Documenting the subjective patient experience of first vs second eye during immediately sequential bilateral cataract surgery

Patients undergoing immediate sequential bilateral cataract surgery often perceive the second surgery as longer, less comfortable, more painful, and less relaxing than the first, despite equivalent surgical durations.

Abstract

Purpose:

To investigate if patients had a subjectively inferior experience during second-eye surgery vs first-eye surgery during immediate sequential bilateral cataract surgery (ISBCS) as both operations were performed within the same surgical visit.

Setting:

Multisurgeon ophthalmic surgical center.

Design:

Survey-based prospective design.

Methods:

Patients of the center undergoing routine cataract surgery who enrolled in the study completed a questionnaire immediately after surgery to describe their surgical experience for each eye. Survey questions measured patient pain, discomfort or pressure, comfort, relaxation, estimated length of surgery, and predicted visual outcome.

Results:

Patient-reported level of pain during the second-eye surgery was significantly greater than for the first eye (P < .001). Furthermore, the order of surgery was found to be a strong predictor of patient-reported pain (P < .001), more so than surgical length (P < .008), additional anesthesia (P < .35), patient age (P < .44), or patient sex (P < .88). Overall, surgery during the first eye was reported as more comfortable (P < .001) and shorter in duration (P < .001), while discomfort and pressure were reported as worse for the second eye (P < .001).

Conclusions:

Understanding differential experiences between eyes can help surgeons when counselling patients regarding expectations for ISBCS and related visual outcomes.

Cataract surgery is the most common ambulatory surgery performed worldwide with a very high surgical success rate.¹ Most patients with bilateral cataracts have surgery first performed in the eye with greater visual deficit and more complex condition as a precautionary measure to preserve vision in the better eye in the event any complications arise.^2–5 The time between surgeries is usually 1 to 6 weeks. The term-delayed sequential bilateral cataract surgery (DSBCS) has been applied to differentiate this surgical routine from immediately sequential bilateral cataract surgery (ISBCS) in which both cataract surgeries are successively performed on the same day. Recently, ISBCS has become increasingly popular among ophthalmologists because the benefits of this procedure become more evident and practical.^6,7 In Ontario, Canada, the number of ISBCS performed increased from 1.02% in 2003/2004 to 2.36% in 2009/2010.⁶ ISBCS increased from 1% to 10% from 2016 to 2022 because of the pandemic.⁸ Nevertheless, there are still barriers to more widespread adoption of ISBSC.^6,9

Advantages of ISBCS include faster rehabilitation of the patient's visual system, lower cost, and simplicity for patients who require general anesthesia.^10–13 Disadvantages include not knowing the refractive outcome of the first eye when planning for second-eye surgery and the risk of bilateral endophthalmitis.^14,15 However, with the advancement of biometry and aseptic techniques, these risks are minimized. When performing ISBCS, each eye must be treated as individual and autonomous.^16,17 If there are any unresolved significant surgical problems during the first surgery, consideration should be given to defer the second surgery.¹⁸ There has been no report of bilateral simultaneous endophthalmitis when these precautionary measures are followed.⁶

During DSBCS, topical anesthesia is used as the preferred anesthesia technique to reduce pain in addition to neurolept anesthesia such as lorazepam, midazolam, and fentanyl.^{2–4,19–21} However, patients still frequently report significant intraoperative pain and anxiety.²⁰ It has been well documented that patients experience different levels of anxiety, discomfort, and awareness between the first-eye and second-eye surgeries despite similar operative and anesthesia conditions.^{2,3,5,19,22,23} Patients often report the second surgery as the more painful procedure.² There are suggestions that memory of the event is distorted over time resulting in more pain and discomfort felt during the second-eye surgery.^5,19,23,24 Despite these perceived differences, numerous studies have shown similar patient satisfaction and visual outcomes when comparing DSBCS and ISBCS.^25–30

Although multiple studies have investigated the differing experiences for DSBCS, we are among the first to investigate it with ISBCS. The goal of our investigation was to compare intraoperative anxiety, pain and discomfort, and awareness between first-eye and second-eye surgeries in patients undergoing ISBCS using a prospective intraindividual observational study. The results of our study can help surgeons better counsel their patients' expectations when considering ISBCS because preoperative education in adult patients is beneficial for surgical outcomes.³¹

