Journal of refractive surgery最新文献

Purpose: To compare visual and refractive outcomes and patient-reported visual quality of life between topography-guided laser in situ keratomileusis with novel geographic imaging system (TG-GIS LASIK)-based software versus wavefront-optimized (WFO) LASIK.

Methods: This was a prospective, multi-site, randomized, clinical trial. Patients with bilateral myopic LASIK were randomized 1:1 to undergo bilateral TG-GIS LASIK or WFO LASIK using the Wavelight EX500 laser (Alcon Laboratories, Inc). The main outcome measure was the percentage of patients with monocular uncorrected distance visual acuity (UDVA) of 20/16 or better at 3 months. The Patient Reported Outcome With LASIK questionnaire was administered preoperatively and 3 months postoperatively.

Results: One hundred seventeen patients (234 eyes) were enrolled. For monocular UDVA, 29% in the WFO LASIK group achieved 20/12.5 and 74.6% achieved 20/16 or better versus 18% (P = .05) and 67% of the TG-GIS LASIK group, respectively (P = .29). For mean refractive spherical equivalent, the percentage of eyes within ±0.50 diopters (D) of plano was 97% in the WFO LASIK group and 91% in the TG-GIS LASIK group (P = .09). The WFO LASIK group had 14% of eyes gain two lines of corrected distance visual acuity versus 7% (P = .09) in the TG-GIS LASIK group. Overall satisfaction was similar between groups (93.66, 91.77, P = .18) but there was increased satisfaction as it relates to magnitude of starbursts in the TG-GIS LASIK group (85.74 TG-GIS LASIK group, 81.62 WFO LASIK group, P = .03).

Conclusions: WFO LASIK trended toward higher rates of 20/12.5 UDVA but achieved similar rates of 20/16 UDVA and slightly superior refractive outcomes compared to TG-GIS LASIK. Overall, visual and refractive outcomes were favorable in both groups. Both groups had high patient satisfaction. [J Refract Surg. 2025;41(7):e625-e634.].

Purpose: To investigate the corneal endothelial integrity in patients who underwent corneal cross-linking (CXL) with the Sub400 protocol, which treats progressive ectasia not eligible for standard CXL due to a stromal thickness of less than 400 µm.

Methods: This was an investigator-initiated, retrospective, single-center study conducted at the Department of Ophthalmology at the University Hospital Zurich in collaboration with the ELZA Institute in Zurich, Switzerland. Confocal endothelial measurements were performed before and up to 24 months after CXL. We applied a linear mixed-effect model to compare endothelial cell density (ECD) differences depending on time and treatment. At the 1-month follow-up visit, the demarcation line (DL) depth was assessed using anterior segment optical coherence tomography.

Results: From August 2021 to August 2024, 17 eyes from 17 patients (3 [17.6%] women) were included, all receiving unilateral treatment. The median (IQR [range]) age was 33.1 (24.5 to 35.8 [16.8 to 70.2]) years. The median (IQR [range]) corneal thickness was 357 (317 to 367 [210 to 388]) µm. None of the patients showed clinical signs of endothelial decompensation. The median (IQR [range]) distance from the DL to the endothelium was 80 (45 to 91 [21 to 174]) µm. The mean difference in ECD measurements before and after treatment was 56.4 (95% CI: -9.6 to 122.4) cells/mm² (P = .09).

Conclusions: This study demonstrated the safety of the Sub400 protocol based on ECD measurements, clinical outcomes, and the observed DL, which aligns with the initial depth estimate initially proposed. Future studies should reevaluate the endothelium in a larger study population and include other morphologic endothelial parameters. [J Refract Surg. 2025;41(7):e682-e689.].

Purpose: To compare the corneal densitometry and higher order aberrations (HOAs) following corneal cross-linking (CXL), deep anterior lamellar keratoplasty (DALK), and minimally invasive lamellar keratoplasty (MILK) for keratoconus.

Methods: Twenty-five eyes treated with CXL (CXL group), 17 eyes treated with DALK (DALK group), and 25 eyes treated with MILK (MILK group) were included in this prospective study. Corneal densitometry and HOAs were evaluated preoperatively and at 1, 3, 6, 12, 24, and 36 months postoperatively.

