell preparations.

Table 7-1

Scott AW, Lutty GA, Goldberg MF. Hemoglobinopathies. In: Ryan SJ, Schachat AP, Wilkinson CP, Hinton DR, Sadda SR, Wiedemann P, eds. Retina. Vol 1. 5th ed. Philadelphia: Elsevier/Saunders; 2013:1071–1082.

Nonproliferative Sickle Cell Retinopathy

The retinal changes in nonproliferative sickle cell retinopathy (NPSR) are caused by arteriolar and capillary occlusion, similar to white or hemorrhagic infarcts of the central nervous system. Anastomosis and remodeling occur in the periphery, as does the resorption of blood in the area of the infarct. Salmon-patch hemorrhages represent areas of intraretinal hemorrhage occurring after a peripheral retinal arteriolar occlusion. Refractile spots are old, resorbed hemorrhages with hemosiderin deposition within the inner retina just beneath the internal limiting membrane (ILM) (Fig 7-1). Black “sunburst” lesions are localized areas of retinal pigment epithelial hypertrophy, hyperplasia, and pigment migration in the peripheral retina, probably caused by hemorrhage.

Figure 7-1 Salmon patch in sickle cell retinopathy. A, Peripheral fundus photograph of a patient with sickle cell disease. The image shows a retinal hemorrhage unrelated to proliferation but the result of infarction of the retina from a vascular occlusion—a salmon patch. B, Peripheral fundus photograph of an iridescent, or retractile, patch that represents an area of previous, now resorbed, retinal hemorrhage (salmon patch). (Courtesy of G. Baker Hubbard III, MD.)

Occlusion of parafoveal capillaries and arterioles is one cause of decreased visual acuity in sickle cell retinopathy. Spontaneous occlusion of the central retinal artery may also develop in patients with sickle cell hemoglobinopathies.

Proliferative Sickle Cell Retinopathy

Serious ocular complications of proliferative sickle cell retinopathy (PSR) are more characteristic of sickle cell hemoglobin C (SC) and sickle cell thalassemia (SThal) than of SS disease, although SS disease results in more systemic complications. The ocular complications result from ischemia secondary to infarction of the retinal tissue by means of arteriolar, precapillary arteriolar, capillary, or venular occlusions, and they include retinal neovascularization, preretinal or vitreous hemorrhage, and tractional retinal detachment.

PSR has been classified into 5 stages based on the following pathogenetic sequence:

1.Peripheral arteriolar occlusions (stage 1) lead to peripheral nonperfusion and

2.peripheral arteriovenular anastomoses (stage 2), which are dilated, preexisting capillary channels.

3.Preretinal sea fan neovascularization (stage 3) may occur at the posterior border of areas of nonperfusion and lead to

4.vitreous hemorrhage (stage 4) and

5.tractional retinal detachment (stage 5).

PSR is one of many retinal vascular diseases in which extraretinal fibrovascular proliferation occurs in response to retinal ischemia. Whereas the neovascularization in proliferative diabetic retinopathy (PDR) generally begins postequatorially, that in PSR is located more peripherally (Fig 7- 2). Another way in which PSR differs from PDR is in the frequent occurrence in PSR of

autoinfarction of the peripheral neovascularization, resulting in a white sea fan neovascularization (Fig 7-3). Table 7-2 presents a differential diagnosis of peripheral retinal neovascularization.

Table 7-2

Figure 7-2 Wide-field fundus montage images of the left eye of a 26-year-old African American man with a history of SC sickle cell disease. A, Hemorrhaging has occurred at the anterior border of the proliferative lesions. B, The wide-field montage fluorescein angiogram shows leakage from the sea fan lesions in the periphery and peripheral nonperfusion anterior to the sea fans. (Courtesy of Asheesh Tewari, MD.)

Figure 7-3 Fundus photograph of peripheral neovascularization (sea fan neovascularization) with autoinfarction, as illustrated by the white atrophic vessels. (Courtesy of Harry W. Flynn, Jr, MD.)

