Clinical outcomes of SMILE and WFG-LASIK used to treat myopia and astigmatism: A systematic review and meta-analysis.

PURPOSE: To evaluate the safety, efficacy and postoperative visual quality of small incision lenticule extraction (SMILE) and Wavefront-Guided Laser in situ keratomileusis (WFG-LASIK) and to analyze their efficacy in correcting astigmatism. METHODS: A systematic literature search was performed using Cochrane Collaboration methodology. Databases searched included PubMed, Embase, the Cochrane Library and Web of Science. RevMan software version 5.3.0 was used for meta-analysis. RESULTS: A total of 976 eyes were included in 8 studies, of which 539 eyes underwent SMILE and 437 eyes underwent WFG-LASIK. There were no statistically significant differences in the proportion of eyes achieving uncorrected distance visual acuity of 20/20 or better (P=0.18), the proportion of eyes within±0.50 diopter of target refraction postoperatively (P=0.10), or the postoperative magnitude of cylinder (P=0.10). Regarding the Alpins vector analysis of astigmatism, there was no statistically significant difference in the surgical magnitude of error (P=0.09) between the two groups. WFG-LASIK has a lower surgical angle of error (P= 0.002) and higher surgical correction index of cylinder (P=0.03) than SMILE. In terms of aberrations, higher order aberrations (P=0.46), spherical aberrations (P=0.22) and trefoil (P=0.56) were not statistically different, while WFG-LASIK induced less coma than SMILE surgery (P=0.02). CONCLUSION: Both SMILE and WFG-LASIK are safe and effective ways to correct myopia and astigmatism. Compared with SMILE, WFG-LASIK has a lower surgical angle of error, higher surgical correction index of cylinder and induces less coma.

The comparison of corneal higher-order aberration and surgically induced astigmatism between the clear corneal incision and the limbus tunnel incision of posterior chamber implantable collamer lens implantation.

BACKGROUND: This study aimed to compare the corneal high-order aberrations and surgically induced astigmatism between the clear corneal incision and limbus tunnel incision for posterior chamber implantable collamer lens (ICL/TICL) implantation. METHODS: A total of 127 eyes from 73 myopic patients underwent ICL V4c implantation, with 70 eyes receiving clear corneal incisions and 57 eyes receiving limbus tunnel incisions. The anterior and back corneal surfaces were measured and the Root Mean Square of all activated aberrations (TRMS) was calculated, including higher-order aberration (HOA RMS), spherical aberration Z40, coma coefficients (Coma RMS) Z3-1 Z31, and surgically induced astigmatism (SIA). The measurements were taken preoperatively and postoperatively at 1 day, 1 week, and 1, 3, and 6 months. In this study, the corneal higher-order aberration was estimated as the Zernike coefficient calculated up to 5th order. The measurements were taken at a maximum diameter of 6.5 mm using Pentacam. RESULTS: One week after the operation, the corneal back Z31 of the clear corneal incision group was 0.06 ± 0.06, while the limbus tunnel incision group showed a measurement of 0.05 ± 0.06 (p = 0.031). The corneal back Z40 of the clear corneal incision group was -0.02 ± 0.25, compared to -0.04 ± 0.21 in the limbus tunnel incision group (p = 0.01). One month after the operation, the corneal back SIA of the clear corneal incision group was 0.11 ± 0.11, compared to 0.08 ± 0.11of the limbus tunnel incision group (p = 0.013), the corneal total SIA of the clear corneal incision group was 0.33 ± 0.30, compared to 0.15 ± 0.16 in the limbus tunnel incision group (p = 0.004); the clear corneal incision group exhibited higher levels of back astigmatism and total SIA than the limbus tunnel incision in the post-operation one month period. During the 6- month post-operative follow-up period, no significant difference in Z31, Z40, and other HOA RMS data was observed between the two groups. The total SIA of the corneal incision group and the limbus tunnel incision group were 0.24 ± 0.14 and 0.33 ± 0.32, respectively (p = 0.393), showing no significant difference between the two groups 6 months after the operation. CONCLUSION: Our data showed no significant difference in the high-order aberration and SIA between clear corneal incision and limbus tunnel incision up to 6 months after ICL-V4c implantation.

Neurological event rates and associated risk factors in acute type B aortic dissections treated by thoracic aortic endovascular repair.

