Comparison of various excimer laser (EL) combination therapies for vitiligo: a systematic review and network meta-analysis

AIM

This study aimed to compare the efficacy and safety of excimer laser (EL)-based combination regimens in improving repigmentation.

METHODS

A comprehensive search was conducted in PubMed, Web of Science, Cochrane Library, and Embase on July 1, 2023, to include randomized controlled trials of EL combination treatments for vitiligo that met the criteria. The primary outcome measure was a repigmentation rate ≥ 75%, and the secondary outcome measures were a repigmentation rate of ≤ 25% and adverse events.

RESULTS

Eleven studies involving 348 patients were included. Network Meta-Analysis showed that EL combined with antioxidants (SUCRA = 98.8%), EL combined with calcipotriol (SUCRA = 59.8%) and EL combined with tacalcitol (SUCRA = 59.6%) were the three optimal interventions achieving repigmentation rates ≥ 75%. EL alone (SUCRA = 77.6%), EL combined with tacalcitol (SUCRA = 61.7%) and EL combined with antioxidants (SUCRA = 57.2%) were the three interventions with the highest rates of treatment failure. Adverse events in all groups mainly included erythema, burning sensation and hyperpigmentation. Based on the results of the current study, EL combination therapies were safe with mild adverse events.

CONCLUSION

EL combined with antioxidants was the preferred regimen for vitiligo, whereas EL alone was the regimen with the highest rate of treatment failure in vitiligo.

Use of In Vivo Corneal Confocal Microscopy to Guide Excimer Laser With Adjunctive Mitomycin C for Treatment of Recalcitrant Acanthamoeba Keratitis

PURPOSE

The aim of this study was to describe 3 cases of recalcitrant Acanthamoeba keratitis (AK) that were successfully treated using in vivo corneal confocal microscopy (IVCM) to guide excimer laser ablation depth with adjunctive mitomycin C 0.02%.

METHODS

Three patients diagnosed with AK did not respond to several weeks of intensive topical therapy with antiamoebic agents. The patient underwent phototherapeutic keratectomy with topical mitomycin C 0.02% application. The maximum stromal depth of cysts measured by IVCM was 80 μm, 100 μm, and 240 μm, and the stromal ablation depths were 80 μm, 100 μm, and 100 μm, respectively.

RESULTS

In all 3 eyes, AK resolved after a single excimer laser application, and topical treatment was gradually discontinued within 6 weeks afterward. In 1 eye, penetrating corneal transplantation was performed 6 weeks after phototherapeutic keratectomy because of ongoing severe corneal pain. IVCM and histology of the corneal transplant did not reveal any Acanthamoeba cysts within the excised corneal button. No recurrence was observed during the follow-up period of 19 to 34 months.

CONCLUSIONS

IVCM-guided phototherapeutic keratectomy with mitomycin C 0.02% seems to be a safe and successful approach for the treatment of AK, especially in cases of resistance to topical treatment. Corneal IVCM should be performed before laser application to measure cyst depth, determine ablation depth, and assess postoperative treatment success.

Factors Predicting Loss of Best-Corrected Visual Acuity After Hyperopic Laser-Assisted In Situ Keratomileusis

PURPOSE

The aim of this study was to identify risk factors for the loss of corrected distance visual acuity (CDVA) after uncomplicated hyperopic laser-assisted in situ keratomileusis (LASIK).

METHODS

A retrospective study including hyperopic patients who underwent microkeratome-assisted LASIK between January 2000 and December 2019 at Care-Vision Laser Centers, Tel-Aviv, Israel. Loss of CDVA was defined as ≥ 2 lines (0.20 logarithm of the minimum angle of resolution [logMAR] increase). Excluded were patients who had loss of CDVA because of intraoperative or postoperative complications or developed cataract at their final visit.

RESULTS

Overall, 1998 eyes of 1998 patients were included in the study, of which 35 eyes (1.75%) had CDVA loss at final follow-up (mean 387 days). The vision-loss group had a significantly greater spherical treatment (3.4 vs. 2.8 D, P = 0.02), ablation depth (69.4 vs. 53.8 μm, P = 0.01), a higher proportion of treatments with a smaller optic zone (6.0 mm) (31.4% vs. 13.4%, P = 0.002), treatment with the EX200 (Alcon) excimer rather than the EX500 (Alcon) (74.3% vs. 39.0%, P < 0.001), and treatment with the Moria M2-90 microkeratome rather than the Moria Sub-Bowman's keratomileusis (SBK) microkeratome (65.7% vs. 29.6%, P < 0.001). In multivariate binary logistic regression, factors that remained significant predictors of CDVA loss were a greater spherical treatment (per 1 D treatment, odds ratio = 1.42, 95% CI, 1.11-1.81, P = 0.004) and the use of the Moria M2-90 microkeratome (odds ratio = 4.66, 95% CI, 2.30-9.45, P < 0.001).

CONCLUSIONS

In patients undergoing uncomplicated hyperopic LASIK, a greater spherical hyperopic treatment is associated with a higher risk for vision loss. Transition to a newer microkeratome model significantly reduced vision loss rate.

Comparison of refractive surgeries (SMILE, LASIK, and PRK) with and without corneal crosslinking: systematic review and meta-analysis

Corneal crosslinking (CXL) is used for treating keratoconus and post-laser in situ keratomileusis ectasia. However, refractive surgery is not usually performed with prophylactic CXL. Therefore, we performed a meta-analysis comparing outcomes of refractive surgeries with vs without prophylactic CXL. We systematically searched databases for studies comparing refractive surgeries for myopic correction with vs without prophylactic corneal crosslinking. Review Manager 5.4.1 was used to perform statistical analysis. We included 2820 eyes from 28 studies. Compared with refractive surgery alone, surgery with prophylactic CXL resulted in decreased central corneal thickness, corrected distance visual acuity logMAR, and safety and efficacy indices. There were no significant differences in postoperative uncorrected distance visual acuity of 20/20 or better at ≥12 months and other visual outcomes among both groups. More randomized controlled trials with standard crosslinking protocols are needed to analyze the prophylactic use of crosslinking with refractive surgeries.

Tel-Aviv Protocol for Postrefractive Surgery Corneal Ectasia: A Case Series

PURPOSE

The aim of this study was to describe the safety and efficacy of the Tel-Aviv Protocol (epithelial photorefractive keratectomy and corneal cross-linking) as a treatment for postrefractive surgery corneal ectasia.

METHODS

This study includes 8 eyes from 7 patients, each diagnosed with postrefractive surgery ectasia years after refractive surgery and treated with the Tel-Aviv Protocol. The procedure included transepithelial PRK using the EX500 excimer laser, a 50-μm laser ablation of the epithelium and anterior stroma, delivered on the visual axis with cyclotorsion correction, treating up to 50% of refractive astigmatism. After the epithelial photorefractive keratectomy, all patients underwent corneal cross-linking.

RESULTS

The mean keratometry (K) and maximal K both decreased [from 43.37 ± 2.23 to 41.84 ± 2.01 ( P = 0.03) and from 44.95 ± 3.08 to 42.78 ± 2.19 ( P = 0.03), respectively]. Astigmatism was significantly reduced (from 3.53 ± 2.36 to 0.88 ± 0.89 diopter; P = 0.02). Uncorrected visual acuity improved significantly in all patients from a mean of 0.56 ± 0.32 to 0.15 ± 0.14 logMAR ( P = 0.01). Best-corrected visual acuity improved from 0.22 ± 0.24 to 0.06 ± 0.06 logMAR ( P = 0.07; 1-tail P = 0.04). All patients maintained visual acuity during the follow-up period, up to 25 months, mean = 329 days. The Tel-Aviv Protocol was found to be safe [mean safety index: 1.63 ± 1.03 (range: 1.00-4)] and effective [mean efficacy index: 1.29 ± 0.66 (range: 0.71-2.1)].

CONCLUSIONS

The Tel-Aviv Protocol, developed initially for keratoconus treatment, is a safe and promising procedure to stop postrefractive surgery ectasia progression while significantly improving vision, thereby avoiding keratoplasty.

Femtosecond thin-flap laser assisted in situ keratomileusis for correction of post-penetrating keratoplasty ametropia: long-term outcome

PURPOSE

To evaluate the long-term clinical outcomes of femtosecond thin-flap LASIK (femto-LASIK) for correction of refractive error after penetrating keratoplasty in keratoconus-affected eyes.

SETTING

a private ophthalmology clinic.

DESIGN

Prospective interventional case series.

METHODS

This prospective interventional case series enrolled 22 eyes of 22 patients who underwent femto-LASIK for the management of post-penetrating keratoplasty ametropia. The refractive error, uncorrected (UDVA), and corrected (CDVA) distance visual acuities and vector analysis were reported in short-term and long-term period after surgery.

