Pars Plana Vitrectomy Port Sizes: A Meta-Analysis of Randomized Controlled Trials
Bibliographic record
Abstract
BACKGROUND AND OBJECTIVE: The uptake of small-gauge (SG; ie, 23-gauge [23-G], 25-gauge [25-G], and 27-gauge [27-G]) pars plana vitrectomy (PPV) has grown. We aim to investigate the advantages and disadvantages of various PPV port sizes in a meta-analysis of randomized controlled trials (RCTs). MATERIALS AND METHODS: A systematic literature search was performed for RCTs comparing PPV port sizes for any indication. Weighted mean differences (WMDs) and risk ratios (RRs) were calculated, and meta-analysis was performed with random-effects models. RESULTS: A total of 1,678 eyes from 22 RCTs were included. Risk-of-bias assessment found some concerns in 13 studies. Compared with 20-gauge PPV, there was no significant difference in the final or change in best-corrected visual acuity (BCVA; five studies analyzed each) relative to that of SG PPV. SG PPV was associated with a significantly greater incidence of hypotony ( RR = 3.79; 95% confidence intervals [CI], 2.02 to 7.10; P < .0001; six studies) and choroidal detachment ( RR = 5.65; 95% CI, 1.01 to 31.71; P = .05; three studies). Compared with 25-G PPV, there was no significant difference in BCVA at any time point with 23-G (two studies), and significantly more frequent port suturing was required with 23-G ( RR = 0.46; 95% CI, 0.25 to 0.84; P = .01; two studies). Compared with 25-G PPV, 27-G was associated with a significantly better final BCVA (WMD = −0.06 logMAR; 95% CI, −0.11 to −0.01; P = .02; five studies) and a significantly lengthened surgery (W MD = 4.11 minutes; 95% CI, 0.18 to 8.05; P = .04; three studies). CONCLUSIONS: There was no significant difference in visual or surgical outcomes following 20-gauge PPV relative to SG PPV (Grading of Recommendations, Assessment, Development, and Evaluation recommendation: low certainty), and there was an increased risk of postoperative complications with SG PPV (moderate certainty). Compared with 25-G PPV, 23-G required more frequent port suturing (moderate certainty), whereas 27-G may be associated with a better final BCVA but longer surgery (low and moderate certainty, respectively). [ Ophthalmic Surg Lasers Imaging Retina. 2022;53:152–158.]
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.027 | 0.056 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.019 | 0.052 |
| Bibliometrics | 0.005 | 0.006 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.004 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.005 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".