OBJECTIVES: Thoracic endovascular aortic repair is the method of choice in patients with complicated type B acute aortic dissection. However, thoracic endovascular aortic repair carries a risk of periprocedural neurological events including stroke and spinal cord ischemia. We aimed to look at procedure-related neurological complications within a large cohort of patients with type B acute aortic dissection treated by thoracic endovascular aortic repair. METHODS: Between 1996 and 2021, the International Registry of Acute Aortic Dissection collected data on 3783 patients with type B acute aortic dissection. For this analysis, 648 patients with type B acute aortic dissection treated by thoracic endovascular aortic repair were included (69.4% male, mean age 62.7 ± 13.4 years). Patients were excluded who presented with a preexisting neurologic deficit or received adjunctive procedures. Demographics, clinical symptoms, and outcomes were analyzed. The primary end point was the periprocedural incidence of neurological events (defined as stroke, spinal cord ischemia, transient neurological deficit, or coma). Predictors for perioperative neurological events and follow-up outcomes were considered as secondary end points. RESULTS: Periprocedure neurological events were noted in 72 patients (11.1%) and included strokes (n = 29, 4.6%), spinal cord ischemias (n = 21, 3.3%), transient neurological deficits (n = 16, 2.6%), or coma (n = 6, 1.0%). The group with neurological events had a significantly higher in-hospital mortality (20.8% vs 4.3%, P < .001). Patients with neurological events were more likely to be female (40.3% vs 29.3%, P = .077), and aortic rupture was more often cited as an indication for thoracic endovascular aortic repair (38.8% vs 16.5%, P < .001). In patients with neurological events, more stent grafts were used (2 vs 1 stent graft, P = .002). Multivariable logistic regression analysis showed that aortic rupture (odds ratio, 3.12, 95% confidence interval, 1.44-6.78, P = .004) and female sex (odds ratio, 1.984, 95% confidence interval, 1.031-3.817, P = .040) were significantly associated with perioperative neurological events. CONCLUSIONS: In this highly selected group from dedicated aortic centers, more than 1 in 10 patients with type B acute aortic dissection treated by thoracic endovascular aortic repair had neurological events, in particular women. Further research is needed to identify the causes and presentation of these events after thoracic endovascular aortic repair, especially among women.

A new insight into superacute care for type A acute aortic dissection in the Tokyo Acute Aortic Super Network.

OBJECTIVE: To determine the status of type A acute aortic dissection using the Tokyo Acute Aortic Super Network. METHODS: Data of 6283 patients with acute aortic dissection between 2015 and 2019 were collected. Data of 3303 patients with type A acute aortic dissection were extracted for analysis. RESULTS: Overall, 51.0% of patients were nondirect admissions. On arrival, 23.1% of patients were in shock, 10.0% in cardiopulmonary arrest, and 11.8% in deep coma or coma. Overall, 9.8% of patients were assessed as untreatable. Of 2979 treatable patients, 18.3% underwent medical treatment, whereas 80.7% underwent surgery (open [78.8%], endovascular [1.9%], and peripheral [1.1%] repair). The early mortality rate was 20.5%, including untreatable cases. Among treatable patients, in-hospital mortality rates were 8.6% for open repair, 10.7% for endovascular repair, and 25.3% for medical treatment. Advanced age, preoperative comorbidities, classical dissection, and medical treatment were risk factors for in-hospital mortality. Nondirect admission did not cause increased deaths. The mortality rates were high during the superacute phase following symptom onset. CONCLUSIONS: This study demonstrated current practices in the emergency care of type A acute aortic dissection via the Tokyo Acute Aortic Super Network system, specifically a high rate of untreatable or inoperable cases and favorable outcomes in patients undergoing surgical treatment. High mortality rates were observed during the super acute phase after symptom onset or hospital arrival.

Moisture chamber goggles for the treatment of postoperative dry eye in patients receiving SMILE and FS-LASIK surgery.

