Pathological Myopia.pptx

Pathological Myopia

1. Presented by: Dr. Mohammad Abdullah B awtag Pathological Myopia Sankara Nethralay a– Chennai, India 2014

2. History of Pathological Myopia

3. - 1977 Brian J. Curtin Classification scheme for staphyloma Myopia - New Latin …… was derived from the original Greek word “ mŭopia ” … contracting or closing the eye. PM - 1988 Takashi Tokoro …Definition of pathologic myopia Staphyloma - is a pathognomic feature of PM - 1801 Antonio Scarpa First anatomical description of posterior staphyloma, but did not make the link to myopia - 1856 Carl Ferdinand von Arlt First connected staphyloma and myopic refraction - 138–201 Galen was the first to use the term myopia

4. Terminologies of Pathological Myopia

5. Pathological myopia Degenerative myopia Malignant myopia High degree myopia Progressive myopia Magna myopia

6. Definitions of Pathological Myopia

7. Clinically- refractive error > -6 D. Duke-Elder - Myopia with degenerative changes especially in the post. segment. Tokoro - Myopia caused by pathological axial elongation. A more specific - Myopic retinopathy, refers to the degeneration of chorioretinal tissue ass. with axial elongation of the eye.

8. Prevalence of Pathological Myopia

9. Country % Country % Myopia Some Asian countries 70–90% Industrialized -West 10%–25% Taiwan 84% Africa 10–20% Industrialized - East 60%–80% India 6.9% Europe and the US 30–40% PM Asian 9–21% Most countries 1–4% Spain 9.6% USA 2% Singapore 9.1% Bangladeshi 1.8% Japan 8% Czechoslovakia 1% Northern China 4.1% Egypt 0.2% High myopia affects 27%-33% of all myopic eyes in Asia.

10. Lengthening of the post. segment of the eye commences only during the period of active growth. The eye and the brain show precocious growth at the age of 4 years; the brain is 84% and the eye 78% and the rest of the body 21%. Interesting facts After this, both the eye and the brain increase slowly while the body grows more rapidly. However, when axial myopia continues to progress, it is interpreted as a precocious growth which has failed to get arrested…………….!!!!!!!!!! We do not as yet know what this influence is.

11. Pathogenesis of Pathological Myopia

12. Etiology of Myopia is as diverse and controversial as one can imagine. Everything in medicine has been blamed as a cause of Myopia. Two types of theories are put forward: 1) Mechanical and Environmental 2) Biological

13. Mechanical theories - distension of normal sclera - Increased IOP caused by the action of EOMs or IOMs or by insidious chronic glaucoma. Others theories : weakening of the sclera - venous congestion, inflammation or dietary deficiency.

14. Classification of Myopia

15. Type of Class. Classes of Myopia Cause Axil Myopia Refractive Myopia ( Curvature & Index ) Clinical Entity Simple myopia Nocturnal myopia Pseudomyopia Degenerative myopia Induced myopia Degree Low myopia (<-3.00 D) Medium myopia (-3.00 D - -6.00 D) High myopia (>-6.00 D) Age of Onset Congenital myopia (present at birth and persisting through infancy) Youth-onset myopia (<20 years of age) Early adult-onset myopia (20-40 years of age) Late adult-onset myopia (>40 years of age)

16. Simple Myopia - not progressive, good vision- optical correction. Pathological Myopia - changes in the posterior segment, lengthening of AP axis of the globe. High Myopia is classified in a simple manner as: i ) Simple ii) pathological

17. Risk factors

18. Risk factors Description Race & ethnicity Asians Age Middle aged (working life) or younger Gender Female Social group Children(Asian) professional working adults Geography Industrialised /developed nations Lifestyle Time spent outdoors Education High level of education/academic achievement Occupation Near work indoors (e.g. lawyers, physicians, microscopists and editors) Familial inheritance (parental refraction) Genetic

19. Genetic factors

20. Family studies and twin studies have revealed the heritability of myopia since the 1960s. In familial studies and twin studies, linkage analysis using microsatellite markers has identified 19 loci for myopia: MYP1 to MYP19. AD High Myopia AR High Myopia X-Linked High Myopia Common Myopia MYP1 MYP13 MYP18 MYP2 MYP3 MYP4 MYP5 MYP11 MYP12 MYP15 MYP16 MYP17 MYP19 MYP7 MYP8 MYP9 MYP10 MYP14 MYP17

21. Manifestations of Pathological Myopia Anatomical Manifestations Functional Manifestations Ocular Manifestations

22. Anatomical Manifestations Corneal astigmatism Deep AC Angle iris processes Zonular dehiscences Vitreous syneresis Lattice retinal degeneration Scleral expansion and thinning ↓ Ocular rigidity ↑ AL Post. staphyloma Tilted disc Temporal crescent or halo atrophy Macular lacquer cracks Pigment epithelial thinning Choroidal attenuation Peripapillary detachment in PM Foveal retinoschisis

23. Functional Manifestations Suboptimal binocularity Image minification Anisometropic amblyopia Subnormal visual acuity Visual field defects Impaired dark adaptation Abnormal color discrimination

