Patient Satisfaction After LASIK

Am J Ophthalmol. 1994 Mar 15;117(3):394-8.Links
Keratorefractive surgery, success, and the public health.
Maguire LJ.

From the article:
"A [LASIK] patient may simultaneously be happy with the result of surgery and have degraded vision – how can refractive surgery be a potential public health problem if patients are happy with the results? Inherent in this question is the assumption that a patient without complaint is a patient without optical degradation. That argument does not hold up to closer scrutiny. The [LASIK] literature contains disturbing examples of patients who have visual handicaps that place themselves and others at significant risk for nighttime driving accidents and yet they are happy with the results".

Note: In the following case report, the patient developed ectasia, a devastating complication which may require corneal transplantation. This is a perplexing example of patient satisfaction in spite of a serious, sight-threatening complication.

Journal of Cataract & Refractive Surgery
Analysis of ectasia after laser in situ keratomileusis: Risk factors
Volume 33, Issue 9, Pages 1530-1538 (September 2007)
Perry S. Binder

From the article:
Two contralateral eyes developed ectasia 2 years after LASIK (Figure 1). This patient was still satisfied with the surgery as the least involved eye has 20/30 uncorrected visual acuity.

CLAO J. 2001 Apr;27(2):84-8.
Patient satisfaction after LASIK for myopia.
Miller AE, McCulley JP, Bowman RW, Cavanagh HD, Wang XH.
University of Texas Southwestern Medical Center at Dallas, USA.

PURPOSE: To determine satisfaction among patients treated with laser-in-situkeratomileusis (LASIK) for various degrees of myopia (-0.75 D to -16.00 D) and myopic astigmatism (+0.50 D to +4.50 D) and assess factors which may affect satisfaction.

METHODS: One-hundred seventy-four consecutive patients treated with LASIK between November 1, 1997 and October 31, 1998 were surveyed. Charts were reviewed to collect refractive data.

RESULTS: Eighty-three patients (163 eyes) returned surveys for a response rate of 53%. Of the responders, 55% were female, the average age was 39.6 years (range 21-59), the mean preoperative sphere was -6.36 +/- 0.23 D, cylinder +0.94 +/- 0.07 D, and spherical equivalent-5.89 +/- 0.23 D. Ninety-six percent of eyes enjoyed freedom from corrective lenses following LASIK. Twenty-nine percent reported reduced night vision clarity following LASIK and 27% noted more eye dryness following LASIK. Overall, 84.8% were at least "very pleased" with the results of the procedure and 97% indicated that they would decide again to have LASIK. Uncorrected visual acuity and lower preoperative cylinder correlated positively with satisfaction, while increased postoperative dry eyes correlated negatively with satisfaction.

CONCLUSIONS: This study demonstrates a very high level of patient satisfaction following excimer laser treatment for myopia and myopic astigmatism. A great deal of literature has evaluated objective outcomes of LASIK, but this is one of few studies to examine patient satisfaction.

Note: The patient In this case report has considerable compound myopic astigmatism after LASIK. The surgical goal of reduced dependency on glasses or contact lenses was not achieved. This patient's outcome does not meet the definition of a "successful" LASIK by anyone's standards, yet the patient claims to be satisfied.

J Refract Surg. 2007 Nov;23(9):937-40
Fifteen-year follow-up after LASIK: case report.
Kymionis GD, Tsiklis N, Pallikaris AI, Bouzoukis DI, Pallikaris IG.

PURPOSE: To present 15-year follow-up of one of the first LASIK-treated patients.

METHODS: A 40-year-old woman underwent LASIK in the left eye for myopia in July 1991.

RESULTS: Fifteen years after LASIK, spherical equivalent error was statistically significantly reduced from preoperative -8.75 -3.75 x 025 degrees to postoperative -4.25 -2.75 x 010 degrees. Six months postoperatively, refractive and topographic stability was obtained and remained stable during follow-up with no significant changes between interval mean time (-3.75 -3.00 x 020 degrees 6 months postoperatively to -4.25 -2.75 x 010 degrees 15 years postoperatively). No early or late postoperative complications were observed, and confocal microscopy revealed a regenerated nerve plexus and normal cornea. However, increased scattering and presence of debris were observed at the flap interface even after 15 years. Despite moderate predictability (residual refractive error) and small optical zone, the patient was satisfied with final outcome.

