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MOHAMMAD REZA AKHLAGHI MD

MOHAMMAD REZA AKHLAGHI MD. HEREDITARY MACULAR DYSTROPHIES. HEREDITARY MACULAR DYSTROPHIES. The hereditary dystrophies of the posterior segment constitute a large and potentially confusing group of disorders. . CLASSIFICATIONS.

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MOHAMMAD REZA AKHLAGHI MD

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  1. MOHAMMAD REZA AKHLAGHI MD

  2. HEREDITARY MACULAR DYSTROPHIES

  3. HEREDITARY MACULAR DYSTROPHIES • The hereditary dystrophies of the posterior segment constitute a large and potentially confusing group of disorders.

  4. CLASSIFICATIONS • ANATOMICAL CLASSIFICATIONS have divided the disorders by apparent layer of involvement, such as retina, macula, retinal pigment epithelium (RPE), choroid, and vitreous-retina. many dystrophies overlap and may have multiple layers of involvement. • INHERITANCE PATTERN OF THE DISEASE: Approximately 60% of thorough pedigrees give useful information. • DISEASE PHENOTYPE by clinical examination AND ELECTROPHYSIOLOGICand psychophysical testing. • Careful analysis of the information gathered by these 3 approachesallows most patients to be assigned to a disease group, and many can be given a specific clinical diagnosis that can be CONFIRMED BY MOLECULAR TESTING.

  5. Macular Dystrophies ~ Six Categories • 1. Nerve Fiber Disease • 2. Photoreceptor & RPE Diseases • 3. RPE Diseases • 4. Bruch’s Membrane Diseases • 5. Possible Inflammatory Diseases • 6. Miscellaneous Macular Diseases

  6. Macular Dystrophies ~ Nerve Fiber Diseases • X-linked Juvenile Retinoschisis • Familial ILM Dystrophy

  7. Macular Dystrophies Photoreceptor & RPE • Cone Dystrophies • Other Bull’s Eye Lesions: a. Olivopontinocerebellar atrophy b. Benign Concentric Annular c. Duchenne Muscular Dystrophy • Stargardt’s Disease

  8. Macular Dystrophies ~ RPE Diseases • Best Vitelliform Dystrophy • Adult Vitelliform Dystrophy • Fundus Flavimaculatus • Patterned Dystrophy • Reticular RPE Dystrophy • Dominant Cystoid Macular Dystrophy • Dominant Drusen • Dominant Radial Drusen • North Carolina Macular Dystrophy

  9. Macular DystrophiesBruch’s Membrane • 1. Sorsby’sMacular Dystrophy • 2. Angioid Streaks • 3. Age-related Macular Degeneration • 4. High Myopia

  10. PRESENTATION • The most common presentation is a history of slowly progressive central vision loss occurring in the first 3 decades of life • With rare exceptions, have bilateral symmetric involvement. • When unilateral ocular involvement is seen, other causes, such as birth defect, intrauterine or antenatal infection, and inflammatory disease, should be considered

  11. Cone Dystrophies

  12. Cone Dystrophies Characterized by : • loss of cone cell • Normal Rods • Cone dystrophies can be either stationary or progressive. • These different syndromes encompass a wide range of clinical and psychophysical findings

  13. Cone Dystrophies HISTOPATHOLOGY • The outer nuclear segment of coneshad disappeared completely • RPE showed pronounced pigment changes

  14. Cone Dystrophies Main Symptoms • loss of visual acuity, • from 20/100 to CF • age of onset ranging from the late teens to the sixties • photophobia • hemeralopia(day blindness) • dyschromatopsia,

  15. Ophthalmoscopy : • Normal fundus in early stags definite macular changes usually occur well after visual loss • Bull's-eye pattern of macular atrophy (consists of a doughnut-like zone of atrophic pigment epithelium surrounding a central darker area) • demarcated circular macular lesions. • Mild to severe temporal optic atrophy

  16. FLUORESCEIN ANGIOGRAPHY • Fluorescein angiography is a useful adjunct it may detect early changes in the retina that are too subtle to be seen by ophthalmoscope. For example, FA may reveal areas of hyperfluorescence, indicating that the RPE has lost some of its integrity,

  17. Electeroretiongraphy(ERG) remains the best test for making the • Abnormal cone function • The relative sparing of rod • In more severe or longer standing cases, subnormal scotopic records.

