Ectopia lentis and its low vision management

Ectopia lentis and its low vision management

1. a nd its low vision managment Indra P Sharma Master of Clinical Optometry ( Y ear I ) Amity Medical School ECTOPIA LENTIS

2. Objective To have a better understanding about ectopia lentis with regard to its pathophysiology, etiology, clinical manifestation and management. To understand the management of ectopia lentis with low vision aids

3. Contents An overview Signs and symptoms Etiology of ectopia lentis Workup and evaluation Treatment Low Vision Management Conculsion Reference

4. An overview Signs and Symptoms Etiology of ectopia lentis Workup and evaluation Treatment Low Vision Management Conculsion Reference An Overview

5. Introduction Ectopia lentis is defined as displacement or malposition of the crystalline lens of the eye. 1749 - Berryat first reported case of lens dislocation 1856- Stellwag coined the term “ ectopia lentis ” Ectopia lentis can be : 1. Subluxation 2. Luxation (dislocated) Sharma IP

6. Subluxation Condition when the crystalline lens is partially displaced but contained within the lens space. Few zonular attachment present Sharma IP

7. Dislocation Also known as luxated W hen lens lies completely outside the lens patellar fossa , in the anterior chamber, free-floating in the vitreous, or directly on the retina. Sharma IP

8. Anatomy of zonules The lens is suspended in its anatomic position by ciliary zonules ( zonules of Zinn or suspensory ligament of Zinn ) Zonules fibers which run from ciliary body and insert into the outer layer of the lens capsule around the equato r ( 1.5 mm anterior ly and 1mm posterior ) Stronger zonules in anterior capsule Each zonule measures 5 to 30µm in diameter and is composed of bundles of microfibrils Sharma IP

9. Pathophysiology U nderlying pathophysiology - Disruption or dysfunction of the zonular fibers of the lens, regardless of cause (trauma or heritable condition) The degree of zonular impairment determines the degree of lens displacement. Sharma IP

10. Epidemiology Frequency A rare condition. Incidence in the general population is unknown. Mortality/Morbidity Can cause marked visual disturbance, depending the degree of lens displacement and the underlying etiolog y Sex M ore common in males. Age A t any age (A t birth or it may manifest late in life ) Sharma IP

11. An overview Signs and Symptoms Etiology of ectopia lentis Workup and evaluation Treatment Low Vision Management Conculsion Reference Signs and Symptoms Sharma IP

12. Symptoms Distance visual acuity (moderate to severe impairment) depending on position of lens 1. Fluctuating vision dramatically as the vision may alternate between phakia and aphakic 2. Progressive movement of the lens- Extreme hyperopic shift or myopic astigmatism Poor near vision Due to loss of accommodative power due to weakened, stretched or broken zonules Sharma IP

13. Contd... Monocular diplopia Visual field defects (Due to lens induced secondary glaucoma) Source: Sihota R Sood NN, Argarwal He. 1995. Traumatic glaucoma.Acta Ophthalmol Scand 73:252-254. A 1963 histological study found that crystalline lenses that were dislocated anteriorly were associated with glaucoma 77.2% of the time and that crystalline lenses that were subluxed or dislocated posteriorly were associated with glaucoma 87.5% of the time. Sharma IP

14. Contd.... P ainful red eye (secondary to trauma) Glare and photophobia Sharma IP

15. An overview Signs and Symptoms Etiology of ectopia lentis Workup and evaluation Treatment Low Vision Management Conculsion Reference Etiology of ectopia lentis Sharma IP

16. T raumatic dislocation Traumatic dislocation is most common cause of ectopia lentis. Sharma IP

17. Hereditary ectopia lentis without systemic manifestations Single (isolated) ectopia lentis A utosomal dominant inheritance G enetic defect located on chromosome 15, causing a dysfunctional zonular apparatus. Microspherophakia is common. P resent at birth, can even onset late Typically, supertemporal displacement Sharma IP