METHODS

Study Design

We conducted a prospective observation cohort study on patients undergoing ISBCS at the Kensington Eye Institute, an ambulatory surgical center affiliated with the Department of Ophthalmology & Vision Sciences at the University of Toronto in Toronto, Canada. For this study, 200 patients scheduled for ISBCS under the care of 5 surgeons from January 2023 to December 2023 were surveyed by research staff immediately after the second eye was completed while recovering in the postanesthesia care unit (PACU). Inclusion criteria were any patient undergoing ISBCS who was willing to consent and participate in the survey. If any complication occurred during the first-eye surgery, the second eye would be cancelled, excluding the patient from the study. Any complication during the second-eye surgery would also exclude the patient from the study. Patients were given a questionnaire to compare their first-eye and second-eye surgical experience about surgery duration, comfortability, discomfort/pressure, relaxation, and prediction of relative visual outcome (Appendix 1, available at http://links.lww.com/JRS/B429). Level of pain experienced during the surgery was ranked on a numerical scale ranging from 0 to 10. This questionnaire was adapted from a previous study investigating pain differences between eyes during DSBCS.²

Cataract surgery at Kensington Eye Institute is routinely performed under conscious sedation. Patients receive intravenous administration of intraoperative sedation (midazolam and fentanyl) along with topical anesthetic (tetracaine) and intracameral anesthetic (lidocaine). Patients with increased anxiety and/or sympathetic response (increase in blood pressure, heart rate, and respiratory rate) are given additional medication based on the anesthesiologist's assessment. The order of eye surgery was randomly selected by the surgeon.

The study was approved by the Institutional Review Ethics Boards of the University of Toronto and Kensington Research Institute. Written informed consent was obtained from all patients surveyed.

Statistical Analysis

Statistical analysis and figure preparation were performed using GraphPad Prism (v. 8.0.2 for Windows, Graphpad Software, Inc., www.graphpad.com). All statistical tests used are reported as 2-tailed P values. The Wilcoxon matched pairs signed-rank test was used to compare the mean pain scores. An unpaired t test was used to compare the surgical length between eyes. To determine how different surgical and demographic factors related to mean pain scores, we used a cumulative link mixed models from the R ordinal package (Christensen R, Ordinal-Regression Models for Ordinal Data) (R Core Team, R: A Language and Environment for Statistical Computing). Observed frequencies for questionnaire responses were compared using 2 binomial tests. The first binomial test compared the frequency of responses with a preference for 1 surgery (first surgery + second surgery) with the frequency of responses which reported no difference. For questions which demonstrated significance, a second test was performed to compare the frequencies of patients with a preference for the first surgery to patients with a preference for the second surgery. The “no difference” response served as a neutral answer. Furthermore, responses of “unsure” were omitted from statistical analysis.

RESULTS

Patients (n = 200) undergoing ISBCS were recruited to evaluate their experience between the first and second cataract surgeries (Table 1). The mean age of the study population was 72.6 ± 9.3 years old with an almost equal distribution of men to women, 99 (49.5%) and 101 (50.5%) patients, respectively. All patients completed both surgeries as planned, and there were no reports of any intraoperative complication. Mean length of total surgical time was consistent between eyes at 15.4 ± 4.3 minutes and 14.9 ± 4.5 minutes for the first and second eye, respectively. The overwhelming majority of patients, 190 (95.0%) patients received only midazolam, fentanyl, and oxygen as an anesthetic regimen, with 10 (5.0%) patients receiving adjunct medication as determined by the treating anesthetist. Anesthesia medication was topped off for 135 (67.5%) patients before proceeding with the second eye.

Table 1.

Summary of study demographics and relevant surgical information

Parameter	Group size (n = 200), n (%)	Mean ± SD
Age (y)		72.6 ± 9.3
30-69	64 (32.0)
70-79	93 (46.5)
80+	43 (21.5)
Sex
Male	99 (49.5)
Female	101 (50.5)
Length of each surgery
First eye	200 (100)	15.4 ± 4.3 min
Second eye	200 (100)	14.9 ± 4.5 min
Surgical anesthesia
M/F/O only	190 (95.0)
M/F/O + other	10 (5.0)
Top off before second surgery	135 (67.5)
No top off before second surgery	65 (32.5)

