Ocriplasmin found to be a useful alternative
The vitreous of the eye is a clear, gellike structure with complex pathogenic mechanisms. Recent research is proving that abnormalities in vitreoretinal adhesion play an integral role in a variety of retinal diseases. Liquefaction and detachment of the vitreous from the retina is relatively common and does not cause problems. However, incomplete separation of the vitreous from the retina, vitreomacular adhesion (VMA), can cause tractional forces that distort vision and lead to other pathologies.
VMA is implicated in the pathophysiology of numerous visual disorders including macular holes, agerelated macular degeneration (AMD), retinal vein occlusions and diabetic macular oedema (DME). A study of diseases of the vitreomacular interface found that VMA existed in 16% of cases of macular hole and 52% of cases of epiretinal membrane. In exudative AMD, incidence of VMA can be as high as 38%. While the exact cause–effect relationship is not known, it seems clear that VMA is the initiator to a variety of ocular pathologies.
Advancements in high-resolution optical coherence tomography (OCT) allow physicians to verify the presence of VMA before deterioration of visual acuity is detectable. Thus the current treatment paradigm for VMA consists of 'watchful waiting' to see if the adhesion will resolve itself by evolving to complete posterior vitreous detachment. If notable visual symptoms occur, visual acuity can deteriorate rapidly and efficient intervention is required to halt progression.3
In a study of untreated eyes with DME, only 25% (n = 60) of eyes with VMA at study entry showed spontaneous vitreomacular separation, and the prevalence of improved visual acuity of more than two lines was significantly higher in eyes with vitreomacular separation at study entry (36%, n = 22) than in eyes without (15%, 9/60).4
When symptoms deteriorate, the accepted method of relieving adhesion and the resulting tractional forces is vitrectomy. While this has been shown to be successful, mechanical separation has also been known to leave vitreous fibrils on the internal limiting membrane, which may lead to cell proliferation and the forming of a scaffold that would generate further traction.8,9 Without those additional complications, vitrectomy remains a major surgical procedure with associated risks, and in some cases requires considerable face-down time for the patient.