RESULTS

The mean age was 32.7 ± 7.5 years (range, 23 to 47 years) at the surgery time. The average time between PK and femto-LASIK was 42.5 ± 31.7 months. The average follow-up duration after femto-LASIK was 81.2 ± 18.6 months. The mean preoperative UDVA significantly improved from 0.47 ± 0.15 logMAR to 0.35 ± 0.14 logMAR at 12 months (P = 0.048) and 0.4 ± 0.17 at final follow-up exam (P = 0.007). CDVA was 0.22 ± 0.1 at baseline which improved to 0.18 ± 0.15 and 0.15 ± 0.1 logMAR at 12 and 81 months, respectively. (Ps = 0.027, 0.014). The mean cylinder before surgery was - 5.04 ± 1.4D which significantly decreased to -1.5 ± 0.8 D at 12 months postoperatively. (P < 0.001). There was a significant increase in refractive astigmatism from 12 months to 81 months postoperatively (-3.1 ± 2.0, P = 0.002). At the final visit, the efficacy index was 0.83, and the safety index was 1.16.

CONCLUSIONS

Despite the short-term outcome indicated that femo-LASIK was effective for correction of post-keratoplasty ametropia during short-term period, a notable regression in its effect was observed in the long-term follow-up. Therefore, the predictability of this technique might decrease in the long-term.

Refraction and topographic risk factors for early myopic regression after small-incision lenticule extraction surgery

We sought to evaluate the topographic risk factors for early myopic regression after small-incision lenticule extraction (SMILE). A retrospective case‒control study was conducted, and individuals who underwent SMILE surgery were enrolled. Among them, 406 and 14 eyes were categorized into the nonregression and regression groups, respectively. The preoperative and postoperative parameters in the two groups were collected, including spherical refraction (SE), axial length (AXL) and topographic data. A generalized linear model was adopted to analyze the difference in each parameter between the two groups. After 6 months, UCVA decreased in the regression group, and SE increased in the regression group (both P < 0.05). The increase in the CCT at the thinnest point (P = 0.044), flat corneal curvature (P = 0.012) and TCRP (P = 0.001) were significantly greater in the regression group. Regarding the risk factors for myopic regression, preoperative SE, preoperative sphere power, preoperative AXL, preoperative flat corneal curvature, preoperative SA, early postoperative SE, early postoperative sphere power, early postoperative AXL and early postoperative CCT difference were significantly greater in the regression group (all P < 0.05). The SE, sphere power, AXL, preoperative flat corneal curvature, preoperative SA, and postoperative CCT difference correlate with early myopic regression after SMILE.

Comparative visual outcomes of the first versus second eye following small-incision lenticule extraction (SMILE)

BACKGROUND

This study aimed to compare the visual outcomes of the first operated eyes with those of the second operated eyes following small-incision lenticule extraction (SMILE).

METHODS

A total of 202 patients (404 eyes) underwent SMILE using the tear film mark centration method for myopia and myopic astigmatism correction. Baseline characteristics, objective optical quality, decentered displacement, induced corneal aberrations, and modulation transfer function (MTF) values were assessed. Linear regression analyzed the relationship between decentration and visual quality parameters, including corneal aberrations and MTF values.

RESULTS

No significant difference was observed in objective visual quality, efficacy, and safety indexes between the two groups (all P > 0.05). The average decentered displacement for the first and second surgical eyes was 0.278 ± 0.17 mm and 0.315 ± 0.15 mm, respectively (P = 0.002). The horizontal coma in the first surgical eyes were notably lower than in the second (P = 0.000). MTF values at spatial frequencies of 5, 10, 15, and 20 cycles/degree (c/d) were higher in the first surgical eyes compared to the second (all P < 0.05). Linear regression indicated that high-order aberrations (HOAs), root mean square (RMS) coma, spherical aberration, horizontal coma, vertical coma, and eccentric displacement were all linearly correlated. Furthermore, MTF values exhibited a linear relationship with eccentric displacement across these spatial frequencies.

CONCLUSIONS

There was no discernible difference in visual acuity, efficacy, or safety between the two operated eyes. Nonetheless, the first operated eyes exhibited reduced decentered displacement and demonstrated superior outcomes in terms of horizontal coma and MTF values compared to the second operated eyes following SMILE. The variations in visual quality parameters were linearly correlated with decentered displacement.

Factors affecting long-term myopic regression after corneal refractive surgery for civilian pilots in southwest China

BACKGROUND

The purpose of this study was to analyze myopic regression after corneal refractive surgery (CRS) in civilian pilots and to explore the factors that may cause long-term myopic regression.

METHODS

We included civilian pilots who had undergone CRS to correct their myopia and who had at least 5 years of follow-up. We collected retrospective data and completed eye examinations and a questionnaire to assess their eye habits.

RESULTS

A total of 236 eyes were evaluated in this study. 211 eyes had Intrastromal ablations (167 eyes had laser in situ keratomileusis, LASIK, 44 eyes had small incision lenticule extraction, SMILE) and 25 eyes had subepithelial ablations (15 eyes had laser epithelial keratomileusis, LASEK and 10 eyes had photorefractive keratectomy, PRK). The mean preoperative spherical equivalent (SE) was - 2.92 ± 1.11 D (range from - 1.00 to -5.00 D). A total of 56 eyes (23.6%) suffered from myopic regression after CRS. Comparisons of individual and eye characteristics between the regression and non-regression groups revealed statistically significant differences in age, cumulative flight time, postoperative SE (at 6 months and current), uncorrected visual acuity (UCVA), accommodative amplitude (AA), positive relative accommodation (PRA), postoperative period, types of CRS and eye habits. Generalized propensity score weighting (GPSW) was used to balance the distribution of covariates among different age levels, types of CRS, cumulative flying time, postoperative period and continuous near-work time. The results of GPS weighted logistic regression demonstrated that the associations between age and myopic regression, types of CRS and myopic regression, continuous near-work time and myopic regression were significant. Cumulative flying time and myopic regression, postoperative period and myopic regression were no significant. Specifically, the odds ratio (OR) for age was 1.151 (P = 0.022), and the OR for type of CRS was 2.769 (P < 0.001). The OR for continuous near-work time was 0.635 with a P value of 0.038.

CONCLUSIONS

This is the first report to analyze myopic regression after CRS in civilian pilots. Our study found that for each year increase in age, the risk of civilian pilots experiencing myopic regression was increased. Intrastromal ablations had a lower risk of long-term myopia regression than subepithelial ablations. There is a higher risk of myopic progression with continuous near-work time > 45 min and poor accommodative function may be related factors in this specific population.

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.

Changes in Corneal Epithelial Thickness in Different Areas After Femtosecond Laser-Assisted LASIK in Patients With High Astigmatism

PURPOSE

To explore changes in corneal epithelial thickness (CET) after femtosecond laser-assisted laser in situ keratomileusis in patients with high astigmatism.

METHODS

CET was measured at every intersection of the concentric circles and specific axes using AngioVue optical coherence tomography (Angio-OCT) preoperatively and 1 month postoperatively. The average thickness of corneal central, paracentral, and peripheral regions was the mean of the points within the central 2, 2 to 5, and 5 to 7 mm areas, respectively. Correlation analysis was performed to investigate the association between CET along different axes and other preoperative and postoperative parameters.

RESULTS

Forty-two eyes of 28 patients were included. CET along the astigmatic (K1) and perpendicular (K2) axes in the central and paracentral areas increased (P < .001), whereas that along the K2 axis decreased in the peripheral area 1 month postoperatively (P = .001). The amount of CET change in the peripheral area between the K1 and K2 axes was significantly different (P < .001). In the central area, the change in CET along the K2 axis was positively correlated with ablation depth (r = 0.315, P = .042) and negatively with refractive power after surgery (r = -0.347, P = .024). In the peripheral area, the changes in CET along both K1 and K2 axes were negatively correlated with ablation depth (r = -0.431, P = .004; r = -0.387, P = .011, respectively).

CONCLUSIONS

Epithelial modeling differed between the different astigmatism axes after refractive surgery. The compensatory response of the corneal epithelium is more pronounced along the steeper axis. [J Refract Surg. 2024;40(4):e239-e244.].

