Good Hope Eye Clinic

Myopic Macular Degeneration

David Kinshuck

 

Myopia and macula

The macula is the central part of the retina, and is responsible for detailed vision, such as r reading, seeing faces, and watching TV etc. Myopia is an optical condition caused by having an  extra-long eyeball, so the eye may be 28 mm long instead of the normal 22.3mm, for example. Because the eyeball is extra long the retina becomes very thin and may become damaged. If the macula is damaged (the central area of the retina), central vision will be affected. There may be distortion with bendy lines, or there may be a patch in the centre with no vision.

macula..where light is focused

In myopia the eye is extra long, and the retina extra thin. This may lead to damage to the central area of the retina (the macula).

 

Myopic macular degeneration ...atrophy

macular scar diagram ARMD

Thin atrophic patches develop in the macula area. photo    enlarge

The main type of macula change in myopia is thinning of the retina in the macula area. This is not treatable, and gets worse very slowly with age. Central vision is affected, and reading, TV, crossing roads, seeing bus numbers, become difficult Everyone keeps their side vision, and no one becomes completely blind. Generally the worst outcome is partial sight. .Low visual aids and help from the low vision team can be very helpful indeed.  

More severe thinning (atrophy) may occur after CNV (immediately below). Myopic retinal changes may progress 2010

Myopic CNV

early cnv (macular degeneration)

Myopic CNV: new vessels growing under the central retina in myopia 
 (similar anatomically to regular CNV)     
enlarge      photo    photo  

 

 

In this type of myopic macula disease, new vessels grow in the macula area. 5% of highly myopic eyes (more than -6.00d) develop CNV. This is similar to wet ARMD, but in myopia it may occur in much younger people. However, it is much commoner in older people with myopia.

These new vessels are called 'CNV'...choroidal new vessels or choroidal neoovascularisation, as the blood vessels originate in the choroid and grow under the retina. The CNV cause retinal leakage and swelling. The condition progresses to cause a scar in the macular area. If the scar is small, sight is reasonable; if large, the sight can be very poor. Myopic CNV respond well to anti-VEGF treatment, needing less treatment that pure ARMD. The long term prognosis is getting better. Younger patients have a better prognosis..the CNV get walled off.

All types of wet ARMD (CNV) will progress 4 times faster in smokers, a 400% increase. In addition to smoking, high blood pressure, poor diet, lack of exercise increase the likelihood of progression and progression rate. Treatment below

 

Treatment of myopic CNV

Standard treatment anti-VEGF drugs; BJO 2013, Retina 2012Retina 2012BJO 2012BJO 2011,  Retina 11Eye 2011. Young patients Retina 2011 . PDT, second line, VIP study:    Retina 2011 . Anti-VEGF preferred Retina14 .

Avastin Retina17

  

Suprachoroidal cavitation

  • This is discussed here,
  • with a photo here.
  • overlaps with myopic schisis (? same condition

 

Peripapillary atrophy

  • see
  • haemorrhage= tear in laminr cribosa

Dome shaped maculopathy

  • Retina 17     "┬áDome-shaped macula is a condition associated with myopic eyes that seems to remain stable over time in terms of vision and macular profiles. It is often associated with chronic SRF, for which no effective treatment is current available. However, SRF does not seem to be a significant cause of visual impairment."
  • serous macular detachment Retina 17: serous macular detachment in eyes with staphyloma, dome-shaped macula or tilted disk syndrome
  • Horizonatal ridge Retina 17

Serous macular detachment

 

Case 2, 43y

 

6/9 vision, History of melanoma, and tachycardia, ex smoke Rpe changes and central subretinal fluid, developed subretinal haemorrhage

Right eye

no cnv seen on ffa ,treated as occult, iva x7 ,

Left eye

Distortion, subretinal fluid has increased a lot, and rped,reduplication, bilateral ,thickened choroid,

  • Called here dome shaped maculopathy with csr features,
  • stopped injections,
  • Occur in highly myopic eyes with staphylomas, DOME SHAPED maculopahty
  • secondary to choroidal thickenin
  • No response to injections..this should have been a clue this was a different condition,
  • Do respond to pdt...ffa ..no cnv
  • Another patient did respond to antivegf, despite no cnv present

Lacquer cracks