Introduction
The breakdown of the inner blood retinal barrier and abnormal pericytes lead to plasma leakage into the vessel walls. These walls buldge to give a telangiectatic appearance.
- Tactic vessels typically found in the peripheral retina near the equator and ora serrata
- The bulging can lead to exudation of lipids, leading to hard exudates and cystic oedema, which can affect the macular and central vision
- ~1/3 of cases also affect area between equator and vascular arcades
Typically diagnosed in the 1st/2nd decade
- Presents with xanthocoria (yellow pupil), leukocoria (white pupil), nystagmus and/or strabismus and ptosis
- Unilateral 95% of the time, and more common in younger males (75%)
- Rarely presents in adults
Dead Giveaways
The biggest giveaway is in the fundus appearance
Fundus:
Area of exudation surrounding anomalous vessels This is a very classical apperance.
Overtime, this area can migrate towards the macular, impacting central vision
Angiography:
Note the telangiectatic vessels In last stage disease, OCT-A can be very helpful in identifying leakage, telangiectatic vessels. Dark areas, similar to IRMA, indicate areas of non-perfusion.
OCT:
Especially with foveal exudation, retinal detachment, cystic spaces can develop, but also the increase in exudative mass
This interferes with OCT signals, blocking it out
Note massive cystic space, and extensive dense exudation blocking signal
diagnostic features
Sequelae
Can lead to exudative RD
The damage to the vascular endothelium can lead to ischaemia in the area of the tactic vessels
VA can vary from 6/6 to no light perception
Extent of vision loss depends on whether exudative detachment/fibrosis occur near the macular, and if there's oedema
Epiretinal membrane and optic atrophy can also be associated, leading to further loss
Anterior Segment Involvement:
Corneal oedema
Megalocornea
Shallow ant. chamber angle
Iris NV
Cataracts
Stages:
Characterised by retinal telangectasia
Foveal exudation
Exudative retinal detachment
Fibrosis can occur, along with sclerotic vessels Typically, this pigmented fibrotic tissue indicates chronicity in Coat's disease
NV glaucoma onset (painful blind eye)
End-stage
End-stage disease