Suboptimal visual outcome after femto-LASIK ablation in a high myopic patient

A 28-year-old nurse had an aberration-free femto-laser in situ keratomileusis (LASIK) performed for her myopia of -6.25 -0.50 × 096 and -6.75 -0.50 × 175 in the right and left eye, respectively. Corrected distance visual acuity (CDVA) preoperatively was 20/16. Preoperatively, there were no abnormalities on Scheimpflug imaging, and a pachymetry of 585 μm was measured in both eyes. Flap thickness was 115 μm. The patient was quite nervous during the surgery. Since the surgery, her uncorrected distance visual acuity (UDVA) and CDVA are suboptimal at 20/30 and 20/20 in the right eye, and 20/20 and 20/16 in the left eye. 3 months postoperatively, there is a stable manifest refraction of +0.25 -1.25 × 030 and +0.25 -0.00 × 0. The keratometric astigmatism in the Scheimpflug imaging is 1.2 diopter (D) × 114 and 0.4 D × 78 in the right and left eyes, respectively (FIgures 1 and 2). Thinnest pachymetry is 505 μm and 464 μm in the right and left eye, respectively. Her wavefront analysis shows refraction in a 6 mm zone of -0.99 -1.22 × 32 and -0.91 -0.36 × 136. The cycloplegic refraction is 1.25 -1.00 × 023 and +1.00 -0.25 × 006 (Figures 3 and 4). What is the cause of the suboptimal visual outcome in this case? What would be your treatment strategy to improve visual outcome?

Ten-year outcomes following small incision lenticule extraction for up to -10Dioptres myopia

CLINICAL RELEVANCE

More than 6 million small-incision lenticule extraction (SMILE) procedures have been performed worldwide since 2011. Therefore, its long-term safety and efficacy should be investigated.

BACKGROUND

This study aimed to evaluate 10-year refractive outcomes, corneal stability, axial length, and wavefront aberrations in patients who underwent SMILE to correct myopia.

METHODS

Thirty two patients (32 eyes) who underwent SMILE-based myopic correction. Corrected distance visual acuity, uncorrected distance visual acuity, corneal stability, axial length, and wavefront aberrations were evaluated preoperatively and at 1 month and 1, 5, and 10 years postoperatively.

RESULTS

At 10 years postoperatively, the safety and efficacy indices for the patients included in this study were 1.19 ± 0.21 and 1.04 ± 0.27, respectively. For 26 (81%) and 30 eyes (94%), correction to within ±0.50 D and ±1.00 D of the target was achieved, respectively. Over the 10-year follow-up duration, a mean -0.32 ± 0.56 D regression was observed (-0.03 ± 0.06 D/year). Relative to baseline, horizontal and vertical comas significantly increased, as did the incidence of higher-order aberrations (all P < 0.001), whereas axial length and corneal elevation remained stable during follow-up.

CONCLUSION

These results indicate that the SMILE-based correction for myopia of up to -10 Dioptres is safe, effective, and stable, with relatively constant wavefront aberrations and corneal stability over time after treatment.

Visual Quality Assessment After FS-LASIK Using Customized Aspheric Ablation Profile for Age-Related Accommodation Deficiency Compensation

PURPOSE

To evaluate clinical outcomes and visual quality 12 months after femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) performed with the Custom-Q algorithm for correction of myopia with or without astigmatism and compensate for age-related accommodation deficiency.

METHODS

Patients who had Custom-Q FS-LASIK for myopia and myopic astigmatism with age-related accommodation deficiency were included in this retrospective study. Distance, intermediate, and near visual acuities, objective and subjective refractions, Q-factor, corneal higher order aberrations (HOAs), accommodation function, defocus curve, contrast sensitivity, and a subjective questionnaire assessing visual quality were evaluated 12 months postoperatively.

RESULTS

Clinical data of 43 cases were analyzed. The mean age was 42.02 ± 1.85 years (range: 40 to 48 years). At the 12-month follow-up visit, there were 43 (100%), 42 (97%), and 33 (77%) patients who achieved a binocular uncorrected distance, intermediate, and near visual acuity, respectively, better than 20/20 separately. Defocus curves revealed better distance vision in the dominant eyes, and the nondominant eyes performed better at intermediate and near vergence (P < .001). The Q-value and corneal spherical aberration coefficient were more positive in the dominant eyes than those in the nondominant eyes (P < .001). The accommodative amplitude and relative accommodation improved binocularly (P < .001). The questionnaire demonstrated high patient satisfaction with near vision, and no one reported having severe visual disturbance.

CONCLUSIONS

For myopic patients with age-related accommodation deficiency, the Custom-Q algorithm proved to be an effective way to achieve acceptable near vision without compromising distance vision. [J Refract Surg. 2024;40(4):e245-e252.].

Suitability of Slaughterhouse-Acquired Pig Eyes as Model Systems for Refractive Ultraviolet and Infrared Femtosecond Laser Research

PURPOSE

To elucidate whether it is feasible to use porcine eyes from scalded, abattoir-acquired animals for refractive femtosecond laser research.

METHODS

An infrared laser (FS 200) and an ultraviolet laser (prototype version) were tested for their applicability on scalded pig eyes. Fifty porcine eyes were divided into two equally-sized groups and assigned to either the infrared or the ultraviolet laser. Both laser groups were comprised of five subgroups of n = 5 eyes each. Group A: non-scalded eyes (negative control); group B: eyes taken from tunnel-scalded animals; group C1: eyes taken from tank-scalded animals without opaque corneal lesion; group C2: eyes taken from animals with opaque corneal lesion; group D: eyes scalded in toto in the laboratory (positive control). In each group the lasers were employed to create a stromal flap. The quality of the laser cuts and the resulting flap beds, as well as of the porcine corneas themselves, was examined by anterior segment optical coherence tomography and scanning electron microscopy.

RESULTS

All scalded specimens exhibited substantial corneal swelling, most pronounced in group C2. After ultraviolet laser application, the tank- and tunnel-scalded samples displayed marked irregularities and an increased degree of surface roughness in the flap beds. After infrared laser application, this was only the case in the tank-scalded specimens.

CONCLUSION

It is not recommended to use eyes taken from scalded pigs for ultraviolet femtosecond laser experiments. For infrared femtosecond lasers, eyes taken from tunnel-scalded animals may represent an acceptable alternative, if non-scalded eyes are not available.

308 nm excimer laser and tacrolimus ointment in the treatment of facial vitiligo: a systematic review and meta-analysis

This study aimed to investigate the effects and safety of 308 nm excimer laser (308 nm EL) and tacrolimus ointment (TO) in the treatment of facial vitiligo (FV). We searched Cochrane Library, PUBMED, EMBASE, CNKI, and WANGFANG from inception to June 1, 2023. Outcomes included overall response rate (ORR), total adverse reaction rate (TARR), recurrence rate at 3-month (RR-3) and recurrence rate at 6-month (RR-6). The outcome data were presented as odds ratios (OR) with 95% confidence intervals (CI). The risk of bias was assessed by Cochrane risk-of-bias tool and data analysis was performed by RevMan 5.4 software. This study included a total of 19 trials involving 2085 patients. When comparing 308 nm EL monotherapy with 308 nm EL plus TO, significant differences in the ORR (OR = 4.29, 95% CI [2.97, 6.19], I2 = 0%, P < 0.001), RR-3 (OR = 0.18, 95% CI [0.05, 0.69], I2 = 0%, P = 0.01), and RR-6 (OR = 0.38, 95% CI [0.14, 1.03], I2 = 39%, P = 0.06) were found between the two managements. When comparing TO monotherapy with TO plus 308 nm EL, its results showed significant differences in the ORR (OR = 4.21, 95% CI [2.90, 6.11], I2 = 0%, P < 0.001), TARR (OR = 0.42, 95% CI [0.22, 0.81], I2 = 4%, P = 0.009), and RR-3 (OR = 0.32, 95% CI [0.01, 8.03], P = 0.49) between the two modalities. The results of this study suggest that the combination of 308 nm EL and TO is more effective than either treatment alone for the treatment of FV.

Photorefractive Keratectomy in Student Naval Aviators: Outcomes of the U.S. Navy Accessioning Study

PURPOSE

To present the outcomes of the U.S. Navy photorefractive keratectomy (PRK) accessioning study conducted between 2000 and 2005 that helped lead to the acceptance of laser vision correction within the U.S. aviation industry.

METHODS

In this prospective masked study, a total of 301 students who had PRK and underwent naval flight training were compared to 4,368 untreated peers. Three training pipelines were compared: propeller/jet transport, jet fighters, and helicopters. The evaluated metrics were flight and academic performance (assessed for the primary and advanced stage of the training as normalized Navy Standard Score [NSS]), as well as the student attrition rate from training.

RESULTS

The attrition rate was lower in the PRK group compared to controls (15.9% vs 23.2%; P = .004). In the primary stage of training, students who had PRK outperformed controls in flight training performance in the propeller/jet transport pipeline (average NSS after PRK: 52.4 ± 7.5 vs controls: 50.7 ± 6.4, P = .02), but the flight performance in the jet fighter and helicopter pipelines was comparable between the two groups. Academic performance in the primary stage of training was approximately 7% to 13% higher in students who had PRK for all training pipelines. During the advanced training stage, there was no difference in the flight performance between the groups in any of the presented pipelines. Academic performance was significantly better for students who had PRK in the helicopter pipeline (51.2 ± 11.0 vs 46.7 ± 11.7 P < .001) but comparable between the two groups in the remaining pipelines.

