Lost Fovea
𝘖𝘤𝘶𝘭𝘰𝘤𝘶𝘵𝘢𝘯𝘦𝘰𝘶𝘴/ 𝘖𝘤𝘶𝘭𝘢𝘳 𝘈𝘭𝘣𝘪𝘯𝘪𝘴𝘮
Albinism is a congenital disorder causing reduced pigmentation due to complete or partial absence of melanin pigment affecting the skin, hair and eye.
Absence or defect of tyrosinase which is involved in production of melanin.
𝘛𝘸𝘰 𝘵𝘺𝘱𝘦𝘴:
𝐎𝐜𝐮𝐥𝐨𝐜𝐮𝐭𝐚𝐧𝐞𝐨𝐮𝐬 𝐚𝐥𝐛𝐢𝐧𝐢𝐬𝐦
● Involves the eye, skin and hair
● Autosomal recessive
● Many types - OCA Type 2 is the most common type
𝐎𝐜𝐮𝐥𝐚𝐫 𝐚𝐥𝐛𝐢𝐧𝐢𝐬𝐦
● Limited to the eyes
● X linked recessive
● Two types (1 and 2)
𝘊𝘭𝘪𝘯𝘪𝘤𝘢𝘭 𝘧𝘦𝘢𝘵𝘶𝘳𝘦𝘴:
● Poor visual acuity
● Strabismus & Amblyopia
● Photophobia - Sensitivity to bright light and glare
● Refractive errors- Hypermetropia/Myopia, Astigmatism is very common
● Pendular nystagmus
● Iris transillumination defects
● Depigmented fundus
● 𝐅𝐨𝐯𝐞𝐚𝐥 𝐡𝐲𝐩𝐨𝐩𝐥𝐚𝐬𝐢𝐚 - absence of the foveal pit
1. RPE pigmentation is inappropriate for macular development
2. OCT will show absence of normal foveal pit
3. Foveal avascular zone is small or coexistent with vessels crossing the area 2 disc
diameter temporal to the optic disc margin
4. Contributes to poor visual acuity
● Abnormal decussation of the visual pathway
1. Crossing of upto 90% of the fibres at the chiasma to the contralateral side
2. Loss of stereopsis and strabismus
𝘊𝘰𝘮𝘮𝘰𝘯 𝘴𝘺𝘴𝘵𝘦𝘮𝘪𝘤 𝘢𝘴𝘴𝘰𝘤𝘪𝘢𝘵𝘪𝘰𝘯𝘴:
1. Hermansky Pudlak syndrome (platelet storage deficiency)
2. Chediak-Higashi syndrome (abnormal lysosomal trafficking- recurrent infections)
𝘛𝘳𝘦𝘢𝘵𝘮𝘦𝘯𝘵:
● Recognize refractive errors and treat to minimize amblyopia
● Low vision examination and visual rehabilitation
● Sunglasses to reduce photosensitivity
● Prisms can help reduce nystagmus
● Genetic counselling
● Surgery to align the eyes, when necessary
Image from Rajan Eye Care Hospital
#ophthalmology #ophthal #doctor #health #medical #vision #education #optometry #medicalstudent #optometrist #medicine #eye #ophtho #ophthalmologist #ophthalmo #med #medicaleducation #ophthalmologyresident #ophthalmologyresidency #retina #fovea #albinism #oculocutaneousalbinism #ocularalbinism #macula #melanin #fovealpit #fovealhyoplasia
