Posterior vitreous detachment (PVD) refers to the separation of the vitreous gel from the retina. It occurs naturally with age as the vitreous liquefies. Symptoms include floaters, flashes of light, and blurred vision. Signs include seeing the detached vitreous gel and hemorrhage in the eye. Ultrasound and OCT can confirm PVD. Patients with risk factors or new concerning symptoms should be examined and followed up, while others may not need follow up unless symptoms return.

1. POSTERIOR VITREOUS DETACHMENT
S. PERSIS BENETTA, M.OPTOM 2ND YEAR

2. INTRODUCTION
 Posterior vitreous detachment (PVD) refers to separation of the cortical vitreous, along with the
delineating posterior hyaloid membrane (PHM), from the neurosensory retina posterior to the vitreous
base.
 PVD occurs due to vitreous gel liquefaction with age (synchysis) to form fluid-filled cavities and
subsequently condensation (syneresis), with access to the preretinal space allowed by a dehiscence in
the cortical gel and/or PHM
 The prevalence of PVD increases with age, and in individuals in their 80s is likely to be at least 60%.
 It is typically spontaneous, but can be induced by events such as cataract surgery, trauma, uveitis and
panretinal photocoagulation.

3. • Perifoveal hyaloid detachment is followed by foveal separation, then detachment from the posterior
retina as far as the equator, attachment initially being retained at the optic disc.
(A) Synchysis and syneresis (B) complete posterior vitreous detachment

4. CLINICAL FEATURES - SYMPTOMS
 Flashing lights (photopsia) in PVD is often described as a lightning-like arc induced by eye or head
movement, and is more noticeable in dim illumination.
 Floaters (myodesopsia) are mobile vitreous opacities most evident against a bright pale background.
 They are often described as spots, cobwebs or flies (muscae volitantes), and are commonly present in
individuals without a PVD, especially myopes.
 A Weiss ring is the detached former attachment to the margin of the optic disc, and may be seen by the
patient as a circle or other large solitary lesion; its presence does not necessarily indicate total PVD, nor
does its absence confirm the absence of PVD since it may be destroyed during the process of separation.

5.  (C) biomicroscopy showing vitreous
condensation in a pseudophakic eye
 (D) vitreous degenerative condensation on wide-
field imaging
 (E) Weiss ring on slit lamp biomicroscopy, with
the optic disc in the background
 (F) Weiss ring on wide-field imaging

6.  Floaters can also be due to vitreous blood.
 Blurred vision. A diffuse haze may be due to dispersed haemorrhage within the vitreous gel, with a
variable accompanying reduction in VA
 Bleeding can arise from a torn retinal blood vessel or from the site of a retinal break.
 Blurring can also be caused by a visually significant PHM or floaters in the visual axis, which may also
cause impairment of acuity.

7. SIGNS
 The detached PHM can often be seen clinically on slit lamp examination as a crumpled translucent membrane
in the mid-vitreous cavity behind which the cavity is optically clear.
 Haemorrhage may be indicated by the presence of red blood cells in the anterior vitreous or as (usually small)
focal intragel collections, or preretinally, when it sometimes forms a crescent shape bordering the limit of PHM
detachment.
 Pigment granules in the anterior vitreous on slit lamp examination (the Shafer sign or ‘tobacco dust’) are
larger, darker and less reflective than red blood cells. Their presence raises the possibility of a retinal break
 Vitreous cells, if numerous, may signify the presence of a break.
 Retinal breaks.

8.  (A) Biomicroscopy showing detached and
collapsed gel.

10. INVESTIGATION
 B-scan ultrasound can demonstrate the extent of PVD.
 OCT can show posterior pole separation.

11.  (B) ultrasound B-scan
 (C) OCT showing macular PVD

12. MANAGEMENT
 Patients should be examined with acute symptoms of PVD, usually in the presence of risk factors such as,
Myopia, RD, high risk syndromes like, stickler’s syndrome and symptoms like visual field defects, reduced
vision or prominent floaters.
 If there is only a single small floater and no photopsia, evidence suggests the risk of retinal break in the
symptomatic eye.

13. EXAMINATION
 The anterior vitreous should be assessed for the presence of blood and pigment.
 Examination of the ors seratta and 360° should be performed
 Binocular indirect ophthalmoscopy or contact lens scleral indentation.
 An asymptomatic fellow eye should always be examined.

14. SUBSEQUENT MANAGEMENT
 If there are no suspicious findings (e.g. vitreous blood) on examination and no pre-existing risk factors as
discussed above then routine review may not be necessary.
 The presence of features associated with higher risk should lead to review after an interval of 1–6 weeks
depending on individual characteristics.
 Some authorities recommend further review in 6–12 months.
 Patients who present with multiple prominent floaters or hazy vision should be reviewed carefully as this
has been found to be associated with a higher risk of retinal break.

15.  Discharged patients should be given clear instructions emphasizing the need to re-attend urgently in the
event of significant new symptoms.
 Optimally, written information about the advice should be provided.
 If an area of the fundus cannot be viewed clearly due to obscuration by blood then weekly review is
prudent.
 Presentation with diffuse fundus-obscuring vitreous haemorrhage (in the absence of a condition
predisposing to non-PVD vitreous haemorrhage) is associated with a very high risk of retinal break (90%)
and retinal detachment (40%).

16.  B-scan ultrasonography performed regularly until resolution in order to exclude an underlying
detachment or identifiable break.
 A very low threshold for vitrectomy should be adopted, particularly in the presence of other risk factors,
notably prior RD in the fellow eye.
 The management of retinal breaks should be carried out in the case of Retinal
breaks