Uncomplicated cataract extraction is usually conducted under topical anesthesia. Perioperative pain management not only reduces the patient’s anxiety before and after cataract surgery, but also improves the patient’s intraoperative cooperation. Therefore, pain management is particularly important when performing cataract surgery.
Currently, phacoemulsification plus implantation of an intraocular lens under topical anesthesia is the main surgical approach to treat cataract. Topical anesthesia significantly reduces the perceived pain at the time of making the clear corneal incision and small incision, as compared with historical techniques [
Previous studies, including our clinical practice, have revealed that patients experience more painful sensations during second-eye surgery. Although an earlier study found no significant difference in the mean pain scores between patients undergoing second cataract extraction compared with patients undergoing first cataract extraction [
Several studies have examined the possible causes of the increased pain during second-eye surgery. For example, Ang et al. found that nearly 20% of patients reported frightening intraoperative visual experiences that were associated with previous cataract extraction [
Therefore, we used subjective and objective measures in the perioperative period, with the following aims: (1) to compare the anxiety and pain scores between first-eye and second-eye cataract surgery, (2) to identify factors correlated with the severity of pain during cataract surgery, and (3) to help surgeons evaluate and manage perceived pain during cataract surgery.
The Ethics Committee of the Eye and Ear, Nose, and Throat Hospital, Fudan University, approved our study. Patients with bilateral age-related cataract were considered eligible for this study. Exclusion criteria included baseline eye pain, deafness, poor compliance to cataract surgery under tropical anesthesia, involuntary movement, history of allergy to topical anesthetics, posterior capsule organization, or other complicated cataracts. Patients were enrolled between April 2013 and July 2013. Written informed consent was obtained from all patients after they were informed of the nature and possible consequences of the study. The consent procedure was approved by the hospital’s ethics committee.
Preoperative anxiety was evaluated using the validated simplified State-Trait Anxiety Inventory (STAI; 6 questions) [
Postoperative pain was evaluated using a VAS for pain, which was presented as a numbered line ranging from 0 (no pain) to 10 (unbearable pain) [
The preoperative anxiety assessments were completed while the patient was in the waiting room before surgery. The assessments were orally administered by a trained investigator. The postoperative pain assessments were completed when the patient was transferred to the recovery room. The questionnaires were administered by the same investigator. Patients who were unable to read the VAS for pain by themselves were asked to verbally report the perceived pain using the same scale.
Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate were measured using an electric sphygmomanometer (HEM-907, OMRON, Kyoto, Japan) by an experienced nurse at the following times: before surgery, during phacoemulsification, and in the recovery room. Mean arterial pressure (MAP) was calculated using the following formula: MAP = SBP × 1/3 + DBP × 2/3.
The preoperative examination and surgery were strictly performed according to established outpatient surgical procedures in all patients. The same operating room was used for all procedures with the same surgical equipment and instruments. Tropicamide was administered 30 min before surgery to fully dilate the pupil. The conjunctival sac was rinsed with povidone iodine (0.02%) 5 min before surgery. Topical anesthesia consisted of 3 applications of 2% lidocaine before surgery, 1-2 drops per time, with the first application 5 min before surgery, the second application at 1 min before surgery, and the final application after placing the eyelid retractor. Oral and intravenous sedatives or analgesics were not permitted. All procedures were performed by the same right-handed surgeon (Yi Lu).
After topical anesthesia, a 2.6 mm temporal clear corneal incision was created, followed by viscoelastic (DisCoVisc; Alcon Laboratories, Inc., Fort Worth, TX, USA) injection and 5.5 mm continuous curvilinear capsulorhexis. Hydrodissection, chopping, nucleus rotation, and phacoemulsification were then performed. A foldable intraocular lens (SN60WF; Alcon Laboratories, Inc.) was implanted using a dedicated injector. After aspiration of residual viscoelastic, the incision was hydrated with balanced salt solution and checked for water tightness.
All statistical analyses were performed using SPSS version 13.0 (SPSS Inc., Chicago, IL, USA). Quantitative data are presented as the mean ± standard deviation. The
Between 1 April 2013 and 30 July 2013, 167 ARC patients undergoing cataract surgery were enrolled in this study. These 167 patients were administered the questionnaires, of which 159 provided valid responses and were analyzed in this study. The valid patients were divided into two groups, as follows: 106 patients underwent first-eye surgery and 53 underwent second-eye surgery. There were no significant differences between the two groups in terms of age and proportions of males/females (Table
Patient characteristics.
Parameter | First-eye surgery | Second-eye surgery |
|
---|---|---|---|
Patients ( |
106 | 53 | / |
Mean age (y) ± SD |
|
|
0.424 |
Gender (male/female) | 40/66 | 22/31 | 0.646 |
SD, standard deviation.
