Four-year visual outcomes and optical quality of SMILE and implantable collamer lens V4c (EVO-ICL) implantation for high myopia: a retrospective study.

BACKGROUND: To compare the 4-year visual outcomes of implantable collamer lens V4c (EVO-ICL) implantation and small incision lenticule extraction (SMILE) for high myopia and astigmatism. METHODS: This retrospective case study included 64 eyes of 40 patients. These patients with preoperative manifest refraction spherical equivalent (SE) between - 6.00 and - 10.00 diopters (D) were screened from the database of SMILE and EVO-ICL implantation procedures in 2015. The ICL group [32 eyes of 19 patients (mean age, 29.6 ± 6.3 years); mean SE, -8.71 ± 1.06 D] and SMILE group [32 eyes of 21 patients (mean age, 27.7 ± 5.6 years); mean SE, -8.35 ± 0.65D] were compared. All patients were then prospectively examined at a four-year follow-up for routine postoperative examinations, higher-order ocular aberrations, retinal image quality and a questionnaire. RESULTS: The safety indexes were 1.15 ± 0.14 and 1.22 ± 0.21 (P = 0.36) for the SMILE and ICL groups, respectively. No eyes lost two or more lines of CDVA in either group. The efficacy indexes were 0.97 ± 0.16 and 0.96 ± 0.19 (P = 0.87), respectively. Twenty-three eyes (72%) in ICL and 26 eyes (81%) in SMILE groups were within ± 0.5 D of the attempted SE (P < 0.01). ICL-treated eyes had significantly less spherical aberration and coma (P < 0.01 and < 0.05, respectively) postoperatively. Halos were the prevalent visual disturbance in both groups. CONCLUSION: SMILE and EVO-ICL implantation provided safe and effective correction of high myopia. SMILE showed slightly better long-term predictability. Mild postoperative visual disturbances were observed after ICL and SMILE at 4-year follow-up.

A novel quick contrast sensitivity function test in Chinese adults with myopia and its related parameters.

PURPOSE: This study is to investigate the contrast sensitivity function (CSF) using the quick CSF (qCSF) test in Chinese adults with myopia. METHODS: This case series study included 320 myopic eyes of 160 patients (mean age 27.75 ± 5.99 years) who underwent a qCSF test for acuity, area under log CSF (AULCSF), and mean contrast sensitivity (CS) at 1.0, 1.5, 3.0, 6.0, 12.0, and 18.0 cycle per degree (cpd). Spherical equivalent, corrected-distant visual acuity (CDVA), and pupil size were recorded. RESULTS: The spherical equivalent, CDVA (LogMAR), spherical refraction, cylindrical refraction, and the scotopic pupil size of the included eyes were - 6.30 ± 2.27 D (- 14.25 to - 0.88 D), 0 ± 0.02, - 5.74 ± 2.18 D, - 1.11 ± 0.86 D, and 6.77 ± 0.73 mm, respectively. The AULCSF and CSF acuity were 1.01 ± 0.21 and 18.45 ± 5.39 cpd, respectively. The mean CS (log units) at six different spatial frequencies were 1.25 ± 0.14, 1.29 ± 0.14, 1.25 ± 0.14, 0.98 ± 0.26, 0.45 ± 0.28, and 0.13 ± 0.17, respectively. A mixed effect model showed significant correlations between age and acuity, AULCSF, and CSF at 1.0, 12.0, and 18.0 cpd. Interocular CSF differences were correlated with the interocular difference of spherical equivalent, spherical refraction (at 1.0 cpd, 1.5 cpd), and cylindrical refraction (at 12.0 cpd, 18.0 cpd). The lower cylindrical refraction eye had higher CSF compared with the higher cylindrical refraction eye (0.48 ± 0.29 vs. 0.42 ± 0.27 at 12.0 cpd and 0.15 ± 0.19 vs. 0.12 ± 0.15 at 18.0 cpd). CONCLUSIONS: The age-related decrease in contrast sensitivity is at low and high spatial frequencies. Higher-degree myopia may show a decrease in CSF acuity. Low astigmatism was noted to affect the contrast sensitivity significantly.

Corneal biomechanical stiffness and histopathological changes after in vivo repeated accelerated corneal cross-linking in cat eyes.