CONCLUSIONS

Refractive surgery did not have adverse effects on flight performance metrics. Pilots who had PRK had comparable or better outcomes than their untreated peers. [J Refract Surg. 2024:40(3):e173-e181.].

Comprehensive Assessment of Posterior Corneal Asphericity Change Calculated by Tangential Radius of Curvature After FS-LASIK and SMILE

PURPOSE

To evaluate changes in posterior corneal asphericity (ΔQ) using the tangential radius of curvature after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE) procedures.

METHODS

One hundred twenty right eyes of myopic patients who underwent either FS-LASIK or SMILE procedures were analyzed using Sirius 3D corneal topography for assessment. The tangential radius was employed to calculate both preoperative and postoperative posterior corneal Q-values across each semimeridian. After both surgical interventions, the ΔQ value variations across the 360° semimeridional regions of the posterior corneal surface were compared.

RESULTS

A marked postoperative increase in the posterior corneal Q-value was documented. No significant differences were noted between the postoperative Q-values or ΔQ-values of the two surgical approaches. Among patients with moderate myopia, postoperative Q-value exhibited considerably lower increases and ΔQ-value significantly smaller than their counterparts with high myopia. Moreover, the fluctuation in ΔQ across semimeridional regions was less evident in patients with moderate myopia than in those with high myopia. Notably, the degree of ΔQ fluctuation across semimeridional regions was similar between both surgical categories. These data offer insights into variations in the posterior corneal surface after refractive surgeries depending on the degree of myopia, illuminating their clinical relevance.

CONCLUSIONS

Both FS-LASIK and SMILE introduce notable changes to posterior corneal asphericity among patients with different myopia intensities. Furthermore, the influence on the asphericity across the entire posterior surface is similarly distributed between FS-LASIK and SMILE techniques. [J Refract Surg. 2024;40(3):e133-e141.].

Fourier analysis of corneal irregular astigmatism after small-incision lenticule extraction and transepithelial photorefractive keratectomy: A comparative study

To compare changes in the spherical component, regular astigmatism, and irregular astigmatism of the anterior surface of the cornea after small-incision lenticule extraction (SMILE) and transepithelial photorefractive keratectomy (TransPRK). Fifty-six patients underwent SMILE in 56 eyes, and 68 patients underwet TransPRK in 68 eyes. The right eye was chosen to enter the group. Six months after the procedure, Scheimpflug images were acquired, and Fourier analysis of the anterior surface of patients' corneas was performed using the Pentacam built-in software. Fourier parameters encompass various measurements such as the steepest radius of the curvature and average eccentricity of the spherical components (SphRmin and SphEcc), maximum decentration (MaxDec), central and peripheral regular astigmatism (regular astigmatism at the center [AstC] and regular astigmatism at the periphery [AstP]), and irregularity (Irr). At 6 months postoperatively, SphEcc decreased significantly (P < .001), MaxDec increased significantly (P < .001), and Irr increased insignificantly (P = .254) in the SMILE group. SphEcc decreased significantly (P < .001) and MaxDec and Irr increased significantly (P < .001) in the TransPRK group. TransPRK caused greater changes in SphEcc, MaxDec, and Irr on the anterior corneal surface than SMILE (P < .05). The amount of MaxDec-induced changes in SMILE and TransPRK was significantly correlated with the amount of higher-order aberrations and spherical aberration changes (P < .05). SMILE and TransPRK increase overall irregular astigmatism on the anterior surface of the cornea, more so with TransPRK, where changes in decentration are associated with with increased higher-order aberrations.

Ray-Tracing Transepithelial Excimer Laser Central Corneal Remodeling Plus Pachymetry-Guided Accelerated Corneal Crosslinking for Keratoconus

PURPOSE

The aim of this study was to report the 12 to 96 months results of a tissue-preservation algorithm based on ray-tracing-guided transepithelial excimer laser central corneal ablation (RT t-PRK) combined with individualized pachymetry-guided accelerated crosslinking (M nomogram ACXL) in young adult patients with stable keratoconus (KC).

METHODS

This was a prospective interventional study including 38 eyes of 38 young adult patients (stage II KC) with a mean age of 35 years (range 26-46 years) who underwent simultaneous RT with t-PRK plus pachymetry-based ACXL in the worst eye. The treatments were performed using the iViS Suite iRES Excimer Laser (Ligi, Taranto, Italy). Ray-tracing-guided treatments were planned using the customized interactive programmed transepithelial ablation (CIPTA) 2 web software and diagnostic data were assessed by the Precisio 2 tomographer (Ligi, Taranto, Italy) and Sirius tomographer (C.S.O., Florence, Italy). The main outcome measures included uncorrected distance visual acuity, best spectacle-corrected visual acuity, Kmax, high-order aberrations, minimum corneal thickness, and posterior elevation, with a mean follow-up of 52 months (range 12-96 m).

RESULTS

The mean UDVA improved + 3.5 ±1.28 Snellen lines (SL); 38% gained ≥ 4 ±1.34 SLs, 35% ≥ 3 ±1.21 SLs, 22% ≥ 2 ±1.12 SLs, and 5% ≥ 1 ±0.75 SLs. The mean best spectacle-corrected visual acuity increased by + 4.3 ±1.3 SL. Sixty-eight percent gained ≥ 4 ±0.88 SLs and 30% ≥ 3 ±0.78 SL. No SLs were lost.

CONCLUSIONS

RT t-PRK plus ACXL significantly improved the quality of vision in patients with KC, preventing overcorrection and minimizing tissue consumption.

Vitamin D supplementation can enhance therapeutic effects of excimer laser in patients with vitiligo

PURPOSE

Vitiligo is a disease of acquired depigmentation characterized by the destruction of melanocytes. A theoretical association between low level of 25-hydroxyvitamin D [25(OH)D] and vitiligo has been previously suggested. The objective of this study was to determine the efficacy of intramuscular injection of cholecalciferol with excimer laser compared with the excimer laser alone for vitiligo treatment.

METHODS

This study included 26 patients diagnosed with non-segmental vitiligo and low serum 25(OH)D levels (<20 ng/mL). The participants were randomly divided into two groups through randomization. The treatment using a 308-nm excimer laser was administered to both groups, and the study group additionally received cholecalciferol injection.

RESULTS

The Vitiligo Area Scoring Index (VASI) scores showed an 83.6% improvement over the initial score in the study group, whereas the control group showed a 54.7% improvement after 6 months of treatment. After 6 months of treatment, the study group showed a significantly higher proportion of patients who achieved VASI50 and VASI75 compared with the control group.

CONCLUSION

Intramuscular injection of cholecalciferol can be a supplemental option for the treatment of vitiligo patients with vitamin D deficiency with excimer laser therapy.

Combined Rotational excimer lASER coronary atherectomy (RASER) in non-crossable, non-dilatable coronary artery disease: observations from a single center

BACKGROUND

Balloon non-crossable stenoses represent a challenging subset of coronary artery disease (CAD). They are clinically associated with patients who are older, frailer, and with multi-morbidities, and angiographically with increased tortuosity and coronary artery calcification. Combined rotational (RA) excimer laser coronary atherectomy (ELCA), or RASER, may facilitate stent delivery and deployment in non-crossable, non-dilatable severely calcified lesions. In this study, we assessed preliminary safety and efficacy of the RASER hybrid technique.

METHODS

RASER feasible percutaneous coronary intervention (PCI) procedures performed at a large tertiary hospital in the northeast of England were retrospectively analyzed from September 1, 2008, to February 28, 2022. Major endpoints were in-hospital death from any cause, as well as procedural and angiographic success, defined by stent delivery with less than 50% residual stenosis and without clinical or angiographic complications, respectively.

RESULTS

From 74 unique cases, there were 28 RASER, 24 ELCA/RA, 16 balloon angioplasty ± stenting, and 6 medically treated patients. In-hospital mortality rate was 5.2%, including 1 ELCA- and 3 RASER-treated patients. Successful stent delivery was achieved in significantly more RASER-treated patients compared to ELCA/RA- or balloon-treated patients: 96.4% (27/28), 25% (6/24), and 31.3% (5/16) respectively (P less than .001).

CONCLUSIONS

In our retrospective, single-center study, patients with CAD who were deemed appropriate for RASER PCI had a high peri-procedural mortality rate. In this context, adjunctive RASER therapy provides acceptable safety and efficacy as a bailout strategy, with at least 3 out of 5 patients achieving satisfactory procedural and angiographic results. Randomized controlled trials are needed to comprehensively compare the clinical outcomes of high-risk RASER PCI vs conservative medical therapy.