Results: In CXL and MILK, corneal densitometry values peaked at 1 month (P < .001), returned to the preoperative level at 6 months (P = .334, 0.224), and declined below baseline at 36 months (P < .001, P = .129); the changes from preoperatively to 36 months postoperatively between groups were not significant (P = .713). In DALK, corneal densitometry values were still higher at 36 months than before surgery (P = .007). The root mean square value of total HOAs from the whole cornea was decreased by 0.192 ± 0.457, 0.823 ± 0.926, and 3.938 ± 1.873 µm at 36 months postoperatively for CXL, MILK, and DALK, respectively (P = .047, <.001, <.001); the differences between groups were all statistically significant. The total HOA or spherical aberration changes from the whole cornea correlated with maximum keratometry changes for CXL (P < .001; R² = 0.490), MILK (P < .001; R² = 0.599), and DALK (P < .001; R² = .558).

Conclusions: MILK and CXL showed a similar improvement in corneal densitometry. HOAs improved most in DALK, followed by MILK and CXL, corresponding to maximum keratometry changes. The coma and spherical aberrations improved in MILK and DALK, but not in CXL. [J Refract Surg. 2025;41(7):e715-e723.].

Purpose: To compare clinically achieved vaults with the predicted NK-formula V2 (NK-V2) and NK-formula V3 (NK-V3) vaults in a White and Asian population in patients undergoing Implantable Collamer Lens (ICL) surgery.

Methods: Data were collected retrospectively from three surgeons for all patients who had ICL surgery for myopia between September 2020 and August 2022 at Moorfields Eye Hospital. ICL sizing was performed using the optimal NK-V2 sizing formula. The postoperative vault was measured using anterior segment optical coherence tomography. Back calculation was used to evaluate predicted versus achieved vaults for the newer NK-V3 formula.

Results: A total of 136 eyes from 72 patients were eligible. Seventy-two eyes of 72 patients were included in the analysis, 50 White (69%) and 22 Asian (31%). The mean residual vault for NK-V2 was -0.08 and -0.11 (P = .76) and NK-V3 was 0.04 and 0.02 (P = .78) for White and Asian, respectively. Mean absolute errors of the White sample were 0.2 and 0.16 for NKV2 and NK-V3, respectively (P = .23). Mean absolute errors of the Asian sample were 0.31 and 0.22 for NK-V2 and NK-V3, respectively (P = .16). There was no statistical significance when comparing mean absolute errors from White and Asian samples for NK-V2 or NK-V3.

Conclusions: NK-V2 formula for ICL sizing, originally derived from an Asian population sample, appeared to perform at least as well in Whites with no adverse outcomes or safety issues. NK-V3 was superior in predicting postoperative vault compared to NK-V2 in Asian eyes and comparable for White eyes. [J Refract Surg. 2025;41(7):e702-e708.].

Purpose: To evaluate the importance of the anterior chamber depth (ACD), lens thickness (LT), and white-to-white distance (WTW) in predicting the final postoperative refraction using modern formulas.

Methods: This was a retrospective study of 140 consecutive eyes that underwent cataract surgery at the Department of Ophthalmology, Edith Wolfson Medical Centre, Holon, Israel. The Barrett Universal II (BUII), Kane, and Hill-RBF 3.0 formulas were calculated for each eye with all combinations of omitting ACD, LT, and WTW, as possible by each formula. Lens constant optimizations were executed. The results were compared to the postoperative refraction.

Results: For the BUII formula, the ACD only variation exhibited a statistically significant increase in mean absolute deviation (MAD) (0.024 diopters [D], P = .010) and standard deviation of prediction error (SD-PE) (0.022, P = .002) compared with BUII using all parameters, whereas no other variations showed statistically significant differences in MAD or SD-PE. For the Hill-RBF 3.0 formula, both the ACD only (0.012 D, P < .001) and ACD+WTW (0.009 D, P = .016) variations demonstrated a statistically significant increase in MAD, although no statistically significant differences were observed in SD-PE. For the Kane formula, excluding the LT parameter resulted in a statistically significant increase in MAD (0.020 D, P = .034), whereas the increase in SD-PE (0.020, P = .266) was not statistically significant.

Conclusions: The BUII, Kane, and Hill-RBF 3.0 formulas demonstrated statistically significant, but not clinically meaningful, differences in SD-PE and MAD when ACD, LT, and WTW were excluded in normal biometric eyes. Further research involving eyes with atypical biometric characteristics is warranted to enhance refractive accuracy and minimize outliers. [J Refract Surg. 2025;41(7):e662-e666.].

