Abnormal ocular conditions- L13 and L14 Part 4 Peripheral Retina Disorders Likely to Affect Vision

Peripheral retinal conditions that are

likely to affect vision

Retinoschisis

• Degenerative

• Juvenile

• Lattice degeneration

• Snail-track degeneration

• Cystic Tuft

• Atrophic retinal hole (retinal break)

• Operculated retinal hole (retinal break)

• Retinal tears

• Rhegmatogenous retinal detachment

• Retinitis Pigmentosa

• Albinism

• Malignant melanoma

Degenerative Retinoschisis aetiology

Splitting of the neurosensory retina (schisis =splitting), usually between the inner nuclear and outer plexiform layers

Degenerative Retinoschisis prevalence

1.5 to 7% of patients over 40 yrs old

Degenerative Retinoschisis symptoms

Usually asymptomatic as peripheral,

absolute scotoma on field testing

Degenerative Retinoschisis signs

Bilateral in up to 80%

• Usually inferotemporal location

• Smooth, immobile dome-shaped elevation of the retina (like a blister)

• Does not move with eye movements

• May have sclerotic vessels on surface

• May have snow-flake bodies on surface

• May have associated retinal holes

Degenerative Retinoschisis differential diagnosis

Chronic retinal detachment (opaque and corrugated appearance)

Degenerative Retinoschisis complications

Only occasionally leads to retinal detachment

• Foveal involvement is very rare

Degenerative Retinoschisis management

If no associated retinal holes can review in 6 months for progression

• ENSURE that patient is educated correctly regarding symptoms of retinal

detachment

• If in any doubt refer

Juvenile Retinoschisis aetiology

Rare inherited condition (X-linked recessive)

• Defect in Muller cells → Splitting of RNFL from the rest of the NS retina

• Bilateral maculopathy, with peripheral retinoschisis 50%

Juvenile Retinoschisis signs and symptoms

Presents in males aged 5-10 years

• Difficulty with near vision

• Macular - cystoid changes appear stellate

• Peripheral schisis - infero-temporal quadrant

Juvenile Retinoschisis complications

Vitreous and intra-schisis haemorrhages in 40%

• Neovascularisation

• Predisposes to retinal detachment (25% of cases)

Juvenile Retinoschisis prognosis

Poor due to progressive maculopathy

Management

Refer

• No good treatment - monitor for retinal detachment

• Low vision service

Lattice degeneration prevalence

6-10%

• Peak incidence 2nd-3rd decade

• More common in moderate myopes

Lattice degeneration- aetiology

Retinal thinning with discontinuation of the ILM and variable atrophy of the neurosensory retina

• Overlying area of vitreous liquefies

• Strong attachment at the margins

Lattice degeneration symptoms

asymptomatic

Lattice Degeneration: Signs

Appears as a linear track circumferentially

• Usually bilateral, temporal and superior location

• Between the equator and ora serrata/posterior vitreous base

• Sclerosed vessels ('lattice-like')

• +/- 'snowflakes' (Muller cell remnants)

• Associated RPE hyperplasia

• Chorioretinal atrophy may be present

• Small holes are common

Lattice degeneration: Complications

• Rare

• Risk of retinal detachment 0.05 to 0.1% (decreases with age)

• Tears 2° to PVD (strong adhesion)

• Atrophic holes rarely (2%)

• Found in 30% or eyes with RD

Lattice degeneration: management

No retinal breaks or symptoms - review in 6 to 12 months

- ENSURE that patient is educated correctly regarding symptoms of retinal detachment

• If in any doubt refer

Snailtrack Degeneration aetiology

Precursor to lattice degeneration

• Sharply demarcated bands of tightly packed 'snowflakes'

• Give the peripheral retina a white frost-like appearance

• Prophylactic treatment for snailtrack and lattice degeneration not widely

considered necessary

Cystic Tuft aetiology

Congenital abnormality

• Up to 5% of the population (seen more with widefield imaging)

