Effect of Photorefractive Keratectomy On Visual Functioning and Quality of Life

Update on Pain Management After Advanced Surface Ablation

PURPOSE

To provide an update for postoperative pain control strategies to help ophthalmic surgeons establish a more effective management plan for patients who underwent advanced surface ablation surgeries.

METHODS

Google Scholar, Scopus, ScienceDirect, and PubMed were the main resources used to search the medical literature.

RESULTS

The postoperative cornea's healing process is accompanied by intense pain as the chief complaint in the first days after the operation. Several strategies were developed to relieve postoperative pain after surface ablation procedures. These strategies included different preoperative, intraoperative, and postoperative methods. Considering the preoperative demographic and emotional factors, underlying dry eye, alternative epithelial removal techniques, bandage contact lenses, and topical or oral therapeutic agents are some examples of postoperative pain treatments after surface ablation procedures.

CONCLUSIONS

The current review revealed that despite the development of numerous protocols to relieve postoperative pain following surface ablations, the best approach could be a combination of different strategies. In practice, no validated and standardized strategy is available for total elimination of postoperative pain following advanced surface ablation surgeries. [J Refract Surg. 2021;37(11):782-790.].

Past and present of corneal refractive surgery: a retrospective study of long-term results after photorefractive keratectomy and a prospective study of refractive lenticule extraction

Surgical correction of refractive errors is becoming increasingly popular. In the 1990s, the excimer laser revolutionized the field of corneal refractive surgery with PRK and LASIK, and lately refractive lenticule extraction (ReLEx) of intracorneal tissue, using only a femtosecond laser, has become possible. Two new procedures were developed, ReLEx flex (FLEX) and ReLEx smile (SMILE). Until this thesis, only a few long-term studies of PRK with a relatively limited number of patients had been published; therefore, this thesis intended to retrospectively evaluate long-term outcomes after PRK for all degrees of myopia for a large number of patients. Furthermore, a prospective contralateral eye study comparing FLEX and SMILE, when treating high to moderate degrees of myopia, had not been performed prior to this study. This was the second aim of this thesis. In the first study, results from 160 PRK patients (289 eyes) were presented. Preoperative spherical equivalent ranged from -1.25 to -20.25 D, with 78% having low myopia (<-6 D). Average follow-up time was 16 years (range 13-19 years), making this the longest published follow-up study on PRK patients. Outcomes from eyes with low myopia were generally superior to outcomes from eyes with high myopia, at final follow-up. Seventy-two percent were within ± 1.00 D of target refraction, as compared to 47% of eyes with high myopia. However, results from a subgroup of unilateral treated PRK patients indicated that refraction at final follow-up was affected by myopic progression. Fifty percent of eyes with low myopia had uncorrected 20/20 distance visual acuity or better, as compared to 22% of eyes with high myopia. Haze did not occur if attempted corrections were <-4 D, and only eyes with high myopia lost two lines or more of CDVA (corrected distance visual acuity). Eighty-one per cent were satisfied or very satisfied with their surgery.

CONCLUSION

The results support the continued use of the excimer laser for corneal surface ablation as a treatment option for correction of low degrees of myopia, and as the treatment of choice for subgroups of refractive patients (thin corneas, etc.). The results also highlight that treatment of higher degrees of myopia with standard PRK should only be done today under special circumstances, due to low refractive predictability, and high risk of corneal haze. Technological advances since then should be taken into account when comparing these results with contemporary techniques. In the second study, 35 patients were randomized to receive FLEX in one eye and SMILE in the other. Preoperative spherical equivalent refraction ranged from -6 to -10 D with low degrees of astigmatism. A total of 34 patients completed the 6 month follow-up period. Refractive and visual outcomes were very similar for the two methods, as well as tear film measurements and changes in corneal biomechanics. Ninety-seven percent were within ± 1.00 D of target refraction, no eyes lost two lines or more of CDVA, and contrast sensitivity was unaffected after both procedures. The changes in higher-order aberrations were also very similar. There were also no differences in tear film parameters 6 months after surgery, although less postoperative foreign body sensation was reported within the first week after surgery in SMILE eyes. Corneal sublayer pachymetry measurements demonstrated equally increased epithelial thickness 6 months after surgery. Contrary to expectations, it was not possible to measure the theoretical biomechanical advantages of a small corneal incision in SMILE as compared to a corneal flap in FLEX. The main differences between FLEX and SMILE were found when the corneal nerves and intraoperative complications were evaluated. Thus, corneal sensitivity was better preserved and corneal nerve morphology was less affected after SMILE, but intraoperative complications occurred more frequently, although without visual sequela. Finally, 97% were satisfied or very satisfied with both their surgeries.

