Diseases Of The Vitreous

Diseases Of The Vitreous

Vitreous liquefaction (synchysis)

• Most common degenerative change
• Causes: Senile, myopic degeneration, post- inflammatory, post-traumatic.

Posterior vitreous detachment (PVD)

• PVD with vitreous liquefaction (synchysis) and collapse (syneresis) is of common occurrence in majority of the normal subjects above the age of 65 years.

• Flashes of light and floaters may be associated

• A ring like opacity (Weiss reflex) representing a ring of vitreous attachment at the optic disc margin is pathognomic.

• May be complicated by retinal break, retinal and/ or vitreous haemorrhage and cystoid maculopathy.

Diseases Of The VitreousVitreous Haemorrhage

• Causes are diabetic retinopathy, Eales’ disease, trauma, retinal breaks and/or posterior vitreous detachment, anaemia, leukaemia and sickle cell retinopathy, central retinal vein occlusion, and bleeding disorders – haemophilia, purpura.

Complications include retinitis proliferans, vitreous liquefaction and degeneration, and ghost cell glaucoma in aphakes.

• Vitrectomy is indicated if vitreous haemorrhage does not absorb in three months.

Persistent hyperplastic primary vitreous

• Usually unilateral

• Typically presents as a white reflex in pupil

• Associations are: Long ciliary processes, microphthalmos, cataract, glaucoma, and vitreous detachment

Vitrectomy: indications

• Along with lensectomy
• Endophthalmitis
• Vitreous haemorrhage not getting absorbed in 3 months
• Proliferative retinopathies
• Dropped nucleus and intraocular lens
• Intraocular foreign bodies
• Vitreous amyloidosis.

Miscellaneous points

• Synchysis (liquefaction) and syneresis (collapse) are the two most common degenerative changes in the vitreous gel.

• The optimum time for vitrectomy in a patient of bacterial endophthalmitis not responding to conservative treatment is 24 hours after the intravitreal injection of antibiotics.

• Vitreous gel never regenerates.

• The strongest attachment of the vitreous is to the ora serrata (vitreous base attachment).

• Most common cause of vitreous haemorrhage is trauma.

• Most common cause of spontaneous vitreous haemorrhage is proliferative diabetic retinopathy.