congenital glaucoma part 1


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glaucoma of the childhood: classification , development of angle structure. pathogenesis, primary infantile glaucoma, differential diagnosis.... rest will be continued in other presentations of mine

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congenital glaucoma part 1

  1. 1. Dr Nidhi Thaker CHILDHOOD GLAUCOMA
  2. 2. DEFINITION 0CGRN/WGA 2013 0Based on national criteria; Glaucoma in children less than 18 yrs of age(USA): < 16 yrs of age(UK,Europe) 0Noted by Hippocrates 0First recognised by Von Muralt in 1869
  4. 4. CONGENITAL GLAUCOMA 0Primary congenital glaucoma/ primary infantile glaucoma/ primary congenital open angle glaucoma 0Definition: Glaucoma in children less than 2yrs of age that can be primary infantile or secondary infantile associated with ocular or systemic syndromes and with surgical aphakia.
  5. 5. Definition of glaucoma 2 or more required 1) IOP > 21 mm Hg 2) Optic disc cupping: 0 progressive in CDR 0 asymmetry of cup: >0.2 0 focal rim thinning 3) cornea;l findings: 0 Haab striae 0 Increase diameter of cornea 4) Progressive myopia/ myopic shift: 5)Reproducible visual field defect consistant with glaucomatous optic neuropathy
  6. 6. Definition of glaucoma suspect Atleast 1 required 1) IOP > 21 mm Hg on 2 separate occasions 2) Suspicious optic disc cupping: 0 progressive in CDR 0 asymmetry of cup: >0.2 0 focal rim thinning 3) Increase diameter of cornea and increase axial length 4) suspicious visual field defect
  8. 8. EPIDEMIOLOGY AND GENETICS Primary congenital glaucoma – 50-70-% of the congenital glaucomas Occurs less frequent than primary adult glaucoma Rare – 1:10,000 births M:F ; 3:2 b/l in 65-80% Of pediatric glaucoma cases - 20% diagnosed as newborn 60% - diagnosed by the age of 6 months 80% within the 1st year of life
  9. 9. EPIDEMIOLOGY AND GENETICS 0 Sporadic 90% 0 Only 10% familial Autosomal recessive pattern with incomplete or variable penetrance and possibly multifactorial inheritance  3 major loci of recessively inherited primary congenital galucoma  GLC3A - on chromosome 2 (2p21), CYP1B1 gene  GLC3B -on chromosome 1 (1p36)  GLC3C – on chromosome 14 (14q24.3) LTBP2 gene • Genetic counselling- for parents of child w/ pediatric glaucoma & adults w/ childhood onset glaucoma
  10. 10. Development of Angle structures At 5 months' gestation, a continuous layer of endothelium (e) creates a closed cavity of the anterior chamber (according to most studies), and the anterior surface of the iris (i) inserts in front of the primordial trabecular meshwork (tm).
  11. 11. In the 3rd trimester,endothelial layer progressively disappears from the pupillary membrane (pm) and iris and cavitates over the anterior chamber angle (aca), possibly becoming incorporated in the trabecular meshwork. At the same time, the peripheral uveal tissue begins to slide posteriorly in relation to the chamber angle structures
  12. 12. C: Development of the trabecular lamellae and intertrabecular spacebegins in the inner, posterior aspect of the primordial tissue and progresses toward the Schlemm canal (Sc) and Schwalbe line (Sl) D: The normal anterior chamber angle is not fully developed until 1 year of age.
  13. 13. PATHOPHYSIOLOGY 1. Mann: Retention of an abnormal mesodermal tissue due to imcomplete atrophy 2. Barken : incomplete resorption of mesodermal cells which forms a membrane across the TM (barken’s membrane) 3. Allen: incomplete cleavage of mesoderm to form AC structures 4. Worst: combined theory of atrophy and resorption
  14. 14. 5. Maumenee: 0 abnormal anterior insertion of cilliary musculature into TM 0 absence of schlemm’s canal in histologic specimen 6. Anderson : 0Premature or excessive formation of collagenous beams in TM preventing posterior sliding of CB and peripheral iris 7. Kupfer at all : 0Faulty migration or differentiation of neural crest cells
  15. 15. summary 0Primary congenital glaucoma is due to failure or abnormal development of the trabecular meshwork . 0Maldevelopment of trabeculum including the iridotrabecular junction (trabeculodysgenesis) is responsible for impaired aqueous outflow resulting in raised IOP. 0Trabeculodysgenesis is characterized by absence of the angle recess with iris having a flat or concave direct insertion into the surface. 0The iris may not completely separate from the cornea that the angle remains closed by persistent embryonic tissue.