CONCLUSION

The results support the continued use of both FLEX and SMILE for treatment of up to high degrees of myopia. Overall, refractive and visual results for both procedures were good and similar, but from a biological point of view, the less invasive SMILE technique is more attractive, as demonstrated in this study, despite being slightly more surgically demanding than FLEX.

Quality of life of myopic subjects with different methods of visual correction using the NEI RQL-42 questionnaire

PURPOSE

To evaluate different aspects of the visual-related quality of life using the National Eye Institute Refractive Error Quality of Life (NEI RQL)-42 questionnaire in low and moderate myopic subjects corrected with different refractive treatments including laser-assisted in situ keratomileusis (LASIK), orthokeratology (OK), soft contact lenses (SCLs), and spectacles.

METHODS

The NEI RQL-42 questionnaire was administered to 217 subjects at one single clinic. All the questions consisted of 13 different subscales that were analyzed separately. The results from subjects with -1.00 to -3.00 diopter myopia corrected with LASIK (n=41), OK (n=37), SCLs (n=44), or spectacles (n=45) were compared with each other and with emmetropic subjects (n=50).

RESULTS

Statistically significant differences among all groups were found in all subscales, except for satisfaction with correction (P=0.135). The average decrease in quality of life compared with emmetropes were -7.1% (P=0.021) for LASIK, -13.0% (P<0.001) for OK, -15.8% (P<0.001) for spectacles, and -17.3% (P<0.001) for SCLs.

CONCLUSIONS

Although all patients in each group were considered to be successfully visually corrected, quality of life related to vision was markedly different in certain NEI RQL-42 categories. LASIK showed the lowest average decrease in quality of vision compared with emmetropes. OK was comparable with LASIK in independence of visual correction, and SCL wear was superior to LASIK and OK lens wear in glare. Except for glare and diurnal fluctuations, contact lenses (SCL and OK) were comparable with or superior to spectacle correction.

The Refractive Status and Vision Profile (RSVP): Translation Into Persian, Reliability and Validity

PURPOSE

To translate and test the reliability and validity of a Persian translation of the Refractive Status and Vision Profile (RSVP), a vision-related quality of life questionnaire, in Iran.

METHODS

Forward & backward translation, committee review and pilot testing were performed to develop a final Iranian version of the RSVP. Seventy-three consecutive patients with refractive error before or after refractive surgery at the LASIK ward of Farabi Eye Hospital completed the questionnaire. A convenience sample of 14 patients completed the questionnaire twice within one week. Reliability was measured by internal consistency (Cronbach's alpha) and the intraclass correlation coefficient for test-retest reliability. Validity was evaluated by correlation between the different RSVP subscales, known groups comparison analysis, and correlation between the subscales versus global items and traditional clinical measures.

RESULTS

Internal consistency was high (Cronbach's alpha : 0.71-0.92; except for the subscale expectations, alpha : 0.6). Test-retest reliability of subscales and the overall RSVP scale, as estimated by the intraclass correlation coefficient, was high except for optical problems and glare. Comparisons between pre- and post-operative groups of patients showed significantly higher (worse) scores for concern, physical/social functioning, and the overall score in the pre-operative group. Almost all subscales showed desirable inter-scale correlations.

CONCLUSION

The Iranian version of the RSVP is a reliable and valid measure of vision-related quality of life in patients with refractive error.

Factors influencing patient choice of refractive surgery or contact lenses and choice of centre

PURPOSE

To explore patient demographics and motivations in choosing refractive surgery (RS) or contact lenses (CL) and factors influencing their choice of practice.

METHODS

A questionnaire was presented to 212 RS and 115 CL patients at four RS centres and three CL centres, respectively. The authors, with consent from the clinics and patients, collected all data. No patient or clinic refused to participate in the study.

