Tear Proteins Altered in Patients with Persistent Eye Pain after Refractive Surgery: Biomarker Candidate Discovery.

Some patients develop persistent eye pain after refractive surgery, but factors that cause or sustain pain are unknown. We tested whether tear proteins of patients with pain 3 months after surgery differ from those of patients without pain. Patients undergoing refractive surgery (laser in situ keratomileusis or photorefractive keratectomy ) were recruited from 2 clinics, and tears were collected 3 months after surgery. Participants rated their eye pain using a numerical rating scale (NRS, 0-10; no pain-worst pain) at baseline, 1 day, and 3 months after surgery. Using tandem mass tag proteomic analysis, we examined tears from patients with pain [NRS ≥ 3 at 3 months (n = 16)] and patients with no pain [NRS ≤ 1 at 3 months (n = 32)] after surgery. A subset of proteins (83 of 2748 detected, 3.0%) were associated with pain 3 months after surgery. High-dimensional statistical models showed that the magnitude of differential expression was not the only important factor in classifying tear samples from pain patients. Models utilizing 3 or 4 proteins had better classification performance than single proteins and represented differences in both directions (higher or lower in pain). Thus, patterns of protein differences may serve as biomarkers of postsurgical eye pain as well as potential therapeutic targets.

Comparison of early changes in tear film protein profiles after small incision lenticule extraction (SMILE) and femtosecond LASIK (FS-LASIK) surgery.

BACKGROUND: Small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (LASIK) are widely used surgical methods to correct myopia with comparable efficacy, predictability, and safety. We examined and compared the early changes of tear protein profiles after SMILE and FS-LASIK surgery in order to find possible differences in the initial corneal healing process. METHODS: SMILE operations for 26 eyes were made with Visumax femtosecond laser. In FS-LASIK surgery for 30 eyes, the flaps were made with Ziemer FEMTO LDV Z6 femtosecond laser and stromal ablation with Wavelight EX500 excimer laser. Tear samples were collected preoperatively, and 1.5 h and 1 month postoperatively using glass microcapillary tubes. Tear protein identification and quantification were performed with sequential window acquisition of all theoretical fragment ion spectra mass spectrometry (SWATH-MS). RESULTS: Immediately (1.5 h) after we found differences in 89 proteins after SMILE and in 123 after FS-LASIK operation compared to preoperative protein levels. Of these differentially expressed proteins, 48 proteins were common for both surgery types. There were, however, quantitative differences between SMILE and FS-LASIK. Upregulated proteins were mostly connected to inflammatory response and migration of the cells connected to immune system. One month after the operation protein expressions levels were returned to baseline levels with both surgical methods. CONCLUSIONS: Our study showed that immediate changes in protein profiles after SMILE and FS-LASIK surgeries and differences between the methods are connected to inflammatory process, and the protein levels quickly return to the baseline within 1 month. The differences in protein profiles between the methods are probably associated with the different size of the epithelial wound induced.

Longitudinal analysis of wound healing response post SMILE and LASIK surgery using proteomic profiling of tears.

Different types of refractive surgeries often exhibit differences in wound healing responses. The current study investigated post-operative tear protein profiles in subjects who underwent LASIK and SMILE to elucidate global changes to the proteomic profile during the period the patient cornea undergoes healing. In this study, 10 patients underwent LASIK and SMILE surgery with a contralateral paired eye design. Tear samples were collected using Schirmer's strips preoperatively, at 1 month, 3 months and 6 months postoperatively. Quantitative ITRAQ labeled proteomics was performed and the tear protein ratios were normalized to pre-operative protein levels for each subject. Whole proteomics identified 1345 proteins in tears from LASIK and 1584 proteins in SMILE across time points. About 67 proteins were common in LASIK and SMILE tears across all the time points. Wound healing responses were differentially regulated between two refractive surgeries (SMILE and LASIK). The proteins Ceruloplasmin, Clusterin, Serotransferrin were upregulated at 1 month and 3 months and downregulated at 6 months post operatively in LASIK surgery where as in SMILE these were downregulated. Galectin 3 binding protein showed upregulation at 1 month and the levels decreased at 3 months and 6 months postop in LASIK tears whereas the levels increased at 3 months and 6 months post-op in SMILE tears. The levels of proteins that protect from oxidative stress were higher in SMILE as compared to LASIK postoperatively. The extracellular matrix proteins showed an increase in expression at 6 months in SMILE tears and was stabilized at 6 months in LASIK tears post operatively. Different refractive surgeries induce distinct wound healing responses as identified in tears. This study has implications in targeting key proteins for improving the clinical outcome postrefractive surgery.