BACKGROUND: The incidence of refractive surgery-related dry eye disease (DED) is rising due to the increasing popularity of corneal refractive surgery. The moisture chamber goggles (MCGs) have been shown to tear evaporation by increasing local humidity and minimizing airflow. The current study aims to evaluate the efficacy of moisture chamber goggles for refractive surgery-related DED. METHODS: In this nonrandomized open-label controlled study, 78 participants (156 eyes) receiving refractive surgery were enrolled between July 2021 and April 2022, and sequentially allocated to MGC and control groups. 39 participants were allocated to the MGC groups, of which 53.8% received small-incision lenticule extraction (SMILE) and 46.2% received femtosecond laser-assisted in situ keratomileusis (FS-LASIK), and were instructed to wear MCGs for the duration of 1 month postoperatively, in addition to the standard postoperative treatment received by the control groups (56.4% SMILE, 43.6% FS-LASIK). Participants underwent full ophthalmic examinations, including visual acuity, manifest refraction, DED evaluations, and higher-order aberrations (HOAs), both preoperatively and at routine follow-ups 1 day, 1 week, and 1 month after surgery. DED parameters included non-invasive tear film break-up time (NIBUT), tear meniscus height (TMH), conjunctival congestion, lipid layer thickness (LLT), and ocular surface disease index (OSDI) questionnaires. Student's t-test was used for comparisons between control and MCG groups, and between preoperative and postoperative parameters within groups. RESULTS: Postoperative NIBUT decreased in both SMILE and FS-LASIK control groups 1 day after the surgery (SMILE, P = 0.001; FS-LASIK, P = 0.008), but not in the corresponding MCG groups (SMILE, P = 0.097; FS-LASIK, P = 0.331). TMH in the MCG group was significantly higher at 1 week (P = 0.039) and 1 month (P = 0.015) in SMILE, and 1 day (P = 0.003) in FS-LASIK groups. In FS-LASIK participants, significantly lower HOAs and coma levels in the MCG group were observed 1 day (total HOAs, P = 0.023; coma, P = 0.004) and 1 week (total HOAs, P = 0.010, coma, P = 0.004) after surgery. No consistent statistically significant intergroup difference was observed between MCG and control groups in conjunctival congestion, LLT, and OSDI. CONCLUSIONS: MCGs effectively slowed tear evaporation, increased tear film stability, and improved HOAs in patients receiving SMILE and FS-LASIK surgeries. MCG is an effective adjuvant therapy in the comprehensive management of refractive surgery-related DED.

Asymmetric All-Femtosecond Laser-Cut Corneal Allogenic Intrastromal Ring Segments.

PURPOSE: To describe a novel technique for cutting asymmetric allogenic segments using the femtosecond laser for the management of cases of keratoconus with non-coinciding astigmatism and coma axes. METHODS: Four eyes of 2 patients with irregular keratoconus and asymmetric allogenic segments were included. Visual, refractive, tomographic, and aberrometric outcomes, and optical coherence tomography (OCT) sections were measured preoperatively and 6 months postoperatively. Evaluations included slit-lamp examination, manifest refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuity, and simulated and maximum anterior keratometry (Kmax) using anterior segment OCT. RESULTS: Spherical and cylindrical refractive errors decreased from -2.38 ± 2.96 and -2.94 ± 2.16 to -1.81 ± 2.77 (P = .04) and -1.75 ± 2.07 (P = .01) diopters (D), respectively, 6 months postoperatively. There was an average gain of three lines of CDVA. Kmax decreased from 50.02 ± 1.99 to 47.89 ± 3.05 D (P= .03) and coma from 1.05 ± 0.21 to 0.21 ± 0.19 D (P = .01). CONCLUSIONS: Asymmetric femtosecond laser-cut allogenic segments allow a higher level of customization based on size, shape, and arc length, in contrast to the limited range of available synthetic asymmetrical segments. [J Refract Surg. 2023;39(12):856-862.].

Comparing Effective Optical Zones After Myopic Ablation Between LASIK, PRK, and SMILE With Correlation to Higher Order Aberrations.

PURPOSE: To explore size, decentration, and eccentricity of effective optical zones (EOZs) in laser in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), and small incision lenticule extraction (SMILE) and correlate them to higher order aberrations (HOAs). METHODS: This was a retrospective chart review of 188 eyes that underwent refractive surgery for compound myopia (61 LASIK, 84 PRK, 43 SMILE). EOZ measurements were determined using 1-year postoperative Pentacam (Oculus Optikgeräte GmbH) tangential difference maps. HOA data were measured using Pentacam wavefront aberration Zernike polynomials. Correlations between EOZs and HOAs were analyzed. RESULTS: The EOZs of LASIK and PRK are smaller than SMILE at 19.54 ± 1.44, 19.39 ± 1.66, and 22.18 ± 2.61 mm2, respectively (P < .001). No difference existed in absolute decentration from corneal vertex (P = .078) or pupil center (P = .131), but horizontal and vertical components differed significantly (P < .001). Smaller EOZ areas were correlated with greater spherical aberration induction (rLASIK = -0.378, rPRK = -0.555, rSMILE = -0.501) and total HOA induction in all groups. Absolute decentration from corneal vertex positively correlated with total HOA (rLASIK = 0.396, rPRK = 0.463, rSMILE = 0.399) and directional vertical coma induction negatively correlated with vertical decentration from the corneal vertex (rLASIK = -0.776, rPRK = -0.665, rSMILE = -0.576) in all groups. CONCLUSIONS: SMILE results in a larger EOZ than LASIK and PRK, and absolute decentration remains comparable regardless of surgical reference center, despite horizontal/vertical differences. Surgical planning to ensure adequate EOZ size and centration may reduce induction of HOAs, including spherical aberrations and vertical coma. [J Refract Surg. 2023;39(11):741-750.].