Corneal cross-linking (CXL) has been proved efficiency for treating progressive keratoconus and other corneal ectasia diseases by stabilizing corneal geometry and biomechanics. However, the necessity of repeated CXL treatment in patients is unknown. This study aimed to investigate corneal biomechanical stiffness and change in corneal histopathological characteristics after repeated accelerated CXL (A-CXL) in cat eyes. A-CXL was performed with 0.1% riboflavin applied for 10 min, followed by ultraviolet A irradiation at 30 mW/cm2 for 3 min at 365 nm in 15 domestic cats. Corneas (n = 30) were divided into three groups: one-time accelerated corneal cross-linking (A-CXL*1 group), repeated accelerated corneal cross-linking (A-CXL*2 group), and an untreated control group. In A-CXL*2 group, A-CXL was repeated at 1-month intervals. In vivo ocular examinations were performed pre- and postoperatively. Biomechanical analysis was performed using a biotester biaxial testing system. We used the Mooney-Rivlin strain-energy function to describe corneal material properties. No infection in any case after A-CXL was observed. Biomechanical tests showed that the stress-strain curves of the two A-CXL groups were significantly different from those of the control group (P < 0.01), whereas stress-strain curve of the A-CXL*2 group was similar to that of the A-CXL*1 group (P > 0.05). Delayed epithelial healing and haze were observed 1 month after surgery. Stromal demarcation line depth measured with anterior spectral-domain optical coherence tomography was 187.6 ± 20.4 and 197.1 ± 11.5 µm for the A-CXL*1 and A-CXL*2 groups, respectively (P > 0.05). These results show that A-CXL can increase corneal biomechanics in cat eyes. The biomechanical enhancement of cat corneas treated with repeated A-CXL at 1-month intervals was similar to that of performing a one-time A-CXL. Repeated cross-linking procedures at short intervals may increase the risk of adverse reactions, and more caution should be taken in clinical applications.

Refractive outcomes and optical quality of PRESBYOND laser-blended vision for presbyopia correction.

AIM: To investigate the one-year refractive outcomes and optical quality following PRESBYOND laser-blended vision (LBV). METHODS: This retrospective study included 20 patients who underwent PRESBYOND treatment between Jan 2019 and Aug 2020. The patients were asked to attend a follow-up outpatient visit one year after surgery. Distance and near visual acuity as well as subjective refraction were examined. Optical quality was assessed using wavefront-supported custom ablation. A questionnaire evaluating optical quality and satisfaction was completed at the last visit. RESULTS: The average patient age was 48.1±7.4y (range, 41 to 58y). The mean preoperative spherical equivalent was -7.59±2.39 D. At the one-year follow-up, two eyes (both dominant eyes) lost one line of corrected distance visual acuity (CDVA), while the remaining eyes (38/40) maintained or gained lines of CDVA. The average binocular uncorrected distance visual acuity improved from 0.15±0.03 to 0.90±0.26 (decimal vision; P<0.001). The average binocular uncorrected near visual acuity increased from 0.34±0.28 to 0.97±0.07 (P<0.001). The spherical aberration was 0.04±0.06 µm in the nondominant eye and 0.09±0.09 µm in the dominant eye (P=0.02). All patients were satisfied with or accepted the outcomes of the surgery. The primary complaints were related to disturbances in night vision and relatively inferior near vision. CONCLUSION: Over the one-year observation period, PRESBYOND is a safe and effective option for presbyopia correction. The optical quality and near vision deserve further investigation.

Factors leading to realignment or exchange after implantable collamer lens implantation in 10 258 eyes.