Factors associated with changes in posterior corneal surface following laser-assisted in situ keratomileusis.

PURPOSE: To identify factors associated with changes in the posterior corneal curvature following laser-assisted in situ keratomileusis (LASIK). METHODS: This retrospective study included myopic astigmatic eyes that underwent LASIK between January and December 2013 at Care-Vision Laser Center, Tel-Aviv, Israel. The average posterior keratometry was measured with the Sirius device at a radius of 3 mm from the center. The correlations between the surgically induced change in average posterior keratometry and preoperative parameters such as preoperative sphere, cylinder, spherical equivalent, central corneal thickness (CCT), refraction, Baiocchi Calossi Versaci (BCV) index, ablation depth, percent of tissue altered (PTA), and residual stromal bed (RSB) are reported. RESULTS: A total of 115 eyes with a mean age of 32.5 ± 8.3 years (range 22-56 years) were included. Central corneal thickness (p < 0.005), preoperative sphere (p < 0.001), spherical equivalent (p < 0.005), and preoperative posterior inferior/superior ratio (p < 0.05) were all significantly correlated with the percentage of change in the mean posterior K. According to ranked stepwise multiple regression analysis, 22% of the variance of change in posterior K could be explained by the examined factors. The factors that remained significant were the percentage of change in posterior inferior/superior ratio, preoperative subjective sphere, and preoperative mean posterior K (for all, p < 0.001). CONCLUSIONS: The percentage of change in posterior inferior/superior ratio, subjective sphere, and preoperative mean posterior K are all correlated with change in the mean posterior K after LASIK. Understanding of the variables that can influence posterior corneal changes following refractive surgery may play a role in the prevention of iatrogenic keratectasia.

Accuracy of intraoperative aberrometry versus modern preoperative methods in post-myopic laser vision correction eyes undergoing cataract surgery with capsular tension ring placement.

PURPOSE: To assess the accuracy of intraoperative wavefront aberrometry (IWA) versus modern intraocular lens formulas in post-myopic laser vision correction (LVC) patients undergoing cataract surgery with capsular tension ring placement. METHODS: This is a retrospective chart review conducted at an academic outpatient center. All post-myopic LVC eyes undergoing cataract surgery with IWA from a single surgeon from 05/2017 to 12/2019 were included. All patients received a capsular tension ring (CTR). Mean numerical error (MNE), median numerical error (MedNE), and percentages of prediction error within 0.50D, 0.75D, and 1.00D were calculated for the above formulas. RESULTS: Twenty-seven post-myopic LVC eyes from 18 patients were included. In post-myopic LVC, MNE with Optiwave Refractive Analysis (ORA), Barrett True K (BTK), Haigis, Haigis-L, Shammas, SRK/T, Hill-RBF v3.0, and W-K AL-adjusted Holladay 1 were + 0.224, - 0.094, + 0.193, - 0.231, - 0.372, + 1.013, + 0.860, and + 0.630 (F = 8.49, p < 0.001). MedNE were + 0.125, - 0.145, + 0.175, + 0.333, + 0.333, + 1.100, + 0.880, and + 0.765 (F = 7.89, p < 0.001), respectively. BTK provided improved accuracy in both MNE (p < 0.001) and MedNE (p = .033) when compared to ORA in pairwise analysis. If the ORA vs. BTK-suggested IOL power were routinely selected, 30% and 15% of eyes would have projected hyperopic outcomes, respectively (p = 0.09). CONCLUSIONS: Our study suggests that in post-myopic LVC eyes undergoing cataract surgery with CTRs, BTK performed more accurately than ORA with regard to accuracy and yielded a lower percentage of eyes with hyperopic outcomes. Haigis, Haigis-L, and Shammas yielded similar results to ORA with regard to accuracy and percentage of eyes with hyperopic outcomes. On average, Shammas and Haigis-L suggested IOLs that would yield outcomes more myopic than expected when compared to BTK.

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.

Ocular surface changes following computer use in post-LASIK patients.

