Optimal Timing for Intraocular Pressure Measurement Following Phacoemulsification Cataract Surgery: A Systematic Review and a Meta-Analysis

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The author filtered a significant amount of literatures and patient samples to investigate the relationship between IOP increase and time point after cataract surgery. This review is informative. Just some minor suggestions about the format.

1. Typo: there are several numbers left in the text, which may due to the change of reference. For example, "1" in line 31, "13" in line 105. 

2. Figures: the letter is very small in the figure to read. Please increase the font size in the figure, if possible.

4. Discussion: the line 325-328 was not relevant to the paper. 

Author Response

Thank you very much for your thorough review of our manuscript focused on the optimal timing for intraocular pressure measurement following phacoemulsification cataract surgery. Please find the detailed responses below and the corresponding revisions highlighted in the re-submitted files.

Comment 1: Typo: there are several numbers left in the text, which may due to the change of reference. For example, "1" in line 31, "13" in line 105. 

Response 1: Thank you so much for bringing this typo to our attention. We have revised the manuscript to now use consistent in-text reference number formatting throughout on page 1, paragraph 1, line 31 and on page 3, paragraph 3, line 105.

Comment 2: Figures: the letter is very small in the figure to read. Please increase the font size in the figure, if possible.

Response 2: Thank you for brining attention to the small lettering in each figure. We have updated each figure to now include larger numbering as the text has been increased from font size 10 to 16. These changes can be seen in figures 2, 3, 4, 5, 6, and 8.

Comment 3: Discussion: the line 325-328 was not relevant to the paper. 

Response 3: Thank you for your comment regarding discussion line 325-328. We have now removed these lines to only include text relevant to the paper.

Thank you kindly. 

Reviewer 2 Report

Comments and Suggestions for Authors

This is an interesting article, describing the results of a comprehensive literature search, performed on MEDLINE and EMBASE.  Two independent reviewers examined in two phases articles reporting IOP measurements after uncomplicated cataract surgery.

As reported by the authors themselves, the results examined show a high rate of heterogeneity, with values of I² >50% for each follow up time taken into consideration (except in graph e, fig 2 where it stands at 48.9%). The high heterogeneity suggests that the results of the studies differ from each other for reasons that cannot be explained by chance alone, as shown by the low values of p (<0.001). However, the cause of this heterogeneity is not explicitly discussed in the meta-analysis. 

In this regard, authors did not provide any information about several issues, such as:

- IOP measuring methods (in paragraph 2.2 line 86 authors generally mention “tonometry”) (doi:10.1007/s10792-024-03210-w.)

2.               - Time of the day in which the measurements were performed (doi:10.1186/s12576-024-00905-8)

3.               - position (clinostatism vs orthostatism) (doi: 10.3390/jpm14080826)

4.               - possible corrections related to pachymetry or astigmatism (doi: 10.18240/ijo.2023.10.07)

All these issues should be discussed. 

 

In addition, "the date of publication of studies varies from 1992 to 2023, with 65.5% of studies conducted in the last 20 years" (line 164). To narrow the examined time window would be more appropriate.

Lines 172-174: besides the  typo errors, (57 instead of 58 studies), more than 50% of the studies considered by the authors are at high-moderate risk of bias assessment. To exclude these articles would therefore be more appropriate.

 

Regarding figure 2, as the authors correctly state, the plot d (6h) is simmetric, However, further investigations should be carried out for the 1h , 4h and 8h timepoints (graphs A, C, E) which appear asymmetric.

Funnel plots are the first step to start investigating publication bias and their interpretation is highly subjective. Therefore, each analysis should be followed by further quantitative investigations, such as Egger's regression or trim and fill procedure.

From the analysis of figures 4 and 7, it seems that data at 1h after surgery derived from two studies from the same author ( in which both eyes o were analysed).

Regarding data at 2h after surgery, only three studies were provided, that analysed both eyes.

Given the uncertainty of the values obtained immediately after surgery, it might be necessary to use several inclusion criteria (e.g. more recent studies, more homogeneous studies for the IOP  measuring technique, exclude studies in which both eyes are evaluated).

Comments on the Quality of English Language

Moderate editing of English language is required

Author Response

Please see the attachment, thank you.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This interesting meta-analysis focused on the postoperative intraocular pressure increase after uncomplicated phacoemulsification cataract surgery. The methodology and the results are presented thoroughly answering an important clinical question regarding the IOP spices after phaco surgery. 

However, this meta-analysis showed a mild increase in IOP at three time points and only on the first day of the surgery. This IOP increase (0.83 mmHg to 1.38 mmHg was statistically significant but would not be considered clinically significant in the vast majority of subjects undergoing cataract surgery. This should be clearly stated by the authors in the conclusion section of the manuscript. Therefore, the statement of the authors in the conclusion section "Complications such as pain, nausea, vomiting, corneal edema, and blurred vision as a result of acute IOP spikes cause patients to both worry and complain that something went wrong during surgery" is not justified from the results of the current study, is misleading and should be deleted or modified. 

Author Response

Thank you very much for your thorough review of our manuscript focused on the optimal timing for intraocular pressure measurement following phacoemulsification cataract surgery. Please find the detailed responses below and the corresponding revisions highlighted in the re-submitted files.

Comment 1: However, this meta-analysis showed a mild increase in IOP at three time points and only on the first day of the surgery. This IOP increase (0.83 mmHg to 1.38 mmHg was statistically significant but would not be considered clinically significant in the vast majority of subjects undergoing cataract surgery. This should be clearly stated by the authors in the conclusion section of the manuscript. Therefore, the statement of the authors in the conclusion section "Complications such as pain, nausea, vomiting, corneal edema, and blurred vision as a result of acute IOP spikes cause patients to both worry and complain that something went wrong during surgery" is not justified from the results of the current study, is misleading and should be deleted or modified. 

Response 1: Thank you for your comment regarding the clinical implications of the increase in IOP found at three time-points. We agree with your comment and as such have revised the manuscript by removing the outlined statement in the conclusion section.

 

Thank you kindly.