RESULTS

There was no statistical difference between RS and CL groups for gender (p = 0.28), although in both groups more females presented than males. The mean age of RS patients was 39.2 +/- 10.6 years and for CL patients was 32.0 +/- 12.4 years (p < 0.0001). The occupational differences between RS and CL patients were found to be significant (p < 0.0001). Primary motivations for RS or CL were cosmesis and inconvenience of CL and spectacles. The main reason why RS patients did not choose CL was due to the inconvenience; there was little difference in this whether patients had previously worn CL or not. CL patients did not choose refractive surgery due to lack of information and apprehension. RS and CL patients selected their respective centres primarily due to reputation.

CONCLUSIONS

Refractive surgery appears increasingly to be a lifestyle choice, possibly based on perceptions and psychological aspects that need to be investigated. The popularity of cosmesis as a highly popular factor for RS and CL patients, together with a few patients citing minor contact lens complications suggests that contact lens clinicians may be able to hold onto patients through better management.

Assessing the Value of Laser in situ Keratomileusis by Patient-reported Outcomes Using Quality of Life Assessment

PURPOSE

To assess the value of laser in situ keratomileusis (LASIK) by patient-reported outcomes using quality of life assessment.

METHOD

This study included 288 consecutive patients treated by LASIK between July and December 2001 at two eye clinics. A Myopia-specific Quality of Life Questionnaire was developed in this study. The baseline quality of life corresponding to the situation where refractive error was corrected by glasses or contact lenses before LASIK treatment was evaluated by self-administered questionnaire. The evaluation was repeated at 4 days, and 1, 3, and 6 months after LASIK treatment. All question items were rated on a scale ranging from 1 (maximal dysfunction) to 5 (minimal dysfunction).

RESULTS

Factor analysis identified 34 questions in 4 subscales-visual function, visual symptoms, social role function, and psychological well-being. The Myopia-specific Quality of Life Questionnaire subscales proved to be internally consistent (Cronbach alpha = 0.70-0.95). Criterion validity was assessed by evaluating Spearman correlation between the overall or domain-specific quality of life and traditional measures of patient status. Overall Myopia-specific Quality of Life Questionnaire score changed from 3.21 preoperatively to 3.76, 4.00, 4.07, and 4.11 at 4 days, and 1, 3, and 6 months after surgery, respectively. Social role function showed the biggest improvement (score change: 1.51, P < .05), followed by psychological well-being (0.90, P < .05), visual function (0.72, P < .05), and visual symptoms (0.49, P < .05). Regression analysis results showed that the degree of uncorrected visual acuity, discomfort associated with myopia preoperatively, and location of eye center were significant factors affecting the magnitude of changes in quality of life after LASIK.

CONCLUSIONS

This study confirms that the value of LASIK went beyond the clinical achievement of refractive correction and extended to the improvement of quality of life.

Development of a Questionnaire to Assess Subjective Vision Score in Myopes Seeking Refractive Surgery

PURPOSE

To assess vision in patients with myopia and myopic astigmatism before and after refractive surgery.

METHODS

A prospective controlled study of visual quality amongst myopes and astigmatic myopes. Focus groups, ophthalmic surgeons, and questionnaire experts devised a Subjective Vision Questionnaire (SVQ), modified after a pilot trial. Participants were administered the SVQ before clinical evaluation. Items answered by over 95%, with factor loadings > 0.55 were included. Test-retest reliability was assessed by repeat testing. Factor analysis identified groups of questions measuring particular dimensions of data.

RESULTS

Sixty-seven items were answered by 128 patients and reduced to 24 items in a final questionnaire. Factor analysis identified six types of questions within the questionnaire, the most important of which was related to driving.

CONCLUSION

The simplicity, low cost, and psychometric properties of the Subjective Vision Questionnaire support its use clinically and in research.

Defining the content of patient questionnaires: reasons for seeking laser in situ keratomileusis for myopia

PURPOSE

To determine the relative importance of patients' motives for having laser in situ keratomileusis (LASIK) for myopia.

SETTING

The Corneal Diseases and Excimer Laser Research Unit, University of Dundee, Ninewells Hospital and Medical School, Dundee, Scotland.