Corneal Higher Order Aberrations and Epithelial Remodeling With Femtosecond Laser-Assisted LASIK Topography-guided and Customized Asphericity Ablation in the Contralateral Eye: A Randomized, Double-Blind, Prospective Study.

PURPOSE: To evaluate refractive results, corneal higher order aberrations (HOAs), and epithelial remodeling in the preoperative and postoperative period of regular corneas that had topography-guided femtosecond laser-assisted laser in situ keratomileusis (LASIK) (Contoura WaveLight; Alcon Laboratories, Inc) and compare them with the contralateral eye that underwent ablation customized by asphericity (Custom-Q WaveLight; Alcon Laboratories, Inc) in myopic eyes with or without astigmatism. METHODS: A prospective, randomized, and double-blind study was conducted. Patients underwent preoperative and postoperative epithelial mapping and corneal tomography to assess the epithelial thickness map, HOAs of the corneal anterior surface, visual acuity, and refractive evaluation. RESULTS: This study enrolled 96 normal eyes of 48 patients. Uncorrected distance visual acuity of 20/20 or better was achieved in 97% of patients and gains in corrected distance visual acuity and effectiveness in correcting refractive astigmatism were similar in both techniques. Seventeen sectors of the corneal epithelium map were assessed by spectral-domain optical coherence tomography and no significant differences were found between techniques preoperatively and postoperatively (P > .05). HOA root mean square, coma Z3±1, trefoil Z3-3, and tissue consumption exhibited statistically significant between-technique differences (P < .05). CONCLUSIONS: The Contoura and Custom-Q techniques were similar with respect to refractive and visual outcomes after 3 months, as well as in epithelial remodeling. The Contoura provides lower postoperative HOA root mean square, coma Z3±1, and trefoil Z3-3 values, but the techniques showed no differences in the correction of the corneal astigmatic wavefront component and in the spherical aberration after 3 months. [J Refract Surg. 2023;39(11):751-758.].

Comparison of Higher Order Aberrations between Wavefront Optimized Photorefractive Keratectomy and Laser in situ Keratomileusis in Myopic Patients.

OBJECTIVE: To compare the higher order aberrations (HOA) between wavefront optimized (WFO) laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) in myopic patients. STUDY DESIGN: Quasi-experimental study. Place and Duration of the Study: Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan, from December 2021 to December 2022. METHODOLOGY: Forty-four patients underwent wavefront optimized PRK and fifty-seven patients underwent wavefront optimized LASIK. All variables were recorded before the procedure and at 1, 3, 6, and 12 months postoperatively and included uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), root mean square (RMS) of HOAs, spherical aberration (SA), and coma aberration (CA). RESULTS: A total of 101 eyes of 51 patients were considered in the final analysis. Patients were divided into two groups. Group A comprised of 44 (43.6%) eyes of 22 patients who underwent PRK while group B comprised of 57 (56.4%) eyes of 29 patients who underwent LASIK. UCVA significantly improved postoperatively at 3 and 6 months in both PRK and LASIK groups (p<0.001 for both groups). In this study, the increase in root mean square (RMS) of higher order aberrations from baseline value was 77% after PRK and 28% after LASIK, similar ratio was observed in spherical aberration (SA). The trend of rise in Coma aberrations was more in LASIK group 66.49% as compared to 46.2% in PRK group. CONCLUSION: Both Wavefront Optimized PRK and LASIK are safe and have elicited comparable results of post-procedure visual recovery. There was a marked increase in RMS of HOAs in PRK group as compared to WFO LASIK group while coma aberration increased more in LASIK as compared to PRK postoperatively. KEY WORDS: LASIK, PRK, RMSh, HOAs, Spherical aberration, Coma, Myopia.

Influence of decentration of plate-haptic toric intraocular lens on postoperative visual quality.

