25-gauge PPV for retained lens fragments

1 February 2016 | Sofia Rokerya | EYE - Vitreo-Retinal

This was a retrospective study including 40 eyes of 40 patients with mean age of 78 years, 19 females and 21 males, who underwent 25-gauge pars plana vitrectomy (PPV) for retained lens fragments with a minimum of six months of postoperative follow-up. PPV was performed within seven days after complicated cataract extraction in 24 cases (early) and 16 eyes after >7 days (late vitrectomy).The amount of dislocated nuclear material was graded by the surgeon intraoperatively, and the patients were divided into two groups according to the nuclear grading: group A (≤50% dropped nucleus) and group B (>50% dropped nucleus). The presence of brunescent nuclear pieces was considered. All patients were operated by a single vitreoretinal surgeon using the same PPV technique. The outcomes measured included best-corrected visual acuity (BCVA) and postoperative complications such as retinal detachment, cystoid macular oedema (CMO) and postoperative ocular hypertension or hypotonia. In early vitrectomy group all patients, except two, underwent PPV in the same setting of cataract extraction (mean interval 0.63 ± 2.2 days; range 0-7). In the late vitrectomy group, the mean interval between cataract extraction and PPV was 12.0 ± 3.1 days. There was no statistically significant difference in the grade of retained lens material between patients undergoing early and late PPV. The mean surgical vitrectomy time was 35.4 ± 16.9 min, ranging from 13 to 75 min. At six months of follow-up, the mean BCVA improved to 20/32 (logMAR = 0.23 ± 0.3), with no differences in terms of BCVA between patients with early or late PPV. At six months, the mean IOP was 17.1 ± 4.6mmHg, with no statistically significant difference between patients undergoing early or late PPV (17.0 ± 4.6 and 17.3 ± 4.5mmHg, respectively; p=0.78, two-tailed t test). There was no statistically significant correlation between the final postoperative IOP and the nucleus grade (p=0.79). During the follow-up, a rhegmatogenous retinal detachment occurred in four patients (10%). In all cases, the retinal detachment occurred in the late postoperative period, between three and five months after PPV. Retinal detachment occurred only in patients of group B, with two patients having grade 3, and two patients having grade 4 of retained nuclear material, and this difference was found to be statistically significant (p<0.002, two-tailed t test). Four patients with late PPV developed postoperative CMO, with no case of CMO among patients with early vitrectomy (p=0.014). CMO resolved with topical and systemic indomethacin (50mg/day). Although 25-gauge PPV proved effective irrespective of nuclear grading, when analysing surgical times a significant positive correlation was found between nuclear grade and duration of the PPV. In case of retained nuclear fragments ≤50% (grades 0-2), the mean surgical time was 26.5 min, whereas when dislocated nuclear material was >50% (grades 3-4), surgery became considerably longer (mean time 56.2 min), questioning the actual convenience of the 25-gauge approach for the management of higher amounts of retained lens material. Limitations of the study include its retrospective and single surgeon nature, small sample size, the lack of lens material density grading and the lack of comparison with 20- and 23-gauge PPV groups.