CONCLUSIONS: One of the first LASIK-treated patients was presented 15 years after surgery. LASIK in this patient had low predictability, although refractive and topographic stability occurred after the sixth postoperative month. No long-term, sight-threatening complications were identified during follow-up.

From the full text: "Unexpectedly, the patient was satisfied with the final outcome despite considerable residual compound myopic astigmatism."

J Cataract Refract Surg. 2005 Oct;31(10):1943-51.
Functional outcomes and patient satisfaction after laser in situ keratomileusis for correction of myopia.
Tahzib NG, Bootsma SJ, Eggink FA, Nabar VA, Nuijts RM.

From the article:
" A total of 92.2% of patients were satisfied or very satisfied with their surgery, 93.6% considered their main goal of surgery achieved, and 92.3% would choose to have LASIK surgery again. Satisfaction with uncorrected vision was 3.03 +/- 0.71. The mean score for glare was 3.0 +/- 0.9. At night, glare from lights was believed to be more important than before surgery by 47.2%. Glare from oncoming car headlights after surgery was reported by 58.4% and was believed to be more bothersome for night driving than before surgery by 52.8%. Night driving was rated more difficult than before surgery by 39.4%, whereas 59.3% had less difficulty driving at night."

J Cataract Refract Surg. 2005 Dec;31(12):2313-8.
Sensitivity of the National Eye Institute Refractive Error Quality of Life instrument to refractive surgery outcomes.
Nichols JJ, Twa MD, Mitchell GL.

From the article:
"One might also predict these 2 groups to report a significant difference in glare. However, the design of the clinical trial for these LASIK patients limited enrollment to those who were unlikely to experience this problem (ie, low to moderate myopia and pupil sizes less than 7.5 mm)."

Cesk Slov Oftalmol. 2006 May;62(3):206-17.
Effect of lasik on objective and subjective visual functions in patients with myopia
Hejcmanova M, Horackova M.
Ocni klinika, LF MU, FN Brno-Bohunice. m_hejcmanova@hotmail.com

PURPOSE: To determine the effect of laser in situ keratomileusis (LASIK) on visual functions: visual acuity (VA) and contrast sensitivity (CS) and to evaluate functional complaints.

PATIENTS AND METHODS: Prospective study includes results of VA and CS preoperatively and 1, 3, 6 and 12 months after the surgery in patients with middle and high myopia. 105 eyes of 53 patients (37 females, 16 males) were divided according to spherical equivalent into 2 groups: group A (more than -5D, 51 eyes) and group B (less than -5D, 54 eyes). Mean patients'
age was 28,2 years. Visual acuity was measured on log MAR charts. Contrast sensitivity at spatial frequency of 3, 6, 12 and 18 c/deg was tested using CSV 1000 Contrast sensitivity Unit. Influence of glare on CS was determined by BAT (Brightness Acuity Tester). Functional complaints were evaluated using a wide-ranging questionnaire focusing on 4 main topics.

RESULTS: Visual acuity preoperatively in both groups was significantly decreased in comparison to controls. A considerable decrease can be detected at 1 month postoperatively but later (1 year after the surgery) it reaches the values of 1.02. Postoperatively, a significant decrease of CS can also be detected, above all at intermediate spatial frequencies. During postoperative period, values of CS slowly increase in both groups. However, only in group B (with less than -5D), the preoperative values have been reached. Further, glare has decreased CS at spatial frequency of 6 c/deg, i.e. the most sensitive spatial frequency for human eye. The satisfaction with final outcome has reached 91%. However, some patients (14%) reported reduced vision under dim illumination and at night and also difficulty with night time driving.

CONCLUSIONS: Our study suggests that both used methods (VA and CS) are very sensitive to evaluation of visual functions after refractive surgery. Changes of contrast sensitivity can reveal even slightly changed optic factors of cornea that can
cause subjective complaints of patients.

Ophthalmology. 2002 Jan;109(1):175-87.
Laser in situ keratomileusis for myopia and astigmatism: safety and efficacy: a report by the American Academy of Ophthalmology.
Sugar A, Rapuano CJ, Culbertson WW, Huang D, Varley GA, Agapitos PJ, de Luise VP, Koch DD.
Ophthalmic Technology Assessment Committee 2000-2001 Refractive Surgery Panel.

OBJECTIVE: This document describes laser in situ keratomileusis (LASIK) for myopia and astigmatism and examines the evidence to answer key questions about the efficacy and safety of the procedure.