  18. .

  19. INHERIDENCE • Cone dystrophy usually occurs sporadically. Hereditary forms are usually autosomal dominant, and instances of autosomal recessive and X-linked inheritance also occur.

  20. The cone dystrophies should not be confused with congenital color blindness, in which there are color deficits for specific colors but no associated visual loss and retinal degeneration and do not show signs of progressive disease.

  21. DIFFERENTIAL DIAGNOSIS • Other macular dystrophies ( Central areolar pigment epithelial (CAPE) dystrophy, Stargardt'sdisease, pattern dystrophy, Best disease . . .) as well as the hereditary optic atrophies must be considered • Fluorescent angiography, ERG, and color vision tests are important tools to help facilitate diagnosis in early stages

  22. MAMAGMENT • reducing photophobia: • Dark sunglasses • miotics • low vision aids • magnifiers, • closed-circuit television devices • software for computer screen text enlargement

  23. Cone-Rod Dystrophies • CRDs are inherited retinal dystrophies that belong to the pigmentary retinopathies group • The term cone-rod comes from electroretino-graphic testing, in which the cone-isolated ERG waveform is proportionately worse than the rod-isolated signal, and both are abnormal • Prevalence of CRDs is estimated at 1/40,000 (thus, CRDs are ten times less frequent than RP)

  24. Clinical description • CRDs present first as a macular disease or as a diffuse retinopathy with predominance of the macular involvement

  25. SIGNS AND SYMPTOMS In the first stage • decreased visual acuity, usually discovered at school, does not significantly improve with spectacles • intense photophobia • variable degree of dyschromatopsia • Visual field losscentral scotomas, while periphery is spared

  26. In the second stage • night blindness becomes more apparent • loss of peripheral visual field progresses. • visual acuity continues to decrease to a level where reading is no longer possible. • At this stage, patients are legally blind (visual acuity <20/400

  27. SIGNS AND SYMPTOMS Fundus in early stage • Normal looking macula • fine macular lesions • optic disc pallor, particularly on the temporal side At this stage, the question is to differentiate Stargardt disease, cone dystrophies

  28. SIGNS AND SYMPTOMS

  29. SIGNS AND SYMPTOMS • Latter stage • Pigmentary deposits resembling bone spicules, frequently in macular area • Attenuation of the retinal vessels • Waxy pallor of the optic disc • Various degrees of retinal atrophy

  30. SIGNS AND SYMPTOMS

  31. SIGNS AND SYMPTOMS

  32. SIGNS AND SYMPTOMS fluorescein angiography fluorescein angiography and fundus autofluorescenceshow that the peripheral retina is also involved with heterogeneity in the fluorescence, but to a lesser extent than the macula.

  33. SIGNS AND SYMPTOMS

  34. SIGNS AND SYMPTOMS • Visual field • Central scotoma appears first, preventing fluent reading • Patchy losses of peripheral vision follow • Severe loss of vision occurs earlier than in retinitis pigmentosa

  35. SIGNS AND SYMPTOMS Electroretinogram (ERG) • Dramatic decrease of amplitudes of both a- and b-waves • Predominant involvement of photopic (cones) over scotopic (rods) responses

  36. Electroretinograms showing the responses to white stimuli of a normal proband and patients 1 to 3. DA indicates responses at dark adaptation at low (first row) and maximum (second row) stimulus intensity. The next row shows the dark-adapted oscillatory potentials. LA indicates single-flash responses at light adaptation. The cone flicker response was measured at 30 Hz

  37. INHERITENCE • Three Mendelian types of inheritance have been reported • Today, there are 13 genes responsible for CRDs (10 cloned, 3 mapped).

  38. DIAGNOSIS • Clinical diagnosis is based on the early decrease of visual acuity and photophobia, lesions in fundus, hypovolted ERG traces with predominant cone involvement, and progressive worsening of these signs • Full field ERG is the key test, particularly when patients are symptomatic and show normal fundus at early stages • It is important to repeating the examination one or two years after it has been first established.

  39. DIFFERENTIAL DIAGNOSIS • Retinitis pigmentosa • Leber’s congenital amaurosis (LCA) • Stargardt disease • Cone dystrophies

  40. MANAGMENT • light protection • Vitaminotherapy • filtrating spectacles to minimize photophobia • low vision aid • treating the complications such as cataract, macular edema, inflammation,

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