Degenerative Myopia

1. DEGENRATIVE MYOPIA,
OUTLINE
• Definition
• History of PM
• Epidemiology
• Classification
• Pathophysiology
• Ocular manifestation
• Treatment
• Complication

2. Definition
• Myopia is the results of complex hereditary and environmental
factors. there is a strong evidence for a causative association with
long-term intensive near visual activity, particularly reading and using
personal computers.
• A refractive error of more than -6 D constitutes a common definition
of high myopia in which axial length is usually greater than 26mm.

3. History of pathological myopia
• myopia was derived from the original Greek word “muopia” meaning
contracting or closing the eye
• Galen was the first to use the term “myopia”
• Antonio scarpa (1801) first anatomical description of posterior
staphyloma, but did not make the link to myopia
• Carl Ferdinand von arlt(1856) first connected staphyloma and myopia
refraction
• Brian j. curtin (1977) classification scheme for staphyloma
• Takashi tokoro (1988) definition of pathologic myopia

5. Epidemiology
• affects over 2% of adults in western Europe or American populations
and may be as high as 10% in east Asia .
• Italy-5%
• Japan 5-8%
• Singapore 15%
• Taiwan 38%

6. classification
Has been classified into five categories based on ohno-matsui’s
modified classification
• Category 0-No myopia retinal lesions
• Category 1-tessellated fundus only
• Category 2-diffuse chorioretinal atrophy
• Category 3-patchy chorioretinal atrophy
• Category 4-macular atrophy

7. pathophysiology
• degenerative myopia is characterized by progressive anteroposterior
elongation of the sclera envelope associated with arrange of
secondary ocular changes, principally thought to relate to mechanical
stretching of the involved tissues
• The pathogenesis of PM is possibly related with biomechanics. It is
believed that the excessive elongation of the globe and sclera
staphyloma are the most important factor in the development of
degenerative changes in pathologic myopia
• it is a significant cause of legal blindness, with maculopathy the most
common cause of visual loss.

8. Ocular manifestations and diagnosis
• staphyloma is a peri-papillary or macular ectasia of the posterior
sclera due to focal thinning and expansion present in about a third of
eyes with pathological myopia. Association include macular hole
formation and dome –shaped macula
• Peri-papillary) intra-choroidal cavitation , formerly described as peri-
papillary detachment of pathological myopia( pdpm)
• Sub-retinal ‘coin’ hemorrhages may develop from lacquer cracks in
the absence of CNV
• acquired optic disc pit formation is not uncommon and is thought to
be due to expansion of the peri-papillary region as the eye enlarges
over time

9. Signs; Large and pale optic disc
Apale tessellated appearance
Is due to diffuse attenuation
Of the RPE with visibility of
Large choroidal vessels

10. Cont,
• anomalous optic nerve head. may appear unusually small, large or
anomalous with a ‘tilted’ conformation. peripapillry chorioretinal
atrophy is very common , most commonly as a temporal crescent of
thinned or absent RPE

11. Myopic crescent
• Rarely occurs on the nasal border
Of myopic eye. Its primarily caused
By atrophic changes that are genetically
Determined, with a minor contribution
From stretching due to elongation of the
Eyeball

12. Tigroid/ blond fundus
• Blonde fundus-the retina is less pigmented
than normal
• Tigroid-anormal fundus to which a deeply
Pigmented choroid gives the appearance of
Dark polygonal areas between the choroidal
Vessels,especially in the periphery.

13. Chorioretinal atrophy
• focal chorioretinal atrophy is
characterized by patchy visibility
of choroidal vessels and often sclera

14. Peripheral vitreous detachment

15. Lacquer cracks
• lacquer cracks are ruptures in the rpe-bruch membrane
choriocapillaris complex characterized by
fine irregular yellow lines criss-crossing
at the posterior pole in around 5% of
high myopic eyes and can be
complicated by cnv

16. lattice degeneration
• This involves abnormal thinning of the
Peripheral retina, leading to poor
Perfussion causing ischemia and
Fibrosis.

17. Cobblestone degeneration
• This is characterized by multiple
Rounded, punched-out areas of
Chorioretinal atrophy with
Prominent underlying choroidal
Vessels and pigmented borders

18. Foster-fuch’s spots
• fuchs spot is a raised , circular,
pigmented lesion at the macula
developing after a subretinal
haemorrhage has absorbed

19. Peripheral retinal holes

20. Macular holes

21. Choroid neovascularization

22. Deferential diagnosis
• Neovascular AMD
• Myopic macular haemorrhage due to lacquer cracks
• Punctate inner choroidopathy
• Multifocal choroiditis
• Idiopathic CNV

23. Treatment
• There is currently no cure for pathological myopia.
• Followed up regularly for visual acuity, refraction, and general
ophthalmic health.
• Glasses or contact lenses -stable high myopathy can be corrected by
altering the way in which light rays bend in the eye
• low dose atropine 0.01% instilled at bed-time can significantly slow
the progression of myopia in children
• although best approach is to offer treatment between the age 5 -15
years whose myopia is increasing at more than 1 d per year

24. complication
• Retinal detachment
• Complicated cataract
• Vitreous and choroidal hemorrhage
• Strabismus fixus convergence
• Normotensive glaucoma
• Myopic foveoschisis
• Posterior staphyloma