Corneal biomechanical change assessment using biomechanical waveform analyzer parameters: Contralateral comparison of eyes having femtosecond lenticule extraction and small-incision lenticule extraction for moderate to high myopia

Purpose To examine whether the amplitude of accommodation, the accommodative response, and the accommodative facility is affected and correlated with changes in higher-order aberrations for patients with high myopia surgically treated with small-incision lenticule extraction (SMILE). Methods 35 highly myopic eyes (myopic spherical equivalent of at least 6 diopters) of 35 patients treated with SMILE were included. Assessments were made before and 3 months after surgery. Donders push-up-method was used to measure the amplitude of accommodation. The accommodative response was assessed using an open-field autorefractor”Grand Seiko WAM-5500” (Grand Seiko Co. Ltd., Hiroshima, Japan) in combination with a Badal optometer and stimuli of accommodation at 0.0, 0.5, 1.25, 2.0, 3.0, and 4.0 D, respectively. Accommodative facility was measured at 40 cm with ±2,00D flipper lenses. All measurements of accommodation were performed monocularly with the refractive error corrected with soft contact lenses. Results The amplitude of accommodation did not change statistically significantly (mean difference -0.24 D (SD 0.98), 95% CI of mean difference -0.58 D to 0.11 D, paired-sample t(34) = -1.39; P = 0.17). The accommodative responses at 0.0, 0.5, 1.25, 2.0, 3.0, and 4.0 D did not statistically significantly change either (F(6,29) = 1.15; P = .36). Finally, the accommodative facility was also unchanged with a mean difference of 1.11 cycles per minute (SD 5.11, 95% CI of mean difference -0.64 to 2.87, paired-sample t(34) = 1.29; P = 0.21). No clinically significant associations between changes in accommodation and higher-order aberrations were found. Conclusions SMILE does not alter the amplitude of accommodation, the accommodative response, nor the accommodative facility for highly myopic patients, and the surgically induced corneal higher-order aberrations do not affect the accommodative function.

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Implantable collamer lens versus small incision lenticule extraction for high myopia correction: A systematic review and meta-analysis

BMC Ophthalmology ◽

10.1186/s12886-021-02206-9 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Kai Cao ◽

Jingshang Zhang ◽

Jinda Wang ◽

Mayinuer Yusufu ◽

Shanshan Jin ◽

...

Keyword(s):

Systematic Review ◽

High Myopia ◽

Meta Analysis ◽

Cochrane Central Register ◽

Safety Index ◽

Small Incision Lenticule Extraction ◽

Implantable Collamer Lens ◽

Small Incision ◽

Lenticule Extraction ◽

Efficacy Index

Abstract Purpose To compare the efficacy, safety, predictability and visual quality between implantable collamer lens (ICL) implantation and small incision lenticule extraction (SMILE) for high myopia correction in adults. Methods A systematic review and meta-analysis was conducted. A comprehensive literature search was done based on databases including PubMed, Science Direct, Embase, and the Cochrane Central Register of Controlled Trials. The efficacy index, safety index, changes in Snellen lines of corrected distance visual acuity (CDVA), predictability (difference between post-operative and attempted spherical equivalent error, SER), incidence of halos, and change in higher-order aberrations (HOAs) were compared. Mean difference (MD) and 95% confidence interval (CI) was used to estimate continuous outcomes, risk ratio (RR) and 95%CI was used to estimate categorical outcomes. Results Five observational studies involving 555 eyes were included in this review. Studies’ sample sizes (eyes) ranged from 76 to 197. Subjects’ refraction ranged from -6 diopter (D) to -12D. Study duration of most researches were 6 months or 12 months. Compared to SMILE, ICL implantation showed better efficacy index (MD=0.09, 95%CI:0.01 to 0.16) and better safety index (MD=0.08, 95%CI: 0.00 to 0.16). Compared with SMILE, more ICL-treated eyes gained one or more Snellen lines of CDVA (RR=1.54, 95%CI:1.28 to 1.86), more gained two or more lines (RR=2.09, 95%CI:1.40 to 3.13), less lost one or more lines (RR=0.17, 95%CI:0.05 to 0.63). There was no difference in predictability between two treatments, RRs of predictability of within ±0.5D and ±1D were 1.13 (95%CI: 0.94 to 1.36) and 1.00 (95%CI: 0.98 to 1.02). Compared with SMILE, ICL implantation came with a higher risk of halos [RR=1.79, 95%CI: 1.48 to 2.16] and less increase in total HOAs (MD=-0.23, 95%CI: -0.42 to -0.03). Conclusion Compared with SMILE, ICL implantation showed a higher risk of halos, but equal performance on SER control, and better performance on efficacy index, safety index, CDVA improvement and HOAs control. Overall, ICL implantation might be a better choice for high myopia correction in adults.