A significantly greater proportion of patients who underwent second-eye surgery (46/53 patients, 85%) reported pain during cataract surgery compared with patients who underwent first-eye surgery (37/106 patients; 35%) (
Differences between first- and second-eye cataract surgery.
Parameter | First-eye surgery ( |
Second-eye surgery ( |
|
---|---|---|---|
Pain rate (%) | 35 (37/106) | 87 (46/53) | <0.001 |
Median pain scores (range) | |||
VAS pain | 1 (0, 8) | 2 (0, 6) | 0.001 |
Wong-Baker Faces Pain Rating Scale | 2 (0, 6) | 2 (0, 6) | 0.003 |
Median anxiety scores (range) | |||
STAI | 8 (6, 24) | 7 (6, 24) | 0.815 |
VAS anxiety | 2 (0, 8) | 1 (0, 8) | 0.047 |
Median cataract (range) | |||
Nuclear | 3 (2, 5) | 3 (2, 5) | 0.113 |
Cortical | 0 (0, 1) | 0 (0, 1) | 0.564 |
Posterior subcapsular | 0 (0, 1) | 0 (0, 1) | 0.576 |
Mean operating room time (min) ± SD | 11 ± 3 | 10 ± 2 | 0.817 |
Mean phacoemulsification time (min) ± SD | 0.9 ± 0.7 | 0.8 ± 0.6 | 0.842 |
Mean arterial pressure = systolic blood pressure × 1/3 + diastolic blood pressure × 2/3.
VAS, visual analog scale, STAI, State-Trait Anxiety Inventory; SD, standard deviation.
Regarding the subjective anxiety measures, the median anxiety scores were lower in patients who underwent second-eye surgery than in patients who underwent first-eye surgery, especially the VAS score for anxiety (Wilcoxon rank-sum test,
VAS scores for pain exceeding 0 were considered to indicate perceived pain during surgery. We found that significantly more patients who underwent second-eye surgery perceived pain during surgery than patients who underwent first-eye surgery (89.79% versus 34.91%, resp.;
Regarding the objective measures, there were no significant differences between the two groups in terms of the type of cataract, mean operating room time, or phacoemulsification time. Furthermore, there were no significant differences in perioperative blood pressure or heart rate between the two groups of patients (Figure
Comparison of blood pressure and heart rate among cataract patients who underwent first-eye or second-eye surgery. SP, systolic pressure; DP, diastolic pressure; MAP, mean arterial pressure; HR, heart rate.
We next analyzed the correlations between the perioperative changes in objective measures (blood pressure and heart rate) and the subjective measures (preoperative anxiety and postoperative pain).
The preoperative VAS anxiety score was significantly and negatively correlated with the postoperative WBS pain score (Spearman’s
Among patients who underwent first-eye surgery, the STAI and VAS anxiety scores were significantly and positively correlated with preoperative heart rate (STAI: Spearman’s
Among patients who underwent second-eye surgery, the VAS anxiety score was significantly and positively correlated with preoperative SBP (Spearman’s
Patients who underwent second-eye surgery (
Differences between two subgroups of patients who underwent bilateral sequential cataract surgery.
Parameter | More pain ( |
Same or less pain ( |
|
---|---|---|---|
Mean age (y) ± SD | 71 ± 11 | 66 ± 8 | 0.073 |
Gender (male/female) | 11/20 | 11/11 | 0.300 |
Median pain (range) | |||
VAS-pain | 2 (1, 8) | 1.5 (0, 4) | 0.032 |
Wong-Baker Faces Pain Rating Scale | 2 (0, 6) | 2 (0, 6) | 0.003 |
Median value of anxiety (range) | |||
STAI | 6 (6, 24) | 9.5 (6, 17) | 0.566 |
VAS anxiety | 1 (0, 8) | 1.5 (0, 5) | 0.293 |
Median cataract (range) | |||
Nuclear | 3 (2, 3) | 3 (2.5, 4) | 0.260 |
Cortical | 0 (0, 1) | 0 (0, 1) | 0.513 |
Posterior subcapsular | 0 (0, 1) | 0 (0, 1) | 0.807 |
Mean operating room time (min) ± SD | 10 ± 2 | 10 ± 4 | 0.831 |
Mean phacoemulsification time (min) ± SD | 0.7 ± 0.3 | 1 ± 0.8 | 0.061 |
SBP/DBP (mmHg) ± SD | |||
Preoperative | 147 ± 21/82 ± 11 | 145 ± 25/83 ± 14 | 0.760/0.815 |
Intraoperative | 153 ± 23/85 ± 13 | 155 ± 22/89 ± 14 | 0.769/0.335 |
Postoperative | 146 ± 23/79 ± 13 | 140 ± 22/78 ± 15 | 0.326/0.640 |
Mean arterial pressure (mmHg) ± SD | |||
Preoperative | 104 ± 13 | 103 ± 17 | 0.959 |
Intraoperative | 108 ± 15 | 110 ± 16 | 0.660 |
Postoperative | 102 ± 15 | 99 ± 15 | 0.451 |
Heart rate (bpm) ± SD | |||
Preoperative | 76 ± 13 | 73 ± 15 | 0.418 |
Intraoperative | 76 ± 12 | 76 ± 14 | 0.960 |
Postoperative | 75 ± 11 | 71 ± 17 | 0.203 |
Mean arterial pressure = systolic pressure × 1/3 + diastolic pressure × 2/3.
