Patient and surgeon experience during laser in situ keratomileusis using 2 femtosecond laser systems

Perioperative Recommendations for Corneal Refractive Surgery Patients With Inherited Bleeding Disorders

PURPOSE

To synthesize the current literature regarding patients with inherited bleeding disorders and suggest comprehensive evaluation and preoperative recommendations for these patients before undergoing corneal refractive surgery.

METHODS

The literature search was conducted through PubMed, Embase, and Google Scholar databases for publications through January 4, 2024 for reports of ocular bleeding manifestations in patients with inherited bleeding disorders and reports of patients without a history of bleeding disorders who had intraoperative or postoperative hemorrhagic complications with corneal refractive surgery. Additional cases from the literature and a retrospective chart review at a corneal practice were obtained describing patients with inherited bleeding disorders who underwent corneal refractive surgery.

RESULTS

Four articles were found detailing ocular bleeding manifestations in patients with inherited bleeding disorders who underwent ocular surgery other than corneal refractive surgery. Thirty articles were found detailing intraoperative and postoperative bleeding manifestations in patients without a history of inherited bleeding disorders who underwent corneal refractive surgery. Eight cases (3 patients from the literature search and 5 patients from a retrospective chart review) were found regarding patients with inherited bleeding disorders who underwent corneal refractive surgery.

CONCLUSIONS

For corneal refractive surgery with topical anesthesia, the perioperative risk and need for any hemostasis intervention in individuals with an inherited bleeding disorder depends on the type of disorder, status of preoperative factor level concentrations, or a prior history of bleeding. If required, clotting factor optimization should be tailored to each candidate on a case-by-case basis.

Refractive outcomes of small lenticule extraction (SMILE) Pro® with a 2 MHz femtosecond laser

PURPOSE

To evaluate the initial visual outcomes of Small Incision Lenticule Extraction (SMILE) Pro® using a 2 MHz femtosecond laser (VisuMax 800, Carl Zeiss Meditec) and to assess the efficacy, safety, predictability, accuracy, and complication rate.

METHODS

This retrospective analysis included eyes which underwent the SMILE Pro® procedure using VisuMax 800 femtosecond laser to correct myopia. All surgeries were performed by one surgeon (DB). Follow-up was conducted 3 months postoperatively to evaluate visual outcomes after neuroadaptation, corrected visual acuity (CDVA) and intra- and postoperative complications.

RESULTS

One hundred and fifty-two eyes of 82 patients (mean age 31 ± 6 years) results at 3 months are presented. The mean spherical equivalent (SE) was - 4.44 ± 1.86 D preoperatively while -0.24 ± 0.32 D postoperatively. 99% of eyes achieved SE within ± 1.0 D of attempted correction and 91% were within ± 0.5 D. Efficacy index was 0.93 while the safety index was 1. No complications occurred intra- or postoperatively. No eyes lost more than 1 line of their preoperative CDVA. All highly myopic eyes (- 6.25 to - 10.00 D; n = 18) achieved 20/20 at 3 months postoperatively and were within 0.5 D from the attempted SE and no eyes lost more than 1 line of CDVA.

CONCLUSION

The SMILE Pro® is a safe, efficient, and predictable procedure for the treatment of myopia and myopic astigmatism, with comparable results of conventional SMILE surgery. High myopic eyes achieve better results than low and moderate myopia. No complications were recorded in our patients.

[Complications of femto-LASIK and features of cavitation injuries]

Modern approach to refractive laser surgery features three main types of lamellar surgery. Two of them are types of open laser keratomileusis (LASIK and femtosecond laser-assisted LASIK), and the third - closed (SMILE). All of these techniques allow achieving good clinical outcomes but differ in possible complications. This article reviews the complications of femto-LASIK and specifically the post-operative cavitation injuries, describes the mechanism of their occurrence, variants of their course, and presents the prevention measures.