M/F/O = midazolam, fentanyl, and oxygen; other medications used included ephedrine, ativan, labetalol, phenylephrine, or ondansetron

Patients reported that the level of pain during the second surgery was significantly greater than that of the first surgery (P < .001) with pain scores of 0.935 for the first surgery and 1.475 for the second surgery (Figure 1). Furthermore, this trend of increased pain with the second surgery was observed when we subanalyzed patients for sex, age, and those who received an anesthesia top off before the second surgery (Figure 1B–H). Male (P < .001) and female (P < .001) patients both reported a significantly higher level of pain in the second eye as compared with the first eye (Figure 1B and C). Similarly for age, patients younger than 70 (P < .001), 70 to 79 (P < .001), and 80 or older (P = .007) all reported significantly higher pain with the second eye when compared with the first (Figure 1D–F). Both patients who received additional anesthesia before the second surgery (P < .001) and those who did not (P < .001) reported significantly more pain during the second-eye surgery (Figure 1G and H). In addition, we wanted to evaluate whether differing surgical length for the 2 eyes could be confounding the difference in patient-reported pain. We found the mean surgical length to be similar for both eyes with no significant difference when comparing the first eye with the second eye (P = .21) (Figure 1I).

Figure 1.

The second surgery of ISBCS is associated with greater pain than the first surgery. Patient self-reported pain scores using a 0 to 10 ranking scale were obtained for both surgeries shortly after completion of ISBCS. (A) Mean pain scores were compared with the Wilcoxon matched pairs signed-rank test (n = 200). Subanalyses were also conducted for (B) men (n = 99), (C) women (n = 101), (D) ages younger than 70 (n = 64), (E) ages 70 to 79 (n = 93), (F) ages 80 and older (n = 43), (G) patients who did not receive an additional anesthesia top off before the second surgery (n = 65), and (H) patients who did receive an additional anesthesia top off before the second surgery (n = 135). (I) Mean surgical length for the first eye was compared with the second eye using a unpaired t test (n = 200). **P < .01, ***P < .001. ISBCS = immediately sequential bilateral cataract surgery

We next sought to determine how these surgical and demographic factors of surgical order, length, anesthesia, sex, and age contributed to the pain from ISBCS reported by patients. To do this, we then used an ordinal regression model which could explain how each of these factors influenced patient-reported pain (Table 2). We found that surgical order significantly influenced patient-reported pain with the second surgery being 4.48 times more likely to be found painful than the first (P < .001). Surgical length was also found to be significantly associated with increased pain from ISBCS (P = .008); each additional minute of surgery increased the odds of reporting greater pain by 11%. Furthermore, while receiving an additional anesthesia top off before the second eye was associated with an 84% increase in likelihood of reporting greater pain, this association was not significant (P = .35). For sex, male patients were 1.61 times more likely to report higher levels of pain than female patients; however, this association was also nonsignificant (P = .44). Patient age was weak and nonsignificantly (P = .88) associated with patient-reported pain levels, with each year of age increasing the odds of reporting greater pain by 0.5%.

Table 2.

Effects of surgical and demographic factors on patient pain during ISBCS

Factor	Coefficient	Odds ratio	Standard error	z value	P value
Surgery order	1.50	4.48	0.25	5.98	<.001
Length	0.1056	1.11	0.040	2.67	.008
Additional anesthesia	0.612	1.84	0.65	0.935	.35
Sex	0.477	1.61	0.611	0.78	.44
Age	0.0052	1.005	0.034	0.153	.88

ISBCS = immediately sequential bilateral cataract surgery

To further evaluate patient experience during each eye of ISBCS, we also administered a qualitative component of the questionnaire to record which eye patients believed had greater surgical length, more comfort, more relaxation, worse discomfort/pressure, and which eye they felt would have better vision based on their surgical experience.

Patients were first asked to evaluate which eye had a longer surgical procedure, with 124 (62.0%) patients reporting a difference in estimated surgical length between the 2 surgeries (P < .001) (Table 2). The second surgery was associated with greater estimated length by 83 (66.9%) of patients (P < .001). In addition, patients were asked to estimate this difference in length between the 2 surgical durations. We found that patients who reported the second eye as having taken longer estimated a slightly larger albeit nonsignificant surgical length than those who reported a longer surgical duration for the first eye (P = .11) (Supplemental Figure 1, available at http://links.lww.com/JRS/B429). Despite this belief by patients, the actual surgical length trended toward the first surgery being longer than the second, although nonsignificantly (P = .21) (Figure 1I). Taken together, we observe a significant discrepancy in patient perception where on average they overestimate the length of the second surgery in comparison with the first surgery (P = .01) (Supplemental Figure 2, available at http://links.lww.com/JRS/B429).