24. Ocular Manifestations Strabismus： exophoria ／ exotropia Cataract. Glaucoma.. pigmentary / normal-tension glaucoma Tigroid , or blond fundus, with choroidal visible underneath Tilted optic nerve with peripapillary atrophy Peripapillary detachment Chororetinal atrophy PVD RD Lacquer cracks Lattice degeneration (spontaneous breaks in Bruch's membrane) Cobblestone degeneration Fuch's spot (RPE hyperplasia in response to CNV) Scleral thinning Peripheral retinal holes Macular holes causing RD CNV

25. Complications of Pathological Myopia This review aims to provide an overview on some of the important complications associated with PM. Peripheral retinal degenerations & RRD Myopic foveoschisis & Macular hole Lacquer cracks CNV in PM Vitreous degeneration Post. Staphyloma

26. Vitreous degeneration Syneresis Vitreous liquefaction, fibril aggregation & condensation Associated with floaters Caused by myopia, senescence, trauma, inflammations, hereditary causes PVD

27. Liquefaction of the vitreous gel Hole in the posterior hyaloid membrane Fluid tru defect into retrohyaloid space Vitreous gel collapses synchytic fluid in space Detachment of posterior vitreous from ILM Acute PVD

28. PVD with gel collapse Without vitreous hage , 4% develop retinal breaks With vitreous hage , 20% develop breaks PVD without gel collapse Associated with future retinal hole or vitreous hage Scaffold for proliferative new vessels

29. Flow chart illustrating the natural history of an acute PVD Symptomatic PVD Approx 10-15 % Retinal breaks at first assessment Approx 90 % uncomlicated at first assessment High risk break Low risk break Low risk of detachment Approx 98 % uncomplicated At 4-6 weeks 1.5-3.4% Retinal breaks At 4-6 weeks Detachment In 33-46% Within 6 weeks

30. Ultrasound picture showing PVD. Note that the vitreous is still attached at the optic disc and the ora serrata .

31. Vitreous changes in PM Vitreous liquefaction Early PVD Presence of CPVD Larger posterior precortical vitreous pocket Residual posterior cortex in CPVD Years PM control 20- 39 27.8% 40-59 43% 8% 60 - 79 91% 60%

32. Myopic Foveoschisis Prevalence – 9% to 34% Pathogenesis : 1. Attachment of Contracted vitreous cortex to retinal surface 2. ERM 3. Retinal vascular traction 4. Rigidity of ILM 5. Progression of posterior staphyloma

33. Natural history: Varied course with diverse visual outcomes- stable to development of macular holes Eyes with anterior traction had worst prognosis Progressive disease with poor outcomes Treatment: PPV+ILM peeling(traditional/ foveal sparing) +/- tamponade – useful to relieve internal surface anterior traction Scleral buckling – Addresses disparity between retina and elongated sclera Suprachoroidal buckling – hyaluronic acid injected through a catheter into suprachoroidal space in the area of staphyloma to indent choroid Complications : Choroidal hemorrhage and hyperpigmentation around area of indentation.

34. Myopic macular hole may occur, but the exact mechanism is unknown. Whether attenuation of the neural retina and its supportive pigment epithelium and choroid are responsible is speculative. Macular hole

35. Various surgical procedures have been performed for macular hole with or without RD and they include : PPV with gas or silicone oil tamponade Macular buckling Scleral shortening surgeries.

36. Myopic macular chorioretinopathy DEF : is a rare, genetic eye disorder that causes vision loss. Grading(shih et al) MO - Normal post pole M1 - Tesselation & choroidal pallor M2 - M1+post staphyloma M3 - M2+lacker cracks M4 - M3+ focal deep choroidal atrophy M5 - M4+geographic atrophy, CNV M3>- myopic maculopathy

37. “Lattice degeneration is a common retinal degeneration.” 1. Epidemiology 8-10% of general population (but 20-40% of RD) More commonly in moderate myopes and is the most important degeneration directly related to RD Location: Commonly - temporal superiorly fundus Between equator and ora serrata 2. Pathology Discontinuity of internal limiting membrane Atrophy of inner layers of retina Overlying pocket of liquefied vitreous Adherence of vitreous to edge of lattice (posterior edge) Sclerosis of retinal vessels Peripheral retinal degenerations & RRD

38. Lattice degeneration - predispose to RRD Retinal tears - posterior and lateral margins of the lattice degeneration Role of prophylactic Laser photocoagulation: History of RD in the fellow eye Family history of RD Prior to ocular surgeries Symptomatic pt

39. In eyes with RD, laser photocoagulation alone is insufficient to treat the condition and V-R surgery is required. Surgical modalities for RRD - pneumatic retinopexy , SB surgery with cryopexy , and PPV+BB+EL+ C3F8/ SIO. CLINICAL PEARLS Lattice degeneration both with and without atrophic holes is generally benign and does not require prophylactic treatment, as the complications of treatment are more severe than the natural history of the untreated condition.

