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To assess the influence that hydration applied on the sclerotomy edges may have on incisional closure resistance after transconjunctival sutureless vitrectomy (TSV).Experimental, randomized and observer-masked study in which 23-gauge TSV was performed in 80 cadaveric pig eyes. Once each vitrectomy was finished, hydration with balanced salt solution (BSS) was applied on the sclerotomy edges of one of the superior incision sites; no maneuver was performed on the other superior sclerotomy. Intraocular pressure (IOP) was gradually increased by means of the vitrectomy system (Accurus; Alcon Laboratories, TX) until one of the superior sclerotomies opened, allowing internal ocular solution to escape.In 45% of cases (36 of 80 eyes), sclerotomies subjected to hydration allowed intraocular fluid escape (p = 0.43). There were no differences when comparing opening pressure values of hydrated and non-hydrated sclerotomies (p = 0.19).Scleral hydration did not demonstrate increase in the sclerotomy closure resistance in our experimental model. Given the widespread use of sutureless TSV around the world, the results obtained in our research, in spite of being negative, may contribute to the knowledge of the behavior of sutureless sclerotomies.

To evaluate the influence that the origin of incisional vitreous incarceration may have on the presence of postoperative conjunctival blebs over sclerotomies after transconjunctival sutureless vitrectomy (TSV). Blebs are formed by incisional leakage due to incompetent closure.Twenty-three-gauge TSV was performed in 83 cadaveric pig eyes. Once each vitrectomy was finished, ultrasound biomicroscopy (UBM) was used to assess the presence of postoperative conjunctival blebs over the sclerotomy sites, as well as the existence of vitreous incarcerated in incisions. Vitreous strands may come from the perisclerotomy area, running parallel to the sclera toward the inner hole of the sclerotomies, or may radiate from the core of the vitreous cavity.Vitreous entrapment was found in 73.9% of the sclerotomies; 43.4% of the incisions showed vitreous strands coming parallel to the sclera (12.9% of them showed conjunctival bleb), 19.7% of the wounds presented vitreous aiming toward the core of the vitreous cavity (2% of them had conjunctival bleb) and 10.8% of the entrances presented both vitreous incarceration sources (none of them showed bleb). Incisions with vitreous entrapment parallel to the sclera were associated with a significantly greater sclerotomy leakage rate.Sclerotomies with vitreous incarceration coming from the core of the vitreous cavity showed a greater incisional closure competency than that observed in incisions with vitreous entrapment coming from the pericannular area; if these results were confirmed in humans, different postoperative suture rates may be expected on sclerotomies according to the vitrectomy degree performed in different areas of the vitreous cavity.

To compare ultrasound biomicroscopy (UBM), anterior-segment optical coherence tomography (AS-OCT), and direct visualization for detecting conjunctival blebs in sutureless sclerotomies after vitrectomy. Conjunctival blebs are formed by sclerotomy leakage due to incompetent closure.Experimental, randomized, and observer-masked study in which 23-gauge vitrectomies were performed in cadaveric pig eyes. Postoperative conjunctival blebs were assessed by UBM, AS-OCT, and direct visualization. No conjunctival blebs were classified as Grade 0 (G0), thin blebs (less than or equal to one-half of scleral thickness) as Grade 1 (G1) and thick blebs (greater than one-half of scleral thickness) as Grade 2 (G2).Fifty pig eyes were included. Conjunctival blebs were found in 13.3% (8% G1, 5.3% G2) of the incisions analyzed by UBM, in 20% (14.7% G1, 5.3% G2) of the sclerotomies studied by AS-OCT, and in 7.3% (2% G1, 5.3% G2) of the wounds evaluated by direct visualization. AS-OCT was the most sensitive method for identifying conjunctival blebs when compared with UBM and direct visualization (p0.001). In turn, UBM was better than direct visualization for observing sclerotomy blebs (p=0.004).AS-OCT is the most sensitive technique for detecting subclinical blebs (G1) and thus, it may be useful in research for studying the influence that surgical factors and maneuvers may exert on sclerotomy closure capacity after vitrectomy. Direct visualization, that is used in routine clinical practice to determine which sclerotomies should be sutured, is useful only to identify thick blebs (G2) after vitrectomy.