Refractive results of photorefractive keratectomy comparing trans-PRK and PTK-PRK for correction of myopia and myopic astigmatism

PURPOSE

To compare refractive outcomes after transepithelial photorefractive keratectomy (tPRK) and combined phototherapeutic keratectomy (PTK-PRK) procedure using two different excimer laser platforms for correction of myopia and myopic astigmatism.

METHODS

In this retrospective multicenter study, we compared the results of two different PRK methods. The first group received a tPRK treatment with the Amaris750 excimer laser (Schwind eye-tech solutions). The second group received a combined PTK-PRK treatment with the MEL90 excimer laser (Carl Zeiss). Only healthy eyes with no previous surgery and a spherical equivalent (SE) of -1 to -8 diopters (D) were included. Preoperative spherical equivalent (SE), age, and sex were matched among the two groups. All treatments were performed by the same surgeon in different clinics. This study was approved by the local Ethics Committee (No. 2022-1980).

RESULTS

We included 154 eyes of 86 patients in our study. There was no difference in predictability of SE between the two groups. Efficacy and safety indices were equally high in both groups. Similarly, no significant differences were seen in change of higher order aberrations (HOA) between the two groups (p > 0.05). No complications occurred.

CONCLUSION

Both investigated methods provide safe and effective refractive results. The combination of PTK with PRK may be a suitable option to the already used one-step tPRK for the correction of myopia.

Impact of removing soft contact lenses 1 day versus 1 month before surgery on the outcomes of microkeratome laser in situ keratomileusis

PURPOSE

To compare the outcomes, safety, efficacy, and predictability of microkeratome laser in situ keratomileusis (LASIK) 24 h and one month or more after removing soft contact lenses.

SETTING

ULTRALASIK Eye Center, Dubai, United Arab Emirates.

METHODS

The patients were divided based on the time of discontinuation of the soft contact lenses before LASIK (Group 1 at 24 h and Group 2 at one month or longer), and the two groups were well matched. Schirmer's testing, tear break-up time, corrected distance visual acuity, uncorrected distance visual acuity, manifest refraction spherical equivalent, and infection rate were evaluated preoperatively and at one week, one month, and six months after treatment.

RESULTS

Group 1 (G1) comprised 1025 eyes, and group 2 (G2) had 1052 eyes. The groups were comparable preoperatively. The overall-mentioned outcomes were comparable between groups with uncorrected distance visual acuity of - 0.084 ± 0.12 logMAR in G1 and - 0.078 ± 0.17 logMAR in the G2 at 6 months (P = 0.322). Tear break-up time as well as Schirmer's testing results was also comparable with no evidence of increased risk of dry eyes or non-inflammatory complications in any of the groups on follow-up visits at 1 week (P = 0.421), 1 month (P = 0.101), and 6 months (P = 0.399) postoperatively. Finally, no infectious complications were recorded in either of the groups.

CONCLUSION

With the absence of corneal warpage, no statistical or clinical difference in microkeratome LASIK outcomes and safety was spotted between the groups despite the difference in SCL discontinuation time before the procedure.

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.

Comparison of 110- and 145-µm Small-Incision Lenticule Extraction Cap Thickness: A Randomized Contralateral Eye Study

PURPOSE

To investigate the visual, refractive, and biomechanical outcomes of small incision lenticule extraction (SMILE) with two different cap thicknesses.

METHODS

Thirty-four patients were included in this prospective, randomized, contralateral eye study. Subjects were randomized to receive SMILE surgery with a 110-m cap thickness in one eye and 145-µm cap thickness in the fellow eye. Uncorrected and corrected distance visual acuity, contrast sensitivity (CS), total higherorder aberrations (THOAs) and corneal biomechanical properties were compared 3 months after surgery.

RESULTS

Postoperative refractive and visual outcomes, CS and THOAs were similar between the two groups ( P > 0.05 for all parameters). At 3 months postoperatively, there was a significant difference in Corvis ST Biomechanical Index (CBI); stiffness parameter at first applanation (SP A1), and Integrated Radius between the two groups (all P < 0.05).

CONCLUSIONS

Eyes with thicker SMILE corneal caps showed no advantage regarding visual acuity, CS and THOAs over eyes with thinner caps. However, higher cap thickness may result in better corneal biomechanical properties postoperatively.

Prevention and Treatment of Persistent Epithelial Defects After Common Refractive Surgery Procedures

PURPOSE

To discuss the prevention and treatment of persistent epithelial defects after the most common refractive surgeries-photorefractive keratectomy, laser in situ keratomileusis, or small incision lenticule extraction.

METHODS

PubMed was used to search the medical literature.

RESULTS

Persistent epithelial defects are infrequent after photorefractive keratectomy, laser in situ keratomileusis, or small incision lenticule extraction. In the authors' opinion, any persistent epithelial defect present at 1 week or beyond after surgery should be treated aggressively with a properly fit bandage contact lens, lubrication with non-preserved artificial tears, and treatment of any eyelid abnormalities, including nocturnal lagophthalmos. Consideration should be given for presumptive treatment for herpes simplex virus or varicella zoster virus infection. If the persistent epithelial defect does not close within 2 weeks, then other measures should be considered, such as autologous serum drops, topical losartan, amniotic membranes, and topical human recombinant nerve growth factor to limit corneal scarring fibrosis and microbial infection.

CONCLUSIONS

Persistent epithelial defects are among the most feared complications of refractive surgery. Timely and aggressive treatment should be instituted to close the epithelium prior to the development of scarring fibrosis and/or microbial corneal infection. [J Refract Surg. 2024;40(2):e117-e124.].

Factors Predicting the Need for Re-treatment After Laser Refractive Surgery in Patients With Mixed Astigmatism

PURPOSE

To identify risk factors that increase the likelihood of re-treatment following refractive surgery in patients with mixed astigmatism.

METHODS

This was a retrospective study including patients who underwent either laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) between 2000 and 2019 and had mixed astigmatism (spherical error of +0.50 D or greater and spherical equivalent of less than 0.00 diopters [D]). Patients were divided into two groups according to whether they underwent re-treatments during the study period.

RESULTS

Overall, 785 eyes (785 patients) were included. In total, 5.2% of the eyes (n = 41) underwent re-treatment. The re-treatment group was more likely to have preoperative high astigmatism (80.5% vs 48.3%, P < .001), moderate to high hyperopia (36.6% vs 22.3%, P = .035), and to have undergone surgery earlier during the study period (P < .001). They were also more likely to have undergone surgery using the Wave-Light EX200 rather than the EX500 laser platform (Alcon Laboratories, Inc) (P < .001), have a treated optical zone of 6 mm rather than 6.5 mm (P < .001 for both), and their maximum ablation depth was greater (P < .001). There was no difference between the re-treatment and control groups regarding procedure type (PRK vs LASIK). Binary logistic regression found preoperative high astigmatism (odds ratio = 3.97, P < .001) and the type of laser platform used (EX200, odds ratio = 7.78, P < .001) as the only independent factors associated with re-treatment.

CONCLUSIONS

Re-treatment rates following correction of mixed astigmatism were 5.2% over 20 years. Use of a sixth-generation laser platform significantly reduced the risk of re-treatment. Presence of high astigmatism is a significant risk factor for re-treatment. There was no difference in retreatment risk between PRK and LASIK. [J Refract Surg. 2024;40(2):e73-e78.].

Corneal Irregularity Induced by Transepithelial Photorefractive Keratectomy in a Patient With Partial Limbal Stem Cell Deficiency

PURPOSE

The aim of this study was to present a case of transepithelial photorefractive keratectomy (trans-PRK) laser ablation in a patient with partial limbal stem cell deficiency (LSCD) that resulted in corneal irregularity.

METHODS

A 23-year-old man with bilateral partial LSCD underwent trans-PRK for myopia correction 2 months before presentation to our department. Trans-PRK ablation was performed with a phototherapeutic keratectomy ablation profile set at 60 μm in the OD and 57 μm in the OS and 8 mm zone. At the time of presentation, the patient complained of decreased visual acuity. Corrected distant visual acuity was 20/20 (-3.25, -0.75 × 180 degrees) and 20/50 (-3.00, -3.00 × 180 degrees) in the OD and the OS, respectively. No further ocular history was reported other than prolonged soft contact lens use for myopia. Pre-trans-PRK tomography (WaveLight Oculyzer II diagnostic system, WaveLight GmbH, Germany) revealed bilateral superior steepening with corresponding epithelial thinning as obtained by the epithelial map using Optovue optical coherence tomography (Visionix Luneau technology). Slit-lamp examination showed bilateral superficial neovascularization, suggestive of early-stage LSCD.