  16. 16. Pathogenesis of Glaucomatous Ocular Damage Main Theories are: 1 Mechanical changes due to the rise of intraocular pressure; and 2 Vascular perfusion of the optic nerve head 3 Defective autoregulation
  17. 17. CLINICAL FEATURES 1. Photophobia,blepharospasm,lacrimatio n:are often occur together. o caused by irritation of corneal nerves, which occurs as a result of the elevated IOP. o Photophobia is usually the initial sign, but is not enough by itself to arouse suspicion in most cases. 2 others: cloudy cornea , enlarged cornea or eye, red eye , irritability , poor vision & pain
  18. 18. EXTERNAL EXAMINATION Corneal signs : Corneal haze is the first sign Corneal oedema – Epithelial and stromal edema Sec to raised IOP clears with normalization of the pressure Severe cases: acute hydrops
  19. 19. Corneal enlargement- It occurs along with enlargement of globe-buphthalmos especially when the onset is before the age of 3yrs. 0The healthy newborn's cornea has a horizontal diameter ranging from 9.5 to 10.5 mm, which enlarges about 0.5 to 1.0 mm in the first year of life . 0A corneal diameter larger than 12 mm in the first year of life is a highly suspect finding.
  20. 20. 0Tears and break in Descement’s membrane(Haab’s straie)-These occur because Descement’s membrane is less elastic than the corneal stroma. 0Breaks in Descement’s membrane 0Migration of endothelial cells overthere 0Lay down new basement membrane 0Ridges develop along the sepersted edges 0Horizontal straie
  21. 21. 3. Sclera becomes thin and appears blue due to underlying uveal tissue. 4. Anterior Chamber becomes deep. 5. Iris may show iridodonesis and atrophic patches due to stromal hypoplasia and loss of crypts 6. Lens becomes flat due to stretching of zonules and may even subluxate.
  22. 22. 7. Optic disc may show variable cupping and atrophy especially after third year. 8. IOP is raised which is neither marked nor acute 9. Axial myopia may occur because of increase in axial length which may give rise to anisometropic ambylopia.
  23. 23. Buphthalmos • Hydrophthalmia • enlargement of the eye that may occur with this condition , these terms should not be used as synonyms for PCG because enlargement of the globe is seen with other childhood glaucomas if they occur early enough in life.
  24. 24. Refractive Error 0The enlargement of the globe with elevated IOP in the first 3 years of life 0 myopic shift anisometropia amblyopia 0presence of Haab striae often produces significant astigmatism, which also contributes to amblyopia, especially in unilateral or asymmetric cases. 0Children between 3 and 10 years of age: refractive changes have been attributed to continued scleral stretching .
  25. 25. Tonometry 0Perkins applanation tonometer 0Tono-Pen (i.e., a handheld Mackay-Marg-type tonometer) 0Goldmann applanation tonometry: children as young as 3 or 4 years of age can often cooperate 0Icare tonometer 0The normal IOP in childhood :10 to 22 mm Hg 0Infants with PCG : 30 to 40 mm Hg with unanesthetized IOPs 0falsely elevated in a struggling patient and is often unpredictably altered by systemic sedatives and anesthetics
  26. 26. Fundoscopy 0 Done with anesthetized or sedated child,using a direct ophthalmoscope with a Koeppe gonioscopy lens on the cornea 0 Normally: pink , but slight pallor physiological cupping 0 In PCG: loss of neuronal tissue in vertical poles 0 Enlarged scleral canal in horizontal meridian 0 Cupping is rapid but reversible
  27. 27. Above is shown a typical nerve appearance with damage from glaucoma. Note that the center of the nerve has an excavated or "scooped out" appearance.
  28. 28. ULTRASONOGRAPHY 0 documenting progression of infantile glaucoma by recording changes in the axial length 0 axial length may decrease by as much as 0.8 mm after surgical reduction of the IOP 0 helpful when glaucoma drainage-device surgery is being contemplated 0 After such surgery, helpful in confirming the presence of fluid around the device's reservoir, especially in patients in whom the bleb cannot easily be visualized