BACKGROUND: To evaluate the influence of decentration of plate-haptic toric intraocular lens (IOLs) on visual quality. METHODS: This study enrolled 78 eyes of 78 patients. Patients in group A were implanted with toric IOLs, and patients in group B were implanted with monofocal IOLs. All patients were divided into group A1 and B1 (decentration below 0.3 mm) and group A2 and B2 (decentration above 0.3 mm). The uncorrected distance visual acuity (UDVA), best corrected visual acuity (BCVA), modulation transfer function cutoff (MTF cutoff), objective scatter index (OSI), strehl ratio (SR), optical interference and patients' satisfaction were measured in different pupils at three months postoperatively. The associations between decentration and visual quality were analyzed by Spearman correlation. RESULTS: There were no significant differences in UDVA, BCVA, MTF cutoff, OSI, SR, optical interference and patients' satisfaction among subgroups. The differences in decentration between groups A and B were not statistically significant. In group A2, the total higher order aberrations (tHOAs) at pupil sizes of 3 mm (P = 0.046), 5 mm (P = 0.014), spherical aberrations at pupil sizes of 3 mm (P = 0.011), 4 mm (P = 0.014), 5 mm (P = 0.000), secondary astigmatism at pupil sizes of 3 mm (P = 0.002), 4 mm (P = 0.005) were higher than in group B2. Compared to group A1, group A2 had higher spherical aberrations at pupil sizes of 4 mm (P = 0.042), 5 mm (P = 0.001), 6 mm (P = 0.038), secondary astigmatism at pupil sizes of 3 mm (P = 0.013), 4 mm (P = 0.005), 6 mm (P = 0.013). Group B2 has higher coma and secondary astigmatism than group B1 at 6-mm pupil (P = 0.014, P = 0.045). Significant positive correlations were found between spherical aberrations and the decentration of group A1 and A2 at 6-mm pupils. CONCLUSION: The decentration above 0.3 mm negatively affected visual quality due to increased tHOAs, spherical aberrations, coma and secondary astigmatism aberrations, the influence become larger with increasing pupil diameter. And toric IOLs are more affected by decentration than monofocal IOLs.

Comparison of higher-order aberrations between implantable collamer lens V4c implantation and simulated spectacle correction in patients with high myopia.

PURPOSE: To investigate the differences in higher-order aberrations between non-toric or toric implantable collamer lens (ICL or TICL) V4c implantation and simulated spectacle correction. METHODS: Patients with high myopia who underwent ICL/TICL V4c implantation were enrolled. The "total no defocus" pattern of iTrace aberrometry to simulate the condition of spectacle correction was measured before ICL/TICL implantation, and higher-order aberrations in this condition were compared to those 3 months after surgery. Related factors with changes in coma were comprehensively analyzed. RESULTS: A total of 89 right eyes of 89 patients were included. Compared to simulated spectacle correction, total-eye coma (P<0.0001 ICL, P<0.0001 TICL) and internal coma (P<0.0001 ICL, P<0.001 TICL) decreased in the ICL- and TICL-treated groups after surgery. Total-eye secondary astigmatism (P<0.0001 ICL, P=0.007 TICL) and internal secondary astigmatism (P<0.0001 ICL, P=0.009 TICL) were also decreased in both groups postoperatively. Spherical error showed positive correlations with variation in total-eye coma (r=0.37, P=0.004 ICL; r=0.56, P=0.001 TICL) and internal coma (r=0.30, P=0.02 ICL and r=0.45, P=0.01 TICL). Axial length revealed negative correlations with changes in total-eye coma (r=-0.45, P<0.001 ICL; r=-0.39, P=0.03 TICL) and internal coma (r=-0.28, P=0.03 ICL and r=-0.42, P=0.02 TICL). CONCLUSIONS: Both ICL- and TICL-treated groups demonstrated a decrease in coma and secondary astigmatism after 3 months, postoperatively. ICL/TICL may confer a compensatory effect on coma aberration and secondary astigmatism. Patients with a higher myopia achieved a greater improvement in coma and may benefit more from ICL/TICL implantation than from spectacle correction implantation than from spectacle correction.

Sub-Bowman keratomileusis versus femtosecond laser in situ keratomileusis on the long-term visual recovery: A comparative study.

Purpose: To explore the long-term visual quality of the same subjects after sub-Bowman keratomileusis (SBK) or femtosecond laser in situ keratomileusis (FS-LASIK). Methods: This prospective study included patients screened for corneal refractive surgery at the Refractive Surgery Center of our Hospital between November 2017 and March 2018. One eye underwent SBK, while the other eye underwent FS-LASIK. Total higher-order aberrations, coma aberrations, and clover aberrations were evaluated before and at 1 month and 3 years after the procedure. The visual satisfaction of both eyes was investigated, respectively. The participants completed a surgical satisfaction questionnaire. Results: Thirty-three patients were included. There were no significant differences in total higher-order aberrations, coma aberrations, and clover aberrations between the two procedures before and 1 month and 3 years after surgery (all P > 0.05), except for the total coma aberrations in FS-LASIK were significantly higher compared with the SBK group at 1 month after surgery [0.51 (0.18, 0.93) vs. 0.77 (0.40, 1.22), P = 0.019]. The surgical satisfaction questionnaire scores of the SBK group and the FS-LASIK group were 9.8 ± 0.8 and 9.8 ± 0.8, respectively, at 1 month, and 9.7 ± 0.9 and 9.7 ± 1.0, respectively, at 3 years (all P > 0.05). Conclusion: There were no differences in corneal aberrations and satisfaction between SBK and FS-LASIK procedures at 1 month and 3 years.