PURPOSE: To assess the impact of computer use on the ocular surface of individuals after laser in situ keratomileusis (LASIK). METHODS: The dry eye symptoms and ocular surface of 18 post-LASIK young individuals and 18 controls were evaluated before and after performing a 30-min task on a computer without (Visit 1) and with (Visit 2) initial instillation of artificial tears. Symptoms were assessed using the Ocular Surface Disease Index (OSDI), Symptom Assessment in Dry Eye questionnaire version two (SANDE II) and Computer Vision Syndrome Questionnaire (CVS-Q). The ocular surface was assessed by measuring corneal higher order aberrations, tear meniscus height (TMH), conjunctival redness, blink rate and incomplete blinking, lipid layer thickness (LLT) and non-invasive keratograph break-up time (NIKBUT). RESULTS: SANDE II scores were >0 after the computer task in both groups (p ≤ 0.01). SANDE II and CVS-Q scores did not differ between LASIK and controls (p ≥ 0.43). Greater bulbar-temporal conjunctival redness, TMH and LLT and shorter NIKBUT were found after computer use in the LASIK group (p ≤ 0.04), whereas no changes were observed in the controls (p ≥ 0.20). Lower SANDE II and CVS-Q scores were reported at Visit 2 compared with Visit 1 in both groups (p ≤ 0.01). Likewise, no worsening of dry eye signs was observed at Visit 2 (p ≥ 0.11). CONCLUSIONS: Ocular symptoms reported during computer use were comparable between the groups. However, a worsening of dry eye signs was mostly observed in post-LASIK individuals. The instillation of artificial tears was effective in preventing the effects of computer use on the ocular surface in post-LASIK patients.

LASIK is associated with early cataract surgery in healthy patients.

PURPOSE: To evaluate the association between LASIK and early cataract phacoemulsification surgery (PE). METHODS: A matched case-control study was conducted. Cases were otherwise healthy adults with a history of LASIK. Groups were paired according to corrected-distance visual acuity (CDVA), axial length, and cataract grade. RESULTS: A total of 213 patients were included. 85 patients were classified as post-LASIK group and 128 as controls. The mean age at the time of LASIK was 42.32 ± 9.24 years. The mean CDVA before PE was 0.29 ± 0.19 Log MAR in post-LASIK group and 0.34 ± 0.22 Log MAR in controls (p = 0.07). The mean axial length was 23.99 ± 1.78 mm in post-LASIK group and 23.62 ± 0.98 mm in controls (p = 0.085). The mean nuclear cataract grading was 1.36 in post-LASIK group and 1.47 in controls (p = 0.34). The mean age at the time of PE was 60.18 ± 7.46 years in post-LASIK group and 67.35 ± 9.28 in controls (p < 0.0005). The difference between the mean age of LASIK and the mean age of PE was 17.85 ± 5.72 years. There was a positive association between the post-LASIK group and the age of PE ≤ 55 years (OR: 4.917, 95% CI: 2.21-10.90, p < 0.001). CONCLUSION: LASIK may be associated with early PE. Patients with LASIK had a 7-year earlier PE compared to a matched control group.

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.

[Effect of refractive surgery on Maklakov tonometry results]. / Vliyanie keratorefraktsionnoi khirurgii na rezul'taty tonometrii po Maklakovu.

