Macular holes + VMT

Week 1 Tri A

Why do macular holes occur

As a result of a combination of antero-posterior traction from the vitreous, and tangential traction from the internal limiting membrane

Average diameter of a macular hole

About 400 microns, less than a third of the optic disc diameter

Staging for macular holes

Stage 1 - impending FTMH

Stage 2 - FTMH

Where should the hole diameter be measured

-At the narrowest point of the hole

-Should be diameter and not a chord

Where is the basal diameter measured from

Where the retina joins the RPE

Natural history for macular holes

Stage 1 - majority do not progress

Stage 2 - some will close

Stage 3 - spontaneous closure rare, not unknown

Presentation of macular holes

-May be an incidental finding

-Loss of central vision, almost ever better than 6/18

-Metamorphopsia

-F>M, 4:1

-Approx 1:6 risk of bilateral hole

-Prevalence 3/1000 in >50's

Differential diagnosis of macular hole

Lamellar hole

-Clearer classification, degenerative lamellar hole and ERM foveoschisis

-Vision usually 6/18 or better

-No treatment shown to be beneficial

Degenerative lamellar hole

-Irregular foveal contour

-Lamellar hole-associated epiretinal proliferation (LHEP) 1

-Foveal cavitation and loss of foveal tissue 2

-Foveal bump 3

-Ellipsoid zone disruption 4

Top to bottom 1-4

Epiretinal membrane foveoschisis

-Epiretinal membrane contraction

-Thickening and splitting of the retina

-Outer retina remains intact

Pseudohole

-Hole in an epiretinal membrane over the fovea

-VA 6/18+

-Edges are not elevated

-Treat as an epiretinal membrane

-Only refer if symptomatic

Referral for full thickness macular hole

-Refer all

-Urgent if

Do you refer a lamellar hole

-Do not refer

-Monitor in community

-Non-urgent referral only if symptomatic and documented loss of VA due to macular change

Management of FTMH

-Observe as unlikely to improve, delay reduces visual recovery

-Surgery (PPV, ILM peel and gas +/- phaco and IOL) very effective

Risks of FTMH

-Cataract, will 100% develop, may do lens surgery at the same time

-Retinal detachment

-Poor outcome, unable to predict final VA, some patients improve less than 10 letters, some patients do not improve for 6-12 months

Current outcomes for FTMH surgery

-95% of holes close with one operation

-VA improvement averages 0.5 logMAR but can be unpredictable

-Improvement of VA is greater for near than distance

-Adverse effects and RD are rare

VMT

-Vitreous adheres to macular, causing elevation plus or minus distortion

-Usually asymptomatic, may lead to FTMH in a few patients

-May cause metamorphopsia/blurring

Management of VMT

If asymptomatic

-None, as does not need treatment

-Do not refer

If symptomatic

-Vitrectomy and peel

Epiretinal membrane

Glial tissue on surface of retina which contracts, distorting the retina and results in retinal elevation and theickening

Symptoms of epiretinal membrane

Metamorphopsia and reduced VA

Signs of an epiretinal membrane

-Pre-macular sheen, shiny appearance

-Retinal folds

-Distortion of blood vessels, straightened/wrinkled

-Visible white/grey pre-retinal membrane

Causes of epiretinal membrane

-PVD, damage to ILM allows glial proliferation

-Retinal breaks, RPE cells migrate through break and proliferate over macula

-Retinal vein occlusion

-Diabetes

-Unknown

Management of epiretinal membrane

-Nil, unless symptomatic

-If symptomatic, vitrectomy and membrane peel +/- cataract surgery

-80% report improved, metamorphopsia can improve even if VA unchanged, VA improvement may take 6 months

Do you refer an epiretinal membrane

Only if they are symptomatic

-Do they close ERM eye to see better with good eye? if so refer lowk

-Non-urgent referral, as ERM progress very slowly, if at all

-Name, DoB, VA, refraction, previous eye history