18. Ectopia lentis et pupillae U sually is bilateral and typically autosomal recessive. characterized by asymmetric eccentric pupils that are displaced in the opposite direction of the lens dislocation (toward the most dysfunctional zonular fibers). The irides often appear atrophic with transillumination defects Cataracts  ( common ) Sharma IP

19. Pupil may be displaced in opposite direction ( ectopia lentis et pupillae ) Single (isolated) ectopia lentis Sharma IP

20. Systemic conditions associated with ectopia lenti s Marfan syndrome ( most frequent cause of her editary ectopia lentis ) Homocystinuria ( second most common cause of hereditary ectopia lentis ) Weil- Marchesani syndrome Sulfite oxidase Hyperlysinemia Sharma IP

21. Marfan syndrome T ransmitted as an autosomal dominant trait P revalence : approx . 5 per 100,000. M utations involving the fibrillin gene on chromosomes 15 and 21 and may relate to incompetent zonular fibers. Sharma IP

22. Systemic associat ion of Marfan Limb-trunk disproportion Arachnodactyly Pectus excavatum High-arched palate Aortic dilatation, dissection and regurgitation Mitral valve prolapse Sharma IP

23. Ocular manifestation Super io- temporal dislocation of a lens in 80% of cases Zonules usually intact Blue sclera Sharma IP

24. Contd.. Cornea plana Axial myopia Lattice degeneration Angle anomaly and glaucoma Sharma IP

25. Homocystinuria It is an inborn error of metabolism . M ost often caused by a deficiency of cystathionine b- synthetase (the enzyme that converts homocysteine to cystathionine ). Sharma IP

26. Systemic and ocular manifestation Malar flush and fine fair hair Marfanoid habaitus Increased platelet stickiness Mental retardation-50% Inferonasal lens subluxation -90% Disintegretation of zonules Sharma IP

27. Weil- Marchesani Syndrome R are syndrome characterized by skeletal malformations The inheritance pattern is not well understood. Pupillary block glaucoma is common; therefore, prophylactic laser peripheral iridotomies are recommended . Sharma IP

28. Systemic and ocular manifestation Short stature Short stubby fingers ( brachydactyly ) Mental handicap Microspherophakia (most common) Anterior lens subluxation (usually) Angle analomy and glaucoma Sharma IP

29. Sulfite oxidase deficiency E xtremely rare disorder caused by a defect in sulfur metabolism. Salient features are: P rogressive CNS abnormalities that develop within the first year of life E ctopia lentis . Sharma IP

30. Hyperlysinemia E xtremely rare autosomal recessive enzymatic defect of amino acid metabolism Salient features: M ental retardation and lens dislocation. Diagnosis is made by demonstration of increased plasma levels of lysine. Sharma IP

31. Primary ocular disorders associated Congenital glaucoma/ buphthalmos Pseudoexfoliation syndrome Syphilis/chronic uveitis Retinitis pigmentosa Hypermature cataract Intraocular tumor High myopia Sharma IP

32. Systemic diseases rarely associated Ehlers- Danlos syndrome Crouzon disease Refsum syndrome Kniest syndrome Mandibulofacial dysostosis Sturge -Weber syndrome Conradi syndrome Pfaundler syndrome Pierre Robin syndrome Wildervanck syndrome Sprengel deformity Sharma IP

33. An overview Signs and Symptoms Etiology of ectopia lentis Workup and evaluation Treatment Low Vision Management Conculsion Reference Workup and evaluation Sharma IP

34. Detailed history H istory of ocular trauma. H istory investigating possible systemic disease associations. Cardiovascular disease in Marfan syndrome Skeletal problems in Marfan syndrome , Weil- Marchesani syndrome or homocystinuria Pertinent family history Consanguinity M ental retardation U nexplained deaths at young age Sharma IP

35. Ophthalmic evaluation Visual acuity Amblyopia is a common cause of decreased vision in congenital ectopia lentis . External ocular examination O rbital anatomy for hereditary malformations ( eg , enophthalmos with facial myopathic appearance seen in Marfan syndrome). Measure corneal diameter ( megalocornea i n Marfan syndrome). Strabismus is common (secondary to amblyopia ). Sharma IP