PURPOSE: The study investigates the influence of changes in keratometric parameters after refractive surgery on the results of Maklakov tonometry. MATERIAL AND METHODS: The study examined a total of 61 people (121 eyes). The patients were divided into a control group with no history of surgery (16 people, 31 eyes), a LASIK group (13 people, 26 eyes), a femtosecond-assisted LASIK (FS-LASIK) group (16 people, 32 eyes), and a photorefractive keratectomy (PRK) group (16 people, 32 eyes). The patients underwent standard examination, keratometry (Km), Maklakov tonometry with a 10 g weight, and elastotonometry with 5, 7.5, and 15 g weights. RESULTS: In the LASIK group, the indentation diameter with 5 and 7.5 g weights correlated with Km in the central and near-paracentral zone (r=0.3-0.5). Tonometry with a 10 g weight did not correlate with anything. Tonometry with a 15 g weight inversely correlated with Km in the paracentral points (4 mm) of the strong meridian (r= -0.5 ... -0.7). In the FS-LASIK group, a significant inverse correlation with Km was observed only for the indentation diameter with a 10 g weight in the paracentral (3-4 mm) zone (r= -0.4 ... -0.5). In the PRK group, weak (r<0.4) correlations were found between Km and the indentation diameter of the 7.5 and 10 g weights for the central zone (1-2 mm). No significant correlations were found for 5 and 15 g weights.In the control group, there were practically no correlations for 5 and 7.5 g weights. The indentation diameter of the 10 g weight evenly correlated with Km at all points (r= -0.38 ... -0.60), the indentation of the 15 g weight correlated mainly with the curvature of the horizontal meridian (r= -0.37 ... -0.49). CONCLUSION: Tonometry readings with the 10 g weight are the most dependent on Km in different groups, and the readings with the 5 g weight are the least dependent. LASIK is characterized by the largest scatter of dependencies for weights of different masses, FS-LASIK - by the smallest. Tonometry readings with the 5 g weight correlated with Km only in the LASIK group, and this was the only direct correlation. Considering the inverse nature of most correlations, higher Km may be associated with an overestimation of tonometry results, and lower Km - with its underestimation.

Clinical results of topography-guided laser-assisted in situ keratomileusis using the anterior corneal astigmatism axis and manifest refractive astigmatism axis.

PURPOSE: To evaluate the clinical results of primary topography-guided femtosecond laser-assisted in situ keratomileusis (TG-FS-LASIK) using the Pentacam-measured anterior corneal astigmatism axis (ACA) or manifest refractive astigmatism axis (MRA). METHODS: In this prospective cohort study, all eyes were treated with primary TG-FS-LASIK using the manifest cylinder. Thirty-two right eyes were treated using ACA with axis disparity > 5° in the experimental group, and 32 right eyes were treated using MRA with axis disparity ≤ 5° in the control group. Visual, refractive outcomes, and corneal higher-order aberrations were evaluated. Vector analysis of astigmatism was performed using Alpins method with the ASSORT software. RESULTS: The mean logMAR UDVA in the experimental group was - 0.12 ± 0.06, - 0.05 ± 0.08, and - 0.08 ± 0.08 at 1-week, 1-month, and 3-month follow-up, whereas - 0.05 ± 0.06, - 0.12 ± 0.06, and - 0.14 ± 0.06 in the control group (p = 0.017, p < 0.001, and p = 0.003). At 3-month follow-up, 79% eyes achieved a UDVA of 20/16 or better, 9% gained one line of corrected distance visual acuity, the mean manifest cylinder was - 0.375 ± 0.254 D, 84% showed a manifest cylinder within ± 0.50 D, the mean magnitude of difference vector was 0.41 ± 0.35 D, the mean absolute angle of error (AE) was 7.36 ± 6.21°, and 41% exhibited an arithmetic AE within ± 5° in the experimental group, whereas 94%, 19%, - 0.203 ± 0.148 D, 100%, 0.21 ± 0.15 D, 3.39 ± 3.68°, and 69% in the control group (all p < 0.05). The postoperative and preoperative corneal spherical aberrations were comparable in both groups (p > 0.05). CONCLUSION: Primary topography-guided FS-LASIK using Pentacam-measured anterior corneal astigmatism axis exhibited slightly inferior clinical results to that using the manifest refractive astigmatism axis. Both methods achieved comparable postoperative and preoperative corneal spherical aberrations.

VisuMax Flap 2.0: a flap plus technique to reduce incidence of an opaque bubble layer in femtosecond laser-assisted LASIK.

