This is a practical presentation highlighting the pathological posterior hyaloid & the anomalous interface changes that are associated with it & which have to be addressed in vitreo-retinal surgery

1. ANOMALOUS PVD IN THE
PATHOGENESIS OF
VITREO-RETINAL DISEASES
A.L. Siam
CAIRO - EGYPT

2.  This is a practical presentation highlighting
the pathological posterior hyaloid & the
anomalous interface changes that are
associated with it & which have to be
addressed in vitreo-retinal surgery.
 The induction of PVD and adequate removal
of the posterior hyaloid is vital for the
achievement of both anatomical & functional
success.

3.  The realization of vitreo-retinal interface
pathologies and their bearing on the currently
performed complex vitreo-retinal procedures
is crucial for better handling of these
pathologies.
 The understanding of anomalous vitreous
modifications in various vitreo-retinal disease
settings is basic for performing safe
microsurgical maneuvers to induce PVD with
less difficulty & less complications.

4. Anomalous PVD
When & how happens ?
When the extent of vitreous liquefaction exceeds the degree
of vitreo-retinal interface weakening resulting in traction at the
vitreo-retinal interface
Both liquefaction and vitreo-retinal dehiscence need to
occur in tandem to constitute normal PVD

5.  The vitreous is 98% water; yet it maintains the gel consistency
due to the presence of hyaluronan which confers visco-elasticity;
& collagen, which provides the structural framework)
 Both liquefaction & vitreo-retinal dehiscence need to occur
concurrently so that an innocuous PVD can result
 When there is liquefaction without vitreo-ret. dehiscence,
anomalous PVD occurs with its tractional effects

6.  In periphery causes retinal tears & detachment
 At the optic disc & along the retinal vessels : plays an important role in
PDR (PDVR) & other cases of vitreous hge
 In the macula: the splitting of outer layer of vitreous cortex can result in vitreoschisis , with
the outer layer remaining attached to the retina which may play a role in macular pucker,
PDVR & macular holes
 Progressive PDR in spite of adequate laser photocoagulation
 Traction at the macula can lead to persistent macular edema in progressive PDR
Untoward Effects of Anomalous PVD

7. The advent of many breakthroughs in vitreo-
retinal surgery allowed us to deal with such
complicated diseases such as proliferative
diabetic vitreo-retinopathy (PDVR), macular
holes & proliferative vitreo-retinopathy (PVR)

8. 1. Bright endo-illumination with xenon light
2. Wide-angle viewing system – I currently use the ROLS system of VOLK
3. Modern operating microscopes with large depth of focus
4. The introduction of heavy liquids
5. The use of Triamcinolone Acetonide for better visualization of the vitreous
framework & posterior hyaloid . Triamcinolone Acetonide also allowed
complete removal of the vitreous & posterior hyaloid leaving insignificant
remnants
6. Fine instruments to do what could not be done before, particularly fine ILM
forceps
Breakthroughs in Vitreo-retinal
Surgery in Recent Years:

9.  Thickened & taught posterior hyaloid
 Vitreo-retinal adhesions (epicentres)
 Vitreo-vascular adhesions
 Vitreo-macular traction
 Bursa premacularis
 “Preretinal” blood pockets
 Vitreoschisis
 Residual posterior cortical islands
In this Presentation the Following Changes
in the Posterior Hyaloid & its Relation to the
ILM will be shown: