Ординатура / Офтальмология / Английские материалы / Oxford American Handbook of Ophthalmology_Tsai, Denniston, Murray_2011

386 CHAPTER 12 Vitreoretinal

Exudative retinal detachment

Exudative (serous) retinal detachment (ERD) is relatively rare. It arises from damage to the outer blood-retinal barrier, allowing fluid to access the subretinal space and separate retina from the RPE (see Table 12.11).

Clinical features

•Distortion and dVA (if macula involved), which may fluctuate; relative field defect; floaters (if uveitic).

•Retinal detachment: smooth, convex dome that may be shallow or bullous; in bullous ERDs the fluid moves rapidly to the most

dependent position (“shifting fluid”); the fluid may be clear or cloudy (lipid-rich); no retinal breaks or evidence of traction.

•May also have irregular pigmentation of previously detached areas and evidence of underlying disease (e.g., abnormal Coats’ vessels).

Investigation and treatment

This is directed toward the underlying disease process. All patients require a full ophthalmic and systemic examination, blood pressure, and urinalysis. Consider B-scan ultrasound, especially if posterior scleritis is suspected.

Table 12.11 Common causes of exudative retinal detachments

RETINOSCHISIS 387

Retinoschisis

Retinoschisis is by definition a splitting of the retina layers, usually occurring at the outer plexiform/inner nuclear level. Degenerative retinoschisis is common, being present in about 5% of the normal adult population.

Degenerative retinoschisis

Degenerative retinoschisis is more common in hypermetropes and is usually bilateral. In typical senile retinoschisis, the break is at the outer plexiform/inner nuclear level. In the less common reticular type, the split is at the nerve fiber layer (i.e., as in X-linked juvenile retinoschisis, p. 389).

Clinical features

•Asymptomatic (unless very posterior extension); absolute field defect.

•Retinoschisis: split retina with inner leaf ballooning into the vitreous cavity; usually inferotemporal; arises in areas of peripheral cystoid degeneration.

Complications

•Inner leaf breaks (small/round) and/or outer leaf breaks (less common; large with rolled edges).

•Retinal detachment: either low-risk limited type (outer leaf break only with fluid from the schisis cavity causing local retinal elevation) or high-risk rhegmatogenous type (inner and outer leaf breaks with retinal elevation).

Investigations

This is mainly a clinical diagnosis, but laser uptake by the posterior leaf or OCT findings can differentiate from retinal detachment (Table 12.12).

Treatment

No treatment is necessary unless retinoschisis is complicated by retinal detachment.

X-linked juvenile retinoschisis (p. 389)

This rare condition is seen in males and may present in childhood with maculopathy. It results in retinal splitting at the nerve fiber layer (cf. typical degenerative retinoschisis). Visual prognosis is poor.

HEREDITARY VITREORETINAL DEGENERATIONS 389

Hereditary vitreoretinal degenerations

These are rare, inherited conditions characterized by premature degeneration of vitreous and retina. Interestingly, the primary abnormality may be vitreal with secondary retinal changes (e.g., Stickler syndrome) or retinal with secondary vitreous abnormalities (e.g., X-linked juvenile retinoschisis).

Stickler syndrome

This condition arises from abnormalities in type II collagen (COL2A1, Ch12q) and is autosomal dominant with complete penetrance but variable expressivity. Also known as hereditary arthro-ophthalmopathy, it is the most common syndrome of this group of conditions.

Clinical features

•High myopia, optically empty vitreous, perivascular pigmentary changes (lattice-like).

•Complications: retinal tears, giant retinal tears, retinal detachments, cataract (comma-shaped cortical opacities), ectopia lentis, glaucoma (open-angle).

•Systemic: epiphyseal dysplasia ldegeneration of large joints, cleft palate, bifid uvula, midfacial flattening, Pierre–Robin sequence, sensorineural deafness, mitral valve prolapse.