Elagouz M, Jyothi S, Gupta B, Sivaprasad S. Sickle cell disease and the eye: old and new concepts. Surv Ophthalmol. 2010;55(4):359–377.

Other Ocular Abnormalities in Sickle Cell Hemoglobinopathies

Many patients with SS or SC disease exhibit segmentation of blood in the conjunctival blood vessels. Numerous comma-shaped thrombi dilate and occlude capillaries, most often in the inferior bulbar conjunctiva and fornix (the comma sign). Similarly, small vessels on the surface of the optic disc can exhibit intravascular occlusions, manifested as dark red spots (the disc sign of sickling). Angioid streaks have been reported clinically in up to 6% of cases of SS disease and in persons with AS trait. The pathogenetic basis of this association is uncertain.

Management of Sickle Cell Retinopathy

All black patients presenting with a traumatic hyphema should be screened for a sickling hemoglobinopathy (including trait) because of the increased risk of complications in the presence of rigid sickled erythrocytes. Control of intraocular pressure (IOP) may be difficult, and ischemic optic neuropathy may result from short intervals of a modest increase in IOP. Some authors have recommended early anterior chamber washout in the presence of a hyphema with increased IOP. In addition, physicians must be cautious in the use of carbonic anhydrase inhibitors, which may worsen sickling through the production of systemic acidosis.

McLeod DS, Merges C, Fukushima A, Goldberg MF, Lutty GA. Histopathologic features of neovascularization in sickle cell retinopathy. Am J Ophthalmol. 1997;124(4):455–472.

Photocoagulation

Therapeutic approaches to PSR have included diathermy, cryopexy, and photocoagulation. Peripheral scatter photocoagulation, applying lower-intensity light burns to the ischemic peripheral retina, may cause regression of neovascular fronds and thus decrease the risk of vitreous hemorrhage. The decision to treat PSR with scatter photocoagulation should be made cautiously, however, as retinal tears and subsequent rhegmatogenous retinal detachment can occur and do so more commonly after such treatment in PSR than in proliferative diabetic retinopathy.

Elagouz M, Jyothi S, Gupta B, Sivaprasad S. Sickle cell disease and the eye: old and new concepts. Surv Ophthalmol. 2010;55(4):359–377.

Vitreoretinal surgery in PSR

Surgery may be indicated for nonclearing vitreous hemorrhage and for rhegmatogenous, tractional, schisis, or combined retinal detachment. Retinal detachment usually begins in the ischemic peripheral retina. The tears typically occur at the base of sea fans and are often precipitated by photocoagulation treatment. Anterior segment ischemia or necrosis has been reported in association with 360° scleral buckling procedures, particularly when combined with extensive diathermy or cryopexy. During surgery, care should be taken to ensure adequate patient hydration and supplemental nasal oxygenation. Precautions for vitrectomy also include the judicious use of expansile gases to minimize IOP elevations postoperatively, which increase the risk of vascular occlusions. The use of exchange transfusion before vitreoretinal surgery is no longer favored.

Vasculitis

Retinal vasculitis from any cause can lead to similar pathologic sequelae; it may be primarily ocular or be associated with inflammatory disease elsewhere in the body. The early clinical manifestations are generally nonspecific, consisting of perivascular infiltrates and sheathing of the retinal vessels (vascular wall thickening with vessel involution; Fig 7-4). Involvement of exclusively retinal arteries or veins is uncommon. Veins tend to be inflamed earlier and more frequently than arterioles, and combinations are the rule. Causes of retinal vasculitis include

Figure 7-4 Fundus photograph of retinal vasculitis in an eye of a patient with Crohn disease. Retinal hemorrhages and edema are present, as is prominent sheathing of the retinal vessels. (Courtesy of Gary C. Brown, MD.)

giant cell arteritis polyarteritis nodosa systemic lupus erythematosus Behçet disease

inflammatory bowel disease multiple sclerosis

pars planitis sarcoidosis syphilis toxoplasmosis viral retinitides Lyme disease cat-scratch disease

certain medications, such as rifabutin

The masquerade syndromes should also be considered. See BCSC Section 9, Intraocular Inflammation and Uveitis, for further discussion of most of these conditions and Section 5, NeuroOphthalmology, for discussion of multiple sclerosis and giant cell arteritis.