METHODS: A literature search conducted for the years 1968 to 2000 retrieved 486 citations and an update search conducted in June 2001 yielded an additional 243 articles. The panel members reviewed 160 of these articles and selected 47 for the panel methodologist to review and rate according to the strength of evidence. A Level I rating is assigned to properly conducted, well-designed, randomized clinical trials; a Level II rating is assigned to well-designed cohort and case-control studies; and a Level III rating is assigned to case series and poorly designed prospective and retrospective studies, including case-control studies.

RESULTS: The assessment describes randomized controlled trials published in 1997 or later (Level I evidence) and more recent comparative and noncomparative case series (Level II and Level III evidence), focusing on results for safety and effectiveness. It is difficult to extrapolate results from these studies that are comparable to current practices with the most recent generation lasers because of the rapid evolution of LASIK technology and techniques. It is also difficult to compare studies because of variations in the range of preoperative myopia, follow-up periods, lasers, nomograms, microkeratomes and techniques, the time frame of the study, and the investigators' experience.

CONCLUSIONS: For low to moderate myopia, results from studies in the literature have shown that LASIK is effective and predictable in terms of obtaining very good to excellent uncorrected visual acuity and that it is safe in terms of minimal loss of visual acuity. For moderate to high myopia (>6.0 D), the results are more variable, given the wide range of preoperative myopia. The results are similar for treated eyes with mild to moderate degrees of astigmatism (<2.0 D). Serious adverse complications leading to significant permanent visual loss such as infections and corneal ectasia probably occur rarely in LASIK procedures; however, side effects such as dry eyes, night time starbursts, and reduced contrast sensitivity occur relatively frequently. There were insufficient data in prospective, comparative trials to describe the relative advantages and disadvantages of different lasers or nomograms.

LARRY JOACHIM Sugar Land, Texas:
"My eyesight before LASIK was about 20/900--which amounts to being legally blind. Three weeks after LASIK, I am at 20/50. I'm using artificial tears pretty regularly, but I am thrilled that I can see what I could not before. Was I expecting better? Sure! Am I satisfied? You bet!"
http://www.time.com/time/magazine/article/0,9171,992418,00.html

OSN SuperSite Breaking News 9/18/2006
At 5 years, LASIK patients remain happy with results

From the article:
Of those who responded to the questionnaire, 6.2% indicated they had worse vision now than before LASIK, and 21% said their night vision was worse than it was before. "But when you ask people if they would do laser again, everyone, bar none, said they would do it again, and 100% said they would refer a friend," Dr. Cummings said.

J Cataract Refract Surg. 2004 Sep;30(9):1861-6.
Reasons patients recommend laser in situ keratomileusis.
Bailey MD, Mitchell GL, Dhaliwal DK, Wachler BS, Olson MD, Shovlin JP, Pascucci SE, Zadnik K.
Ohio State University College of Optometry, Columbus, OH 43210, USA.
mbailey@optometry.osu.edu

PURPOSE: To evaluate the reasons patients who have had laser in situ keratomileusis (LASIK) recommend it to others and examine the disparity between high levels of satisfaction and patient reports of night-vision symptoms and/or dry eye after LASIK.

SETTING: Northeastern Eye Institute, Scranton, and the University of Pittsburgh, Pittsburgh, Pennsylvania, and the University of California at Los Angeles, Los Angeles, California, USA.

METHODS: Questionnaires assessing symptoms and satisfaction after LASIK were mailed to 2,100 patients. The questionnaires included items about nightvision symptoms and satisfaction and an open-ended question for patients to give their reasons for recommending LASIK to others. The open-ended responses were categorized and tabulated.

RESULTS: Four hundred thirty-four patients provided reasons for recommending LASIK to others. Sixteen categories of reasons were identified. "No more spectacles/contact lenses" was listed by 180 patients (42%), followed by "better vision" (21%) and "convenience" (15%). Women were significantly more likely to cite "better comfort" (27 women versus 3 men; chi square = 8.99, P =.003) and "better quality of life" (41 women versus 9 men; chi square = 7.36, P =.007) as a reason for recommending LASIK. Of the 35 patients who reported dissatisfaction with post-LASIK vision, 20 (57%) would recommend LASIK to a friend because "LASIK helps others."

CONCLUSIONS: Categories of reasons for recommending LASIK to others were similar to reasons given by patients for seeking LASIK. Some patients who reported dissatisfaction with their vision said they would recommend LASIK, suggesting that recommendation of LASIK to others is not necessarily a measurement of the quality of a patient's vision after LASIK.