PURPOSE: To evaluate the incidence of an opaque bubble layer (OBL) in femtosecond laser-assisted in situ keratomileusis (FS-LASIK) flaps created with VisuMax Flap 2.0 as a result of a modification in the parameters of the flap programming. METHODS: This retrospective study was comprised of 1400 eyes of 715 patients who received FS-LASIK surgery. OBLs were measured and reported as a percentage of the flap area to identify the incidence and extent. Flap creation, which is a modification technique, was performed with 8.1-mm flap diameters plus 0.3-mm enlarged interlamellar photodisruption (group Flap 2.0). The same flap diameters without extra photodisruption as the previous standard setting were also implemented (group Flap 1.0). The preoperative measurements, including sphere, cylinder, keratometry, and intraoperative characteristics such as flap size and thickness, were documented. Possible risk factors for the occurrence of OBLs were investigated in this study. RESULTS: The incidence of an OBL was reduced when using the Flap 2.0 program (31.4%) compared to the Flap 1.0 program (63.7%). The area of hard and soft OBLs created by the Flap 2.0 program is smaller than those created by the Flap 1.0 program (P = 0.007 and P < 0.001). Multivariate logistic regression indicated that a thinner flap (P = 0.038) and a higher sphere (P = 0.001) affected the chance of hard OBLs occurring. CONCLUSION: The VisuMax Flap 2.0 program promotes gas venting by enlarging the interlamellar photodisruption size. The incidence and extent of OBLs appear to be reduced significantly when the Flap 2.0 program is applied.

Comparison of risk factors for OBL in FS-LASIK and SMILE correction for myopia and myopia astigmatism.

BACKGROUND: To find out the incidence and risk factors of opaque bubble layer (OBL) in eyes with myopia and myopic astigmatism following femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE). METHODS: A total of 1076 eyes from 569 patients who had FS-LASIK or SMILE were included in the retrospective research. For each kind of surgery, eyes were separated into two groups: "OBL" groups and "no OBL" groups. In the FS-LASIK group, eyes that developed OBL were split into "hard OBL" and "soft OBL" groups. The incidence and size of OBL were analyzed after watching the surgical procedure videotaped during the operation and taking screenshots. Surgical parameters, including sphere, cylinder, keratometry, corneal thickness, flap thickness, cap thickness, lenticule thickness, and visual acuity, were compared. RESULTS: In the FS-LASIK surgery, the incidence of OBL was 63.2% (347 eyes). A thicker central corneal thickness (CCT) was the only independent risk factor affecting the OBL area (ß = 0.126, P = 0.019). One hundred and thirty of these eyes had hard OBL, and the flap thickness of these eyes was thinner than that of those with soft OBL (P = 0.027). In the SMILE group, 26.6% (140 eyes) developed OBL. A higher flat keratometry (K) and a thicker residual stromal thickness (RST) were risk factors affecting the OBL area (ß = 0.195, P = 0.024; ß = 0.281, P = 0.001). CONCLUSION: The incidence of OBL differs between the FS-LASIK surgery and the SMILE surgery. There are differences in the factors influencing OBL between the two surgeries.

Quality of vision after myopic refractive surgeries: SMILE, FS-LASIK, and ICL.

BACKGROUND: To characterize the quality of vision after SMILE, FS-LASIK, and ICL implantation and evaluate the related factors. METHODS: 131 eyes of 131 myopic patients (90 female, 41 male) who underwent refractive surgeries including SMILE (35 patients), FS-LASIK (73 patients), and ICL implantation (23 patients) were analyzed. The Quality of Vision questionnaires were completed 3 months after surgery, and the results were characterized and analyzed with baseline characteristics, treatment parameters, and postoperative refractive outcomes using logistic regression analysis to find out predicted factors. RESULTS: Mean age was 26.5 ± 4.6 years (range: 18 to 39 years) and mean preoperative spherical equivalent was - 4.95 ± 2.04 diopters (D) (range: -1.5 to -13.5). Safety and efficacy index was comparable between different techniques: the safety index was 1.21 ± 0.18, 1.22 ± 0.18, and 1.22 ± 0.16 and the efficacy index were 1.18 ± 0.20, 1.15 ± 0.17, 1.17 ± 0.15 for SMILE, FS-LASIK and ICL respectively. The mean overall QoV score was 13.40 ± 9.11, with mean frequency, severity, and bothersome score of 5.40 ± 3.29, 4.53 ± 3.04, and 3.48 ± 3.18 respectively, and there was no significant difference between different techniques. Overall, the symptom with the highest scores was glare, following fluctuation in vision and halos. Only the scores of halos were significantly different among different techniques (P < 0.000). Using ordinal regression analysis, mesopic pupil size was identified as a risk factor (OR = 1.63, P = 0.037), while postoperative UDVA was a protective factor (OR = 0.036, P = 0.037) for overall QoV scores. Using binary logistic regression analysis, we found that patients with larger mesopic pupil size had an increased risk to experience glare postoperatively; compared to ICL, patients who underwent SMILE or FS-LASIK tended to report fewer halos; patients with better postoperative UDVA were less likely to report blurred vision and focusing difficulty; with larger residual myopic sphere postoperatively, patients experienced focusing difficulties and difficulty judging distance or depth perception more frequently. CONCLUSIONS: SMILE, FS-LASIK, and ICL had comparable visual outcomes. Overall, glare, fluctuation in vision, and halos were the most frequently experienced visual symptoms 3 months postoperatively. Patients with ICL implanted tended to report halos more frequently compared with SMILE and FS-LASIK. Mesopic pupil size, postoperative UDVA, and postoperative residual myopic sphere were predicted factors for reported visual symptoms.