A primary occlusive retinal vasculopathy for which no cause can be found is termed Eales disease. This condition is an occlusive vasculopathy that usually involves the peripheral retina of both eyes and often results in extraretinal neovascularization with vitreous hemorrhage. It typically occurs in males, and there may be associated tuberculin hypersensitivity.

Susac syndrome is characterized by multiple branch retinal arterial occlusions and can be associated with hearing loss and, rarely, with strokes. The syndrome is most commonly diagnosed in women in their third decade, and there is no known cause. Treatment is with corticosteroids or immunosuppression.

A clinical picture indistinguishable from past retinal vasculitis may result from chronic embolism or thrombosis without inflammation. Evaluation includes a search for possible causes: cardiac valvular disease, cardiac arrhythmias, ulcerated atheromatous disease of the carotid vessels, and hemoglobinopathies.

Idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) describes a syndrome characterized by the presence of retinal vasculitis, multiple macroaneurysms, neuroretinitis, and peripheral capillary nonperfusion. Systemic investigations are generally noncontributory, and oral prednisone has demonstrated little benefit. Capillary nonperfusion is often sufficiently severe to warrant panretinal photocoagulation (PRP).

Cystoid Macular Edema

Cystoid macular edema (CME) is characterized by intraretinal edema contained in honeycomb-like cystoid spaces. Fluorescein angiography shows the source of the edema to be abnormal perifoveal retinal capillary permeability, which is visible as multiple small focal fluorescein leaks and late pooling of the dye in extracellular cystoid spaces. Optical coherence tomography (OCT) findings in CME include diffuse retinal thickening with cystic areas of low reflectivity (reduced reflectivity), more prominently in the inner nuclear and outer plexiform layers. This finding correlates with histologic studies that indicate swelling in and between müllerian glia. On occasion, a nonreflective cavity is present beneath the neurosensory retina that is consistent with subretinal fluid accumulation (see Chapter 5, Fig 5-3B, and Chapter 6, Fig 6-12A). Because of the radial foveal arrangement of

both glia and Henle inner fibers, this pooling classically forms a “flower-petal” (petaloid) pattern (Fig 7-5). Severe cases may be associated with vitritis (vitreous cells) and optic nerve head swelling.

Figure 7-5 Cystoid macular edema (CME). Fundus photograph (A) and late fluorescein angiogram (at 5 minutes, 58 seconds) (B) demonstrate petaloid perifoveal hyperfluorescence in a patient with intermediate uveitis. Disc staining is commonly observed in intermediate uveitis. The small patchy areas of hyperfluorescence (leakage) throughout the fundus can also be present in inflammatory disorders. C, Corresponding optical coherence tomography (OCT) scan shows severe CME. D, Following treatment of patient’s intermediate uveitis with an intravitreal dexamethasone sustained-delivery implant, OCT scan shows the CME is completely resolved. (Courtesy of Colin A. McCannel, MD.)

Etiologies for CME

Abnormal permeability of the perifoveal retinal capillaries may occur in a wide variety of conditions, including diabetic retinopathy, central and branch retinal vein occlusion (CRVO, BRVO), any type of uveitis (particularly pars planitis), and retinitis pigmentosa. CME may occur after any ocular surgery, such as cataract extraction (in which case the CME is termed Irvine-Gass Syndrome), retinal detachment surgery, vitrectomy, glaucoma procedures, photocoagulation, and cryopexy. It can also be triggered by prostaglandin analogues used to treat glaucoma. Subretinal disease processes (choroidal neovascularization, choroidal hemangioma, subclinical retinal detachment) must also be considered when CME is detected; see Chapter 4. The nutritional supplement niacin has also been implicated as a cause of atypical CME.