Options and results in managing suction loss during small-incision lenticule extraction

Suction loss is an intraoperative complication in small-incision lenticule extraction (SMILE) that presents a management challenge for the refractive surgeon. The purpose of this review is to evaluate the visual, refractive, and wavefront outcomes after suction loss across the different stages of SMILE with various respective surgical treatments. Surgical management options include immediate re-SMILE by redocking or delayed re-SMILE, with or without adjustment of the laser parameters, conversion to femtosecond laser in situ keratomileusis, transepithelial photorefractive keratectomy, refractive lenticule extraction, or pseudo-SMILE. The restart treatment module on VisuMax provides appropriate retreatment recommendation. Most retreatment options for suction loss, immediate or delayed, resulted in effective, safe, and predictable outcomes, and patients were satisfied with their outcomes. Based on available level II evidence, immediate re-SMILE with or without adjustment to the laser settings achieve favorable visual and refractive outcomes in handling this intraoperative complication across all stages of SMILE.

Clinical outcomes after small-incision lenticule extraction versus femtosecond laser-assisted LASIK for high myopia: A meta-analysis

AIM

To compare postoperative clinical outcomes of high myopia after small-incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK).

METHODS

From March 2018 to July 2020, PubMed, MEDLINE, Embase, the Cochrane Library, and several Chinese databases were comprehensively searched. The studies meeting the criteria were selected and included; the data were extracted by 2 independent authors. The clinical outcome parameters were analyzed with RevMan 5.3.

RESULTS

This meta-analysis included twelve studies involving 766 patients (1400 eyes: 748 receiving SMILE and 652 receiving FS-LASIK). Pooled results revealed no significant differences in the following outcomes: the logarithm of the mean angle of resolution (logMAR) of postoperative uncorrected distance visual acuity (weighted mean difference (WMD) = -0.01, 95% confidence interval (CI): -0.02 to 0.00, I2 = 0%, P = 0.07 at 1 mo; WMD = -0.00, 95% CI: -0.01 to 0.01, I2 = 0%, P = 0.83 at 3 mo; WMD = -0.00, 95% CI: -0.01 to 0.00, I2 = 32%, P = 0.33 in the long term), and the postoperative mean refractive spherical equivalent (WMD = -0.03, 95% CI: -0.09 to 0.03, I2 = 13%, P = 0.30). However, the SMILE group had significantly better postoperative corrected distance visual acuity (CDVA) than the FS-LASIK group (WMD = -0.04, 95% CI, -0.05 to -0.02, I2 = 0%, P<0.00001). In the long term, postoperative total higher-order aberration (WMD = -0.09, 95% CI: -0.10 to -0.07, I2 = 7%, P<0.00001) and postoperative spherical aberration (WMD = -0.15, 95% CI: -0.19 to -0.11, I2 = 29%, P<0.00001) were lower in the SMILE group than in the FS-LASIK group; a significant difference was also found in postoperative coma (WMD = -0.05, 95% CI: -0.06 to -0.03, I2 = 30%, P<0.00001).

CONCLUSION

For patients with high myopia, both SMILE and FS-LASIK are safe, efficacious and predictable. However, the SMILE group demonstrated advantages over the FS-LASIK group in terms of postoperative CDVA, while SMILE induced less aberration than FS-LASIK. It remains to be seen whether SMILE can provide better visual quality than FS-LASIK; further comparative studies focused on high myopia are necessary.

Comparing Patient-Reported Outcomes of Laser In Situ Keratomileusis and Small-Incision Lenticule Extraction: A Review

PURPOSE

Laser in situ keratomileusis (LASIK) and small-incision lenticule extraction (SMILE) are popular refractive surgeries. The objective refractive outcomes of LASIK and SMILE have been studied extensively; both procedures have comparable safety, efficacy, and predictability. However, owing to various psychosocial factors, refractive patients may report dissatisfaction despite good postoperative vision. Hence the importance of studies on subjective patient-reported outcomes. This review discusses the role of psychometric-technique-based validated questionnaires when evaluating subjective outcomes. It also summarizes the literature on patient-reported outcomes for LASIK and SMILE.

DESIGN

A literature search was performed on PubMed database to identify studies that have assessed patient-reported outcomes for LASIK and SMILE.