mEYEstro software: an automatic tool for standardized refractive surgery outcomes reporting.

BACKGROUND: Standardization for reporting medical outcomes enables clinical study comparisons and has a fundamental role in research reproducibility. In this context, we present mEYEstro, a free novel standalone application for automated standardized refractive surgery graphs. mEYEstro can be used for single and multiple group comparisons in corneal and intraocular refractive surgery patients. In less than 30 s and with minimal user manipulation, mEYEstro automatically creates the required journal standard graphs while simultaneously performing valid statistical analyses. RESULTS: The software produces the following 11 standard graphs; Efficacy: 1. Cumulative uncorrected (UDVA) and corrected visual acuity (CDVA), 2. Difference between UDVA and CDVA, Safety: 3. Change in line of CDVA, Accuracy: 4. Spherical equivalent (SEQ) to intended target, 5. Attempted vs. achieved SEQ, 6. Defocus equivalent (DEQ) accuracy, 7. Refractive astigmatism accuracy, 8. Target-induced astigmatism vs. Surgically-induced astigmatism, 9. Correction index histogram, 10. Angle of error histogram, Stability: 11. SEQ stability over time. Percent proportions, means, standard deviations, Cohen's d effect sizes, and p-values are calculated and displayed on each graph. All graphs can be easily exported as high-resolution TIFF images for figures to use in scientific manuscripts and presentations. CONCLUSIONS: mEYEstro software enables clinicians, surgeons, and researchers, to easily and efficiently analyze refractive surgery outcomes using the standardized methodology required by several peer-reviewed ophthalmology journals.

Role of tear vasoactive intestinal peptide on dry eyes after laser keratorefractive surgery.

BACKGROUND: To explore the changes in vasoactive intestinal peptide (VIP) concentration in tears post laser-assisted sub-epithelial keratomileusis (LASEK) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) surgeries and related factors, possible association between postoperative dry eye symptoms and VIP concentration in tears, and factors influencing dry eye symptoms after different periods post LASEK and FS-LASIK surgeries. METHODS: In this prospective, non-randomized, longitudinal cohort study, 23 and 22 subjects were recruited and underwent LASEK and FS-LASIK, respectively. After conducting an intact ophthalmic examination and collecting relevant surgical data, all subjects were examined for VIP concentration in their tears using ELISAs, tear-film breakup time, ocular staining and ocular surface disease index questionnaire before surgery and 1 day, 1 week, and 1 month post-surgery. RESULTS: Tear VIP concentration increased significantly after both LASEK and FS-LASIK, with the highest concentration observed 1 week post-surgery (P ≤ 0.05). Tear VIP concentration correlated negatively with corneal ablation depth (AD). The extent of dry eyes was related to the operation method employed and postoperative recovery period. In FS-LASIK and LASEK subjects, dry eyes were mainly affected by the basic ocular surface status before surgery, and VIP concentration. Furthermore, in LASEK subjects, dry eyes were negatively correlated with AD. CONCLUSION: VIP was stimulated and mobilized as an emergency protection post-refractive surgery and a trauma model affected by AD. It can indirectly indicate the inevitable relationship between postoperative dry eye and nerve injury. Elevated post-surgery tear VIP relieves dry eye symptoms, showing its neuroimmune role in regulating adverse injury stimulation. The present study provides a solution to the pathogenesis of postoperative dry eyes. TRIAL REGISTRATION: The trial registration number: 2021JS22. Date of registration: 10 May 2021.

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.

Comparative analysis of IOL power calculations in postoperative refractive surgery patients: a theoretical surgical model for FS-LASIK and SMILE procedures.