Rare causes of cystic macular change of different pathogeneses (such as X-linked hereditary retinoschisis, Goldmann-Favre disease, some cases of retinitis pigmentosa, and nicotinic acid maculopathy) are distinguishable by the clinical setting, family history, and lack of late-phase fluorescein leakage into the cystlike spaces, as well as by OCT.

Incidence of CME

For patients who have undergone intracapsular lens extraction, the incidence of CME is as high as 60%. Intraocular lens implantation at the time of extracapsular surgery does not appear to increase the incidence of CME. The peak incidence occurs 6–10 weeks postoperatively, with spontaneous resolution occurring clinically in approximately 95% of uncomplicated cases, usually within 6 months. Most such cases of CME are mild and asymptomatic, and distinguishing between symptomatic, or clinical, CME and edema that is apparent only on fluorescein angiography, termed angiographic CME, is relevant. More severe CME may result in permanent vision loss. The incidence of CME is affected by many factors. The presence of predisposing disease, as mentioned under etiologies, is an important factor. Factors affecting the incidence and severity of CME after intraocular, particularly cataract, surgery include the degree of postoperative inflammation and the presence or absence of surgical complications such as vitreous loss or iris prolapse. See also BCSC Section 11, Lens and Cataract.

Johnson MW. Etiology and treatment of macular edema. Am J Ophthalmol. 2009;147(1):11–21.e1.

Treatment for CME

The effect of therapy on CME is difficult to evaluate because of the high rate of spontaneous resolution. Pharmacologic therapy using a combination of topical corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs) has become commonplace for prophylaxis and is well supported by the medical literature for established edema. If CME is severe or refractory to topical therapy, periocular (eg, posterior sub-Tenon triamcinolone acetonide) or intraocular injection of steroid preparations are appropriate escalations of therapy. In chronic CME, systemic acetazolamide treatment can be successful, especially in cases associated with retinitis pigmentosa. For treating CME associated with diabetic retinopathy or ocular venous occlusive disease, also see Chapters 5 and 6.

If CME is associated with vitreous adhesions to the iris or a corneoscleral wound, interruption of the vitreous strands by vitrectomy or Nd:YAG laser treatment may be helpful.

Coats Disease

Coats disease is defined by the presence of vascular dilatations (retinal telangiectasia), including ectatic arterioles, microaneurysms, venous dilations (phlebectasias), and fusiform capillary dilatations, frequently associated with exudative retinal detachment. Usually only 1 eye is involved, and there is a marked male predominance (85%). Although an associated gene has been identified on chromosome 4, it is not hereditary or associated with systemic disease.

The abnormal vessels are incompetent, resulting in the leakage of serum and other blood components, which accumulate in and under the retina. Any portion of the peripheral and macular capillary system may be involved. Despite the presence of retinal capillary nonperfusion shown by angiography, posterior segment neovascularization is unusual. Variation in the clinical findings is wide, ranging from mild retinal vascular abnormalities and minimal exudation to extensive areas of retinal telangiectasia associated with massive leakage and exudative retinal detachment. The severity and rate of progression appear greater in children under the age of 4 years, in whom massive exudative retinal detachment with retina apposed to the lens may simulate retinoblastoma or other causes of leukocoria (Coats reaction; Fig 7-6; see BCSC 6, Pediatric Ophthalmology and Strabismus, for the differential diagnosis of leukocoria) or xanthocoria (yellow pupil).

