Postoperative pain after cataract surgery

Methodological quality of the review: Medium confidence

Author: Porela-Tiihonen S, Kaarniranta K, Kokki H.

Region: Details not provided

Sector: Cataract surgery

Sub-sector: Postoperative pain

Equity focus: None specified

Review Type: Effectiveness Review

Quantitative synthesis method: Narrative analysis

Qualitative synthesis methods: Not applicable

Background

Although cataract surgery is common, there is little research on the incidence and management of postoperative pain and recovery after cataract surgery. The authors suggested that increased knowledge about postoperative pain and related complaints after cataract surgery, specifically phacoemulsification with IOL implantation, is necessary because postoperative pain and associated complaints may negatively impact upon a person’s quality of life after surgery.

Research objectives

‘ (1) To evaluate the incidence and amount of postoperative ophthalmic pain and (2) To identify methods of pain management used after cataract extraction surgery.’

Main findings

21 randomized controlled trials were included in the systematic review, focusing on cataract extraction surgery and pain management. Geographical location of the studies was not addressed by the review. Authors reported the following results:

Objective 1- to evaluate the incidence and amount of postoperative ophthalmic pain:

The incidence of postoperative pain a few hours after surgery was reported in five studies; pain in the first 72 hours after discharge in 10 studies; pain four-15 days after surgery in eight studies; and pain at four weeks in two studies. Heterogeneity in interventions and the measures of pain used limited comparability, however the authors reported that the incidence of reported pain varied from ‘few and over 90%’ in the first postoperative hours, and a similar variation remained during the first week after surgery.

Objective 2 to identify methods of pain management:

Interventions included ‘the use of topical non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, paracetamol, perioperative intraocular injections, eye pads used after surgery, and various surgical techniques’. In terms of effectiveness, the authors reported that in all five studies in which NSAIDs were evaluated, NSAIDs were superior to the placebo.

Authors noted that pain management post-surgery had not, to date, been assessed systematically and that the studies included in this review presented inconsistent findings.  In terms of methodology, authors noted that postoperative pain or postoperative pain management was not a primary aim of any of the studies included in the review. Further systematic clinical trials and more clinical data were required to gain a clearer conclusion.

The authors concluded that patient recovery after cataract surgery is usually uneventful with most studies reporting ‘little to no pain’. However, they found that in some studies, following surgery, patients experienced ‘significant postoperative pain’ lasting several weeks and should receive appropriate pain management.

Methodology

Selected studies were restricted to randomized control trials with interventions on postoperative inflammation and pain. Participants included adult patients with senile or pre-senile cataract who have had cataract surgery. Only studies using phacoemulsification intervention techniques were included in the review and ‘studies using all analgesic agents, anti-inflammatory agents and other postoperative interventions were considered eligible’.

Authors note that the review is based on a search of literature on PUBMED, MEDLINE and Scopus databases and performed according to the Cochrane Handbook for Systematic Reviews of Interventions. Although search filters and language restrictions were not used for the initial search, in the final analysis, reports were excluded if it was only published in a language other than English, German, French and Spanish. It was not clear from the review the search period applied to the database search and whether if the two authors who evaluated studies for inclusion did so independently. It was also noted that the last search was performed in July 2011.

In terms of data synthesis, the review offered a summary description of the 21 included studies; what they evaluated, their study design and interventions. The review identified studies that reported a range of postoperative pain outcomes, and as such meta-analysis would have been inappropriate. The likelihood of bias within the included studies was not addressed, neither was external validity or generalizability of results.

Applicability/external validity

The review did not clearly discuss how generalizable the results are, and did not illustrate methods to assess applicability.

Geographic focus

The authors did not address the geographical location of the included studies.

Quality assessment

This review was attributed medium confidence in the conclusions about the effects of this study. Although authors conducted a search on relevant databases for published and unpublished studies, authors did not avoid language bias and did not contact authors/experts and reviewed reference lists in included studies as part of the search strategy for additional studies. As search date parameters were not reported, it was not possible to determine if authors covered an appropriate time period. It was also not clear if authors used appropriate methods to select studies and extract data from included studies.

In terms of analysis, although the results section did provide a summary description of the studies included and what they evaluated, an explanation was lacking of the primary and secondary outcomes used to assess the different studies and identify heterogeneity between them. It was noted that perioperative pain was the primary outcome measure in only one study whilst postoperative pain was used as one of the outcome measures in 10 studies (half of the studies included). Although 21 studies were identified in total, postoperative pain was not the primary focus of any of them.