This presentation introduces myopia, high myopia, and in more details, pathologic myopia (aka malignant myopia). It is intended for training ophthalmologists, ophthalmology residents, medical students in ophthalmology rotations.

1. Myopia
By: Dr. Saif Aldeen AlRyalat
Department of Ophthalmology, The University of Jordan
saifryalat@yahoo.com

2. Definition
• Myopia: Focusing the image in
front of the retina.
• Due to:
- High axial length
- High refractive power

3. High myopia
• Refractive error with spherical
equivalent exceeding −6 diopters (D)
AND/OR
• Axial length longer than 26.5 mm.

4. Pathological myopia
• High axial myopia.
AND
• Characteristic pathological
changes at the posterior pole.
Also called degenerative or
malignant myopia

5. Epidemiology
• The prevalence varies from 1% to 4% in the general population.
• More prevalent in the Asian population.
• Higher prevalence of PM in women than in men.

6. Pathophysiology
• Excessive axial elongation resulting in
chorioretinal stretching and subsequent
thinning.
• Myopia-related complications increase
proportionally with increase in axial length.
• Choroidal neovascularization (CNV)

7. Outcome
• CNV observed in 5.2% of eyes with pathological myopia.
• Myopic CNV may account for as much as 62% of CNV occurring in
patients younger than 50 years of age.
• Several studies observed poor long-term visual acuity outcome after
CNV.

8. Features
Posterior staphyloma

9. Posterior staphyloma
• Local bulging of the sclera at the posterior
pole of the eye.
• Has a radius of less than the surrounding
curvature of the wall of the eye.
• Pathognomonic for pathological myopia.
• The best way to diagnose by an indirect
ophthalmoscope.

10. Posterior staphyloma
• It is seen as a secondary
depression with bending of
vessels at the margin and a dark
crescentic nasal reflex

11. Features
Myopic maculopathy

12. Classification for maculopathy
• Available classification systems:
- Curtin and Karlin on 1970 (didn’t cover all lesions).
- Avila et al. on 1984 (do not progress sequentially).
- Hayashi et al. on 2010 (do not progress sequentially).
• On 2015, a new study published in AJO by META-analysis for
pathologic myopia study group proposed a new classification system
to overcome previous limitations.

13. The new classification
• 5 categories from 0 to 4.
• 3 plus lesions: Do not fit into
any particular category, and
can develop from, or co-exist,
in eyes with any of the myopic
maculopathy categories.
• % are rates of progression over
13 years.

14. The new classification
• The classification is
based on risk of
developing myopic
choroidal
neovascularization
(myopic CNV) from
different categories
(incidence % over 13
years)

15. Tessellated fundus
• Generalized depigmentation due
to retinal pigment epithelium
atrophy following the myopic
axial elongation.

16. Diffuse chorioretinal atrophy
• Appears as yellowish-
white of posterior pole
of an eye.

17. Patchy chorioretinal atrophy
• Appears as well defined, grayish-
white lesions.
• characterized by a complete loss
of choriocapillaris and can
progress to an absence of outer
retina and RPE.

18. Macular atrophy
• Macular atrophy is a well-defined,
round chorioretinal atrophic lesion
which is grayish-white or whitish
and enlarges with time.
• Macular atrophy is centered on the
central fovea and has a round
shape. Whereas patchy
chorioretinal atrophy is not
centered on the fovea and has
irregular margins.

19. Lacquer cracks (Lc)
• Lacquer cracks are
mechanical breaks of
Bruch’s membrane and are
observed as yellowish thick
linear pattern.
• Lacquer cracks can lead to
bleeding (arrows).

20. Myopic CNV
• An active CNV is determined by
the presence of a CNV and
exudative changes.
• They are located in the
subretinal space, as opposed to
the sub-RPE space in age-
related macular degeneration
(AMD)
• Serous retinal detachments
associated with the CNV can be
present.

21. Fuchs’ spot (Fs)
• Fuchs’ spot is a pigmented
spot representing the
scaring phase of myopic
choroidal
neovascularization.
• Fuchs’ spot is a
consequence of myopic CNV.

22. Features
Others

23. Myopic conus/crescent
• A sharply defined
concentric area of
depigmentation
adjacent to the optic
disc where the inner
surface of sclera is
visible

24. Myopic Macular Retinoschisis
• A schisis-like (i.e. cleft)
thickening of neurosensory
retina into a thicker inner
layer and a thinner outer
layer at the macula.
• Alternatively described as
myopic traction maculopathy
(MTM).

25. Prevention

26. Prevention
• Increased time spent outdoors is the only known protective factor.
• Atropine eye drops are under investigation.
• No intervention can reverse pathological myopia. However,
treatments available for CNV.

27. Management

28. Management: Before 1990s
• Photothermal laser ablation of the new vessels.
• High rate of recurrence
• High tendency of the photocoagulation scars to expand over time and
significantly risked central vision

29. Management: Late 1990s
• Photodynamic therapy (PDT).
• Photosensitive intravenous drug,
verteporfin in combination with a
low power, long duration infrared
laser.

30. Management: Late 1990s
• Selectively target neovascular vessels with lesser collateral damage.
• Photodynamic Therapy has been limited by these observations:
- Up to 13% still have moderate vision losses despite treatment
- Up to 57% with persistent leakage at one year.
- Almost no effect at two years.

31. Management: Nowadays
• Anti-VEGF therapy is now considered first line intervention in patients
with myopic CNV.
• Used off-label for the treatment of myopic CNV.
• A growing number of prospective and randomized trials have been
published or are currently underway.

32. Management: Nowadays
• RADIANCE (A Randomized Controlled Study of Ranibizumab in
Patients with Choroidal Neovascularization Secondary to Pathologic
Myopia).
• Comparing intravitreal ranibizumab to PDT.
• Concluded: “Ranibizumab treatment, irrespective of retreatment
criteria, provided superior BCVA gains versus PDT"

33. Management: Role of vitrectomy
• Patients with decreased vision in the setting of maculoschisis or
foveoschisis.
• Vitrectomy relieve traction on the fovea and prevent formation of
macular holes or macular retinal detachment.

34. Thank you