METHODS

Twenty-one cards printed with potential reasons for having LASIK and 3 blank cards for respondents to include additional motives were posted to 71 patients who had myopic LASIK. The cards were ranked by each respondent in order of personal importance and returned for analysis.

RESULTS

The response rate was 77.5%. The mean age of the 19 male and 37 female respondents was 41.7 years +/- 9.3 (SD) and the mean preoperative spherical equivalent, -9.26 +/- 4.58 diopters. The primary reasons for seeking treatment (percentage of respondents ranking topic within the top 5) were improvement of unaided social vision (69.1%), intolerance to spectacles/contact lenses (65.5%), and freedom from spectacles/contact lenses (61.8%). Almost 70% of respondents ranked 1 of these reasons as the most important. General inconvenience of spectacles/contact lenses and the desire to pursue sports and leisure activities also ranked high (52.7% and 36.4%, respectively).

CONCLUSIONS

Consistent with previous work, better unaided vision, combined with the inconvenience of or intolerance to spectacles or contact lenses, provided the main incentives to have LASIK for myopia, while improved cosmesis was relatively unimportant (29.1%). The results of this study will allow the design of satisfaction questionnaires that are better directed toward establishing satisfaction of specific, relevant functional and psychological aspects of refractive surgery that are important to patients.

Development of a questionnaire for measurement of vision-related quality of life

PURPOSE

To define vision-related quality of life, to outline the development of a vision-specific quality of life instrument and to present the characteristics of a 10-item 'core' questionnaire.

METHOD

A standard method included: 1. Generation of relevant issues by individual interviews with 38 visually impaired adults, consultation with 37 professionals and support workers and literature review. 2. Operationalisation, involving 58 ophthalmic patients. 3. Pre-testing, to maximise face validity and content validity, involving 184 individuals with a variety of different visual problems and social backgrounds. 4. Adoption of a modular approach to item selection. 5. Formal piloting in 92 individuals to establish reliability and construct validity.

RESULTS

More than 232 items were tested of which 139 were considered suitable for a final question pool or 'parent' questionnaire (the VQOL). From this parent questionnaire individual items or groups of items can be selected. Ten broadly applicable items referring to physical, social and psychological issues were selected for the core questionnaire (the VCM1). The VCM1 has high reliability (alpha = 0.93) and validity.

CONCLUSIONS

Any self-reported problem relating to vision may constitute a quality of life issue. A modular approach to item selection may provide the flexibility to investigate vision-related quality of life in a wide range of clinical settings, allowing detailed assessment of specific problems and also cross-study comparisons where appropriate.

Efficacy and safety of the ProTek (Vifilcon A) therapeutic soft contact lens after photorefractive keratectomy

PURPOSE

To test the ProTek (Vifilcon A) therapeutic soft contact lens in the alleviation of post-photorefractive keratectomy pain, its effect on epithelial healing, and its safety.

METHODS

Forty-seven consecutive eligible patients undergoing unilateral excimer laser photorefractive keratectomy for myopia were randomly assigned to receive standard postoperative care with or without the use of a ProTek soft contact lens. Patients prospectively graded a self-administered 5-point scale for pain and a 4-point scale for abnormal sensations at 4, 8, 12, 16, and 20 hours after surgery. They also recorded the type and dose of all medications taken during that time period. All patients were examined on the first and third days after surgery. The lenses were worn continuously for 3 days.

RESULTS

The soft contact lens group (n = 24) disclosed a statistically significant (P < .05) reduction in pain intensity and abnormal sensations that was greatest at 8, 12, 16, and 20 hours postoperatively. Compared with control patients (n = 23), the soft contact lens group showed significant decreased dependence on most pain medications after the 12th hour (P < .05) and faster epithelial healing (P = .03). However, one case of bacterial keratitis, two cases of subepithelial infiltrates, and seven cases of contact lens intolerance were present in the soft contact lens group.

CONCLUSIONS

The ProTek therapeutic soft contact lenses were effective in decreasing pain and other related abnormal sensations after excimer photorefractive keratectomy. They decreased dependence on pain medications and hastened epithelial healing but were not well tolerated in some patients.