Vitreous and Retinal Detachment Flashcards
Vitreous-Retinal attachments:
• Strongest attachment- vitreous base
- At ora serrata
• Looser attachment: posteriorly
- stronger over retinal blood vessels
- stronger at optic disc
Vitreous degeneration:
• Ageing lead to liquefaction of vitreous
• Vitreous synchysis: becoming more fluid
• Vitreous syneresis: shrinking of vitreous
• Floaters due to collagen fibres
• Healthy process
• Degeneration accelerated in myopic eyes
Posterior vitreous detachment: PVD
• Detachment of posterior hyaloid membrane from retina
• Anterior remains intact at ora serata
• Vitreous degeneration causes vitreous to collapse anteriorly
• causes separation at posterior - weak attachments
• Occurs over months, gradually
Posterior vitreous detachment: Risk factors
- Age: 40-50: 8% ; 60-67: 44% ; 80-90: 86%
- Myopia: 4-5x risk
- Female: 2-3x risk
- Cataract surgery: 60% of px after 1 year, 7months after
Posterior vitreous detachment: Symptoms
• Painless
• Usually unilateral (at first)
• Sudden onset symptoms
• Flashing lights (photopsia)
• Floaters
• Many are asymptomatic
Posterior vitreous detachment: Signs (minor)
• Dilated, indirect ophthalmoscopy
• Posterior vitreous floaters- pull joystick back
• Weiss Ring
- Not required for complete PVD (destroyed)
- Doesn’t guarantee complete PVD (can remain attached)
• Detached posterior vitreous
Posterior vitreous detachment: Signs
(Haemorrhages)
• Vitreous Haemorrhage
- Strong attachments to BVS, thin inner limiting membrane
- Tension on strong attachments
- Tension tears BV’s, leading to haemorrhages
• Symptoms: Sudden shower small, dark floaters; blurred/cloudy vision
• Emergency referral to opthalmologist
Posterior vitreous detachment: Management
• Benign - 90% require no treatment
• Examine carefully for retinal break/tear or detachment
• Advise Px to return as emergency if:
- Increase in floaters
- Flashing lights
- curtains/shadows developing over vision
• Risk of delayed retinal break/tear:
- review with dilated fundus in 6weeks
- up to 3.4% of post-PVD retinal breaks delayed by 6 weeks
- Confirm no increase in Sx, examine for break/tear
Rhegmatogenous Retinal Detachment: Describe
• Most common type
• Perforation of retina tissue by break (tear or hole)
- PVD: tension, vitreo-retinal traction
- Break enables liquid vitreous to flow under retina
- Fluid detaches retina from underneath
Rhegmatogenous Retinal Detachment: Risk factors
- PVD: Incomplete PVD
- Age: degeneration of vitreous
- Myopia: Accelerated vit degeneration, reduced retinal thickness
- Ocular Trauma:
- Boxing
- Cataract surgery
Rhegmatogenous Retinal Detachment: Symptoms
• Unilateral
• Painless
• Acute
• Photopsia
• Floaters
• Curtain/veil/shadow
Rhegmatogenous Retinal Detachment: Signs
- Visual acuity
- Normal, unless advanced to macula - Pupils
- Normal, unless large = RAPD - IOP
- Reduction (5mmHg), to other eye - Visual fields
- Peripheral defects, confrontation may reveal - Anterior vitreous
- Tobacco dust, shafers sign; RPE cells, EMERGENCY referral - Retinal tear/break/detachment
Rhegmatogenous Retinal Detachment:
Retinal tear, break, detachment;Signs
• 60% Superior-temporal, 15% inferior temporal
• 15% inferior nasal, 10% inferior-nasal
• U shaped (horseshoe) tear
• Retinal hole
• Can progress to macula detachment if advances enough
Rhegmatogenous retinal detachment: Management
Emergency referral:
• Vitreous haemorrhage
• Positive Shafer’s sign/tobacco dust
• Retinal break/tear/hole
• Retinal detachment
• If confident diagnosis is uncomplicated PVD, normally no referral
• If in doubt, emergency referral for suspected retinal break
Tractional Retinal Detachment: Describe how occurs
• Second most common retinal detachment
• Associated with retinal ischaemia
- Diabetic retinopathy
- Retinal vein occlusions
• Lack of oxygen supply triggers neovascularisation
- fragile, prone to leakage
- Has fibrovascular membrane for support
- Extends to vitreous, attaches, creates tension between vitreous + retina
- Vitreo-retinal traction
- Detaches retina