RESULTS

A nonuniform laser stromal ablation resulting in corneal irregularity and decreased visual acuity was observed 2 months postoperatively. During the 6-month follow-up, corneal tomography was stable with only minimal improvement. At that time, corrected distant visual acuity remained 20/20 (-2.75, -0.75 × 160 degrees) in the OD and 20/50 (-3.00, -3.00 × 180 degrees) in the OS.

CONCLUSIONS

Trans-PRK seems to be a contraindication in cases with corneal epithelial irregularities and could lead to abnormal and nonuniform stromal ablation .

Topographic and surgical risk factors for high postoperative residual astigmatism after small incision lenticule extraction in patients with different degrees of myopia: a retrospective cohort study

BACKGROUND

To evaluate the possible topographic and surgical risk factors for high postoperative residual astigmatism in patients who undergo small-incision lenticule extraction (SMILE) surgery and have different myopia degrees.

METHODS

A retrospective cohort study was conducted, and patients who underwent SMILE surgery were enrolled. A total of 80 and 150 eyes from 40 to 75 individuals, respectively, were selected as the low myopia and high myopia groups. The demographic data, visual acuity, refraction, topographic parameters and surgical settings were recorded. Multiple linear regression with interaction tests were performed to survey the risk factors for high postoperative residual astigmatism in each group.

RESULTS

Five (6.25%) and 9 (6.00%) eyes presented with high postoperative residual astigmatism in the low myopia and high myopia groups, respectively, but these differences were not significant (P = 0.569). A steep corneal curvature was correlated with a greater risk of high postoperative residual astigmatism in the low myopia group (P = 0.015), while a higher degree of cycloplegic cylinder power, steeper corneal curvature, greater topographic cylinder power, smaller optic zone and longer incision length were associated with a high rate of postoperative residual astigmatism in the high myopia group (all P < 0.05). In addition, the interaction effects of cycloplegic and topographic cylinder power and longer incision length on the incidence of high postoperative residual astigmatism development were more evident in the high myopia group than in the low myopia group (all P < 0.05).

CONCLUSIONS

A steep corneal curvature correlates with a high risk of high postoperative residual astigmatism after SMILE surgery, and a higher degree of cycloplegic and topographic cylinder and longer incision are associated with high postoperative residual astigmatism in individuals with high myopia.

Differences in change of post-operative antioxidant levels between laser-assisted lenticule extraction and femtosecond laser in situ keratomileusis

To evaluate the change of total antioxidant capacity (TAC) and ascorbic acid (AA) between femtosecond laser in situ keratomileusis (FS-LASIK) and laser-assisted lenticule extraction (LALEX). A prospective non-randomized study was conducted, and 33 and 75 eyes that had undergone FS-LASIK or LALEX surgeries were enrolled, respectively. The tear films near corneal incisions were collected, and the concentrations of TAC and AA were determined. The generalized linear mixed model was adopted to calculate the adjusted odds ratio (aOR) with 95% confidence interval (CI) of TAC and AA between the two groups. The AA reduction was significant 1 month after the LALEX and FS-LASIK procedures (both p < 0.05), and the decrement in AA level was significantly larger in the FS-LASIK group compared to the LALEX group (p = 0.0002). In the subgroup analysis, the LALEX group demonstrated a lower decrement in TAC level in the individuals with dry eye disease (DED) than the FS-LASIK group (p = 0.0424), and the LALEX group demonstrated a significantly lower AA decrement in the participants with high myopia (p = 0.0165) and DED (p = 0.0043). The LALEX surgery causes lesser AA decrement compared to FS-LASIK surgery especially for the patients with DED.

Evaluation of the effect of artificial tears on corneal epithelial thickness changes after photorefractive keratectomy

PURPOSE

This study aimed to evaluate the corneal epithelial thickness changes after photorefractive keratectomy (PRK) and the impact of long-term artificial tear usage on epithelial thickness changes in these patients.

METHODS

This study was performed on 71 patients (142 eyes) without dry eye disease who received PRK for myopic refractive correction. The corneal epithelial thickness profile was obtained before, one, three, and six months after surgery using anterior segment optical coherence tomography. Patients were randomly divided into two groups: group A, who received preservative-free artificial tears post-surgery, and group B, who did not receive artificial tears.

RESULTS

The epithelial thickness decreased universally in the first month and then increased in the 3- and 6-month follow-ups. Group A had a significantly thicker epithelium in central, paracentral, and midperipheral zones compared with group B in the 3-month follow-up. In the 6-month follow-up, no significant differences were detected between groups. At the last follow-up, the central, paracentral, and midperipheral zone epithelial thicknesses in all patients were significantly higher than preoperative values, but peripheral zone thickness only increased to preoperative values.

CONCLUSIONS

Patients using artificial tears showed a faster thickening, especially in the central and paracentral zones, but there were no significant differences between the two groups in the final follow-up. Artificial tear usage may increase the rate of the epithelial remodeling process in post-PRK patients without significantly altering the final epithelial thickness profile. Further studies are warranted to evaluate the influence of different factors on epithelial remodeling.

Excimer Laser Phototherapeutic Keratectomy for Anterior Corneal Opacification After Descemet Membrane Endothelial Keratoplasty

PURPOSE

The aim of this study was to assess the long-term outcome of excimer laser phototherapeutic keratectomy (PTK) for treating remaining anterior corneal opacities after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

This cohort study analyzed 67 eyes of 66 patients undergoing PTK in addition to and after DMEK between 2012 and 2021 at the Department of Ophthalmology, University of Cologne. Patients who were treated by PTK after previous DMEK on the same eye were included. The outcome parameters were best corrected visual acuity (BCVA), changes in refraction, endothelial cell density, corneal densitometry, central corneal thickness, and total corneal higher order aberrations. Patients with visual limitations in addition to anterior opacification were analyzed separately for their visual outcome. Eyes with severe visual limitations that have a very limited visual potential were excluded from the study. In addition, patients with not at least 1 postoperative follow-up examination were excluded from the study.

RESULTS

In this study, 67 eyes of 66 patients met all inclusion criteria. The median follow-up period was 13.1 (quartiles: 4.1; 30.7; interquartile range 26.6) months. The mean (±SD) BCVA improved from (logarithm of the minimum angle of resolution) 0.54 (±0.32) to 0.38 (±0.27) at the first postoperative visit ( P < 0.001) and remained significantly improved at all follow-up examinations compared with preoperative BCVA. Refraction and endothelial cell density did not change significantly after PTK. There was a significant decrease in corneal backscatter in the anterior corneal layer ( P < 0.001), and the total higher order aberration ( P = 0.02) and central corneal thickness were significantly reduced at the most recent postoperative visit ( P < 0.001). No immune reactions were observed.

CONCLUSIONS

Excimer laser PTK after DMEK for persisting anterior corneal opacities has the potential to significantly improve patients' vision without affecting refractive parameters or endothelial cell density.

Characteristics of disk halo size and its correlation with lenticule quality in small incision lenticule extraction for moderate to high myopia

PURPOSE

To investigate changes in disk halo size after small incision lenticule extraction (SMILE) and the correlation between halo size and lenticule quality in moderate to high myopia.

METHODS

Thirty eyes of 30 consecutive patients (mean age, 24.9 ± 4.5 years; mean spherical equivalent, -6.85 ± 1.18 D) undergoing SMILE were included in this prospective study. Lenticule surface quality was accessed with a scanning electron microscopy by a scoring system. Halo size was measured preoperatively and at 1, 3, and 6 months postoperatively. Multiple linear regression analysis was performed to explore associations between halo size and a range of factors, including lenticule quality.

RESULTS

Disk halo size increased slightly at 1 month and then recovered continually from 3 to 6 months postoperatively, with no difference between halo size during the preoperative period and at 6 months postoperatively (P > 0.05). One month after SMILE, halo size (1 cd/m2, 5 cd/m2) was associated only with uncorrected distance visual acuity (P ≤ 0.004). A halo size of 5 cd/m2 at 3 months postoperatively correlated with the anterior surface quality of the lenticule (P = 0.046). At 6 months postoperatively, a halo size of 1 cd/m2 was associated only with the baseline, accounting for 11.9% of the variability (P = 0.041); no correlations were found for the halo size of 5 cd/m2.

CONCLUSIONS

Disk halo size after SMILE was enlarged at an early stage postoperatively and subsequently declined to the baseline level during a 6-month follow-up. The quality of the lenticule surface influenced halo size changes in the early phase.

Photorefractive keratectomy in flat, normal, and steep corneas

PURPOSE

To compare photorefractive keratectomy (PRK) outcomes in patients with different corneal steepness.

SETTING

Care-Vision Laser Center, Tel-Aviv, Israel.

DESIGN

Retrospective comparative chart review.

