Objective: To show infusion cannula associated jet stream effects on posterior pole of the retina during vitrectomy.
Materials and Methods: For this retrospective study 39 eyes of thirty nine patients were assigned to the two different groups in terms of their infusion cannula position during vitrectomy. Group 1 was consisted the patients that the cannula was placed angled to sclera consistent to the two step entering position of the trocar. Group 2 was consisted the patients that the cannula was fixated perpendicular to the sclera. Preoperative and postoperative examination datas about patients were evaulated.
Results: There were 20 patients in the group 1 and 19 patients in the group 2. There were no significant difference between the groups in terms of preoperative visual acuity (1.79±0.77 loMar for the group 1 and 1.86±0.59 logMar for the group 2, p: 0.989 ). The difference of preoperative IOPs were statistically nonsignificant between the groups (13.3±2.9 mmHg for the group 1 and 13.1±2 mmHg for the group 2, p: 0.460). The mean surgery time for the group 1 was 48±12 minutes and was 50±10 minutes for the group 2 (p: 0.460). The postoperetive visual acuity was 0.24±0.21 logMar for the group 1 and 0.53±0.28 logMar for the group 2. There was statistically signifficant difference between the groups in terms of postoperative visual acuity (p: 0.0001). The difference of postoperative IOPs were statistically nonsignificant between the groups (14.9±4.2 mmHg for the group 1 and 13.4±2.8 mmHg for the group 2, p: 0.289).
Conclusion: The present study shows infusion cannula associated jet stream may reduce postoperative visual acuity. Using new design type of inffusion cannulas or placing the infusion cannula angled manner to avoid the flow force on posterior pole should be considered for better vitrectomy results.
Key words: Infusion cannula; Jet stream; Retina; Vitrectomy
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