Figure 7-8 Parafoveal telangiectasia, type 2. Red-free photographs of right (A) and left (B) eyes, show bilateral parafoveal telangiectasia. Early right-angle branching and fine crystals are visible temporal to the fovea in each eye. Arrows point to the intraretinal pigment migration in the left eye (B), typically present as a late manifestation in this condition. Early (C) and late (D) fluorescein angiography images of the right eye. The early-phase image (C) demonstrates telangiectatic changes of the retinal capillaries temporal to the fovea. The late-phase image (D) demonstrates hyperfluorescence from inner retinal leakage of fluorescein in the perifoveal macula. (Courtesy of Richard F. Spaide, MD.)

Type 3: bilateral parafoveal telangiectasia with retinal capillary obliteration

Type 1, also referred to as aneurysmal telangiectasia, typically occurs in males and resembles a macular variant of Coats disease with a circinate type of exudate, also known as Leber miliary aneurysm. Type 2, or perifoveal telangiectasia, has no sex predilection and affects both eyes. Perifoveal retinal changes typically include thickening, loss of transparency with a grayish appearance, small telangiectatic vessels, and a cystic appearance of the fovea, all most pronounced in the temporal fovea. As the lesion ages, intralesional retinal pigment epithelium (RPE) migration is often present, and choroidal neovascularization may subsequently develop. Vision loss ranges from mild to severe. Approximately one-third of patients with this variant have an abnormal glucose tolerance test result. Cases in type 3 show progressive vision loss from obliteration of the perifoveal capillaries.

On fluorescein angiography, the telangiectatic vessels are readily apparent and usually leak. OCT imaging typically shows a thinned central macular retina, including the fovea, with inner lamellar oblong foveal cavitations in which the long axis is parallel to the retinal surface.

Photocoagulation treatment may be indicated for type 1 cases and can be successful in resolving exudation. Type 2 and type 3 eyes typically do not respond to photocoagulation because leaky vessels are not the predominant feature. Small controlled and uncontrolled trials suggest limited success of management using intravitreal anti–vascular endothelial growth factor (VEGF) drugs. The differential diagnosis includes branch retinal vein or venule obstruction, diabetes mellitus, radiation retinopathy, cystoid macular edema (especially chronic), and carotid artery disease.

Clemons TE, Gillies MC, Chew EY, et al; MacTel Research Group. Baseline characteristics of participants in the natural history study of macular telangiectasia (MacTel) MacTel Project report no. 2. Ophthalmic Epidemiol. 2010;17(1):66–73.

Yannuzzi LA, Bardal AM, Freund KB, Chen KJ, Eandi CM, Blodi B. Idiopathic macular telangiectasia. Arch Ophthalmol. 2006;124(4):450–460.

Phakomatoses

Conventionally, a number of syndromes referred to as phakomatoses (“mother spot”) are grouped loosely by the common features of ocular and extraocular or systemic involvement of a congenital nature. Most, but not all, are hereditary. With the exception of Sturge-Weber syndrome, the phakomatoses involve the neuroretina and its circulation. For further discussion of the phakomatoses, see BCSC Section 5, Neuro-Ophthalmology, and Section 6, Pediatric Ophthalmology and Strabismus.

Von Hippel–Lindau Disease

The phakomatosis von Hippel–Lindau (VHL) disease (also called von Hippel–Lindau syndrome) is caused by a tumor suppressor gene mutation on the short arm of chromosome 3 (3p26–p25), the inheritance of which is autosomal dominant with incomplete penetrance and variable expression. The disease is characterized by retinal and central nervous system hemangioblastomas and visceral manifestations (see BCSC Section 6, Pediatric Ophthalmology and Strabismus); the diagnosis can be confirmed with genetic testing. Central nervous system tumors include hemangioblastomas of the cerebellum, medulla, pons, and spinal cord in 20% of VHL disease patients. Visceral manifestations include renal cell carcinoma, meningiomas, pheochromocytomas, and cysts of the kidney, pancreas, liver, epididymis, and ovary. Diagnosis of a retinal hemangioblastoma warrants systemic workup and possibly genetic testing. The leading causes of death in patients with VHL disease are cerebellar hemangioblastoma and renal cell carcinoma. Patients may incur severe disability from central nervous system lesions and their treatments.