METHODS

Patients included in this study underwent wavefront optimized myopic PRK between January 2013 and December 2019. Patients were divided into 3 groups based on the steepness of the cornea (steep keratometry) (flat: <42 diopters [D], normal: 42 to 46 D and steep: >46 D). One to one matching was performed to verify that baseline parameters (age, preoperative visual acuity and refractive error) were similar between groups. Primary outcome measures were: postoperative corrected/uncorrected distance visual acuity (CDVA/UDVA), efficacy index (postoperative UDVA/preoperative CDVA), safety index (postoperative CDVA/preoperative CDVA), spherical equivalence (SEQ) and cylinder.

RESULTS

After matching, 650 eyes were included in each group, which were similar in baseline parameters. There were no significant postoperative differences between flat, normal, and steep corneas in terms of safety index (1.02 vs 1.03 vs 1.03, P = .28), efficacy index (1.01 vs 1.01 vs 1.02, P = .57), logMAR CDVA (0.01 vs 0.02 vs 0.01, P = .76), logMAR UDVA (0.02 vs 0.03 vs 0.02, P = .68), %SEQ within 0.50 D (73.9% vs 74.2% vs 74.6%, P = .95) or 1.00 D of target (91.9% vs 92.5% vs 92.2%, P = .92), %cylinder within 0.50 D (82.8% vs 82.2% vs 81.4%, P = .81) or 1.00 D of target (96.9% vs 97.1% vs 97.2%, P = .95).

CONCLUSIONS

No significant differences were found between flat, normal and steep corneas following wavefront-optimized myopic PRK. Thus, this procedure may be safely and effectively performed in both flat and steep corneas.

An update on intraocular lens power calculations in eyes with previous laser refractive surgery

PURPOSE OF REVIEW

There is an ever-growing body of research regarding intraocular lens (IOL) power calculations following photorefractive keratectomy (PRK), laser-assisted in-situ keratomileusis (LASIK), and small-incision lenticule extraction (SMILE). This review intends to summarize recent data and offer updated recommendations.

RECENT FINDINGS

Postmyopic LASIK/PRK eyes have the best refractive outcomes when multiple methods are averaged, or when Barrett True-K is used. Posthyperopic LASIK/PRK eyes also seem to do best when Barrett True-K is used, but with more variable results. With both aforementioned methods, using measured total corneal power incrementally improves results. For post-SMILE eyes, the first nontheoretical data favors raytracing.

SUMMARY

Refractive outcomes after cataract surgery in eyes with prior laser refractive surgery are less accurate and more variable compared to virgin eyes. Surgeons may simplify their approach to IOL power calculations in postmyopic and posthyperopic LASIK/PRK by using Barrett True-K, and employing measured total corneal power when available. For post-SMILE eyes, ray tracing seems to work well, but lack of accessibility may hamper its adoption.

Pilocarpine HCl 1.25% for treatment of presbyopia after laser vision correction: pooled analysis of two phase 3 randomized trials (GEMINI 1 and 2)

PURPOSE

To evaluate the efficacy of topical pilocarpine HCl 1.25% (Pilo) in treating presbyopia in individuals with or without a history of laser vision correction (laser-assisted in situ keratomileusis [LASIK] or photorefractive keratectomy [PRK]).

SETTING

Multiple clinical sites.

DESIGN

Pooled analysis of 2 identically designed prospective, randomized, vehicle-controlled studies (GEMINI 1 and 2).

METHODS

Adults aged 40 to 55 years with presbyopia received once-daily Pilo or vehicle bilaterally for 30 days. Responder rates for ≥3-line improvement in mesopic, high-contrast, binocular distance-corrected near visual acuity (DCNVA) were determined on day 30.

RESULTS

Among participants with a history of LASIK/PRK (n = 39 in the Pilo group, n = 41 in the vehicle group), responder rates for ≥3-line improvement in DCNVA on day 30 at hours 0.25, 0.5, 1, 3, 6, 8, and 10, respectively, were 16.7%, 38.9%, 41.7%, 37.8%, 16.2%, 13.9%, and 8.3% with Pilo and 0.0%, 2.6%, 10.5%, 5.1%, 7.7%, 2.6%, and 0.0% with vehicle. Responder rates in the LASIK/PRK subgroup were significantly higher with Pilo than vehicle at hours 0.25 ( P = .0087), 0.5 ( P = .0001), 1 ( P = .0022), and 3 ( P = .0005). In contrast, there were no significant differences in responder rates between Pilo-treated participants with and without LASIK/PRK. Among non-LASIK/PRK participants in the Pilo group (n = 336), responder rates for ≥3-line improvement in DCNVA on day 30 at hours 0.25, 0.5, 1, 3, 6, 8, and 10, respectively, were 16.8%, 32.7%, 39.0%, 28.0%, 17.4%, 12.6%, and 10.5%.

CONCLUSIONS

Pilo treatment effectively and similarly improved DCNVA in presbyopes with or without a history of laser vision correction.

Characterization of postoperative LASIK ectasia features on higher-order aberration excimer ablation maps

BACKGROUND

To characterize anterior corneal higher-order aberration (HOA) excimer ablation map patterns in postoperative LASIK ectasia (POE) and to examine correlations between newly identified corneal HOA ablation map features of POE and known topographic indices.

METHODS

Prospective multicenter non-interventional descriptive study. A total of 28 eyes from 22 POE patients were enrolled. The postoperative HOA ablation map was derived from Topolyzer Vario corneal imaging at the time of POE diagnosis. Features that recurred were identified and then analyzed. Correlations to Orbscan indices were studied.

RESULTS

An arrangement of two elliptical paracentral ablation islands, deep inferior and shallow superior, in direct mirror-like opposition to each other, were identified on all HOA maps. The paracentral islands were accompanied by peripheral ablation crescents. The deep paracentral inferior island 'hot spot' coincided with the topographical apical POE cone and was highly reproducible in angular position (249.3 ± 17.3°). There was significant variation in ablation depth (shallow superior island: 11.5 ± 6.9 μm and deep inferior island: 32.5 ± 18.8 μm). The superior crescents had high variability in depth (34.8 ± 18.9 μm). Strong correlations were found between the corneal irregularity index and the ablation depth difference between the deep and shallow paracentral islands (R = 0.96; P < 0.0001).

CONCLUSION

The corneal HOA excimer ablation map revealed a recurring, distinct, easily recognizable pattern in POE eyes. Validated Orbscan POE indices and HOA ablation map islands showed a strong correlation. It is possible to extract useful information from the corneal HOA ablation map, potentially making it suitable for diagnosing and monitoring POE although more studies are needed.

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.

Late-Onset Chronic Corneal Fistula Following Phototherapeutic Keratectomy: A Case Report and Importance of Early Detection

BACKGROUND We report a case of late-onset chronic fistula in a decompensated cornea after multiple ocular surgeries and a recent phototherapeutic keratectomy (PTK). CASE REPORT A 73-year-old woman presented to our service with a past ocular history of bilateral chronic angle closure glaucoma and pseudophakic bullous keratopathy in the left eye. Given a history of long-term uncontrolled glaucoma with advanced disc cupping and poor visual potential, the patient underwent multiple palliative procedures, including, most recently, a PTK. Few years later she presented with a spontaneous late onset of slowly appearing corneal leak on fluorescein staining upon routine clinical examination. Corrected distance visual acuity was hand motion and intraocular pressure (IOP) was 40 mmHg in the affected eye. Serial anterior segment optical coherence tomography (AS-OCT) sections were obtained, which aided in understanding the current presentation and revealed distinctive multilayer corneal changes during the healing process. The patient was successfully managed with cyanoacrylate corneal gluing and ocular hypotensive medications, which halted the corneal leak. CONCLUSIONS We report a case of a rare finding of corneal fistula in an eye with multiple previous ocular surgeries, and provide an explanation of the possible etiopathogenesis. We also highlight the pivotal role of AS-OCT for evaluating such cases and stress the importance of early detection of similar subtle leaks in the setting of a formed anterior chamber, which can often be missed, carrying a risk of infection.

Late approach for LASIK flap striae

A 24-year-old man was referred for postrefractive surgery evaluation. The patient had a history of uneventful laser in situ keratomileusis (LASIK) in both eyes 3 months previously. According to the surgeon who originally performed the surgery, on slitlamp examination, only microstriae in the left eye was detected on postoperative day 1 and a more conservative follow-up approach was adopted without further immediate intervention. The patient returned only 3 months after surgery, complaining of low vision in the left eye that, according to the patient, had been present since postoperative week 2. The patient was then referred for examination and surgical procedure with a diagnosis of significant postoperative striae. The slitlamp examination revealed a LASIK flap with striae, epithelial filling, and a wrinkled appearance (Figure 1JOURNAL/jcrs/04.03/02158034-202312000-00017/figure1/v/2023-11-20T151558Z/r/image-tiff). There were no signs of infection or inflammation. Originally, the LASIK flap was programmed to be 110 μm. Preoperative manifest refraction in the right eye was -5.25 (20/20) and in the left eye was -5.25 (20/20). Assuming it is a case of late-approach LASIK flap striae, how would you proceed? Would you try to hydrate and lift the flap and just reposition it? Would you avoid lifting and associate phototherapeutic keratectomy (PTK) with excimer laser on top of the flap? Would you consider topo-guided surgery with regularization of the visual axis or even amputation of the flap?

