Let green lead not astray

At the close of the 20th century the medical world was witness to a most remarkable advance when therapy was developed for a previously incurable disease. Macular hole surgery is one of the great success stories in ophthalmology, if not modern medicine. Predicated upon an increased awareness of the role of vitreous in the pathogenesis of retinal disorders, this achievement results from the work of pioneering surgeons who had the ingenuity and courage to devise and attempt a new surgical approach that now restores vision to many grateful patients. However, recent modifications of the surgical technique may jeopardise visual outcomes and “lead us astray” from early successes.

Vitreous is an extended extracellular matrix, whose molecular composition and supramolecular organisation result in a clear gel that firmly adheres to the retina in youth.1–3 Ageing induces liquefaction and vitreoretinal dehiscence, which occur concurrently in the overwhelming majority of individuals, resulting in innocuous posterior vitreous detachment (PVD).4 Anomalous PVD5 results from vitreous liquefaction without sufficient vitreoretinal dehiscence. This may preclude the posterior vitreous cortex from separating cleanly from the internal limiting lamina (ILL) of the retina. The untoward consequences of anomalous PVD vary depending upon where in the vitreous body the gel is most liquefied and where on the retina there is greatest vitreous adherence.5 Anomalous PVD in the periphery, for example, results in retinal tears. Along blood vessels, liquefaction without vitreoretinal dehiscence induces vitreous haemorrhage. Another important effect of anomalous PVD is vitreoschisis, a split in the posterior vitreous cortex that has been identified with biomicroscopy,6 ultrasonography,7 and optical coherence tomography.8 Vitreoschisis has been confirmed by histopathological studies9 and has also been documented during surgery by intravitreal triamcinolone injection.10

Anomalous PVD is hypothesised to …