A fully developed retinal lesion is a spherical orange-red tumor fed by a dilated, tortuous retinal artery and drained by an engorged vein (Fig 7-9). Hemangioblastomas of the optic nerve head and peripapillary region are often flat and difficult to recognize. Multiple hemangioblastomas may be present in the same eye, and bilateral involvement occurs in 50% of patients. Leakage from a hemangioblastoma may cause decreased vision from macular exudates (Fig 7-10) with or without exudative retinal detachment. Vitreous hemorrhage or tractional detachment may also occur.

Hippel–Lindau disease. No obvious lesions are visible. B, The corresponding ultra-wide-angle fluorescein angiography image demonstrates multiple foci of leakage that are early, small retinal hemangioblastomas, some of which are not visible on the photograph or clinically. (Courtesy of Colin A. McCannel, MD.)

Retinal hemangioblastomas may also occur sporadically without systemic involvement; these are termed von Hippel lesions. Vasoproliferative tumors, another form of retinal angiomas, are idiopathic or, rarely, may be present as a late complication of ROP, retinitis pigmentosa, or other conditions. These lesions do not have the dilated feeder and draining vessels seen with hemangioblastomas.

Atebara NH. Retinal capillary hemangioma treated with verteporfin photodynamic therapy. Am J Ophthalmol. 2002;134(5):788– 790.

Gaudric A, Krivosic V, Duquid G, Massin P, Giraud S, Richard S. Vitreoretinal surgery for severe retinal capillary hemangiomas in von Hippel–Lindau disease. Ophthalmology. 2011;118(1):142–149.

Wyburn-Mason Syndrome

In Wyburn-Mason syndrome, congenital retinal arteriovenous malformations occur in conjunction with similar ipsilateral vascular malformations in the brain, face, orbit, and mandible. The lesions are composed of blood vessels without an intervening capillary bed (racemose angioma). The abnormalities may range from a single arteriovenous communication to a complex anastomotic system. In the eye, the lesions are usually asymptomatic, unilateral, and located in the retina and optic nerve. Typically, they do not show leakage on fluorescein angiography. Intraosseous vascular malformations that may occur in the maxilla and mandible can lead to unexpected hemorrhaging during dental extractions. Most commonly, racemose angiomas in the retina are isolated and not part of the full syndrome.

Retinal Cavernous Hemangioma

Although most cases of cavernous hemangioma are sporadic and restricted to the retina or optic nerve head, they may occur in a familial (autosomal-dominant) pattern and may be associated with intracranial and skin hemangiomas. For this reason, cavernous hemangioma may be considered one of the phakomatoses.

Retinal cavernous hemangioma is characterized by the formation of grapelike clusters of thinwalled saccular angiomatous lesions in the inner retina or on the optic nerve head (Fig 7-12). The blood flow in these lesions is derived from the retinal circulation and is relatively stagnant, producing a characteristic fluorescein angiographic picture. These dilated saccular lesions fill slowly during angiography, and plasma-erythrocyte layering occurs as a result of the sluggish blood flow. Fluorescein leakage is characteristically absent, correlating with the absence of subretinal fluid and exudate in the retinal cavernous hemangioma and serving to differentiate the condition from retinal telangiectasia, retinal capillary hemangioblastomas, and racemose aneurysm of the retina.

diabetic retinopathy. Radiation retinopathy can occur after either external-beam or local plaque therapy, typically within months to years after radiation treatment. In general, radiation retinopathy is observed around 18 months after treatment with external-beam radiation and earlier with brachytherapy. Because radiation retinopathy is very similar to other vascular diseases, eliciting a history of radiation treatment is important in establishing the diagnosis. An exposure to doses of 30– 35 grays (Gy) or more is usually required to induce clinical symptoms; occasionally, however, retinopathy may develop after as little as 15 Gy of external-beam radiation. Studies have shown retinal damage in 50% of patients receiving 60 Gy and in 85%–95% of patients receiving 70–80 Gy. The total dose, volume of retina irradiated, and fractionation scheme are important in determining the threshold dose for radiation retinopathy. See BCSC Section 4, Ophthalmic Pathology and Intraocular Tumors, for further discussion of these therapies, including sample dosages.