RESULTS

Several studies have looked into patient-reported outcome measures for LASIK, but the number of equivalent studies for SMILE is limited. Questionnaires (validated and non-validated) are used to evaluate patient-reported outcomes. Validated questionnaires are designed based on psychometric techniques, such as Classic Test Theory, Item Response Theory, and Rasch analysis. The Quality of Life Impact of Refractive Correction (QIRC) questionnaire, a validated questionnaire administered to both LASIK and SMILE patients, suggests that both groups have comparable vision-related quality of life in the first few months postoperatively; but SMILE might confer a slight advantage in the later postoperative period (postoperative month 6).

CONCLUSIONS

Future LASIK-SMILE comparative studies utilizing standardized validated questionnaires for patient-reported outcome measures with longer follow-up durations would be a welcome contribution to this important aspect of refractive surgery.

Predictive Factors for Successful High Myopia Treatment Using High-Frequency Laser-In-Situ Keratomileusis

Aim

To evaluate the predictive factors of LASIK procedure for high myopia with or without astigmatism using a combination of high-frequency femtosecond-assisted LASIK followed by an excimer laser.

Methods

This study was a retrospective interventional case series study to evaluate myopic eyes undergoing high platform LASIK with FEMTO LDV Z2 intervention, followed by WaveLight®EX500 excimer laser machine. Subjects were divided into 2 groups: high myopia (SE of -6.01 to -9.00 D) and very high myopia (SE of -9.01 D or higher). Myopic eyes (Spherical Equivalent/SE) less than -13 D were included in this study. Visual Acuity (VA) was evaluated 1 day and 60 days after the procedure. Predictive factors, such as age, degree of sphere, degree of astigmatism, keratometric reading and axial length were analyzed to detect any influences affecting the final VA results.

Results

A total of 316 myopia eyes underwent intervention, mean age: 25.3±3.8 years. Target treatment was achieved in 96.1% of patients with high myopia and 69.9% of patients with very high myopia. High degree of sphere and astigmatism constitutes an important factor influencing final VA.

Conclusion

Modern machines provide a more promising efficacy and success of LASIK procedure in high myopia: important predictive factors were a high degree of sphere and astigmatism for achieving the optimal final outcome.

Intraoperative Patient Experience and Postoperative Visual Quality After SMILE and LASIK in a Randomized, Paired-Eye, Controlled Study

PURPOSE

To compare intraoperative and postoperative subjective patient experience after small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK.

METHODS

In a prospective, randomized, paired-eye, single-masked clinical trial at Singapore National Eye Centre, 70 patients were randomly treated with SMILE and LASIK in each eye. The intraoperative questionnaire was completed immediately after surgery and included light perception and levels of anxiety, fear, and discomfort. The postoperative 1- and 3-month questionnaires evaluated severity of light sensitivity, eye discomfort, eye dryness, excessive tearing, gritty sensation, glare, halos, blurring, and fluctuations in vision.

RESULTS

Average discomfort scores were higher during tissue manipulation in SMILE (1.9 ± 0.9) than flap lifting in LASIK (1.59 ± 0.8) (P = .020) but comparable during docking and laser application (P > .249). Fear scores were lower in SMILE than LASIK during docking (2.6 ± 1.6 vs 3.4 ± 1.9, P = .024) but similar during occasional blackout, laser application, and lenticule/flap manipulation (P > .364). Fear scores were generally higher in patients with intraoperative suction loss (n = 3). For SMILE, light sensitivity, eye discomfort, blurring, and fluctuations in vision improved from 1 to 3 months (P < .039). For LASIK, improvements were reported for light sensitivity, eye discomfort, eye dryness, gritty sensation, and fluctuations in vision from 1 to 3 months (P < .046). At 1 month, patients experienced more blurring after SMILE than LASIK (2.1 ± 0.8 vs 1.8 ± 0.7, P = .025), but with no differences in any of the visual symptoms at 3 months.

CONCLUSIONS

Tissue manipulation may be more uncomfortable during SMILE than LASIK, but not more frightening. Subjective visual symptoms were comparable after 3 months. [J Refract Surg. 2018;34(2):92-99.].