When asked about pain experienced during surgery, 127 (63.5%) patients reported a difference in discomfort/pressure and 122 (61.0%) patients reported a difference in comfort (P < .001). Of these patients, 106 patients (83.5%) reported worse pain with the second cataract surgery, while only 21 patients (16.5%) reported worse pain during the first surgery (P < .001). Conversely, only 24 patients (19.7%) found the second surgery more comfortable with 98 patients (80.3%) finding the first surgery more comfortable (P < .001).

Similarly for relaxation, 129 patients (64.5%) reported a difference between surgeries (P < .001) (Table 2). Of those patients, 78 (60.5%) reported feeling more relaxed during the first surgery, while 51 (39.5%) reported more relaxation during the second surgery demonstrating a significant association between the second surgery and lower relaxation (P = .03).

When asked to predict which eye will have a better surgical outcome, a minority of 57 patients (28.5%) believed 1 eye would have a better outcome (P = .25). Importantly, this question had 72 patients (36.0%) report “unsure,” a greater frequency than for other questions. However, more patients still predicted the first eye 38 (66.7%) as having better vision outcomes than the second eye 19 (33.3%). Overall, of the 200 patients, 36 (18.0%) reported the first surgery as shorter, more comfortable, more relaxing, and less painful than the second surgery, while only 7 patients (3.5%) found this to be true for the second surgery (Table 3).

Table 3.

Questionnaire responses for patient-perceived surgical duration, comfortability, relaxation, discomfort, and predicted vision outcome

Question	Responses, n (%)				P values
	First surgery	Second surgery	No difference	Unsure	Difference between surgeriesa	Difference was surgery-specificb
Which cataract surgery had worse discomfort/pressure?	21 (10.5)	106 (53.0)	69 (34.5)	4 (2.0)	<.001	<.001
Which cataract surgery was overall more comfortable?	98 (49.0)	24 (12.0)	74 (37.0)	4 (2.0)	<.001	<.001
Which cataract surgery were you more relaxed?	78 (39.0)	51 (25.5)	67 (33.5)	4 (2.0)	<.001	.03
Which surgery took longer?	41 (20.5)	83 (41.5)	57 (28.5)	19 (9.5)	<.001	<.001
Which eye do you think will have better vision?	38 (19.0)	19 (9.5)	71 (35.5)	72 (36.0)	.25	N/A

^aFrequency of (first surgery and second surgery) vs no difference

^bFrequency of first surgery vs no difference

DISCUSSION

Although patient experiences in DSBCS have been the subject of previous studies, the patient experience in individuals undergoing ISBCS has not been thoroughly investigated. In this study, patients undergoing ISBCS were asked to complete a survey comparing length of surgery, comfort, relaxation, and pain level between each surgery. They were also asked to predict which eye would have a superior visual outcome based on their surgical experience.

Our results show that the majority of ISBCS patients perceive a difference in pain, duration, comfort, and relaxation between the 2 surgeries with that difference trending toward a more painful, longer, less comfortable, and less relaxing second surgery. This phenomenon of increased pain during the second surgery was consistent throughout our study population because it was observed for all subanalyses which included patient sex, patient age, and patients who received additional anesthesia before the second surgery. Furthermore, the results of our regression analysis demonstrate that the order of surgery is a major predictor for patient-reported pain, more so than surgical length, anesthesia top offs before the second surgery, patient sex, or patient age. Indeed, the second surgery was 4.48 times more likely to be reported as more painful than the first surgery. Although surgical length was a significant predictor for patient-reported pain, the mean length between surgeries was not significantly different, suggesting surgical length was not a confounder of surgical order in this study. In addition, receiving additional anesthesia before the second surgery was associated with a greater likelihood of reporting more pain; however, these effects were not significant. As well, the differential effects of pain perception during ISBCS were found to not be significantly associated with patient sex or age, further highlighting its independence from these demographic factors.