PURPOSE: To evaluate the incidence, causes, and outcomes of implantable collamer lens (ICL) realignment or exchange after implantation of the EVO-ICL. SETTING: Eye and ENT Hospital of Fudan University, China. DESIGN: Retrospective study. METHODS: The study included 10 258 consecutive eyes after ICL implantation. Preoperative refractive and biometric measurements were compared between eyes with and without realignment or exchange. For eyes with ICL realignment or exchange, visual and biometric outcomes were also compared before and after ICL realignment or exchange. RESULTS: The overall incidence of ICL realignment or exchange was 0.21% 22 eyes. 12 eyes (0.12%) underwent ICL realignment by axis rotation (10 eyes) or ICL exchange (2 eyes) due to toric ICL (TICL) misalignment. After realignment, uncorrected distance visual acuity improved, and residual cylinder decreased from -1.75 ± 0.48 diopters (D) to -0.87 ± 0.59 D ( P = .01). 10 eyes (0.10%) underwent vertical rotation of ICL (3 eyes) or ICL exchange (7 eyes) due to excessive vault. After either vertical rotation or ICL exchange, vault decreased significantly ( P < .05). CONCLUSIONS: The incidence of ICL realignment or exchange after ICL implantation is low. TICL misalignment and excessive vault are 2 main causes. Implant exchange may be performed for excessive vault or misalignment with an insufficient vault. In addition, vertical rotation of an ICL may be a less invasive method to treat excessive vault in certain cases.

Nighttime Symptoms After Monocular SMILE: A Contralateral Eye Study.

INTRODUCTION: To investigate nighttime symptoms in patients with myopic anisometropia after monocular small incision lenticule extraction (SMILE) surgery. METHODS: Thirty-six patients who had undergone monocular SMILE more than 6 months previously were recruited at the Eye & ENT Hospital of Fudan University. The average age at surgery was 25.4 ± 6.1 years. Preoperative spherical equivalent (SE) was -3.77 ± 1.56 D in SMILE-treated eyes and -0.08 ± 0.66 D in unoperated eyes. Main measurements included uncorrected and corrected distance visual acuity, manifest refraction, halo radius, contrast sensitivity, nighttime symptoms, and patient satisfaction. RESULTS: The mean follow-up time was 13.9 ± 3.4 months. The efficacy and safety indexes were 1.18 and 1.28, respectively. The halo radius was not significantly different between SMILE-treated and unoperated eyes under luminance conditions of 1, 5, and 100 cd/m2 (P = 0.055). No significant differences were observed in contrast sensitivity at all spatial frequencies between eyes under both uncorrected and corrected conditions (all P > 0.05). None of the patients reported moderate or severe symptoms at night. Mild symptoms (glare, halo, starburst) were reported and binocularly equal in 13 patients, whereas four patients reported better night vision in SMILE-treated eyes than unoperated eyes, and one of them experienced mild night vision disturbance. The overall satisfaction score was 9.39 ± 0.80. CONCLUSIONS: The disk halo size and contrast sensitivity in SMILE-treated eyes were similar to those in unoperated eyes, and nighttime symptoms almost completely resolved after SMILE.

Visual outcomes after small incision lenticule extraction and implantable collamer lens V4c for moderate myopia: 1-year results.

PURPOSE: To compare 1-year visual outcomes after implantable collamer lens V4c (EVO-ICL) implantation and small incision lenticule extraction (SMILE) for moderate myopia. METHODS: In this retrospective study, 67 eyes of 39 patients with a preoperative manifest refraction spherical equivalent between - 3.00 and - 6.00 diopters (D) were selected from a database of SMILE and ICL implantation procedures performed from April 2018 to December 2018. Thirty-two eyes of 20 patients underwent EVO-ICL implantation, and 35 eyes of 19 patients underwent SMILE. At the routine 1-year follow-up appointment, all selected patients were examined for higher-order ocular aberrations, retinal image quality, and a quality of vision (QoV) questionnaire. This data was then analyzed. RESULTS: No complications were observed. Uncorrected and corrected visual acuities at 1 year after surgery were - 0.13 ± 0.07 and - 0.15 ± 0.06 logMAR in the SMILE group, and - 0.10 ± 0.07 and - 0.16 ± 0.05 logMAR in the ICL group. Twenty-nine eyes (90.6%) which underwent ICL implantation and 34 eyes (97.1%) which underwent SMILE were within ± 0.5 D of the attempted spherical equivalent (P = 0.49). Changes in coma after ICL were significantly less than after SMILE (P = 0.002). The leading complaints after ICL and SMILE were halos (84.4%) and blurred vision (65.7%), respectively. CONCLUSIONS: Both SMILE and ICL implantation provided good safety, efficacy, and predictability in correcting moderate myopia. The subjective visual complaints consisted mainly of halos after ICL and starbursts and blurred vision after SMILE.

Comparison of visual outcomes after non-toric and toric implantable collamer lens V4c for myopia and astigmatism.

