Incisions made during sutureless vitrectomy may allow the entry of ocular surface fluid soon after surgery, according to study results published in the February 2009 issue of the American Journal of Ophthalmology.

Joseph I. Maguire of the Wills Eye Institute at Thomas Jefferson University, Philadelphia, Pennsylvania, US and colleagues performed 20 G, 23 G, perpendicular 25 G and bevelled 25 G pars plana vitrectomy (PPV) sclerectomies in human cadaver eyes. The team then applied India ink to each of the wound sites and, after varying the intraocular pressure (IOP), assessed the presence of remaining India ink particles by histology and spectrophotometry.

No particles of India ink were detected using either method in the 20 G incisions; however, India ink particles were detected along the entire length of the 23 G incisions by both histology and spectrophotometry. Along the entire length of the perpendicular 25 G wounds, India ink particles were detected by at least one method in all eyes studied; in the bevelled 25 G wounds, spectrophotometry failed to detect any India ink particles, although histologic examination noted some particles in one eye.

The researchers concluded that sutureless vitrectomy incisions allow ocular surface fluid to pass, and that this may explain the increased incidence of endophthalmitis in smaller gauge vitrectomy surgeries.