Clinical effect of stem cell transplantation combined with 308-nm excimer laser therapy for 56 cases of vitiligo

OBJECTIVE

To probe the clinical effect of stem cell transplantation in combination with 308-nm excimer laser therapy for vitiligo and to analyze its value in clinical application.

METHODS

A total of 56 patients with stable non-segmental vitiligo in different parts who were not cured by other therapies visiting our hospital from March 2019 to December 2021 were enrolled as study subjects. They were treated by stem cell transplantation combined with 308-nm excimer laser therapy. The treatment efficacy was observed and analyzed.

RESULTS

Among the 56 patients, 38 (67.85%) and 49 (87.5%) patients were cured at 6 and 12 months after treatment, respectively.

CONCLUSION

Stem cell transplantation combined with 308-nm excimer laser therapy for vitiligo achieves significant efficacy, with the cure rate far superior to that of other therapies for vitiligo. The therapy is worthy of popularization in the clinic.

First European results of a new refractive lenticular extraction procedure-SmartSight by SCHWIND eye-tech-solutions

BACKGROUND

To evaluate vision 3 months after SmartSight lenticule extraction treatments.

DESIGN

Case series.

METHODS

This case series of patients were treated at Specialty Eye Hospital Svjetlost in Zagreb, Croatia. Sixty eyes of 31 patients consecutively treated with SmartSight lenticule extraction were assessed. The mean age of the patients was 33 ± 6 years (range 23-45 years) at the time of treatment with a mean spherical equivalent refraction of -5.10 ± 1.35 D and mean astigmatism of 0.46 ± 0.36 D. Monocular corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA) were assessed pre- and post-operatively. Ocular and corneal wavefront aberrations have been postoperatively compared to the preoperative baseline values. Changes in ocular wavefront refraction, as well as changes in keratometric readings are reported.

RESULTS

At 3 months post-operatively, mean UDVA was 20/20 ± 2. Spherical equivalent showed a low myopic residual refraction of -0.37 ± 0.58 D with refractive astigmatism of 0.46 ± 0.26 D postoperatively. There was a slight improvement of 0.1 Snellen lines at 3-months follow-up. Compared to the preoperative status, ocular aberrations (at 6 mm diameter) did not change at 3 months follow-up; whereas corneal aberrations increased (+0.22 ± 0.21 µm for coma; +0.17 ± 0.19 µm for spherical aberration; and +0.32 ± 0.26 µm for HOA-RMS). The same correction was determined using changes in ocular wavefront refraction, as well as changes in keratometric readings.

CONCLUSION

Lenticule extraction after SmartSight is safe and efficacious in the first 3 months postoperatively. The post-operative outcomes indicate improvements in vision.

Comparison of errors in ablation depth calculation after myopic femtosecond laser in situ keratomileusis in patients with different degrees of myopia: a prospective study

BACKGROUND

To investigate the difference between the predicted preoperative corneal ablation depth and the measured ablation depth for femtosecond laser in situ keratomileusis (FS-LASIK) in patients with different degrees of myopia, and to analyze the source of the difference.

METHODS

A total of 55 patients (109 eyes) were included in this study. Multiple logistics regression was applied to analyze the sources affecting postoperative refractive outcomes. The difference between the preoperative predicted corneal ablation depth and the 1-day postoperative ablation depth in patients with different degrees of myopia was explored using linear regression. Corneal biomechanical parameters influencing error in ablation depth calculation were examined using multiple linear regression.

RESULTS

One hundred and nine eyes were divided into low to moderate myopia (55 eyes, myopia of 6 D or less), high myopia (45 eyes, myopia ranging from 6 D to a maximum of 9 D), and very high myopia group (9 eyes, myopia greater than 9 D) based on preoperative refractive error (spherical equivalent). Postoperative visual outcomes were comparable among the three groups of patients, with no significant difference in uncorrected visual acuity (UCVA). We did find notable disparities in spherical equivalent (SE) and central corneal thickness (CCT) in patients with different degrees of myopia at 1 day postoperatively (all p < 0.001). Logistic regression analysis showed that error in ablation depth calculation was an independent risk factor for refractive outcomes one day after surgery (OR = 1.689, 95% CI: 1.366 - 2.089). There was a substantial discrepancy in error in ablation depth calculation at 1 day postoperatively between the three groups. The measured ablation depth of the laser platform was lower than the predicted ablation depth in the low to moderate myopia and very high myopia groups, but the opposite was true in the high myopia group. Pre-operative SE (p < 0.001) and corneal front minimum radius of curvature (Front Rmin) (p = 0.007) obviously influenced the error in ablation depth calculation.

CONCLUSIONS

Error in ablation depth calculation values vary significantly between patients with different degrees of myopia and correlate highly with preoperative SE and Front Rmin. At the same time, the available evidence suggests that error in ablation depth calculation is an influential factor in postoperative refractive status, so it is imperative to control error in ablation depth calculation.

Comparison of Corneal Biomechanics Treated With Femtosecond Laser-Assisted In Situ Keratomileusis and Small-Incision Lenticule Extraction by New Corneal Biomechanical Parameters of Corvis ST II

PURPOSE

The aim of this study was to compare corneal biomechanics treated with femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and small-incision lenticule extraction (SMILE) for myopia and astigmatism using the new corneal biomechanical parameters of Corvis ST II.

METHODS

This was a prospective nonrandomized controlled study. Patients treated with FS-LASIK or SMILE between January 2018 and July 2018 were included. Corvis ST II was performed to measure corneal biomechanical parameters, including deformation amplitude ratio 2.0 mm (DA ratio 2.0 mm), integrated inverse radius (Integr Radius), stiffness parameter at first applanation (SP-A1), and Ambrosio relational thickness through the horizontal meridian (ARTh), preoperatively, 1 month postoperatively, and 6 months postoperatively. Pentacam pachymetry was used to assess the reduction in pachymetry.

RESULTS

Forty-five eyes underwent FS-LASIK, and 45 eyes underwent SMILE. The new parameters obtained by Corvis ST II between preoperative and postoperative measurements showed significant changes after FS-LASIK or SMILE (all P < 0.001). Postoperative SP-A1 significantly decreased in the 2 groups (108.88 ± 14.47-73.32 ± 13.2 in FS-LASIK and 105.79 ± 17.68-73.91 ± 14.81 in SMILE). Eyes with equal preoperative pachymetry, intraocular pressure, and spherical equivalents showed no significant differences in these new parameters measured using Corvis ST II ( all P > 0.05) between the 2 groups. The prediction of the laser platform overestimated the measured pachymetry reduction in the SMILE group (111.93 ± 15.18 μm vs. 87.16 ± 15.47 μm).

CONCLUSIONS

New corneal biomechanical parameters measured using Corvis ST II showed no significant differences between FS-LASIK and SMILE in eyes with homogeneous preoperative parameters. The laser software platform may have overestimated the actual corneal reduction in the eyes treated with SMILE.

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.].

Effective Optical Zone and Centration Following SMILE and FS-LASIK for High Myopia Calculated With a Novel Method

PURPOSE

To compare the effective optical zone (EOZ) and centration in eyes with high myopia after small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) using a novel method.

METHODS

Forty eyes of 40 consecutive patients with high myopia scheduled for SMILE or FS-LASIK were enrolled in the study. The EOZ, optical zone decentration, and corneal aberrations were analyzed using Scheimpflug imaging. These values were then analyzed and compared between the two procedures 6 months after surgery.

RESULTS

The mean EOZ diameter for SMILE (4.41 ± 0.14 mm) was larger than that for FS-LASIK (4.24 ± 0.28 mm; P = .002), corresponding to reductions of 1.60 ± 0.11 and 1.71 ± 0.21 mm, respectively, compared with the programmed optical zone (POZ) (P = .007). Moreover, the total decentration for SMILE (0.33 ± 0.12 mm) was greater than that for FS-LASIK (0.27 ± 0.15 mm; P = .020). The induction of spherical aberration (SA) was lower with SMILE than with FS-LASIK (P = .007).

CONCLUSIONS

A larger EOZ and less SA were observed after SMILE than after FS-LASIK in eyes with high myopia. [J Refract Surg. 2023;39(11):736-740.].