Vitreous

Learning Aim

• Anatomy of Vitreous• Vitreous degenerations, opacities,

and detachment• Vitreous haemorrhage

Vitreous Humor• Transparent gel • Makes up to 80% volume of the eye. • Provides support to the delicate inner

structures of the eye.• Provides clear optical medium. • Provides the pathway for the nutrients

utilized by the lens , ciliary body and the retina.

DiscMacula

Ora

Lens

Vitreous : Structure

• Water 99%• Delicate network of collagen fibrils

that attach to the internal limiting membrane of the retina.

• Hyaluronic acid , hyalocytes , mucopolysacchrides

Properties of vitreous

• It is a hydrophilic gel.• Undergoes turgescence and

deturgescence.• Gets readily liquefied as result of

age changes and trauma.

Vitreous : Attachments

• Posterior lens surface (Weigert ligament) in young.

• Vitreous base(ora serrata)• Optic disc• Paramacular area• Paravascular areas

Age changes in Vitreous• Undergoes significant physical and

biochemical changes with ageing.• Syneresis (liquefaction) is the most

striking change.• Syneresis occurs in most individuals

between 40-70 years of age.• Syneresis occurs earlier in myopic eyes.

Floaters and muscae

• Condensation of fibrils in liquid vitreous

are visible as floaters.

• When they float into optic axis against

white background in various shapes and

size they are called muscae volitantes.

Causes of floaters

• Syneresis• PVD• Vitreous hemorrhage• Intermediate uveitis• Retinal detachment.

Vitreous detachment

Types:

-Posterior

-Basal

-Anterior

Posterior vitreous detachment(PVD)

• A detachment posterior to the vitreous base.

• A senile phenomenon.• Symptoms :flashes ,floaters and ring like

opacity(Weiss ring).• Can be associated with retinal tear and

detachment.

Normal Vitreous Vitreous detachment

Posterior vitreous detachment ( PVD)

Opacities in the vitreous• Developmental opacities: Remnants of hyaloid vascular

syste• Degenerative changes: Asteroid hyalosis, synchisis

scintillans, amyloid degeneration.• Other causes of vitreous opacities : Senile and myopic

eyes, retrolental fibroplasia , Wagner disease, Ehlers-Danlos syndrome, Marfan syndrome , Inflammation, Hemorrhage due to retinal vasculitis , DM , SA hemorrhage , Neoplastic cells , trauma.

Floaters: Management

• Indirect ophthalmoscopy is mandatory.

• No RD/break/traction/ degeneration - reassure.

• Pathological findings- are noticed appropriate treatment.

Asteroid hyalosis

Inflammation of vitreous (endophthalmitis)

- Response to inflammation: liquefaction, opacification,and shrinkage - It is an excellent culture medium: endophthalmitis. - Inflammation results fibrous connective tissueand varying degrees of capillary proliferation.- Organization of membranes may lead to a cycliticmembrane along the anterior hyaloid surface. - Cyclitic membranes often lead to total retinaldetachment.

Vitreous hemorrhage

Vitreous hemorrhage

Etiology:- Proliferative diabetic retinopathy (PDR)- Retinal tears and PVD- Central retinal venous occlusion (CRVO)- Peripheral retinal neovascularisation due to Eales disease and sickle cell retinopathy- Ocular trauma

Vitreous hemorrhage

• Pre retinal

• Intravitreal

• Combined

Subhyaloid hemorrhage

Vitreous Hemorrhage : Symptoms

• Floaters

• Painless diminution of vision

Vitreous Hemorrhage : Diagnosis

• History

• Indirect Ophthalmoscopy under full

pupillary dilatation.

• USG B-scan

• IOP

Differential diagnosis: Vitreous hemorrhage

• Inflammatory exudate

• Endophthalmitis

• An intraocular tumor

Fundus view:vitreous hemorrhage

Vitreous Hemorrhage : Management

• Conservative management and follow up:Rest and head elevation

• Treat the cause• Surgical management by Pars plana

vitrectomy (PPV)

Pars Plana Vitrectomy(PPV)

Pars Plana Vitrectomy(PPV)Indications• Non-resolving vitreous hemorrhage• Retinal detachment with traction ,

GRT,PVR, and macular hole• Vitreous biopsy • During anterior segment surgery • Endophthalmitis • Retained intraocular foreign bodies

Principles of vitreous surgery• Removal of opacities and the traction

bands• Restoration of retinal anatomy• Endo photocoagulation /cryotherapy• Achieving chorioretinal apposition by

- External polmbage-Intraocular silicon oil/gas

Points to Remember

• Anatomy of Vitreous• Cause of floaters before the eyes• Vitreous haemorrhage: etiology

and symptoms