1 Developmental Abnormalities of the Cornea Basic distinction used by the BCSC Peds book Abnormalities of Abnormalities of Corneal Size or Shape Corneal Transparency 2 Developmental Abnormalities of the Cornea Basic distinction used by the BCSC Peds book Abnormalities of Abnormalities of Corneal Size or Shape Corneal Transparency 3 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal Size or Shape Corneal Transparency ? ? ? 4 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal Size or Shape Corneal Transparency Cornea plana Microcornea Megalocornea 5 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal Size or Shape Corneal Transparency Cornea plana Microcornea Megalocornea What is the definition of megalocornea, ie, how ‘megalo’ does it have to be? Corneal diameter > 12 mm at birth, or > 13 mm at age 2 years or older Megalocornea? At age >2 years At birth 7 8 9 10 11 12 13 14 15 Corneal diameter (mm) 6 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal Size or Shape Corneal Transparency Cornea plana Microcornea Megalocornea What is the definition of megalocornea, ie, how ‘megalo’ does it have to be? Corneal diameter > 12 mm at birth, or > 13 mm at age 2 years or older Megalocornea At age >2 years At birth 7 8 9 10 11 12 13 14 15 Corneal diameter (mm) 7 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal Size or Shape Corneal Transparency Cornea plana Microcornea Megalocornea ?? 8 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal Size or Shape Corneal Transparency Cornea plana Microcornea Megalocornea Primary Secondary 9 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal SizeIs primaryor Shape megalocornea a congenital,Corneal or acquired Transparency condition? Congenital—always, and by definition Does it usually present unilaterally, or bilaterally? Bilaterally—always,Cornea plana and by definition Is it an inherited condition? If so, in what manner is it transmitted? MicrocorneaYes; it is X-linked recessive (so is more common in males ) Megalocornea With what other ocular abnormalities is it associated? There are many; they include: --Lens abnormalities: Cataract , ectopia lentis Primary Secondary --Iris abnormalities: Miosis , translucency It can be associated with systemic conditions. Which ones? There are many; they include: --Down syndrome --Marfan syndrome --Alport syndrome 10 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal SizeIs primaryor Shape megalocornea a congenital,Corneal or acquired Transparency condition? Congenital—always, and by definition Does it usually present unilaterally, or bilaterally? Bilaterally—always,Cornea plana and by definition Is it an inherited condition? If so, in what manner is it transmitted? MicrocorneaYes; it is X-linked recessive (so is more common in males ) Megalocornea With what other ocular abnormalities is it associated? There are many; they include: --Lens abnormalities: Cataract , ectopia lentis Primary Secondary --Iris abnormalities: Miosis , translucency It can be associated with systemic conditions. Which ones? There are many; they include: --Down syndrome --Marfan syndrome --Alport syndrome 11 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal SizeIs primaryor Shape megalocornea a congenital,Corneal or acquired Transparency condition? Congenital—always, and by definition Does it usually present unilaterally, or bilaterally? Bilaterally—always,Cornea plana and by definition Is it an inherited condition? If so, in what manner is it transmitted? MicrocorneaYes; it is X-linked recessive (so is more common in males ) Megalocornea With what other ocular abnormalities is it associated? There are many; they include: --Lens abnormalities: Cataract , ectopia lentis Primary Secondary --Iris abnormalities: Miosis , translucency It can be associated with systemic conditions. Which ones? There are many; they include: --Down syndrome --Marfan syndrome --Alport syndrome 12 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal SizeIs primaryor Shape megalocornea a congenital,Corneal or acquired Transparency condition? Congenital—always, and by definition Does it usually present unilaterally, or bilaterally? Bilaterally—always,Cornea plana and by definition Is it an inherited condition? If so, in what manner is it transmitted? MicrocorneaYes; it is X-linked recessive (so is more common in males ) Megalocornea With what other ocular abnormalities is it associated? There are many; they include: --Lens abnormalities: Cataract , ectopia lentis Primary Secondary --Iris abnormalities: Miosis , translucency It can be associated with