Proliferative Vitreoretinopathy: A Review

Proliferative vitreoretinopathy (PVR) is the most common cause for failure of rhegmatogenous retinal detachment repair and is characterized by the growth and contraction of cellular membranes within the vitreous cavity and on both sides of the retinal surface as well as intraretinal fibrosis. Currently, PVR is thought to be an abnormal wound healing response that is primarily driven by inflammatory, retinal, and RPE cells. At this time, surgery is the only management option for PVR as there is no proven pharmacologic agent for the treatment or prevention of PVR. Laboratory research to better understand PVR pathophysiology and clinical trials of various agents to prevent PVR formation are ongoing.

Proliferative vitreoretinopathy: A new concept of disease pathogenesis and practical consequences

During the last four decades, proliferative vitreoretinopathy (PVR) has defied the efforts of many researchers to prevent its occurrence or development. Thus, PVR is still the major complication following retinal detachment (RD) surgery and a bottle-neck for advances in cell therapy that require intraocular surgery. In this review we tried to combine basic and clinical knowledge, as an example of translational research, providing new and practical information for clinicians. PVR was defined as the proliferation of cells after RD. This idea was used for classifying PVR and also for designing experimental models used for testing many drugs, none of which were successful in humans. We summarize current information regarding the pathogenic events that follow any RD because this information may be the key for understanding and treating the earliest stages of PVR. A major focus is made on the intraretinal changes derived mainly from retinal glial cell reactivity. These responses can lead to intraretinal PVR, an entity that has not been clearly recognized. Inflammation is one of the major components of PVR, and we describe new genetic biomarkers that have the potential to predict its development. New treatment approaches are analyzed, especially those directed towards neuroprotection, which can also be useful for preventing visual loss after any RD. We also summarize the results of different surgical techniques and clinical information that is oriented toward the identification of high risk patients. Finally, we provide some recommendations for future classification of PVR and for designing comparable protocols for testing new drugs or techniques.

Characteristics of rhegmatogenous retinal detachment and their relationship to visual outcome

AIMS

To examine pre-operative characteristics of rhegmatogenous retinal detachment (RRD) and their relationship to visual acuity (VA) following surgery.

METHODS

Review of prospectively completed electronic database. Baseline characteristics, retinal drawings and outcomes were analysed.

RESULTS

In all, 847 eyes from 847 patients with a mean age of 62.2 years, 60% males, and 56% right eyes were studied. Mean follow-up was 9.6 months. Preoperative VA correlated with final VA (r(2)=0.21, P<0.0001). Median postoperative VA was 6/9 (Logmar 0.18, quartiles=0.0-0.48) and was significantly related to anatomical success: 70.15% achieved 0.18 or better with fully attached retina and primary success, whereas only 8.33% achieved this when the retina was not fully attached at final follow-up (failure) (P<0.0001). Univariate analysis found multiple variables associated with achieving 0.18 postoperative vision, however, multivariate analysis revealed only primary anatomical success with surgery; absence of proliferative vitreo-retinopathy (PVR), better-presenting VA and fewer quadrants of detachment were associated with a better visual outcome (r(2)=0.26, P<0.0001). Patients with a clinically attached fovea achieved better vision than patients with a clinically detached fovea, independent of the visual loss duration. With foveal detachment however, postoperative VA was better in patients with 1-3 days of visual loss compared with 4-6 days (P=0.013).

CONCLUSIONS

Failure of primary surgery, PVR, extensive RRD and poor-presenting VA are risk factors for poorer visual outcome following surgery for RRD. Fovea off RRD at presentation achieved poorer postoperative VA than fovea attached and visual outcome was poorer when there was a longer duration of visual symptoms.