From the full text:

Previous investigations have characterized patient satisfaction and complaints, such as night-vision symptoms and dry eye, after laser in situ keratomileusis (LASIK).1, 2, 3, 4, 5, 6 Although night-vision symptoms have been reported in 12% to 57% of patients3, 4, 5, 6, 7, 8, 9 and dry-eye symptoms have been reported in 4% to 9%,2, 10 post-LASIK satisfaction remains very high. For example, Hill6 reported that 15 (7.5%) of 200 patients considered their night-vision symptoms to be “considerably worse” than before LASIK. Yet, 195 of them (97.5%) reported they were “extremely happy” and only 1 reported being “slightly unhappy.” Similar disparities have been reported after photorefractive keratectomy (PRK). Brunette et al.11 found that 31.7% of PRK patients reported a decrease in night vision; nevertheless, 91.8% were satisfied or very satisfied with their surgery. In a previous study,9 we characterized the factors associated with nightvision symptoms and decreased satisfaction following LASIK. We also found a disparity between the relatively frequent report of postoperative night-vision symptoms and high patient satisfaction. Ninety-seven percent of patients in our sample of LASIK patients would recommend LASIK to a friend.9 When asked to rate satisfaction with their vision, patients reported a median score of 100% of the maximum value on the visual analogue scale (mean 87.2%). Yet, 30.0% reported halos, 27.2% reported glare, and 24.5% reported starbursts when asked about these symptoms in a questionnaire. While this disparity can be explained by assuming that the symptoms were not severe enough to adversely affect satisfaction reports, there may be other explanations.

The purpose of this study was to further investigate explanations for this disparity by examining and categorizing the reasons post-LASIK patients say they would recommend LASIK to a friend. We also looked for associations between categories of reasons for recommending LASIK and factors known to be associated with an increase in postoperative night-vision symptoms and decreased satisfaction after LASIK. There is more than 1 plausible explanation for the disparity between the relatively common frequency of postoperative complaints and the high levels of satisfaction after LASIK. The first is that the night-vision symptoms and symptoms of dryness after LASIK are mild relative to the benefits of LASIK, so patient satisfaction remains high. There are, however, other explanations.

The discrepancy between symptoms and satisfaction has also been reported after PRK. Brunette et al.11 conclude, “[Patients'] self-conditioning to the belief in the success of this expensive and irreversible surgery was not assessed in the present study. However, if such a psychological process prevailed, one would expect patients to deny the secondary effects such as glare and night vision problems. This was not the case here. Patients may simply adapt to their new condition.” The idea that patients may adapt to their new condition is a second explanation for the disparity between symptoms and satisfaction. The third explanation for this disparity is one that is dismissed by Brunette et al. Although a specific “psychological process” is not mentioned in their report, they may be referring to a process called cognitive dissonance. The theory of cognitive dissonance suggests that individuals need to have consistency among their attitudes or beliefs.15 The theory can apply to many types of decisions, ie, purchases and surgical procedures, and the effects of cognitive dissonance have been investigated in nonocular surgical procedures.16, 17 Certain criteria are required for dissonance to be induced following a decision.18 First, the decision must be important and the consumer/patient must have invested substantial money or psychological cost. Second, the consumer/patient must freely choose to make the purchase or have the surgical procedure. Finally, the commitment must be irreversible. It is evident that the LASIK procedure meets all 3 criteria for inducing cognitive dissonance in patients who have post-LASIK complications/side effects. Homer and coauthors17 predict that cognitive dissonance might have less effect on specific questions about symptoms and a greater effect on questions about the overall success of the surgical procedure, such as whether the patient would have the procedure again or recommend the procedure to others. This prediction is supported by our previous study in LASIK patients and by Brunette et al.9, 11 Cognitive dissonance should be explored in future studies as an explanation for the disparity between the relatively frequent occurrence of postoperative symptoms and the high levels of satisfaction.

J Cataract Refract Surg. 2003 Jun;29(6):1152-8.
Six-year follow-up of laser in situ keratomileusis for moderate and extreme myopia using a first-generation excimer laser and microkeratome.
Sekundo W, Bönicke K, Mattausch P, Wiegand W.
Department of Ophthalmology, Philipps-University Marburg, Germany. sekundo@med.uni-marburg.de

PURPOSE: To evaluate objectively and subjectively the long-term outcome of laser in situ keratomileusis (LASIK) in patients with high and very high myopia.