SD, standard deviation; VAS, visual analog scale, STAI, State-Trait Anxiety Inventory; SBP, systolic blood pressure; DBP, diastolic blood pressure.
The subgroup of patients who perceived the second-eye surgery to be more painful also reported significantly greater VAS and WBS pain scores compared with the other subgroup (Wilcoxon rank-sum test,
There were no significant differences in perioperative blood pressure or heart rate between the two subgroups of patients (Table
In the subgroup of patients who reported that second-eye surgery was more painful than first-eye surgery, the VAS anxiety score was significantly and positively correlated with preoperative SBP (Spearman
In the subgroup of patients who reported that second-eye surgery was more painful than first-eye surgery, the VAS pain score was significantly and positively correlated with differences between intraoperative and preoperative values for DBP (Spearman’s
For many years, cataract surgery was mainly performed under retrobulbar and nerve-block anaesthesia. Now, most of these ophthalmic procedures are carried out under topical anesthesia. This change in the anesthetic method is clinically significant because topical anesthesia reduces the rate of postoperative complications and reduces the postoperative rehabilitation time. However, patients may experience greater anxiety and pain during surgery. Our study revealed that a significantly greater proportion of patients undergoing second-eye surgery reported surgical pain compared with patients undergoing first-eye surgery, and the former group of patients also reported significantly greater VAS and Wong-Baker pain scores. Because there were no significant differences in age, proportions of males/females, type of cataract, and surgical time, our findings indicate that patients were more likely to experience pain during second-eye surgery and reported more severe pain compared with first-eye surgery, which was consistent with the patients’ chief complaint. The greater pain scores in second-eye surgery were correlated with lower preoperative anxiety scores. Moreover, our findings demonstrate the clinical significance of monitoring perioperative MAP and heart rate to evaluate and predict the levels of anxiety and perceived pain during cataract surgery under topical anesthesia.
Our study also showed that cataract patients were more likely to feel pain and reported significantly greater pain scores, during second-eye surgery compared with first-eye surgery. Our findings are consistent with those reported by Ursea et al. [
According to our results, the greater pain scores in second-eye surgery were likely to be correlated with the lower preoperative VAS anxiety scores compared with first-eye surgery, confirming the studies by Ursea et al. [
Recent studies [
We also examined the correlations between anxiety scores and pain scores, and between subjective measures and objective measures. The results of these analyses confirmed our hypothesis described above.
In all of the enrolled patients, the preoperative anxiety scores were correlated with preoperative blood pressure and heart rate. Among patients who underwent second-eye surgery, the preoperative VAS anxiety scores were significantly correlated with postoperative WBS pain scores. Among patients who reported more severe pain in second-eye surgery than in first-eye surgery, the VAS pain scores were significantly and positively correlated with the differences between the intraoperative and postoperative values for DBP, MAP, and heart rate. Our study also showed that the greater perceived pain during second-eye surgery was correlated with lower anxiety levels before surgery, and the increases in MAP and heart rate during surgery may reflect the subjective pain level.
The results of the subjective (pain and anxiety) and objective (blood pressure and heart rate) measures in this study indicate that cataract patients were more sensitive to pain during second-eye surgery than during first-eye surgery. There was a subtle increase in the severity of pain in second-eye cataract surgery relative to first-eye surgery. This increase in pain appears to be associated with decreased preoperative anxiety scores. Preoperative blood pressure and heart rate could reflect the patient’s anxiety level, while perioperative MAP and changes in heart rate could reflect the patient’s perceived pain level. Therefore, despite considering subjective factors, such as preoperative anxiety monitoring, our findings indicate that perioperative MAP and changes in heart rate may be significant markers for preoperative anxiety and could predict the severity of perceived pain during cataract surgery.
The authors alone are responsible for the content and writing of the paper.
The authors declare that there is no conflict of interests regarding the publication of this paper.
Lin Jiang, Keke Zhang, and Wenwen He contributed equally to this work.
This research was funded by research grants from the National Natural Science Foundation of People’s Republic of China (81100653 and 81470613), the National Health and Family Planning Commission of People’s Republic of China (201302015), and Program of Shanghai 100 Medical Scientist (XBR2011056). The authors appreciate very much the helpful support given by the anesthesiologists, nurse managers, and staff nurses from their medical center and all patients who participated in this study.