BACKGROUND: As the two most prevalent refractive surgeries in China, there is a substantial number of patients who have undergone Femtosecond Laser-assisted In Situ Keratomileusis (FS-LASIK) and Small Incision Lenticule Extraction (SMILE) procedures. However, there is still limited knowledge regarding the selection of intraocular lens (IOL) power calculation formulas for these patients with a history of FS-LASIK or SMILE. METHODS: A total of 100 eyes from 50 postoperative refractive surgery patients were included in this prospective cohort study, with 25 individuals (50 eyes) having undergone FS-LASIK and 25 individuals (50 eyes) having undergone SMILE. We utilized a theoretical surgical model to simulate the IOL implantation process in postoperative FS-LASIK and SMILE patients. Subsequently, we performed comprehensive biological measurements both before and after the surgeries, encompassing demographic information, corneal biometric parameters, and axial length. Various formulas, including the Barrett Universal II (BUII) formula, as a baseline, were employed to calculate IOL power for the patients. RESULTS: The Barrett True K (BTK) formula, demonstrated an mean absolute error (AE) within 0.5 D for both FS-LASIK and SMILE groups (0.28 ± 0.25 D and 0.36 ± 0.24 D, respectively). Notably, the FS-LASIK group showed 82% of results differing by less than 0.25 D compared to preoperative BUII results. The Barrett True K No History (BTKNH) formula, which also incorporates measured posterior corneal curvature, performed similarly to BTK in both groups. Additionally, the Masket formula, relying on refractive changes based on empirical experience, displayed promising potential for IOL calculations in SMILE patients compared with BTK (p = 0.411). CONCLUSION: The study reveals the accuracy and stability of the BTK and BTKNH formulas for IOL power calculations in myopic FS-LASIK/SMILE patients. Moreover, the Masket formula shows encouraging results in SMILE patients. These findings contribute to enhancing the predictability and success of IOL power calculations in patients with a history of refractive surgery, providing valuable insights for clinical practice. Further research and larger sample sizes are warranted to validate and optimize the identified formulas for better patient outcomes.

Seven-year corneal densitometry changes after small incision lenticule extraction and femtosecond laser-assisted in situ keratomileusis.

This study aims to investigate the 7-year changes in corneal densitometry (CD) after small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK). Forty-two eyes undergoing SMILE and thirty-one undergoing FS-LASIK were included in this retrospective study. CD was measured preoperatively and at 3 and 7 years postoperatively. Three concentric radial zones (0-2, 2-6, and 6-10 mm) of three different corneal depths (anterior 120 µm, posterior 60 µm, and central layer) were analyzed. In all three zones of the three corneal layers, no significant difference in CD was found between the two groups preoperatively and at 3 and 7 years postoperatively (all P > 0.05). All CD values in the three zones of the anterior and central layers significantly declined at 3 years postoperatively (all P < 0.001), and then increased at 7 years postoperatively compared to corresponding 3-year values (all P < 0.01). In the posterior layer, CD values in the 0-2-mm and 2-6-mm zones decreased at 3 years postoperatively (all P < 0.01) and continued to decrease at 7 years postoperatively (all P < 0.01). Similar CD trends were observed after SMILE and FS-LASIK. Posterior layer CD showed a decrease throughout the study period. In the anterior and central layers, CD values decreased and then increased at 7 years postoperatively. The transparency changes might have been due to age-related three-dimensional growth of collagen fibers and wound-healing reactions.

[Epithelial ingrowth after anterior lamellar keratoplasty (clinical observation)]. / Vrastanie epiteliya posle perednei posloinoi keratoplastiki (klinicheskoe nablyudenie).

Epithelial ingrowth (EI) is a rarely occurring complication of surgeries on the anterior eye segment characterized by migration and proliferation of epithelial cells along the wound tract or into the anterior chamber. Several decades ago, EI often led to severe complications, including enucleation. Modern treatment methods allow not only removing the pathological focus of EI, but also minimizing the risk of its reoccurrence. This article presents a clinical case of EI after anterior lamellar keratoplasty involving formation of implant bed under the pathological focus without cutting open the interface zone. The technique helps minimize dissemination of epithelial cells in the area of the lesion. To prevent growth reoccurrence, the method was supplemented with application of a cytostatic agent. The treatment resulted in stable remission throughout the follow-up period (26 months).