25-gauge sutureless vitrectomy: variations in incision architecture.

BACKGROUND/PURPOSE: To examine the histologic architecture of 25-gauge transconjunctival sutureless vitrectomy incisions.

METHODS

Four groups of sutureless incisions were constructed in cadaver eyes using a 25-gauge trocar-cannula system. In Group 1, oblique incisions were constructed by inserting the trocar to the bevel and then turning vertically to enter the vitreous cavity. Oblique incisions in Group 2 were constructed as in Group 1, but the trocar was inserted to the beginning of the 25-gauge cannula. Incisions in Group 3 were constructed as in Group 2, but before removing the cannula from the eye vitrectomy was performed. Incisions in Group 4 were constructed vertically, and then vitrectomy was performed. Histologic analysis of the incisions was performed.

RESULTS

In Group 1, 5 of 9 incisions (55%) demonstrated a two-plane structure. In Group 2, 3 of 9 incisions (33%) demonstrated a two-plane structure. Scleral fibers in the internal aspect of wounds were frayed in all incisions in Group 1 (100%), in 88% of incisions in Group 2, and in all incisions in Group 3 (100%). All incisions in Group 4 were single-planed and two incisions demonstrated disruption on their inner aspect.

CONCLUSIONS

Oblique incision architecture was inconsistent within each group. Most incisions showed tissue disruptions in their inner aspect. The internal wound edge disruption reduces the effective distance between the ocular surface and the vitreous cavity. Oblique incisions may not be secure in the immediate postoperative period before wound healing.