Incidence of retinal detachment following 23-gauge vitrectomy in idiopathic epiretinal membrane surgery

Abstract

Editor, There is increasing debate about the pros and cons of sutureless microincision transconjunctival vitrectomy (TSV) surgery (Grosso & Panico 2009) in the macular surgery. The 23-gauge TSV surgery was introduced to our Retina Service in October 2005. All patients underwent single-step 3-port 23-gauge core vitrectomy dye-assisted (triamcinolone acetonide to identify the hyaloid + infracyanine green to identify the internal limiting membrane) using Accurus or Dorc Vitrector. The 23-G vitrectomy system (3D mode) was set at a cutting speed of 2500–1800 cuts per minute, infusion pressure of 20 or 40 mmHg and aspiration pressure from 40 to 350–450 mmHg. All procedures were performed under the DORC (Zuidalnd–Holland) disposable flat vitrectomy lens (Cod DR 1284 –DD), in local anaesthesia. Postoperative retinal detachment occurred in two of the 166 consecutive eyes (median age 70, 95 M, 71 F) after 23-gauge TSV surgery (1.2%) in idiopathic epiretinal membrane surgery from October 2005 to May 2009. The retinal detachment is a serious complication after vitrectomy, especially for macular surgery. In recent series of patients who underwent 23-gauge vitrectomy study for epiretinal membrane surgery, the retinal detachment occurred from 0% (Hikichi et al. 2009) to 1.6% of cases. (Haas et al. 2010) The incidence of postoperative retinal detachment following 25-gauge vitrectomy surgery is also reported low in the literature. (Tan et al. 2009). We have retrospectively analysed the clinical charts of patients, and we have found that the two cases of retinal detachment occurred in the first consecutive subgroup of patients. The pathogenesis of retinal detachment in small-gauge vitrectomy can be correlated to the following factors (Parolini et al. 2010): Type of vitrectomy and induction of iatrogenic breaks: incomplete vitrectomy, i.e. core vitrectomy versus vitrectomy as complete as possible plus endolaser; aspiration power and type of duty cycle. We analysed each of these different factors: We perform a core vitrectomy, and therefore a criticism of the technique could be that the residual vitreous in the periphery may cause retinal tractions. However, we have not found retinal breaks at the site of sclerotomies in our series after a scrupulous full 360-degree internal search at the end of each procedure. We know that the duty cycle is extremely important because it may determine possible vitreous traction and consequently retinal tears. Therefore, we set the aspiration flow up to maximum 350 mmHg instead of 450 mmHg after the first 50 cases. Since this modification, no other cases of retinal detachment occurred. We are uncertain about the role of the internal tamponade: some surgeons claim that a BSS – air exchange may help to close the sclerotomies and reduce the risk of postoperative retinal detachment, but further studies are required to validate these preliminary data. We think it is important to share our surgical experience with the scientific community. Further, we are aware about the possible bias publication when we deal with negative results in new surgical techniques. In conclusion, the 23-gauge core vitrectomy with aspiration power of maximum 350 mmHg is a safe technique to treat idiopathic epiretinal membranes. This Study was supported by Compagnia di San Paolo, Torino, Italy (protocollo n 29 SD/FA 2007.3149).