Investigations and treatment

Essentially this is a clinical diagnosis, although genetic testing is available. Multidisciplinary care may include genetic counseling. Treat myopia early to prevent amblyopia. Consider annual dilated funduscopy. Retinal detachments are common (up to 50%) and carry a poor prognosis.

X-linked juvenile retinoschisis

This rare condition appears to arise from abnormalities in an intercellular adhesion molecule (located on Xp22), which results in retinal splitting at the nerve fiber layer. It is seen in males and may present in early childhood with maculopathy. Visual prognosis is poor.

Clinical features

•Foveal schisis with spoke-like folds separating cystoid spaces (superficially resembles CME but no leakage on FA); later nonspecific atrophy; peripheral retinoschisis ± inner leaf breaks (may coalesce to leave free-floating retinal vessels).

•Complications: vitreous hemorrhage, retinal detachment.

Investigations

This is essentially a clinical diagnosis. Scotopic ERG shows selective loss of B-wave and oscillatory potentials. There is absolute visual field loss in schisis areas.

Treatment

There is no indication for prophylactic treatment of schisis, but combined schisis-detachment requires vitrectomy/gas (or silicone oil)/panretinal photocoagulation (PRP) and scleral buckling.

390 CHAPTER 12 Vitreoretinal

Goldmann–Favre syndrome

This very rare condition is similar to juvenile retinoschisis but is autosomal recessive with more marked peripheral abnormalities (RP-like changes with whitened retinal vessels).

Familial exudative vitreoretinopathy

This rare condition usually shows autosomal-dominant inheritance (Ch11q).

Clinical features

•Abrupt cessation of peripheral retinal vessels at the equator (more marked temporally), vitreous bands in the periphery.

•Complications: neovascularization, subretinal exudation (akin to Coats’ disease), macular ectopia (akin to ROP), retinal detachment.

Other hereditary vitreoretinal degenerations

These include Wagner syndrome, erosive vitreoretinopathy, Knobloch syndrome, Goldmann–Favre syndrome, autosomal-dominant neovascular inflammatory vitreoretinopathy, and autosomal-dominant vitreoretinochoroidopthy.

CHOROIDAL DETACHMENTS AND UVEAL EFFUSION SYNDROME 391

Choroidal detachments and uveal effusion syndrome

Choroidal detachments

Choroidal detachments are usually seen in the context of acute hypotony, for example, after glaucoma filtration surgery or cyclodestructive procedures (Table 12.13). They are usually easily distinguished from retinal detachments (Table 12.14).

Clinical features

There is a smooth convex dome(s) of normal or slightly dark retinal color; it arises from extreme periphery (may include ciliary body, and ora serrata becomes easily visible), but posterior extension is limited by vortex vein adhesions to the scleral canals. Choroidal detachments may touch (“kissing choroidals”).

Treatment

Management is either by observation (e.g., if this reflects an appropriate post-trabeculectomy fall in IOP) or by treating the underlying disease process. Choroidal hemorrhage may require surgical drainage.

Uveal effusion syndrome

This is a rare syndrome arising from impaired posterior segment drainage associated with scleral thickening.

Clinical features

There are combined choroidal detachments and exudative retinal detachments.

Treatment

Surgery: scleral windows may decompress the vortex veins.

392 CHAPTER 12 Vitreoretinal

Table 12.13 Common causes of choroidal detachment

Table 12.14 RRD vs. choroidal detachment

EPIRETINAL MEMBRANES 393

Epiretinal membranes

Common synonyms for the disease reflect its appearance (macular pucker, cellophane maculopathy) and uncertain pathogenesis (premacular fibrosis, idiopathic premacular gliosis). The condition is more common with increasing age (present in 6% of those over 50 years), in females, and after retinal insults (Box 12.2).

The membranes are fibrocellular and avascular and are thought to arise from the proliferation of retinal glial cells that have migrated through defects in the internal limiting membrane (ILM); such defects probably arise most commonly during posterior vitreous detachment.