Evaluation of the Effects of Myopic Astigmatism Correction and Anterior Corneal Curvature on Functional Optical Zone After SMILE.

PURPOSE: To evaluate the influence of different degrees of myopic astigmatism correction and preoperative anterior corneal curvature on the functional optical zone (FOZ) following small incision lenticule extraction (SMILE). METHODS: In this retrospective study, 68 patients (106 eyes) treated with SMILE were grouped according to myopic astigmatism correction: control (0.00 diopters [D]), moderate astigmatism (-0.50 to -2.00 D), and high astigmatism (> -2.00 D). The FOZ was measured and compared between the three groups for 3 months. Correlations between attempted correction, anterior corneal curvature, corneal aberrations, and the FOZ were analyzed. RESULTS: The preoperative mean treatment spherical equivalent was comparable among the three groups. The average FOZ was 5.06 ± 0.24 mm in the control group, 5.19 ± 0.25 mm in the moderate astigmatism group, and 5.35 ± 0.20 mm in the high astigmatism group The FOZ showed statistically significant differences among the three groups (P < .001), particularly between the high astigmatism group and the other two groups (P < .001 and .018). Correlation analysis showed that the total higher order aberrations, coma, and spherical aberration change were correlated with the FOZ (P < .001). Preoperative steep keratometry, average keratometry, and corneal astigmatism were significantly correlated with the FOZ (P < .05). The correlation remained after excluding the influence of attempted correction on the FOZ (P < .05). After adjusting for other risk factors using multiple linear regression analysis, there was still a significant positive association between preoperative steep keratometry and the FOZ (P < .001). CONCLUSIONS: Patients with higher myopic astigmatism achieved a larger FOZ and less induced horizontal coma than the control and moderate astigmatism groups. A larger FOZ after SMILE can be achieved in eyes with steeper keratometry. [J Refract Surg. 2023;39(2):135-141.].

Clinical outcomes and higher order aberrations of wavefront-guided LASIK versus SMILE for correction of myopia: A systemic review and meta-analysis.

To systematically evaluate the clinical effect of wavefront-guided laser in situ keratomileusis (WFG-LASIK) and small incision lenticule extraction (SMILE) in terms of refractive errors and high-order aberrations. A systematic literature search of PubMed, EMBASE, the Cochrane Library, Web of Science and China National Knowledge Internet was performed to identify studies evaluating the clinical outcomes of SMILE and WFG-LASIK ended in May 2022. Meta-analyses were performed according to the PRISMA guidelines. The risk of bias of the RCTs was evaluated using the Cochrane Handbook criteria, and the quality of the non-randomised controlled studies was assessed using the Newcastle-Ottawa Scale. In total, 1385 eyes (SMILE group, 750 eyes; WFG-LASIK group, 635 eyes) from 12 studies were included. The meta-analysis demonstrated that spherical aberration was smaller in the SMILE group than in the WFG-LASIK group (standardised mean difference [SMD]: -0.34, 95% confidence interval [CI]: -0.47, -0.22; p < 0.00001), and that the postoperative values of vertical coma (SMD: 0.83; 95% CI: 0.63, 1.03; p < 0.00001) and trefoil (SMD: 0.37; 95% CI: 0.02, 0.72; p = 0.04) were higher in the SMILE group compared to the WFG LASIK group. There were no significant differences in the clinical outcomes and the values of induced total higher order aberrations between the WFG-LASIK and SMILE groups (SMD: 0.05; 95% CI: -0.09, 0.19; p = 0.47). Both SMILE and WFG-LASIK were found to be safe, effective, and predictable. SMILE may induce more vertical coma and trefoil, whereas WFG LASIK may induce more spherical aberrations, but no significant differences were found in the total higher order aberrations between SMILE and WFG-LASIK.

Long-Term Follow-Up of a 150° Arc-Length Intrastromal Corneal Ring Segment Implantation in Post-LASIK Ectasia.