PURPOSE: To evaluate the visual quality of myopic patients after non-toric versus toric implantable collamer lens (ICL and TICL, respectively) V4c, and to investigate the potential risk factors of postoperative night vision disturbances. METHODS: This prospective cohort study included 42 eyes of 21 patients treated with ICL and 46 eyes of 23 patients treated with TICL. Refractive parameters and ocular aberrations were examined before and 6 months after surgery. Subjective quality of vision was scored by a validated questionnaire. RESULTS: The efficacy index at 6 months was 1.14 ± 0.20 for ICL and 1.17 ± 0.16 for TICL; the safety index was 1.20 ± 0.17 for ICL and 1.20 ± 0.19 for TICL. The root mean square of total higher-order aberrations (HOAs) and trefoil was significantly increased, and no statistical differences between groups were detected in HOA changes. Many patients reported haloes (85.7% for ICL and 100% for TICL) and glare (76.2% for ICL and 65.2% for TICL), but most (94.4% for ICL and 95.5% for TICL) were satisfied or very satisfied with visual outcomes. Implantable collamer lens (ICL) toricity was the risk factor for frequency (OR = 2.81, p = 0.01), severity (OR = 3.85, p = 0.003) and bothering effect (OR = 2.89, p = 0.01) of haloes. CONCLUSIONS: Implantable collamer lens and TICL provided comparable efficacy, safety and predictability, induced acceptable level of HOAs and achieved high satisfaction in correcting myopia and myopic astigmatism. Although not severe, haloes and glare have a non-negligible prevalence and ICL toricity is a potential risk factor of haloes.

Comparison of Corneal Biomechanical Properties between Post-LASIK Ectasia and Primary Keratoconus.

PURPOSE: To compare the corneal biomechanical properties between post-LASIK ectasia and primary keratoconus. METHODS: A total of 42 eyes of 42 patients with matching age and central corneal thickness (CCT) were divided into two groups according to diagnosis of post-LASIK ectasia (PLE group; n = 21; age range: 22-47 years) and primary keratoconus (KC group; n = 21; age range: 21-47 years). The corneal biomechanical properties were assessed using Scheimpflug-based technology (Corvis ST; Oculus Optikgeräte, Wetzlar, Germany). The paired t-test and linear regression analysis were performed. RESULTS: The PLE group had significantly higher mean stiffness parameter at the first applanation (SP-A1; 76.65 ± 21.66 vs 52.72 ± 13.65, p ≤ 0.001) and mean stress-strain index (SSI) (SSI: 0.78 ± 0.16 versus 0.64 ± 0.12, p=0.001) than the KC group. SP-A1 was positively correlated with CCT in the PLE group (Pearson's r = 0.816, p ≤ 0.001), but not in the KC group (Pearson's r = -0.014, p=0.952). No statistical correlation was observed between SSI and CCT in either group (Pearson's r = 0.292, p=0.199, and Pearson's r = 0.004, p=0.985, respectively). CONCLUSIONS: In our case series, KC manifested more severe than PLE in biomechanical properties. Since SSI measurements were independent of corneal thickness, it can be used for corneal biomechanical assessment.

Optical transmittance and ultrastructure of SMILE-derived lenticules subjected to three different preservative methods.

PURPOSE: To investigate the optical transmittance and ultrastructure of small incision lenticule extraction (SMILE)-derived lenticules preserved via three different methods. METHODS: A total of 90 lenticules obtained from myopic patients undergoing SMILE surgery were divided into control and experimental groups. Fresh lenticules served as the control. The preserved lenticules of the experimental group were randomly divided into three subgroups according to different storage conditions: anhydrous glycerol, silicone oil and allochroic silica gel groups. Optical transmittance was evaluated, histological changes were analysed by haematoxylin eosin (HE) staining, and collagen fibril densities and necrotic response were assessed via transmission electron microscopy (TEM) at 48 h, 14 days and 4 weeks. RESULTS: After storage for 4 weeks, the mean percentage transmittance values in glycerol and silicone oil groups significantly decreased (P = 0.034 and P = 0.042, respectively), but the lenticules preserved in silica gel remained unchanged when compared with the control lenticules. In all the groups, HE staining results showed a regular arrangement of collagen fibers with a few keratocytes and several cavitation bubbles. TEM revealed that the fibril densities in the glycerol group (273.70 ± 31.42/µm2) after 4 weeks were significant less than those in the other two groups (silicone oil, 335.20 ± 33.09/µm2; silica gel, 371.80 ± 37.60/µm2) and control group (340 ± 33.61/µm2) (all P < 0.001). In each group, a few necrotic and apoptotic keratocytes were observed. CONCLUSIONS: All the three agents, namely glycerol, silicone oil and silica gel, could be used for lenticule preservation. Silica gel facilitates better maintenance of optical transmittance than the other two agents.

