Degenerative Myopia

Question 1

What is considered as degenerative myopia?

Answer 1

• May also be called pathological myopia
• Myopia <6D is physiological
• Myopia >6D is high myopia
• Myopia >6D and continues to increase is pathological myopia
• “The next pandemic”
• In East Asia affects 80-90% of school leavers
• Axial length of eye stabilises usually in late teens, in some people stabilisation never happens, axial length continues to grow, and myopia continues to increase – ongoing stretching of eye which brings with it many problems

Question 2

Risk factors/associations of degenerative myopia?

Answer 2

• Excessive near work – reading, screen time
• Genetic factors – v little can do about
• Systemic Disease:
  o Down Syndrome
  o Marfan’s Syndrome
  o Stickler Syndrome
  o Prematurity
  o Ehlers-Danlos – connective tissue disorder
  o Albinism

Question 3

Degenerative myopia symptoms?

Answer 3

• Progressive change in refraction
• Reduced vision
• Distortion – if develop CNV (choroidal NV)
• Photopsia – flickering lights

Question 4

Signs of degenerative myopia?

Answer 4

• Pale, tessellated (can see choroidal vessels) fundus – everything v stretched
• Tilted disc
• Atrophy – where retina has been stretched
• Laquer cracks – breaks in Bruch’s membrane or stretches within retina
• Haemorrhage (Forster Fuchs spot – haemorrhage at fovea, can later scar over and leave pigment)
• Lattice degeneration in periphery
• Early posterior vitreous detachment (PVD)

Question 5

Degenerative myopia - complications?

Answer 5

• ↑axial length – causes stretching of structures of eye
• Breakdown of RPE and blood-retinal barrier – Secondary choroidal neovascular membrane
• Macular hole
• Retinal tears/detachment
• Retinoschisis

Question 6

Degenerative myopia treatment?

Answer 6

• Prophylactic treatments
  o Outdoor play – in childhood – 1hr per day – helps significantly reduce risk of developing myopia
  o Myopia control CLs – helps reduce children from developing high myopia or progressive myopia
  o Atropine
• No treatment for degeneration/atrophy
• Anti-VEGF injections for secondary CNV
• If have retinal tears/detachment – will need surgical intervention

Question 7

When to refer degenerative myopia?

Answer 7

• Progressive/sudden loss of vision
• New haemorrhage
• Any signs of retinal tear/detachment