retinal/vitreous detachment Flashcards
what is posterior vitreous detachment?
separation of the vitreous membrane from the retina. This occurs due to natural changes to the vitreous fluid of the eye with ageing
rarely the separation of the vitreous membrane can lead to tears and detachment of the retina
epidemiology of PVD?
Occur in over 75% of people over the age of 65
More common in females
RF of PVD?
As people age, the vitreous fluid in the eye becomes less viscous, and thus, does not hold its shape as well. Therefore, it pulls the vitreous membrane away from the retina towards the centre of the eye.
Highly myopic (near-sighted) patients are also at increased risk of developing posterior vitreous detachment earlier in life. This is because the myopic eye has a longer axial length than an emmetropic eye.
symptoms of PVD?
The sudden appearance of floaters (occasionally a ring of floaters temporal to central vision)
Flashes of light in vision
Blurred vision
Cobweb across vision
The appearance of a dark curtain descending down vision (means that there is also retinal detachment)
signs of PVD?
Weiss ring on ophthalmoscopy (the detachment of the vitreous membrane around the optic nerve to form a ring-shaped floater).
ix of PVD?
All patients with suspected vitreous detachment should be examined by an ophthalmologist within 24hours to rule out retinal tears or detachment.
mx of PVD?
Posterior vitreous detachment alone does not cause any permanent loss of vision. Symptoms gradually improve over a period of around 6 months and therefore no treatment is necessary.
If there is an associated retinal tear or detachment the patient will require surgery to fix this.
what is retinal detachment?
Retinal detachment occurs when the neurosensory tissue that lines the back of the eye comes away from its underlying pigment epithelium. It is a reversible cause of visual loss, provided it is recognised and treated before the macula is affected. If left untreated and symptomatic, retinal detachment will inevitably lead to permanent visual loss.
RF of RD?
diabetes mellitus
myopia
age
previous surgery for cataracts (accelerates posterior vitreous detachment)
eye trauma e.g. boxing
features of RD?
new onset floaters or flashes, as these indicate pigment cells entering the vitreous space or traction on the retina respectively
sudden onset, painless and progressive visual field loss, described as a curtain or shadow progressing to the centre of the visual field from the periphery should also raise suspicion of detachment
if the macula is involved, central visual acuity and visual outcomes become much worse
peripheral visual fields may be reduced, and central acuity may be reduced to hand movements if the macula is detached
the swinging light test may highlight a relative afferent pupillary defect if the optic nerve is involved
RD on fundoscopy?
the red reflex is lost and retinal folds may appear as pale, opaque or wrinkled forms
if the break is small, however, it may appear normal.
mx of RD?
any patients with new onset flashes and floaters should be referred urgently (<24 hours) to an ophthalmologist for assessment with a slit lamp and indirect ophthalmoscopy for pigment cells and vitreous haemorrhage
what is vitreous haemorrhage?
Vitreous haemorrhage is bleeding into the vitreous humour. It is one of the most common causes of sudden painless loss of vision. It causes disruption to vision to a variable degree, ranging from floaters to complete visual loss. The source of bleeding can be from disruption of any vessel in the retina as well as the extension through the retina from other areas.
epidemiology of VH?
Spontaneous vitreous haemorrhage has an incidence of around 7 cases per 100000 patient-years1
Incidence by age and sex varies according to the incidence of the underlying causes
common causes of VH?
proliferative diabetic retinopathy (over 50%)
posterior vitreous detachment
ocular trauma: the most common cause in children and young adults