Clinically, affected patients may be asymptomatic or may describe decreased visual acuity. Ophthalmic examination may reveal signs of retinal vascular disease, including cotton-wool spots, retinal hemorrhages, microaneurysms, perivascular sheathing, capillary telangiectasis, macular edema, and disc edema. Capillary nonperfusion, documented by fluorescein angiography, is commonly present, and extensive retinal ischemia can lead to neovascularization of the retina, iris, or disc (Fig 7-13). Other complications may occur, such as optic atrophy, central retinal artery occlusion, central retinal vein occlusion, choroidal neovascularization, vitreous hemorrhage, neovascular glaucoma, and tractional retinal detachment. Vision outcome is primarily related to the extent of macular involvement with cystoid macular edema, exudative maculopathy, or capillary nonperfusion. Occasionally, vision loss may be caused by acute optic neuropathy. Although no clinical trials have been performed, the management of radiation retinopathy is similar to that for diabetic retinopathy and includes focal laser therapy to reduce macular edema or panretinal photocoagulation to treat zones of ischemia and neovascularization. Intravitreal administration of triamcinolone acetonide or anti-VEGF drugs can stabilize or improve visual acuity in some patients, but the effect might not be lasting.

Figure 7-13 Radiation retinopathy. Images of an eye that has undergone plaque brachytherapy for treatment of choroidal melanoma. The melanoma can be seen nasally, obscuring part of the disc. Typical radiation retinopathy changes are apparent. A, In the fundus photograph, cotton-wool spots, exudates (“hard” exudates), and intraretinal blot hemorrhages are visible. B, The fluorescein angiography image shows microvascular abnormalities (representative of capillary nonperfusion) superior to the fovea and adjacent to an enlarged foveal avascular zone. Additional areas of nonperfusion are noted in the macula and near periphery. (Courtesy of Tara A. McCannel, MD, PhD.)

Patel SJ, Schachat AP. Radiation retinopathy. In: Albert DM, Miller JW, Azar DT, Blodi BA, eds. Albert & Jakobiec’s Principles and Practice of Ophthalmology. 3rd ed. Philadelphia: Saunders; 2008:chap 175.

Valsalva Retinopathy

A sudden rise in intrathoracic or intra-abdominal pressure (such as accompanies coughing, vomiting, lifting, or straining for a bowel movement) may raise intraocular venous pressure sufficiently to rupture small superficial capillaries in the macula. The hemorrhage is typically located under the ILM, where it may create a hemorrhagic detachment of the ILM. Vitreous hemorrhage and subretinal hemorrhage may be present. Vision is usually only mildly reduced and the prognosis is excellent, with spontaneous resolution usually occurring within months after onset. The differential diagnosis of Valsalva retinopathy includes posterior vitreous separation, which may cause an identical hemorrhage or a macroaneurysm. Therefore, in all cases, a peripheral retinal tear or an aneurysm along an arteriole must be ruled out.

Purtscher Retinopathy and Purtscherlike Retinopathy

After acute compression injuries to the thorax or head, a patient may experience loss of vision associated with Purtscher retinopathy in 1 or both eyes. Large cotton-wool spots, hemorrhages, and retinal edema are found most commonly surrounding the optic disc, and fluorescein angiography shows evidence of arteriolar obstruction and leakage (Fig 7-14). Occasionally, patients present with disc edema and an afferent pupillary defect. Vision may be permanently lost from this infarction, and optic atrophy may develop.