• Round or oval, discrete, elevated whitishlesion

• Located equatorial or peripheral retina

• Glial tissue

Cystic Tuft associations

Strong vitreoretinal adhesion and small round holes

Cystic Tuft predisposes what

Horse shoe tears and retinal detachment (<1%)

Atrophic retinal holes aetiology

2-3% of the population

• Asymptomatic - incidental finding

• Full or partial thickness

• Pinpoint to 2DD, round, red lesions

• May be surrounded by cuff of whitish oedema or pigment (PRE hyperplasia)

• Pigment is a sign of relative stability hole present for at least 2-3 months

Atrophic retinal holes where it is found and what it is associated with

Usually found between the ora serrata and equator

• Often associated with lattice degeneration

Atrophic retinal holes: Complications

Full thickness hole can allow transmission of fluid → retinal detachment

• Fewer than 7% of atrophic holes develop into retinal detachment

Atrophic retinal holes: management

Management

• An isolated, asymptomatic atrophic retinal hole with no associated cuff of oedema - review 12 months

• Any atrophic hole with cuff of oedema or symptoms should be referred (same day)

• ENSURE that patient is educated correctly regarding symptoms of retinal detachment

• If in any doubt refer

Retinitis Pigmentosa (RP): aetiology

Group of inherited degenerative diseases preferentially affecting rod function

• Prevalence 1 in 5,000

• Age of onset, rate of progression, eventual vision loss and associated ocular features depend on the mode of inheritance

Retinitis Pigmentosa (RP): symptoms

Usually start in childhood or adolescence

• Nyctalopia

• Dark adaptation difficulties

• Photopsia

• Loss of peripheral vision

• Often severely sight impaired by 40 years old

Retinitis Pigmentosa (RP): Signs

Bilateral mid-peripheral 'bone-spicule' pigmentary changes

• RPE atrophy (choroidal vessel visibility)

• Waxy disc pallor

• Blood vessel attenuation

• Midperipheral VF loss → tunnel vision

• Central vision loss in late stages (difficult reading and seeing detail)

Retinitis Pigmentosa (RP): complications

Posterior subcapsular cataract

• Retinal detachment

• Interference with daily activities - driving

Retinitis Pigmentosa (RP): further investigations

Electroretinogram (ERG) to assess retinal function

• Genetic testing

Retinitis Pigmentosa (RP): prognosis

Some people with RP eventually go blind,

most people maintain some vision

Retinitis Pigmentosa (RP): treatment

Conservative, no known cure

• Amber tints - glare

• Supplement e.g. Vitamin A may help to slow progression

• Gene therapy (clinical trials)

What is albinism?

Abnormalities in the synthesis of melanin

• Ocular albinism: Eye alone

• Oculocutaneous albinism: eye, skin and hair

• VA generally reduced due to foveal hypoplasia

ocular albinism features

↓VA, photophobia

• Nystagmus, strabismus, ametropia, iris hypopigmentation/transillumination, foveal hypoplasia, fundus hypopigmentation

ocular albinism : management

Glasses, surgery for strabismus

Oculocutaneous Albinism

As for Ocular albinism

• Hypopigmentation of skin and hair

Malignant choroidal melanoma: aetiology

Rare (6 per million Caucasian individuals)

• Life threatening metastasis

• Risk depends on the size, location and cell type

Early detection & treatment improves prognosis

• Occur in isolation for from pre-existing choroidal naevus

Malignant choroidal melanoma: risk factors

Light coloured iridies

• Fair skin

• Congenital ocular melanocytosis

• Mean age at presentation 60 years

Malignant choroidal melanoma: symptoms

Frequently asymptomatic (30% detected before symptoms develop)

• Photopsia, blurred and distorted vision, floaters,VF loss

Malignant choroidal melanoma: Signs

• Slight to dramatic dome-shaped elevation ('collar stud' may protrude

into vitreous)

• Slate grey to greyish/green to white (amelanotic)

• Generally mottled, clumps of orange pigment (lipofuscin) frequently present

• Round to very irregular

• Indistinct margins

• Generally will display a scotoma (may be larger than size of lesion)

• Secondary retinal detachment often present (SRF seen on OCT)