To evaluate the influence of the cannula removal maneuver on the postoperative incisional vitreous incarceration using an experimental model of vitrectomized eye.Prospective, experimental, randomized and observer-masked experimental study in which 23-gauge transconjunctival sutureless vitrectomy was performed through oblique sclerotomies in cadaveric pig eyes. Once the vitrectomy was finished, one of the superior cannulas was removed with the light probe introduced through it, and the other cannula was extracted with the cannula plug inserted. Postoperative incisional vitreous incarceration was evaluated by ultrasound biomicroscopy (UBM).60 eyes included. Considering the 60 superior sclerotomies whose cannulas were extracted with the light pipe inserted, vitreous incarceration was observed in 35% of them. On the other hand, 71.6% of the incisions whose cannulas were removed with the cannula plug inserted showed vitreous incarceration (p = 0.00013).Interposing the light probe through the cannula when it is removed seems to reduce the postoperative wound vitreous incarceration rate in our experimental model.

To evaluate the influence of superior sclerotomy use (vitreous cutter or illumination probe entrance) on the postoperative sclerotomy closure competency using an experimental model of vitrectomized eye.Prospective, experimental, randomized and observer-masked experimental study in which 23 and 25-gauge transconjunctival sutureless vitrectomy was performed through oblique sclerotomies in the same cadaveric pig eye. Closure competency was determined by the resistance to intraocular fluid leak through the superior incisions in face of a progressive intraocular pressure (IOP) rise.120 eyes included. In 52.5% of cases, the vitreous cutter probe sclerotomy showed intraocular fluid leakage first (p = 0.65). When comparing opening pressure values, there were no significant differences (p = 0.77) between the leakage pressure level of both sclerotomies depending on their use.Different uses of superior sutureless oblique sclerotomies do not seem to influence on TSV incision mechanical resistance to IOP rise in our experimental model.

Javier Benitez-Herreros,1 Lorenzo Lopez-Guajardo,1,2 Cristina Camara-Gonzalez,1 Aurora Perez-Crespo,1 Agustin Silva-Mato,3 Miguel A Teus1,2 1Department of Ophthalmology, University Hospital Príncipe de Asturias, Madrid, Spain; 2Department of Surgery, Medical and Social Sciences, Faculty of Medicine, Alcalá University, Madrid, Spain; 3Department of Health and Sociomedical Sciences, Alcalá University, Madrid, Spain Purpose: To evaluate the influence of sclerotomy use during vitrectomy (vitreous cutter, illumination probe, or infusion-line entrance) on postoperative vitreous incarceration using an experimental model of vitrectomized eye. Materials and methods: Experimental, randomized, and observer-masked study in which 23-gauge transconjunctival sutureless vitrectomy was performed in cadaveric pig eyes. Postoperative incisional vitreous entrapment was evaluated by direct visualization. No vitreous incarceration was classified as grade 0 (G0), thin vitreous entrapment was classified as grade 1 (G1), and thick vitreous strands as grade 2 (G2). Results: A total of 46 eyes were included. Vitreous incarceration was detected in 91.3% (43.5% G1, 47.8% G2) of the sclerotomies used by the vitreous cutter probe, 95.7% (45.7% G1, 50% G2) of the illumination-pipe entrances, and 93.5% (45.7% G1, 47.8% G2) of the infusion-line incisions. No statistical differences were found when comparing incisional vitreous incarceration after vitrectomy according to sclerotomy use. Conclusion: Different manipulation of the sclerotomies, depending on their use, does not seem to influence postvitrectomy vitreous entrapment in our experimental model. Keywords: vitrectomy, vitreous incarceration, direct visualization, sclerotomy use, experimental model