VITREO RETINOPATIA PROLIFERATIVA

Question 1

It is the major cause of treatment failure in retinal detachment surgery even after primarily successful reattachment of the retina

Answer 1

Proliferative vitreoretinopathy (PVR)

Question 2

The incidence of primary PVR in rhegmatogenous retinal detachment (RRD)

Answer 2

5% to 10%

Question 3

Important factors in the pathogenesis of severe PVR

Answer 3

The size of breaks
The extent of detachment
The presence of preoperative inflammation or low-grade PVR Iatrogenic complications

Question 4

PVR develops in a sequence of four overlapping phases:

Answer 4

Inflammation
Cellular proliferation
ECM remodeling
Fibrosis.

Question 5

The key cellular event in the onset of PVR

Answer 5

Epithelial–mesenchymal transition (EMT) of the cells dis- persed in the vitreous as a sequela of the retinal injury

Question 6

Major cell type involved in the development of PVR.

Answer 6

RPE cells

Question 7

Epithelial–mesenchymal transition (EMT)

Answer 7

Process in which RPE cells have been shown to dedifferentiate and exhibit a pseudometaplastic trans- formation into fibroblast-like, spindle-shaped cells, which be- come actively dividing and migratory.

During EMT, RPE cells lose their epi- thelial phenotypes and assume mesenchymal, fibroblast-like properties and phenotype.