Vision-related quality of life and visual outcomes after small-incision lenticule extraction and laser in situ keratomileusis

PURPOSE

To compare vision-related quality of life (VRQoL) scores and clinical outcomes between small-incision lenticule extraction and laser in situ keratomileusis (LASIK).

SETTING

Singapore National Eye Centre, Singapore.

DESIGN

Prospective study.

METHODS

Patients had small-incision lenticule extraction using the Visumax 500 kHz femtosecond laser; or LASIK excimer ablation with the Wavelight Allegretto 400 Hz laser. Primary outcomes were 3-month predictability, efficacy, and safety. Secondary outcomes were intraoperative experience, visual symptoms, and VRQoL (validated Quality of Life Impact of Refractive Correction [QIRC] questionnaire) in 25 a subgroup of patients in each group. Following Rasch analysis, "Functional" and "Emotional," QIRC dimensions were analysed separately.

RESULTS

At 3 months, predictability (82.5% versus 85.3%, ±0.5 diopters attempted correction, P =.453), safety index (1.13 ± 0.19 [SD] versus 1.07 ± 0.16, P = .158), and efficacy index (0.91 ± 0.21 versus 0.97 ± 0.19; P = .002) were found when comparing small-incision lenticule extraction (172 eyes) and LASIK (matched 688 eyes). Intraoperative experience between groups was not statistically different; visual fluctuations (P = .020) and episodes of visual blurring (P = .008) were greater after small-incision lenticule extraction than after LASIK at 1 month but not at 3 months. There was no difference in "functional" (66.7 ± 15.7 versus 55.3 ± 22.2, P = .064) and "emotional" (42.7 ± 23.2 versus 37.9 ± 23.8, P = .394) QIRC dimensions between the 2 groups (25 patients in each group) at 3 months.

CONCLUSION

The study, 3-month predictability, safety, and VRQL scores were not statistically different between small-incision lenticule extraction and LASIK.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Small Incision Lenticule Extraction (SMILE) versus Femtosecond Laser-Assisted In Situ Keratomileusis (FS-LASIK) for Myopia: A Systematic Review and Meta-Analysis

PURPOSE

The goal of this study was to compare small incision lenticule extraction (SMILE) with femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for treating myopia.

METHODS

The CENTRAL, EMBASE, PubMed databases and a Chinese database (SinoMed) were searched in May of 2016. Twelve studies with 1,076 eyes, which included three randomized controlled trials (RCTs) and nine cohorts, met our inclusion criteria. The overall quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group framework. Data were extracted and analysed at three to six months postoperatively. Primary outcome measures included a loss of one or more lines of best spectacle corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA) of 20/20 or better, mean logMAR UCVA, postoperative mean spherical equivalent (SE) and postoperative refraction within ±1.0 D of the target refraction. Secondary outcome measures included ocular surface disease index (OSDI), tear breakup time (TBUT) and Schirmer's 1 test (S1T) as dry eye parameters, along with corneal sensitivity.

RESULTS

The overall quality of evidence was considered to be low to very low. Pooled results revealed no significant differences between the two groups with regard to a loss of one or more lines in the BSCVA (OR 1.71; 95% CI: 0.81, 3.63; P = 0.16), UCVA of 20/20 or better (OR 0.71; 95% CI: 0.44, 1.15; P = 0.16), logMAR UCVA (MD 0.00; 95% CI: -0.03, 0.04; P = 0.87), postoperative refractive SE (MD -0.00; 95% CI: -0.05, 0.05; P = 0.97) or postoperative refraction within ±1.0 D of the target refraction (OR 0.78; 95% CI: 0.22, 2.77; P = 0.70) within six months postoperatively. The pooled analysis also indicated that the FS-LASIK group suffered more severely from dry eye symptoms (OSDI; MD -6.68; 95% CI: -11.76, -2.00; P = 0.006) and lower corneal sensitivity (MD 12.40; 95% CI: 10.23, 14.56; P < 0.00001) at six months postoperatively.

CONCLUSIONS

In conclusion, both FS-LASIK and SMILE are safe, effective and predictable surgical options for treating myopia. However, dry eye symptoms and loss of corneal sensitivity may occur less frequently after SMILE than after FS-LASIK.