Abnormal ocular conditions- L13 and L14 part 3 Benign Peripheral Retinal Disorders

Peripheral retinal conditions that are unlikely to affect vision

White without pressure

• CHRPE

• Chorioretinal scar

• RPE window defect

• Choroidal naevus

• Pavingstone degeneration

• Reticular degeneration

• Cystoid degeneration

• Equatorial drusen

• Pars Plana cyst

White without pressure : aetiology

Asymptomatic

•White-grey appearance of the equator and/or peripheral retina

•Well demarcated scalloped borders

•Seen without scleral indentation (CF: white with pressure)

•Occurs in about 30% of all patients

• More common in patients with dark skin

•Usually bilateral

•Benign

White without pressure: differential diagnosis

-Subclinical retinal detachment

• Retinoschisis

Congenital hypertrophy of the retinal pigment epithelium (CHRPE)

bear tracks (cat's paws)

• Congenital thickening of the RPE

- prevalence: 1.2 %

(CHRPE): three variants

Solitary (unifocal)

• Grouped (multifocal)

• Atypical (bilateral and multifocal)

(CHRPE): risk factors

Typically benign

• No associated preceding event

• Atypical associated colonic polyps and carcinoma

(CHRPE): symptoms

asymptomatic

(CHRPE): signs

Typically round, flat, hyperpigmented lesions

• Dark black to light grey

• Distinct margins

• May have areas of chorioretinal atrophy within lesion (lacunae)

• May have a depigmented halo around lesion

• Normal overlying retina and vasculature, no vitreous traction

• Generally located equatorially

• May cause a scotoma

(CHRPE) : Differential Diagnosis

Choroidal Melanoma

• Choroidal Naevus

• Melanocytoma

• Focal pigmentation (injury, inflammation or drug toxicity)

(CHRPE): prognosis

Generally benign

• Relationship to colonic polyps/carcinoma

• Multiple lesions (4 or more) or bilateral lesions

- or a family history of colon cancer

should undergo further testing

(CHRPE): management

No active intervention usually indicated A typical CHRPE

RPE Window defect aetiology

Relatively common

•Results from the absence of melanin in the RPE (RPE is present)

•Round, well circumscribed, white/yellow area

•No surrounding RPE hyperplasia (unlike in chorioretinal scar)

•Differentiate from retinal holes which appear red/brown with oedema

and/or hyperplasia

Choroidal naevus : Aetiology

Area of increased choroidal pigmentation

•Benign - low malignancy potential

•Common - prevalence of 2-7%

•Prevalence increases with age

Choroidal naevus signs

Typically small, flat, grey lesions

• May be mottled (drusen and RPE variations)

• Variable shape - round to oval to irregular indistinct margins

• Usually no chorioretinal atrophy, no haloes around the lesion

Choroidal naevus- differential diagnosis

Choroidal melanoma

Choroidal Naevi: Management

Baseline colour photography (or careful drawing)

• OCT and autofluorescence to look for sub-retinal fluid and lipofuscin

• Urgent (within 2 weeks) referral:

• Any one of – thickness > 2mm (or LBD > 7mm), collar stud configuration,

documented growth

• Any two of – thickness > 1.5mm (or LBD > 6mm), orange pigment, serous

detachment, symptoms

• Otherwise routine exam with patient education

Pavingstone degeneration: aetiology

Occurs in about 30% of all patients

• Peripheral retinal degeneration

• Small, pale, non-elevated, depigmented areas

• Usually bilateral, mostly seen inferiorly

• Choroidal vessels seen due to RPE and outer retina loss

• May increase with age

• Benign

• Differentiate from chorioretinal scars, retinal holes, lattice degeneration

Peripheral pigmentary (reticular) degeneration: aetiology

• Polygonal, honeycomb pattern of granular pigmentation

• Retinal periphery

• Occurs in 20% over age 40 and increases with age

• Benign

Peripheral pigmentary (reticular) degeneration: differential diagnosis

Retinitis pigmentosa

Cystoid degeneration aetiology

Present in ~100% of eyes over 80 years of age (increases with age)

• Tiny vesicles with indistinct boundaries on a greyish-white background

• Usually close to the ora serrata

• May resemble lattice degeneration -cystoid is elevated while lattice is

depressed

• Benign (although possible link with degenerative retinoschisis)

Equatorial drusen aetiology

Peripheral drusen

•Deposits of material on Bruch's membrane

•Found in over 70% of patients over 50 years of age

•Histologically similar to macula drusen

•Benign (as long as not approaching macula) and not associated with

any other conditions

Pars Plana Cyst: aetiology

Clear bullous elevation of the non-pigmented ciliary epithelium of pars plana

•Seen in 5-10%

•At the vitreous base

•Harmless