What can happen in the presence of pathological myopia starting at 25.5 mm axial length
Up to 25% of population is myopic and pathologic myopia varies with the region of the world. Both hereditary and acquired risk factors. Lots of work showing lots of near work during higher education can further elongate the eye.
Causes of visual loss
- Optic nerve
- RPE mediated (most of the pathology)
- Vitreous mediated
Staphyloma really underlies most of the RPE changes that we see
- Goes through grading system of staphylomas based mostly on location in posterior pole
- Staphyloma itself can cause significant visual loss on its own
Predicting surgical outcomes in these patients
- Challenge is in patients with significant macular pathology
- Is vision down from lens changes or the macular pathology?
- Typically start with an OCT but often problematic with back scatter from the staphyloma
- Angiography should also be kept in mind as cans how fluid that OCT could miss
- A main cause of visual loss in pathological myopia
- Diffuse progressive RPE loss
- Associated with increased age, presence of a staphyloma and more....
- Really deep spikes on OCT can be seen deep to the retina
Choroidal neovasculariztion (CNV)
- Mechanical tissue thinning
- Lacquer cracks
- Sometimes very hard to find the area of leakage within the atrophy
Natural history of CNV is poor with loss of vision over 5 years mostly from atrophic in the area.
Anti-VEGF appears to be the treatment of choice without the secondary RPE loss seen by thermal laser treatments.
Vitreous mediated pathology
- Contracted posterior hyaloid with failure to detach from the retina