Retinal Detachment

Question 1

Pathogenesis of posterior vitreous detachment

Answer 1

• Alterations of the vitreous gel micromolecular structure leads to syneresis or liquefaction of the vitreous gel
• Some eyes with syneresis develop a hole at the posterior hyaloid membrane and fluid from vitreous cavity passes through this hole into the retrohyaloid space
• This process forcibly detaches the posterior vitreous surface from the inner limiting membrane of the neurosensory retina.
• This process is called acute Posterior Vitreous Detachment (PVD)

Question 2

Pathogenesis of PVD leading to Rhegmatogenous RD

Answer 2

No complications occur in most eyes as vitreoretinal attachments are weak and the vitreous cortex detaches completely without causing retinal tears. Re-examined in 1-6 weeks

Retinal tears may develop as a result of transmission of traction at sites of abnormally strong vitreoretinal adhesions as previously described. Through the retinal tear, subretinal accumulation of fluid eventually results in rhegmatogenous retinal detachment

Question 3

Rhegmatogenous RD risk factors

Answer 3

Myopia, Trauma, Peripheral retinal degenerations: Lattice degeneration, snail track degeneration, degenerative retinoschisis, diffused chorioretinal atrophy, white with pressure/ white without pressure

Question 4

Rhegmatogneous RD Signs and Symptoms

Answer 4

Symp: Photopsia, Vitreous floaters, ‘black curtain’ defects
Signs: RAPD, IOP lower by 5mmHg than normal. Weiss ring and tobacco dust in anterior vitreous, RD convex config. slightly opaque, corrugated appearance
SRF extends to ora serrata

Question 5

Rhegmatogenous RD Management

Answer 5

Refer to ophthalmologist urgently
• Prophylactic laser photcoagulation for retinal tears/holes at risk of RD
• Pneumatic retinopexy, scleral buckling, vitrectomy

Question 6

Pathogenesis of Diabetic and Traumatic Tractional RD

Answer 6

Diabetic: caused by progressive contraction of fibrovascular membrane
Traumatic: vitreous incarceration stimulus to fibroblastic proliferation. Contraction of membrane eventually lead to RD

Question 7

Tractional RD Signs and Symptoms

Answer 7

Symp: Photopsia and floaters absent, visual field usually progress slowly
Signs: RD concave config. reduced retinal mobility, shallow SRF that does not extend to ora serrata

Question 8

Pathogenesis of Exudative RD

Answer 8

• Exudative RD is characterised by accumulation of SRF in the absence of breaks or traction
• May occur in multiple diseases affecting NSR, RPE & Choroid. Fluid leaks and accumulate under retina e.g. Wet AMD
• RD does not occur if RPE able to pump fluid into choroidal circulation
• If RPE pump is overwhelmed, or pump activity decreases accumullation of fluid cause RD

Question 9

Exudative RD Signs and Symptoms

Answer 9

Symp: Photopsia absent
Sign: RD convex config. smooth surface, deep &and mobile SRF

Question 10

Exudative RD Management

Answer 10

Refer to ophthamologist URGENTLY
• Prophylactic lasre photocoagulation/ cryotherapy retinal tears/holes at risk
• Pneumatic retinopexy, Scleral buckling, Vitrectomy