SETTING: Department of Ophthalmology, Philipps University, Marburg, Germany.

METHODS: Thirty-three eyes of 19 patients were followed for a mean of 76 months (range 50 to 84 months) after primary LASIK using the Keratom I excimer laser (Schwind) and the ALK microkeratome (Chiron). Refraction, glare, pachymetry, corneal topography, and tear-film secretion and stability were measured. At the last examination, patients also answered a 14-item questionnaire.

RESULTS: Preoperatively, the mean spherical equivalent was -13.65 diopters (D). At 1 year, it was -0.25 D and after 6 years, -0.88 D. Fifteen percent of eyes lost > or =2 lines of best spectacle-corrected visual acuity (BSCVA), and 9% gained > or =2 Snellen lines. At the end of the study, 46% of eyes were within +/-1.0 D of the attempted corrected and 88% were within +/-3.0 D. There were 5 microkeratome-associated complications; 3 resulted in loss of BSCVA. The latest pachymetry showed a mean corneal thickness of 498.5 microm (range 396 to 552 microm). There were no cases of keratectasia. Seventy-five percent of patients noted an increase in their quality of life. Seventy-one percent were satisfied with their postoperative visual acuity; however, 75% noticed glare and halos at night.

CONCLUSIONS: Laser in situ keratomileusis correction of very high myopia did not cause keratectasia in the long term provided the corneal thickness was respected. A flap thickness setting of 130 microm with a first-generation microkeratome resulted in a high number of cut failures. Most patients were happy with the results despite a modest level of accuracy and glare.

From the full text:
"On a scale of 0 to 10 for current satisfaction with one’s visual acuity, the mean score was 5.7. Scores from 0 to 4 were considered “being unhappy”; 29% of patients were not happy with their UCVA. This percentage was smaller than that immediately after surgery, 35%. Eighty-one percent noticed an improvement in their UCVA after surgery as opposed to the time before LASIK. Twenty-eight percent of patients described their BSCVA as “worse than before surgery” and 72%, as better or unchanged. The preoperative refraction of patients who were dissatisfied with their BSCVA was –12.0 D."

"There were no microkeratome-associated complications in this group; however, 2 eyes of the same patient developed severe
dry-eye disease and peripheral epithelial ingrowths and 2 eyes had decentrations of 1.5 mm and 2.0 mm. After almost 7 years, 75% continued to complain of ghosting images and/or halos. Patients who graded their halos between 8 and 10 also felt a decline in their BSCVA (see above) and had irregular flaps due to cut failures or a preoperative refraction greater than –15.0 D. However, 81% of all patients questioned said they would recommend the surgery to friends and would have the surgery again."

"Our study highlights the problems of quality of vision. Often, Snellen acuity, particularly after enhancements, is given as a measure of success.11, 12 Nevertheless, 75% of our patients have glare at night, with the worst symptoms in patients who had decentrations, cut problems, or treatments over –15.0 D with subsequent flat corneas down to 32.5 D in 1 extreme case. Our decentration rate of >0.5 mm was 15%. This relatively high number can be the result of using retrobulbar anesthesia and pilocarpine in contrast to patient self-fixation supported by the eye-tracker technology of modern lasers. Objectively, virtually all patients in this study had poor mesopic vision. Moreover, our study leaves no doubts that this problem continues to persist in the long term and possibly forever."

"A question still to be answered is why 81% of patients appeared to be quite happy with the overall results when all of them had poor night vision."

http://www.sciencedaily.com/releases/2002/01/020115074604.htm

Excerpts:
"Nearly a quarter to a third of patients that underwent LASIK surgery reported problems seeing at night, a new study suggests. Even so, 97 percent of the subjects said they would recommend LASIK to a friend."

"The researchers sent questionnaires to 605 patients, asking if they were satisfied with the surgery or if they had nighttime vision problems. They also examined the patients' medical charts. All subjects in the study had at least six months of recovery time."

"Ninety-seven percent of the patients in the study said they would recommend LASIK to a friend, in spite of the side effects. Of the patients that would make the recommendation, on average, one out of four experienced some nighttime vision problems, compared to an average of two out of three patients who would not recommend the surgery."