40. Myopic RD Incidence of RD in general population range between 0.005 and 0.01 % . RD occurs far more frequently in patients with myopia. Disease Case-control study Group found that subjects with sepherical equivalent refractive error of -1 to -3 diopters had a fourfold greater risk of RD then a nonmyopic individual. For refractive errors greater than -3 diopters the risk was tenfold greater More than half of nontraumatic RRD occurs in myopic eyes.

41. CNV in Pathological Myopia Among various lesions associated with high myopia, macular CNV is one of the most vision threatening complications. It develops in around 5 to 10% of eyes with high myopia and is the commonest cause of CNV in young individuals and accounts for around 60% of CNV in young patients aged 50 years or younger. Macular hage ass. with CNV in high myopia

42. Develops from laquer cracks. Smaller, less exudation. - Type 1 (severe myopic degeneration)- Leakage does not extend beyond initial CNVM border- Quiescent scar. - Type2( Minimal degeneration)- Leakage beyond CNVM borders- Fibrovascular scarring.

43. A possible explanation includes, certainly, the induced hypoxia in the outer retina, which is a large source of VEGF secretion. Chorioretinal stretching, lacquer crack formation, choroidal thinning, choroidal flow disturbance with reduced flow, choroidal filling delay, RPE and overlying retina atrophy, loss of photoreceptors, all of them can be involved in growth factor release and myopic CNV formation. The role of each of these features and the interconnections between them remain unclear The mechanism of CNV formation in myopic CNV is still unclear.

44. Laser photocoagulation of …. no longer performed. Other treatment modalities Submacular surgery Macular translocation surgery The most commonly used currently is PDT with verteporfin . More recently, the use of anti-VEGF agents A combination therapy of PDT with anti-VEGF agents appears efficacious in the treatment of eyes with CNV secondary to pathological myopia, and may afford better visual outcomes as compared to PDT monotherapy Treatment of myopic CNV

45. Features of choroid in PM Stretched choroid without additional vasculature Thinner choroid Choriocapillaries and larger ch.vessel have decreased lumen Choriocapillaries have loss of fenestrations Increased number of vortex veins(>4) Posterior vortex veins( ciliovaginal veins) Reduction of choroidal thickness is proportional to age and refractive status Per diopter myopia caused 8µm reduction in choroidal thickness Per decade causing 12-15µm reduction in choroidal thickness Intrachoroidal cavitation – the expansion of distance between inner wall of sclera and posterior surface of bruch’s membrane Attenuated choroid to absent choroid – myopic chorioretinal atrophy

46. Lacquer cracks Spontaneous ruptures in the Bruch's membrane . Small hages may develop within the lacquer cracks. Lacquer cracks predispose - macular CNV Small ingrowth of fibrovascular tissue may also give rise to small elevated pigmented circular lesions and are known as Fuchs‘ spots.

47. Post. Staphyloma

48. post. staphyloma ( ectasia ) Equatorial staphyloma with scleral dehiscence - STQ. Visual loss is most often due to macular involvement of a post. pole staphyloma.

49. Curtin classified the staphylomas into ten categories. The first five were simpler configurations, while the last five were either more intricate in their configuration

50. Tesselated Fundus Hypoplasia of the RPE following axial elongation reduces the pigment, allowing the choroidal vessels to be seen. Commonly seen in elderly or brunette patients. May not be associated with any clinical significance

51. References

52. Ohno -Matsui K, Yoshida T, Futagami S, Yasuzumi K, Shimada N, Kojima A, et al. Patchy atrophy and lacquer cracks predispose to the development of CNV in PM. Br J Ophthalmol 2003; 87: 570-573. Cheung BT, Lai YY, Yuen CY, et al. Results of high-density silicone oil as a tamponade agent in macular hole RD in patients with high myopia. Br J Ophthalmol 2007;91:719-721. Chinese Medical Journal 2013;126(8):1578-1583 Bhatt N S, Diamond J G, Jalali S, Das T. Choroidal neovascular membrane. Indian J Ophthalmol 1998;46:67-80 Hamelin N, Glacet -Bernard A, Brindeau C, et al. Surgical treatment of subfoveal neovascularization in myopia: macular translocation vs surgical removal. Am J Ophthalmol 2002;133:530-6. Flower RW. Expanded hypothesis on the mechanism of photodynamic therapy action on CNV. Retina 1999;19:365-69. Albert & Jakobiec,Principles and Practice of Ophthalmology, Volume 2, Chapter 154 PM P 2023-2027, 3 rd ed 2008. Pathological Myopia, Richard F. Spaide , Kyoko Ohno -Matsui, Lawrence A. Yannuzzi Editors Kyoko Ohno – Matstui MD, Phd , Muka Moriyama MD, PhD Staphyloma II: Analyses of Morphological Features of Posterior Staphyloma in Pathologic Myopia Analyzed by a Combination of Wide-View Fundus Observation and 3D MRI Analyses Pathological Myopia 2014, pp 177-185

53. Pukhrai Rishi , … et al …..Photodynamic monotherapy or combination treatment with intravitreal triamcinolone acetonide , bevacizumab or ranibizumab for choroidal neovascularization associated with pathological myopia.. 2011

54. Thanks