Ocular Diseases Assoc w/LV Px

Albinism

A congenital condition characterised by lack of pigment. Can be oculocutaneous (skin and eyes) or just ocular. 1 in 20000 of general population. Cat. into Tyrosinase +ve or -ve, -ve has more severe effect on vision 6/60-6/120, +ve better 6/24 which improves over time.

• VF appear full
• Blue irises - transillumination
• Photophobia
• Nystagmus
• Hypoplasia of macula
• High incidence of strab
• Poor stereo
• High refractive error
• SYSTEMIC - white or yellowish hair, eyebrows, eyelashes, pink skin, sensitive to sun damage
• Assoc w/Hermansky-Pudlack syndrome - genetic metabolic disorder

Low vision management involves corrective Rx, aperture control contact lenses, tints, UV protection, magnification for distance and near

Cataracts

The opacification of the crystalline lens, classified according to area affected - ant/post subcapsular, ant/post cortical, equitorial, nuclear. Caused by trauma, metabolism, toxic cause, 2ary to inflammation, drugs, hereditary, age-rel. 95% of those over 65 have some form of lens opacification

• VA varies w/degree and location of opac, most often bilat but asymmetric, nucscler not often assoc w/vision loss - more myopic. Posterior subcap has profound effect on VA especially with small pupil
• VF - ok
• Dull/abnormal ret reflex, refraction more myopic, reduced acuity, increased glare, distortion, monoc diplopia, altered colour perception. Treated by removal

LV management centres around lighting, filters and AR coat for glare and magnification

Diabetes Mellitus (I = juvenile onset, II = adult onset)

Signs and Symptoms are excessive thirst, urination, hunger, fatigue w/weight loss and recurrent infections. DR is the biggest single cause of registered blindness in the UK amongst working age people. Smoking and obesity increase the risk. Type I will tend to show retinopathy within 10 to 12 years, type II after 20. 60% will show some degree of retinopathy.

• VA from 6/6 to total blindness, fluctuates dude to blood sugar level if poorly controlled, lens changes (myopic) and CMO (hyperopic)
• VF - 2ary complications can cause loss - laser burns, retinal detachment, Glaucoma, CMO - macular degen.
• Other complications - accomm insuff, Diplop, Cats, Glau (rubeosis), RD, MD/CMO, decreased corneal sensitivity, neovasc, haemorrhages

LV Vision management - refraction, sunglasses and filters, increased illum, mag/minification, flashlight/torch, non-optical, mobility services support groups.

Glaucoma

Open angle - asymptomatic, closed angle pain, blurred vision, photophobia, halos, nausea, vomiting

• VA generally unaffected until end stage
• VF typically respects horizontal midline, arcuate defects, nasal step. Gradually spreads to periphery and centrally
• Diagnostic testing - ON head, VF, IOP, ant chamb angle

LV management w/magnification, lighting indoors & out, glare control, contrast enhancement, minification, peripheral awareness systems, other professional services

Macular Holes

Round red spots in centre of macula 1/3 to 2/3 DD in size, may have grey halo around it where RD happened. May be caused by trauma, myopia, CMO, inflammation but most are idiopathic.

• VA depending on location 6/9-6/120
• VF full thickness holes = dense central scotoma
• Metamorphopsia and reduced VA

LV management with magnification, eccentric viewing, lighting and filters to increase contrast

Macular Disease

Any degenerative condition affecting the macular area. Eg ARMD, Stargardt's, Best's Disease

• Reduced VA D&N, metamorphopsia, central field loss, reduced colour vision, increased glare and photophobia
• Test w/VF, colour testing (D15 usually shows RG loss), flu angiog

LV management with refraction, magnification, lighting, glare control, non-optical, support groups

Myopic Degeneration

This is excessive stretching and expansion of the posterior segment, with scleral and choroidal thinning.

• VA decreases as condition progresses, may lead to NPL from 2ary complications
• VF varies w/structures involved
• Blurred Dv, flashes/floaters, thinning of RPE, posterior staphyloma, Fuch's spot, Retinal detachment
• Associated syndromes - Down's, Marfan's syndrome, Stickler's Syndrome

LV Management refraction, magnification, lighting and contrast enhancement, glare control and photophobia protection, torch @ night, other professional services

RP

1 in 3000-4000 of the population. Most common in males - autosomal recessive/dominant/x-linked

• VA from 6/6 to NLP
• VF starts in mid-periphery and goes inward and outward
• Nyctalopia, light/dark adaptation affected, attenuated BV, bony spicule pigmentation, waxy disc, posterior subcapsular cataracts, CMO

LV Management - minification, peripheral field awareness, magnification, sunlenses, lighting control, torch at night, genetic counselling

Retinopathy of Prematurity

Abnormal proliferation of retinal blood vessels in premature infants receiving oxygen therapy. About 7% of babies in UK born prematurely.

• VA from 6/6 to NLP
• VF variable depending upon which part of the retina is involved
• High myopia, strabismus, RD, glaucoma, cataract, corneal scarring, glare and photophobia, CVI

LV Management - refraction, magnification, sunlenses, filters, lighting control