Comparison of objective and subjective visual quality early after implantable collamer lens V4c (ICL V4c) and small incision lenticule extraction (SMILE) for high myopia correction.

PURPOSE: To investigate differences in the objective and subjective visual quality of patients with high myopia following implantable collamer lens V4c (ICL V4c) versus small incision lenticule extraction (SMILE) early postoperatively. METHODS: This prospective analysis included 94 eyes of 57 patients (8 males) in the ICL V4c group (mean spherical equivalent (SE), -8.07 ± 1.03 dioptres (D)) and 103 eyes of 57 patients (13 males) in the SMILE group (mean SE, -7.85 ± 0.78 D). Refractive parameters and wavefront aberrations were recorded preoperatively and 6 months postoperatively. Subjective visual quality was scored with the Quality of Vision questionnaire, and operation satisfaction was evaluated 6 months postoperatively. RESULTS: At 6 months postoperatively, the efficacy index was 1.17 ± 0.16 in the ICL and 1.09 ± 0.20 in the SMILE group; the safety index was 1.21 ± 0.18 in the ICL and 1.12 ± 0.16 in the SMILE group. A significant increase in total higher-order aberrations (HOAs) in both the ICL and SMILE groups was observed, but to a lesser degree in ICL (p < 0.05). In the ICL group, trefoil significantly increased (p < 0.05), whereas in the SMILE group, coma, trefoil and spherical aberration significantly increased (p < 0.05). Glare, haloes and blurred vision had the highest incidences after both types of surgery, and postoperative haloes were significantly more common following ICL; 96.1% of ICL-treated and 94.9% of SMILE-treated patients were satisfied with their visual outcomes. CONCLUSION: ICL V4c caused lower HOAs induction than SMILE. Despite the postoperative visual disturbances, both ICL and SMILE provided good efficacy, safety, predictability and high satisfaction in correcting high myopia.

Multiple phototherapeutic keratectomy treatments in a Chinese pedigree with corneal dystrophy and an R124L mutation: a 20-year observational study.

BACKGROUND: To investigate the efficacy and safety of repeated phototherapeutic keratectomies (PTKs) during long-term treatment for corneal dystrophy (CD) in a Chinese pedigree carrying the R124L mutation in TGFBI. METHODS: This was a retrospective review of 20-year medical and genetic records involving five CD patients (10 eyes) from one pedigree. During this period, PTK was conducted for an eye when best-corrected distance visual acuity (BCDVA) reached > 1.0 (LogMAR), due to either primary or recurrent opacities in the cornea. All PTKs were performed by 193-nm excimer laser with or without creation of epithelial flaps. For each eye, routine measurements were conducted for the number of PTKs during follow-up, mean time to recurrence, and BCDVA pre- and post- every PTK (measurements within 3 months from each PTK). Corneal thicknesses measured after the last PTK and at the last visit were analyzed, and subjective satisfaction was assessed. RESULTS: Gene testing revealed an R124L mutation in TGFBI. During 19.60 ± 1.78 years of follow-up, PTKs were conducted twice for three eyes, three times for six eyes, and four times for one eye. After each PTK, effective visual acuity was maintained for 3.60 ± 1.12 years before significant recurrence. BCDVA improved significantly postoperatively than preoperatively for the first PTK for each eye (p < 0.001), as well as the second (p < 0.001) and third one (p < 0.001). After the last PTK and at the final visit, the thinnest corneal thickness was 371.50 ± 56.47 µm and 358.40 ± 101.11 µm, respectively. The average subjective satisfaction score was 8.60 ± 0.89. CONCLUSIONS: Multiple repeated PTKs were effective and safe in a long-term study of CD patients with an R124L mutation in TGFBI.