PURPOSE: To evaluate the outcomes of implanting a 150° arc-length intrastromal corneal ring segment (ICRS) using a femtosecond laser in patients with post-LASIK ectasia throughout a 5-year follow-up period. METHODS: This study enrolled 45 eyes of 45 patients diagnosed with post-LASIK ectasia who underwent a 150° arc-length Ferrara-type ICRS implantation. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, residual refractive errors, and root mean square (RMS) for coma-like aberration were evaluated preoperatively and at 6-, 12-, 36, and 60 months postoperatively. RESULTS: Mean UDVA (logMAR) ameliorated from 0.53 ± 0.33 preoperatively to 0.26 ± 0.24 at 6 months postoperatively (p < 0.0001). Mean CDVA improved from 0.12 ± 0.13 to 0.04 ± 0.06 (p < 0.0001). Mean UDVA and CDVA remained stable throughout the 5-year follow-up (p > 0.1). No eyes lost lines of CDVA at any follow-up visit compared to preoperatively, and most eyes gained lines. The eyes with a refractive cylinder ≤ 2.00 D varied from 26.7% preoperatively to more than 75% at all postoperative follow-up visits. The maximum keratometry was significantly flattened (p < 0.0001), and the RMS for corneal coma-like aberration was halved (p < 0.0001). 93.3% of the eyes did not show signs of disease progression or regression of the visual or refractive outcomes at any follow-up visits. CONCLUSION: These results suggest that implanting a single 150° arc-length Ferrara-type ICRS is a safe, effective and stable procedure for visual restoration in post-LASIK ectasia. In very few cases, visual and/or refractive instability was experienced throughout the follow-up.

Is decompressive craniectomy necessary in malignant posterior reversible encephalopathy syndrome with brain edema caused uncal herniation? A case report of reversible coma without surgical decompression.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is considered a benign entity and is usually reversible with only medical management, but persistent neurologic deficits and disability or death can occur without adequate treatment. Favorable outcomes have been associated with surgical decompression in malignant-type PRES in which hemorrhagic transformation or brain stem compression has developed. CASE DESCRIPTION: Here we report a case of malignant PRES in a 61-year-old female of Asian descent in which the disease rapidly progressed to coma and a near-fatal condition with uncal herniation caused by severe brain edema; however, this patient achieved a dramatic recovery without surgical decompression. CONCLUSION: After reviewing previous reports regarding malignant PRES, we propose that hemorrhagic transformation is a crucial indicator for surgical decompression and an important prognostic factor in malignant PRES.

Meniscus-Shaped Stromal Lenticule Addition Keratoplasty for Corneal Regularization and Thickening in Advanced Keratoconus.

PURPOSE: The aim of this study was to investigate the outcome of the meniscus-shaped stromal lenticule addition keratoplasty (MS-SLAK) in corneal regularization and thickness. METHODS: Patients waiting for deep anterior lamellar keratoplasty for advanced keratoconus with an intolerance to contact lenses (CLs) underwent the MS-SLAK procedure by FSL 80 kHz ablation (VICTUS, Technolas Perfect Vision, DE). Customized positive meniscus-shaped stromal lenticules were obtained and implanted. Examination was performed at baseline and at 3-, 6-, and 12-month follow-up and included corrected distance visual acuity both with spectacles and CLs (spectacle CDVA and CL-CDVA), manifest refraction spherical equivalent, slit-lamp examination, anterior segment optical coherence tomography, corneal topography, and in vivo confocal microscopy. RESULTS: Fifteen patients completed the study. Statistical increases in corneal thickness values were found from the first follow-up ( P < 0.001). Improvement in the Surface Asymmetry Index ( P = 0.04), Symmetry Index ( P = 0.02), spherical aberration ( P < 0.001), coma ( P = 0.18), high-order aberration ( P = 0.37), and anterior asphericity index (Q) ( P = 0.31) were found at 12 months. At the 12-month follow-up, no improvement were found in spectacle CDVA ( P = 0.23); however, all patients reported CL wearing tolerance recovery, and significant improvement in CL-CDVA ( P = 0.002) was found. The confocal microscopy at 12 months showed a significant increase in keratocyte density within the lenticule and absence of fibrotic reactions in both anterior and posterior interfaces. CONCLUSIONS: MS-SLAK seems to be effective in regularizing the corneal surface as showed by the significant improvement in topographic symmetry indices, coma, and high-order aberration. The corneal regularization is also confirmed by the results in anterior Q and the recovery of the CL wearing tolerance.

Comparison of the Functional Optical Zone in Eyes With High Myopia With High Astigmatism After SMILE and FS-LASIK.