Clinical features

•Asymptomatic, metamorphopsia, dVA.

•Membrane may be transparent (look for glistening light reflex), translucent or white; retinal striae; vessels may be tortuous, straightened, or obscured; pseudohole. The features are well demonstrated on red-free light.

•Complications: fovea ectopia; tractional macular detachment; CME; intraor preretinal hemorrhages.

Investigations

•OCT is not usually required, but may differentiate pseudovs. true hole and the thickness of membrane.

•FA is not essential but nicely demonstrates vascular abnormalities and any associated CME. Some surgeons compare preand postoperative FA.

Treatment

•Indications: severely symptomatic membranes; ensure that macular function is not limited by an additional underlying pathology (e.g., ischemia due to a vein occlusion).

•Surgery: vitrectomy/membrane peel; some surgeons assist visualization by staining with triamcinolone acetonide or indocyanine green.

•Complications: cataract (up to 70% rate of significant nuclear sclerosis within 2 years), retinal tears/detachment, worsened acuity (up to 15%), and symptomatic recurrence (5%).

Prognosis

The disease is fairly stable, with over 75% patients showing no further reduction in VA after diagnosis. With surgery, 60–85% patients show visual improvement ( 2 Snellen lines).

Poor prognostic features are duration of symptoms before surgery, underlying macular pathology, and lower preoperative acuity (but may still show significant improvement).

394 CHAPTER 12 Vitreoretinal

Box 12.2 Causes of epiretinal membranes

•Idiopathic

•Retinal detachment surgery

•Cryotherapy

•Photocoagulation

•Trauma (blunt or penetrating)

•Posterior uveitis

•Persistent vitreous hemorrhage

•Retinal vascular disease (e.g., BRVO)

MACULAR HOLE 395

Macular hole

The incidence of macular hole is around 1/10,000/year; it is more common in women (2:1 F:M) and has a mean age of onset of 65 years. In some cases, a predisposing pathological condition is identified (Box 12.3).

In the remaining idiopathic cases, abnormal vitreomacular traction may be observed clinically and with OCT. Release of this traction appears to underlie the success of vitrectomy in treating this condition.

Staging

The developing macular hole may initially be asymptomatic but can cause a progressive drop in acuity to around 20/200. Worsening acuity approximately correlates with the pathological stages described by Gass.

Clinical features

•Stage 1: no sensory retinal defect.

•a: small yellow foveolar spot ± loss of foveal contour.

•b: yellow foveolar ring.

•Stage 2: small (100–200 μm) full-thickness sensory retinal defect.

•Stage 3: larger (>400 μm) full-thickness sensory retinal defect with cuff of subretinal fluid ± yellow deposits in base of hole.

•Stage 4: as for stage 3 but with complete vitreous separation.

•Watzke–Allen test (thin beam of light projected across the hole is seen to be broken) may help differentiate between pseudoand lamellar holes.

Investigations

OCT may assist diagnosis and staging where required.

FA is not usually indicated, but usually shows a window defect.

Treatment

•Refer to vitreoretinal surgeon; delay affects surgical outcome (worse results if present >6 months).

•Surgery: vitrectomy, ILM peel, and gas (will require face-down posturing). Adjunctive agents such as autologous serum/platelets may be used.

•Complications: cataracts (50% rate of significant nuclear sclerosis within 2 years), retinal tears or detachment (around 1%), failure (anatomical up to 10%; visual up to 20%), late reopening of hole (5%) and endophthalmitis.

Prognosis

Stage 1 holes spontaneously resolve in 50% of cases. Without surgery, stage 2 holes almost always progress, resulting in final VA of around 20/200. With surgery, early stage 2 holes show anatomical closure in >90% and visual success ( 2 Snellen lines) in 80%. Around 10–20% develop a macular hole in the other eye.