J Cataract Refract Surg. 2005 Aug;31(8):1537-43.
Changes in quality of life after laser in situ keratomileusis for myopia.
Garamendi E, Pesudovs K, Elliott DB.
Department of Optometry, University of Bradford, Richmond Road, Bradford, West Yorkshire, United Kingdom. e.garamendi2@bradford.ac.uk

PURPOSE: To measure quality of life (QoL) outcome in prepresbyopic myopic patients having laser in situ keratomileusis (LASIK) refractive surgery using the Quality of Life Impact of Refractive Correction (QIRC) questionnaire and to compare the QoL of preoperative patients with a sample of spectacle and contact lens wearers not considering refractive surgery.

SETTING: Department of Optometry, University of Bradford, Bradford, and Ultralase, Leeds, West Yorkshire, United Kingdom.

METHODS: The validated QIRC questionnaire was prospectively completed by 66 patients before and 3 months after LASIK. Patients had myopia greater than 0.50 diopters (D) (range --0.75 to --10.50 D) and were aged 16 to 39 years. Patients were also directly asked to evaluate their QoL after surgery.

RESULTS: Overall QIRC scores improved after LASIK from a mean of 40.07+/- 4.30 (SD) to 53.09+/- 5.25 (F(1,130)=172.65, P<.001). Greater improvements occurred in women (53.83+/- 5.46) than in men (49.39+/- 5.94; F(1,64)=9.37, P<.005). Overall, 15 of the 20 questions (especially convenience, health concerns, and well-being questions) showed significantly improved scores (P<.05). Patients who "strongly agreed" (53.96+/- 4.91, n=33) or"agreed" (51.78+/- 6.19, n=23) had improved QoL and had significantly higher QIRC scores than those who "neither agreed nor disagreed" (44.36+/- 4.97, n=5) or "strongly disagreed" (42.82, n=1) (F(1,60)=11.24, P<.001). The matched group not contemplating LASIK scored 42.41 +/- 3.89 on QIRC overall.

CONCLUSIONS: Large improvements in QIRC QoL scores were found after LASIK for myopia in the majority of patients, with greater improvements in women. Asmall number of patients (4.5%) had decreased QIRC QoL scores, and these were associated with complications. People presenting for LASIK scored measurably poorer than matched patients not contemplating refractive surgery.

From the full-text:
"McDonnell et al.8 assessed refractive-error-related QoL in patients following refractive surgery with the NEI-RQL; a 42-item questionnaire that included subscales related to clarity of vision, expectations, near vision, far vision, diurnal fluctuations, activity limitations, glare scale, symptoms, dependence on correction, worry, suboptimal correction, appearance, and satisfaction with correction. Improved QoL was mostly correlated with expectations, near and far vision, diurnal fluctuations, activity limitations, symptoms, dependence on correction, worry, perceptions about having suboptimal correction, appearance, and satisfaction with correction. However, symptoms of glare were significantly worse after refractive surgery and clarity of vision showed no significant change. Schein and coauthors7 used the RSVP, a 42-item questionnaire to measure vision-related health status in patients with refractive error including domains such as concern, driving, expectations, physical and social functioning, symptoms, optical problems, glare, and problems with corrective lenses. Patients reported significantly improved QoL after refractive surgery in subscales related to expectations, physical and social functioning, and problems with corrective lenses. However, driving, symptoms, optical problems, and glare showed significantly worse scores after surgery."

"A small number of patients (n=3; 4.5%) had overall lower QIRC QoL scores after surgery. One former high myope was very disappointed with her quality of vision, and 2 former moderate myopes reported having better vision with their contact lenses prior to surgery than postoperatively. Their QIRC scores showed a worsening in items related to visual function, symptoms, concerns, and wellbeing. One patient (high myope), who had a significantly lower score postoperatively (preoperative QIRC score 50.57; postoperative QIRC score 42.82), “strongly disagreed” that her QoL improved after refractive surgery. This patient reported some common complications of laser refractive surgery such as having better vision with contact lenses prior to surgery, eyes sensitive to bright light, and misty and unclear vision, especially when driving at night."

"the optical zone was at least 6.0 mm, increased to 0.5 mm greater than the scotopic pupil for pupils over 5.5 mm".

"... other factors, such as the Hawthorne effect and cognitive dissonance, should be considered. Participating in a clinical trial or study can make patients report a significant positive effect of the surgery due to the added attention being made toward them (the Hawthorne effect)."

"Cognitive dissonance states that a change in attitude or belief occurs in an attempt to be consistent with the choice taken. Patients who have chosen to have surgery could justify this choice by indicating that the outcome was successful".