PURPOSE: To compare the functional optical zone (FOZ) in eyes with high myopia with high astigmatism after small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK). METHODS: In total, 45 eyes of 45 patients with high myopia with astigmatism greater than 2.00 diopters (D) who underwent SMILE or FS-LASIK were enrolled. The FOZ, optical zone decentration, and corneal aberrations were analyzed using Scheimpflug imaging. These values were then compared between the two groups 6 months postoperatively. RESULTS: No postoperative complications were observed during follow-up. The mean FOZ diameter was 5.03 ± 0.31 mm for the FS-LASIK group and 5.24 ± 0.27 mm for the SMILE group (P = .007), corresponding to reductions of 1.18 ± 0.23 and 1.01 ± 0.21 mm, respectively, compared with the programmed optical zone (POZ) (P = .013). A significant difference was noted in the FOZ on the short axis between the two groups (P = .002), whereas no significant difference was observed on the long axis (P = .088). The FOZ area in the FS-LASIK and SMILE groups was 65.39 ± 6.14% and 70.09 ± 5.46% of the POZ area, respectively (P = .010). There was no significant difference in decentration between the two groups (0.29 ± 0.13 mm for the FS-LASIK group vs 0.30 ± 0.13 mm for the SMILE group, P = .798). A significant increase in spherical aberration was observed in the FS-LASIK group (P < .001). However, the induction of vertical coma was higher in the SMILE group than in the FS-LASIK group (P = .002). CONCLUSIONS: Eyes with high myopia with high astigmatism following SMILE achieved a larger FOZ and less spherical aberration but a larger vertical coma introduction than following FS-LASIK. [J Refract Surg. 2022;38(9):595-601.].

Long-term visual quality after small incision lenticule extraction (SMILE) and laser assisted subepithelial keratomileusis (LASEK) for low myopia.

BACKGROUND: Few studies have reported the visual outcomes of small-incision lenticule extraction (SMILE) and laser-assisted subepithelial keratomileusis (LASEK) for myopia correction. This study aims to compare the visual quality and corneal wavefront aberrations after SMILE and LASEK for low-myopia correction. METHODS: In this prospective study, we included 29 eyes of 29 patients who received SMILE and 23 eyes of 23 patients who received LASEK between June 2018 and January 2019. The following measurements were assessed: uncorrected (UDVA) and corrected (CDVA) distance visual acuity, manifest refraction, corneal wavefront aberrations, and subjective visual quality. All patients were followed up for two years. RESULTS: All procedures were uneventful. An efficacy index of 1.19 ± 0.17 was established in the SMILE group and 1.23 ± 0.20 in the LASEK group. No eyes lost more than two lines of CDVA. We found that 93% (27/29) of the treated eyes in the SMILE group and 91% (21/23) in the LASEK group had spherical equivalent (SE) within ± 0.25D. The increases in the total corneal spherical aberration and the corneal front spherical aberration were lower in the SMILE group than in the LASEK group (P < 0.01). In contrast, the increases in the total corneal vertical coma and the corneal front vertical coma in the SMILE group were greater than those in the LASEK group (P < 0.01). CONCLUSION: Both SMILE and LASEK have good safety, stability, and patient-reported satisfaction for low myopia. SMILE induced less corneal spherical aberration but greater vertical coma than LASEK.

SMILE after DALK to reduce residual refraction: two-year results.

PURPOSE: To determine the two-year results of small incision lenticule extraction (SMILE) for correcting post-keratoplasty myopia and myopic astigmatism. METHODS: In this case-series study, 10 eyes of 10 patients with a 6- to 10-year history of successful deep lamellar keratoplasty (DALK) underwent SMILE using the VisuMax laser platform. Ophthalmologic examinations and visual acuity and refraction measurement were taken pre- and 1, 3, 6, 12, and 24 months postoperatively. The Pentacam and Sirius imaging were done in the first and last follow-up sessions. RESULTS: The mean age of the patients was 39.60 ± 7.86 years. Six subjects were male. Two years after SMILE, the mean improvement in UDVA and CDVA was 3.60 ± 1.84 (P < 0.001) and 1.60 ± 2.91 (P = 0.231) LogMAR, respectively. The mean decrease in spherical equivalent, spherical error, and cylinder power was 1.92 ± 1.96 diopter (D) (P = 0.013), 0.70 ± 3.05D (P = 0.213), and 2.42 ± 2.91D (P = 0.024), respectively. The vector mean target-induced astigmatism, surgical-induced astigmatism, and difference vector were 1.30D@44˚, 1.11D@24˚, and 0.86D@73˚, respectively. Two years after SMILE, vertical coma, horizontal coma, and spherical aberration increased by 0.44 ± 0.51, 0.23 ± 0.32, and 0.02 ± 0.16 µm, respectively, (all P > 0.05) while trefoil reduced by 0.29 ± 0.75 µm (P = 0.428). CONCLUSION: SMILE can be an effective procedure for reducing refraction and astigmatism after DALK in patients with moderate myopia and moderate to severe astigmatism and improves the visual acuity in these patients. Axis rotation during surgery may result in under-correction of astigmatism. Refinement of SMILE treatment nomogram for post-DALK cases seems necessary.