Objective To evaluate the practicability and safety of 25-gauge (25G) transconjunctival sutureless vitrectomy system (TSV25G) and describe the preliminary experience. Methods Eighteen patients underwent TSV25G. The time of procedures of setting-up the three-port cannulae and closing the cuts were recorded. The pre- and post-operative ocular tension, visual acuity and complications were observed. Results The average time of setting-up the three-port cannulae and closing the cuts was 1 minutes 24 seconds and 32 seconds, respectively. The average preoperative ocular tension was 16.3 mm Hg(1 mm Hg=0.133 kPa); the average postoperative ocular tension at the first day, first week, and first month was 13.0, 15.9, and 16.4 mm Hg, respectively. The visual acuity before and one month after operation the was HM/20 cm～0.2 and HM/50 cm～0.6, respectively. No postoperative complication was found. Conclusion TSV25G may simplify the operation, minimize the surgical induced trauma, and decrease the operating time and the postoperative inflammatory response.

BACKGROUND :Although the conventional 20 G pars plana vitrectomy can improve the prognosis of vitreous-retina diseases,but it would also cause serious operation related injury and much complications.OBJECTIVE:To evaluate the practicability and safety of 25-gauge transconjunctival sutureless vitrectomy system (TSV25G) in the macular surgery, so as to elicit the preliminary clinical experience of mimimally invasive vitrectomy system.DESIGN:Case analysisSETTING: Department of Ophthalmology, General Hospital of Chinese People's Armed Police Force; Department of Ophthalmology, Beijing Sino Japen Friendship Hospital; Department of Ophthalmology and Visual Science, Chinese University of Hong Kong; Department of Ophthalmology,Prince of Wales Hospital, Hong Kong PARTICIPANTS: From July 2003 to July 2004, 16 patients with macular diseases were admitted to the Department of Ophthalmology in the General Hospital of Chinese People's Armed Police Force and taken as subjects (n=16), they were confirmed as epiretinal membrane in 9 eyes, idiopathic macular hole in 3 eyes, traumatic macular hole in 2 eyes and vitreo-macu lar tractional syndrome in 2 eyes. The course of disease ranged from 3 to 36 months with eyesight varied between 0.06 and 0.4.METHODS: 16 eyes underwent preoperative ophthalmic evaluation in cluding visual acuity measurement, Amsler chart test, slit lamp microscopy,.indirect ophthalmoscopy tonometry and optical coherence tomography (OCT). For the macular hole patients OCT was performed. 25-gauge Transconjunctival Sutureless Vitrectomy System (TSV25G) was used to carry on minimally invasive surgery under anesthesia state, the surgical parameter was set as: high speed cutter with rate of 1500 cuts per minute,BSS bottle was hang at height of 40-50 cm, the maximum aspiration of TSV25G was 550 mm Hg with the intraocular pressure remained at around 29-35 mmHg during the operation. Three-beveled trocar were used to make three-transeonjunctival incision on sclera of about 0.5 mm long respectively in the infratemporal, superotemporal, and supraotemporal quan drants, meanwhile a transconjunctival cannula was placed. One end of the infusion tube was inserted into the infratemporal cannula to establish infusion with the other two cannulas used for the intraocular operation with 25-gauge vitreous cutter and other instruments, such as vitreoectomy and membrane dislocation. The surgery was terminated by removing the cannula except for ceaseless leak, the conjunctival and scleral incision were not sutured. Patients received follow-up examination for 1-12 months postoperatively.MAIN OUTCOME MEASURES:①The operative time and the time for the establishment of three access. ② Changes of intraocular pressure after operation. ③ The effusion from the puncture after the intraocular perfor mance. ④ The postoperative vision, operative complication and the sealing of the holes.RESULTS:All of the 16 patients completed the vitrectomy; and entered the data analysis.①16 patients complete the vitrectomy with the operative time of 28-56 minutes (the mean of 37 minutes). The average time for the establishment of three access and closing was 84 s and 32 s respectively.②The average preoperative intraocular pressure was 16.4 mm Hg,comparing with 13.5,15.5,17.9 mm Hg at postoperative 1 day, 1 w and 1 m. ③Water leakage were found in 4 wounds of three patients after operation, 3 wounds were sealed after injecting 1-2 mL disinfected air into the eyes, the other one sutured with 6-0 absorbable suture. ④The mean time of inpatients were 5 days postoperatively. The visual acuity improved in 14 patients by the average of three lines, amongst which visual acuity was found improved to above 0.8 in 5 patients and the visual distortion disappeared in 8 eyes and attenuated in 3 eyes. But still there were 2 cases without improvement.No surgical complications were noted and macular hole gained clinical sealing in totally 5 eyes.CONCLUSION: TSV25G system can simplify the surgical procedure with many other advantages such as decreasing the operation related injury and complications, as well as shortening operative time, which benefits the rapid rehabilitation.