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Clinical outcomes after small incision lenticule extraction versus femtosecond laser-assisted LASIK for high myopia: a Meta-analysis.

10.21203/rs.2.23101/v1 ◽

2020 ◽

Author(s):

Yanyan Fu ◽

Yewei Yin ◽

Yang Zhao ◽

Aiqun Xiang ◽

Ying Lu ◽

...

Keyword(s):

Femtosecond Laser ◽

Clinical Outcomes ◽

High Myopia ◽

Spherical Aberration ◽

Meta Analysis ◽

Small Incision Lenticule Extraction ◽

Small Incision ◽

Significant Difference ◽

Lenticule Extraction

Abstract Background To compare postoperative clinical outcomes of high myopia after being treated by Small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK).Methods Comprehensive studies were conducted on the PubMed, MEDLINE, EMBASE, the Cochrane Library, and Chinese databases.Trials meeting the selection criteria were quality appraised, and the data were extracted by 2 independent authors, and the RevMan 5.3 version software were used in analyzing.Result Ten studies involving 637 patients (1093 eyes;575 eyes in the SMILE group and 518 eyes in the FS-LASIK group) were included in this meta-analysis. Pooled result revealed no significant differences in the following outcomes: the logMAR values of postoperative UDVA(WMD = -0.01, 95% CI: -0.02,0.00, I²=0%, P = 0.10 at postoperative 1mo; WMD =-0.01, 95% CI: -0.00 to 0.01, I²=0%,P = 0.35 at postoperative 3mo; WMD = -0.01, 95% CI:-0.02 to 0.01, I²=17%,P = 0.26 at long term), the logMAR values of postoperative CDVA(WMD = -0.02, 95% CI, -0.04 to 0.00, I²=0%, P = 0.11),and the postoperative mean refractive SE (WMD =0.02, 95% CI:0.04 to 0.08, I²=29%, P=0.60) . In the long-term observation, postoperative tHOA (WMD =-0.10, 95% CI:-0.13 to -0.07, I²=15%, P<0.00001)and postoperative spherical aberration (WMD =-0.13, 95% CI:--0.17 to -0.09, I²=38%, P<0.00001) were found to be less in the SMILE group compared with the FS-LASIK group, but no significant difference was found in postoperative coma (WMD =-0.02, 95% CI:-0.04 to 0.00, I²=98%, P=0.40).We also found greater PCE change post FS-LASIK than SMILE at long term follow-ups(WMD =-0.69, 95% CI:-1.36 to -0.01, I²=0%, P<0.05, however, there was no significant difference between the two groups at 3- or 6- months.(WMD =-0.19, 95% CI:-0.41 to 0.03, I²=31%, P=0.09;WMD =-0.20, 95% CI:-0.50 to 0.10, I²=17%, P=0.20)Conclusion For patients with high myopia, both SMILE and FS-LASIK are safe and efficacious. However, SMILE induced less tHOA and spherical aberration compared with FS-LASIK. Besides, FS-LASIK showed a greater increase in PCE than SMILE only at long term follow-ups. It remains to be seen whether the patients can get a better visual quality after SMILE and more comparative studies focused on high myopia is necessary.

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