Consistent with our findings for ISBCS, several studies report that patients undergoing DSBCS perceive more pain during the second surgery compared with the first one, although other studies found no difference.^2,19,32,33 In previous studies looking at DSBCS, this phenomenon has been attributed to patients' memory of the pain from the first surgery being dampened due to the increase in time lapse between the first surgery and when asked to recall the experience.² These studies, however, focus on DSBCS where the time difference between the 2 surgeries can be up to several weeks. This becomes an important consideration when counselling patients on what to expect during ISBCS.

Another goal of this study was to evaluate differences in patient perception of surgical length between eyes for ISBCS. Our finding that ISBCS patients are more likely to report the second surgery as longer than the first surgery is consistent with findings found in patients undergoing DSBCS.^2,3,19,32 Despite many patients perceiving the second surgery as longer than the first, the second surgery was actually on average shorter than the first. This discrepancy may be caused by the patient waiting in the operating room, while it is being prepped for the second surgery, thereby influencing the patient's perception on the length of the second surgery. Alternatively, the perceived length of the second surgery may be caused by an increase in the patient's anxiety as the overall procedure duration increases. This explanation is in line with our findings because patients felt less relaxed during the second surgery. Interestingly, other studies have reported that patients were more relaxed during their second surgery, whereas our patients found the first surgery to be more relaxing.^2,4,34,35 In DSBCS, it is hypothesized that patients undergoing surgery for the second eye have experienced preparation for cataract surgery and are thus less anxious by then.² In ISBCS, the patient is in the operating room for a longer procedure covering both eyes. There may be a sense of growing anxiety because the patient is being prepared for the second surgery. This difference in relative relaxation between ISBSC and DSBCS is thus an important consideration when counselling patients on expectations regarding possible options for bilateral cataract surgeries.

In DSBCS, the eye with greater visual deficit is operated on first, resulting in a larger visual acuity gain compared with the second surgery setting a level of expectation during the second surgery.² In ISBCS, this level of expectation is not set because the second eye is operated on before the visual outcome of the first eye is appreciated. In our study, a substantial number of patients predicted no difference in visual outcome between the eyes and a greater number of patients predicted better visual outcome in the eye operated on first. Many patients were unable to make this prediction.

Although we have uncovered valuable insight into patient experiences regarding ISBCS, our study has some limitations. We did not have a questionnaire before surgery, which may have enabled us to correlate the presurgery and postsurgery responses. In addition, patient responses could have been obtained after each surgery to evaluate comfort in a noncomparative manner. Furthermore, repeating the survey at a 1-week follow-up would have helped in assessing whether patient perceptions of discomfort and duration regarding their surgery changes over time.

To the authors' knowledge, our study is the first to demonstrate that the DSBCS phenomenon of a more painful second cataract surgery is preserved with ISBCS. The second ISBCS surgery was associated with more pain, less comfort, less relaxation, and a longer patient-perceived duration. The only experiential characteristic for ISBCS differing from DSBCS was patient relaxation. The worse patient experience with the second surgery was also reflected in patients' predicting it to have the worse outcome. However, a larger percentage of patients were unsure or felt there would be no difference. Still more patients had a worse experience during the second surgery than the first. Our study highlights the importance of counselling patients on perceptions regarding the second surgery of ISBCS. Patients can be assured that cataract surgery is a very safe and proven procedure that is well tolerated with most patients reporting an overall low pain score. Patients undergoing ISBCS may be counselled preoperatively that the subjective experience may be different between the first and second surgeries, despite undergoing the same procedure. This discussion regarding expectations may help alleviate anxiety regarding the procedure and improve patient experience.

WHAT WAS KNOWN

• Patients experience different levels of anxiety, discomfort, and awareness between eyes during delayed sequential bilateral cataract surgery, and this has been attributed to the time delay between surgeries

• Benefits of immediately sequential bilateral cataract surgery (ISBCS) are becoming more evident.

• We do not know if there any differences in levels of anxiety, discomfort, and awareness between eyes during ISBCS.

WHAT THIS PAPER ADDS

• The delayed sequential bilateral cataract surgery phenomenon of a more painful second cataract surgery is preserved with ISBCS.

• Our study highlights the importance of counselling patients on perceptions of surgical experience during ISBCS.