-True about keratoconus:
A. Munson sign seen
B. Protrusion of anterior cornea
C. Protrusion of posterior cornea
D. Fleisher’s sign positive
E. None.
A. Munson sign seen
B. Protrusion of anterior cornea
C. Protrusion of posterior cornea
D. Fleisher’s sign positive
E. None.
Ans. (A) Munson’s
sign seen ; (B) Protrusion of anterior cornea ; (D) Fleisher’s sign positive
Keratoconus in a noninflammatory B/L (85%) ectatic condition of cornea in its axial part. It usually starts at puberty and progresses slowly. It involves anterior cornea.
• Important feature of dnterior Keratoconus
— Irregular astigmatism
— Window reflex is distorted.
— Placido disc examination reveals irregularity, of the circles.
— Keratometry depicts extreme malalignment of mires.
— Photokeratoscopy reveals distortion of circles.
— Slit lamp examination shows thinning and ectasia of central cornea, opacity at the apex and Fleisher’s ring at the base of cone.
— On retinoscopy, a yawning reflex and irregular astigmatism is obtained.
— On distant direct ophthalmoscopy, an annular dark shadow is seen which separates the central and peripheral areas of cornea al1d occurs due to total internal reflection of light.
— Munson’s sign i.e. localized bulging of lower lid when patient looks down is positive in late
stages.
• Keratoconus may be, associated with
Ectopia lentis, Congenital cataract, Aniridia, R. Pigmentosa, Marfan’s syndrome, Atopy,
Down’s syndrome, Ehler-Danlos syndrome.
• Rx is by contact lenses imporve the vision in early cases and, in later stages penetrating keratoplasty may be required.
• Posterior keratoconus is a non-progressive congenital unilateral entity, usually occur in female.
Keratoconus in a noninflammatory B/L (85%) ectatic condition of cornea in its axial part. It usually starts at puberty and progresses slowly. It involves anterior cornea.
• Important feature of dnterior Keratoconus
— Irregular astigmatism
— Window reflex is distorted.
— Placido disc examination reveals irregularity, of the circles.
— Keratometry depicts extreme malalignment of mires.
— Photokeratoscopy reveals distortion of circles.
— Slit lamp examination shows thinning and ectasia of central cornea, opacity at the apex and Fleisher’s ring at the base of cone.
— On retinoscopy, a yawning reflex and irregular astigmatism is obtained.
— On distant direct ophthalmoscopy, an annular dark shadow is seen which separates the central and peripheral areas of cornea al1d occurs due to total internal reflection of light.
— Munson’s sign i.e. localized bulging of lower lid when patient looks down is positive in late
stages.
• Keratoconus may be, associated with
Ectopia lentis, Congenital cataract, Aniridia, R. Pigmentosa, Marfan’s syndrome, Atopy,
Down’s syndrome, Ehler-Danlos syndrome.
• Rx is by contact lenses imporve the vision in early cases and, in later stages penetrating keratoplasty may be required.
• Posterior keratoconus is a non-progressive congenital unilateral entity, usually occur in female.
No definite form, though may be
generalised or localised. In localised variety a crater like defect on
posterior surface of cornea with concavity towards ant. chamber. There may have
stromal opacification,thin storma, absent desmets membrane. No known association with anterior
kertoconus.
