Posterior vitreous detachment

most common cause of acute onset of flashes and floaters

• 66% of patients over 70 year
• Caused by
  • age-related change in which the vitreous degenerates
  • shrinks and separates from the retina. 
  • During separation, the vitreous may tug
  • cause mechanical stimulation of the retina, resulting in flashes

Differential Diagnosis

Causes of Photopsia other than posterior vitreous detachment include the following:

• A retinal tear or retinal detachment
• Migraine with aura (classic)
• Migraine headache without aura
• Posterior uveitis (multiple evanescent white dot syndrome, acute idiopathic blind spot enlargement syndrome, acute posterior multifocal placoid pigment epitheliopathy, acute zonal occult outer retinopathy, multifocal choroiditis, and panuveitis, Birdshot retino-choroiditis) [54]
• Both early and the late stage of retinitis pigmentosa 

Causes of floaters other than posterior vitreous detachment include the following:

• Vitreous hemorrhage due to any cause including retinal tear or retinal detachment, proliferative diabetic retinopathy
• Vitreous exudates in posterior uveitis, endophthalmitis
• Vitreous pigments
• Vitreous amyloidosis
• Intravitreal injection of drugs

Clinically

Early Stages:

• Usually asymptomatic
• Often undetected clinically until separation from optic disc margins

Symptoms:

• Flashes of light (photopsia)
  • Quick, temporal quadrant, induced by head or eye movement, noticeable in dim environments
• Floaters (myodesopsia)
  • Small, mobile vitreous particles against a bright background
• patient usually has normal vision
• no visual field defects
  • Blurring of vision (67% of patients) due to vitreous hemorrhage from retinal breaks or ample floaters crowding the visual field
• no relative afferent pupillary defect

Treatment

1. Follow-up and Examination:
   • Acute symptomatic PVD without vitreous hemorrhage and peripheral retinal breaks:
     • Follow-up at 2-4 weeks for precise peripheral retinal examination with scleral indentation
   • Conservative management for patients with floaters:
     • Reassurance that adaptation to visual symptoms will develop over time or floaters may resolve
     • Floaters may persist beyond six months to one year in many cases
2. Vitreous Hemorrhage:
   • Typically mild, with a blob of hemorrhage just in front of the posterior pole
   • May include intraretinal hemorrhage near the optic disc
   • Circular circumferential attachment of the vitreous to the retina around the equator
   • Some preretinal bleed may settle inferiorly behind the posterior vitreous face
   • Associated breaks usually lie in the superior retina
3. Management for Obscured Fundal View due to Vitreous Hemorrhage:
   • Propped up position and bed rest
   • Bilateral eye patching as an option
   • Ultrasonography to rule out the presence of retinal breaks and other retinal conditions
4. Interventional Options for Persistent, Clinically Significant Floaters:
   • For highly symptomatic floaters impacting quality of life:
     • Various interventional options may be considered based on the specific clinical scenario and patient needs.

Complications

•  higher risk of retinal detachment if it is associated with vitreous haemorrhage
• about 70% of these patients have been found to have at least one retinal tear

Aspect	Vitreous Detachment (PVD)	Retinal Detachment (RD)
Definition	Separation of vitreous gel from the retina due to aging-related changes.	Separation of neurosensory retina from underlying retinal pigment epithelium (RPE) and choroid.
Cause	Natural process of vitreous liquefaction and shrinkage.	Usually results from a tear or hole in the retina.
Clinical Features	Floaters, flashes of light (photopsia), transient visual disturbances.	Sudden onset of floaters, flashes of light, shadow or curtain in vision.
Complications	Risk of retinal tears leading to detachment.	Permanent vision loss if untreated, proliferative vitreoretinopathy (PVR) in severe cases.
Management	Observation, monitoring for retinal tears, surgical intervention if indicated.	Urgent surgical repair (e.g., vitrectomy, scleral buckling) to reattach the retina.