36. Contd.. Retinoscopy and and keratometry Careful retinoscopy and refraction is essential, often revealing myopia with astigmatism. Keratometry may help ascertain degree of corneal astigmatism. Slit lamp examination Evaluate lens position, and identify phacodonesis or cataract. Measure intraocular pressure. Dilated fundus examination To rule out r etinal detachment Sharma IP

37. Laboratory studies Perform appropriate diagnostic and laboratory evaluation, if a hereditary condition is suspected C ardiac evaluation for Marfan syndrome C heck serum and urine levels of homocysteine or methionine for homocystinuria . Sharma IP

38. Imaging studies A scan Axial length measurement may be of benefit (patients with Marfan syndrome have large globes) B scan For any other associated vitrous and retinal complications Sharma IP

39. An overview Signs and Symptoms Etiology of ectopia lentis Workup and evaluation Treatment Low Vision Management Conculsion Reference Treatment Sharma IP

40. Refractive management T he key to managing lens subluxation optically is to perform two refractions: 1.F or that portion of the pupil covered by the crystalline lens (myopic astigmatism zone ) and 2. F or that portion of the pupil not covered by the crystalline lens (highly hyperopic zone ). Sharma IP

41. Contd... For moderate to severe subluxation Option: A n aphakic prescription with bifocals and a pharmacologic dilation For lens is subluxed out of the visual axis (bilateral) Best option: A n aphakic prescription Both spectacle and contact lens may be helpful. Sharma IP

42. Medical management If no, history of trauma, patients may possess a systemic disease with potentially deleterious effects; therefore, comanagement with pediatrician or internist is essential. Dietary restrictio n: partially effective in homocystinuria . Sharma IP

43. Contd... Treatment of glaucoma is dependent on the etiologic mechanism. P upillary block requires laser peripheral iridotomy or iridectomy and raised IOP treated medically. Prophylactic laser iridotomy in microspherophak ia. D islodged lens into the AC is initially pharmacological ( mydriasis / cycloplegia ) in conjunction with ocular massage through a closed lid. Treatment of a dislocated lens in the vitreous is surgical . Sharma IP

44. Sugical treatment 1. Nd:YAG laser zonulysis to displace lens out of visual axis 2.Lesectomy Lensectomy is technically challenging and are indication in the following: Lens in the anterior chamber Lens-induced uveitis Lens-induced glaucoma Lenticular opacity with poor visual function Anisometropia or refractive error not amenable to optical correction ( eg , in a child to prevent amblyopia ) Impending dislocation of the lens Sharma IP

45. Prevention and prognsis Deterrence/Prevention Early diagnosis of ectopia lentis with appropriate optical correction can prevent amblyopia . Complications The most common ocular complications include amblyopia , uveitis , glaucoma, and retinal detachment Prognosis Depending on the degree of lens dislocation, the age of onset, and its associated secondary complications, most patients do well. Trauma-associated ectopia lentis – poor visual prognosis Sharma IP

46. An overview Signs and Symptoms Etiology of ectopia lentis Workup and evaluation Treatment Low Vision Management Conculsion Reference Low vision manage ment Sharma IP

47. Rule of thumb Provide LVA to help releive the main symptoms first Sharma IP

48. Why do we need it? To compensate for high hypermetropia or myopic astigmatism Distance viewing devices Sharma IP

49. High power lenses High plus spectacle (aspheric lenses) Aphakic contact lens (Silsoft/silsoft super plus) Sharma IP

50. Roving Ring Scotoma Circular restriction in the peripheral VF due to prismatic effect of high plus lenses. Aspheric lenses reduces this scotoma Sharma IP

51. Telescopes Sharma IP

52. Sharma IP

53. Near optical devices Why is it required? To compensate for high hyperopia and loss of accommodation Preferable near viewing devices Spectacle-mounted Reading Lenses Telemicroscopes M agnifiers Electronic Devices- CCTV Sharma IP