systemic conditions. Which ones? There are many; they include: --Down syndrome --Marfan syndrome --Alport syndrome 13 Developmental Abnormalities of the Cornea Primary megalocornea 14 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal SizeIs primaryor Shape megalocornea a congenital,Corneal or acquired Transparency condition? Congenital—always, and by definition Does it usually present unilaterally, or bilaterally? Bilaterally—always,Cornea plana and by definition Is it an inherited condition? If so, in what manner is it transmitted? MicrocorneaYes; it is X-linked recessive (so is more common in males ) Megalocornea With what other ocular abnormalities is it associated? There are many; they include: --Lens abnormalities: Cataract , ectopia lentis Primary Secondary --Iris abnormalities: Miosis , translucency It can be associated with systemic conditions. Which ones? There are many; they include: --Down syndrome --Marfan syndrome --Alport syndrome 15 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal SizeIs primaryor Shape megalocornea a congenital,Corneal or acquired Transparency condition? Congenital—always, and by definition Does it usually present unilaterally, or bilaterally? Bilaterally—always,Cornea plana and by definition Is it an inherited condition? If so, in what manner is it transmitted? Microcornea Yes; it is X-linked recessive (so is more common in malesM v F ) Megalocornea With what other ocular abnormalities is it associated? There are many; they include: --Lens abnormalities: Cataract , ectopia lentis Primary Secondary --Iris abnormalities: Miosis , translucency It can be associated with systemic conditions. Which ones? There are many; they include: --Down syndrome --Marfan syndrome --Alport syndrome 16 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal SizeIs primaryor Shape megalocornea a congenital,Corneal or acquired Transparency condition? Congenital—always, and by definition Does it usually present unilaterally, or bilaterally? Bilaterally—always,Cornea plana and by definition Is it an inherited condition? If so, in what manner is it transmitted? MicrocorneaYes; it is X-linked recessive (so is more common in males ) Megalocornea With what other ocular abnormalities is it associated? There are many; they include: --Lens abnormalities: Cataract , ectopia lentis Primary Secondary --Iris abnormalities: Miosis , translucency It can be associated with systemic conditions. Which ones? There are many; they include: --Down syndrome --Marfan syndrome --Alport syndrome 17 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal SizeIs primaryor Shape megalocornea a congenital,Corneal or acquired Transparency condition? Congenital—always, and by definition Does it usually present unilaterally, or bilaterally? Bilaterally—always,Cornea plana and by definition Is it an inherited condition? If so, in what manner is it transmitted? MicrocorneaYes; it is X-linked recessive (so is more common in males ) Megalocornea With what other ocular abnormalities is it associated? There are many; they include: --Lens abnormalities: Cataract , ectopia lentis Primary Secondary --Iris abnormalities: Miosis , translucency It can be associated with systemic conditions. Which ones? There are many; they include: --Down syndrome --Marfan syndrome --Alport syndrome 18 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal SizeIs primaryor Shape megalocornea a congenital,Corneal or acquired Transparency condition? Congenital—always, and by definition Does it usually present unilaterally, or bilaterally? Bilaterally—always,Cornea plana and by definition Is it an inherited condition? If so, in what manner is it transmitted? MicrocorneaYes; it is X-linked recessive (so is more common in males ) Megalocornea With what other ocular abnormalities is it associated? There are many; they include: --Lens abnormalities: Cataractword , ectopiatwo words lentis Primary Secondary --Iris abnormalities: Miosis , translucency It can be associated with systemic conditions. Which ones? There are many; they include: --Down syndrome --Marfan syndrome --Alport syndrome 19 Developmental Abnormalities of the Cornea Abnormalities of Abnormalities of Corneal SizeIs primaryor Shape megalocornea a congenital,Corneal or acquired Transparency condition? Congenital—always, and by definition Does it usually present unilaterally, or bilaterally? Bilaterally—always,Cornea plana and by definition Is it an inherited condition? If so, in what manner is it transmitted? MicrocorneaYes; it is X-linked recessive (so is more common in males ) Megalocornea