It is the separation of the sensory retina from the retinal pigment epithelium due to subretinal fluid.
There are two main types: Rhegmatogenous (ragged) and non-regmatogenous.
The rhegmatogenous form is the most common form of detachment in adults.
Trauma is the most common cause of retinal detachments in children.
Rhegmatogenous (ruptured) detachment
It occurs when the liquefied vitreous passes through a retinal tear into the subretinal space.
The vitreous forms the largest volume of the eye and supports the intraocular structures. The vitreous is a clear gel-like substance containing a hydrophilic mucopolysaccharide, hyaluronic acid, and a collagen network.
It can be bilateral.
Predisposing peripheral lesions:
1. Lattice degeneration:
Lattice degeneration is one of the peripheral retinal degenerations.
It is found in 8% of the population and 40% in eyes with detachment.
Marfan syndrome, Stickler syndrome, Ehlers-Danlos syndrome are common in moderate and high myopia.
2. Snailtrack degeneration
3. Degenerative retinoschisis:
70% of the patients are hyperopia.
Detachment is very rare.
4. Whitening without suppression:
Grayish-white retinal areas in the periphery of the retina, indicative of abnormal vitreoretinal tension
The Importance of Myopia
Myopia is present in 40% of cases with detachment.
The larger the refractive error, the greater the risk of detachment.
Those that increase the risk of myopic eye detachment:
- Lattice degeneration, Snailtrack degeneration
Non-Regmatogenous detachments
There is no retinal tear.
tractional retinal detachment
It occurs when the vitreoretinal membranes pull on the sensory retina.
Main reasons:
1. Proliferative retinopathy diabetic
2. Retinopathy of Prematurity
3. Proliferative sickle cell retinopathy
4. Penetrating posterior segment trauma
Exudative (serous) retinal detachment
It is formed by the passage of choroid-derived subretinal fluid over the damaged retinal pigment epithelium into the subretinal space.
Main reasons
1- Choroidal tumors: Melanoma etc.
2- Intraocular inflammations
3- Iatrogenic causes: Various surgeries
4- Subretinal neovascularization
5- Systemic causes: HT, pregnancy toxemia
6- Uveal effusion syndrome
Clinic
Clinical features of rhegmatogenous detachment:
Photopsia (flash of lights) and floaters (flying) at 60%
tobacco dust sign formed by pigment cells in the anterior vitreous
Marcus-Gunn pupil.
Visual field defect: As the subretinal fluid is absorbed in the morning, it increases later in the day.
Clinical features of tractional detachment:
Photopsia and floaters are usually absent.
Visual field defect progresses slowly.
Clinical features of exudative detachment
Photopsia is not expected; but floaters are visible.
Visual field defect is sudden and rapid.