54. Spetacle mounted reading glasses Sharma IP

55. Telemicroscope Eyeglass mounted micro scopes can be made to focus at any working distance. Sharma IP

56. Magnifiers Illuminated and non-illuminated Hand held and stand magnifiers Sharma IP

57. Electronic magnification devices Head mounted video display systems CCTV Sharma IP

58. Visual field enhancing devices Reverse telescope To compensate for VF defects due to secondary Glaucoma. Prisms Mirrors Reverse Telescope system Sharma IP

59. Non-optical aids Relative size and larger assistive devices Glare, contrast, and lighting control devices Handwriting and written communication devices Medical management devices Orientation and mobility management techniques and devices Sharma IP

60. Relative size and larger assistive devices Large print Books, magazines, newspaper, dictionaries, thesauri, atlas, cookbooks, encyclopedias, bibles Photocopy machines ( e.g. A4 size to A3 size) Computer with large prints font Computer software program Large print typewriters Others Telephone dial, bank checks, watches, clocks, calculators etc Games like cross word puzzles, playing cards, chess checkers, bingo etc. Sharma IP

61. Magic 8.0 Large print telephones Sharma IP

62. Large print calculator Playing cards Sharma IP

63. Glare, contrast, and lighting control devices Aphakia allows for increased transmission of UV radiation Shades Tennis shades, caps, hats, side-shields, visors Filters NoIR and CPF lenses Sharma IP

64. Sunglasses/ photochromatic lenses to reduce illumination levels Sharma IP

65. Typoscopes – a reading guide cut off glare Glare cutter ( 390-410nm)- cuts 100% UVB, 99% UVA Sharma IP

66. Diplopia eliminating devices Stenopeic slit Aperture control contact lens Pinhole lenses Sharma IP

67. Color and contrast adjustments Environmental modification Painted edges of Staircase Sharma IP

68. Contrast in kitchen Sharma IP

69. Hand writing and written communication Signature guide Check guides Reading guide Large prints Bold felt-tip pens Bold line paper Large print typewriters Sharma IP

70. Medical management devices Monitoring blood glucose Large print syringe Syringe with magnifiers ( optical device) Preset dosage Pre-filled syringes- filled with clicking sounds Monitoring blood pressure Readout sphygmomanometers for hearing problems Monitoring temperatures Large readout thermometers and talking thermometer Sharma IP

71. Talking colour detector IPS Sharma IP

72. Counselling If a hereditary condition is discovered, appropriate genetic counseling recommended. A ll relatives with potential risk should be examined. Advised against playing contact sports or doing physically strenous activities. Sharma IP

73. An overview Signs and Symptoms Etiology of ectopia lentis Workup and evaluation Treatment Low Vision Management Conculsion Reference Conclusion Sharma IP

74. Take home message Managing patients with ectopia lentis including refraction is usually difficult and needs expertise to manage them well. As most patients with ectopia lentis are syndromic, co-management with other specialist is essential. While managing patient with low vision we need to looks at various cause and other ocular association like glaucoma, retinal detachment and amblyopia. An optometrist needs to understand the need of the patient and prescribe according. Sharma IP

75. An overview Signs and Symptoms Etiology of ectopia lentis Workup and evaluation Treatment Low Vision Management Conculsion Reference Reference Sharma IP

76. Reference Books Jonathan A Jackson, Low Vision Mannual ,2007, Butterworth Heineman Elsevier. William J Benjamin,2006, Borish’s Clinical Refraction , Butterworth Heineman Elsevier. 20: 816-829 Lighthouse International , The Lighthouse Clinician’s Guide to Low Vision Practice   Brilliant Richard L, 1999, Essentials of Low vision Practice, Butterworth Heineman Elsevier. 6.8.9.10 Websites www. emedicine.medscape.com www.rootatlas.com en.wikipedia.org www.google.com/imghp Sharma IP

77. Tashi Delek Sharma IP