Purpose: To assess the agreement of the Lenstar LS900 (Haag-Streit AG), Sirius (CSO), and Pentacam HR (Oculus Optikgeräte GmbH) devices in terms of anterior chamber depth (ACD), flat (K1) and steep (K2) axis keratometry, white-to-white corneal diameter (WTW), and pupil diameter (PD) measurements in healthy eyes and keratoconus cases.

Methods: Measurements were obtained using the Lenstar LS900, Sirius, and Pentacam HR by an experienced technician who was blinded to the results from each modality. The agreement between the devices was evaluated with a Bland-Altman analysis.

Results: One hundred thirty-eight eyes of 138 patients (73 healthy, 65 keratoconus) were examined. There was no proportional error in the K1 and K2 measurements of the devices in healthy eyes (P > .05). In keratoconus cases, there was a proportional error between the K1 and K2 measurements of the devices (for K1, the Lenstar vs the Sirius: P < .001, R² = 0.634, the Lenstar vs the Pentacam: P < .001, R² = 0.322, the Sirius vs the Pentacam: P < .001, R² = 0.333; for K2, the Lenstar vs the Sirius: P < .001, R² = 0.666, the Lenstar vs the Pentacam: P < .001, R² = 0.514, the Sirius vs the Pentacam: P < .001, R² = 0.523)). There was no proportional error between the ACD and WTW measurements of the devices in healthy cases and keratoconus cases (P > .05). Compatibility in PD measurements was noted only between the Lenstar and Pentacam in both groups (P > .05).

Conclusions: The three devices demonstrated agreement for ACD and WTW. The Lenstar LS900 and Pentacam HR were compatible in PD. Keratometry values were in agreement between the three devices in healthy eyes. This agreement did not hold in keratoconus. Using these devices interchangeably to evaluate keratometry in keratoconus may yield misleading results. [J Refract Surg. 2025;41(7):e690-e701.].

Purpose: To summarize recent progress in the clinical and experimental applications of Brillouin microscopy in ophthalmology, highlighting its potential to advance biomechanical understanding in these contexts.

Methods: Literature review.

Results: Employing low-power lasers across visible to near-infrared wavelengths, Brillouin microscopy enables the assessment of tissue's longitudinal modulus or viscoelasticity by analyzing the Brillouin frequency shift. This technique provides valuable insights into the cornea's hydration state and anisotropic biomechanics, improving our understanding of its intrinsic characteristics. Numerous studies have demonstrated the diagnostic potential of Brillouin microscopy for corneal diseases. Experimental research has also shown significant changes in Brillouin biomechanics properties following procedures like corneal flap formation and corneal cross-linking. Additionally, Brillouin microscopy offers a novel perspective on age-related changes in both Brillouin biomechanics and morphology of crystalline lenses. Successful Brillouin measurements have been performed on other ocular tissues, including the limbus, sclera, and retina, in ex vivo studies.

Conclusions: Brillouin microscopy holds great promise as an ophthalmology tool. It offers unique insights into the biomechanical properties, disease-related alterations in ocular tissues, and intrinsic characteristics of biological specimens. The application of stimulated Brillouin microscopy, along with the integration of laser pump and machine learning techniques, can further enhance the acquisition speed and resolution of biological imaging. [J Refract Surg. 2025;41(7):e731-e746.].

Purpose: To evaluate the results of patients with post-laser in situ keratomileusis (LASIK) ectasia who were treated with corneal allogeneic intrastromal ring segments (CAIRS) and corneal cross-linking (CXL).

Methods: Patients with post-LASIK ectasia who had undergone CAIRS and CXL were included in this retrospective series. Preoperative, postoperative, and surgical parameters of all patients were recorded. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, spherical equivalent, flat keratometry (K1), step keratometry (K2), mean keratometry (Kmean), maximum keratometry (Kmax), maximum flattening, Q-value, root mean square (RMS) lower (LOA) and higher (HOA) order aberrations, vertical coma, spherical aberration, and intraoperative surgical parameters used were studied.

Results: Eight eyes with post-LASIK ectasia treated with CAIRS combined with CXL or CACXL were included. UDVA improved from 0.2 ± 0.1 to 0.4 ± 0.16 (decimal equivalent). CDVA improved from 0.63 ± 0.17 to 0.73 ± 0.17 (decimal equivalent). Spherical equivalent decreased from -3.90 ± 2.70 to -1.50 ± 1.90 diopters (D). K1, K2, Kmean, Kmax, and Q-value decreased from 47.65 ± 4.10, 51.40 ± 4.60, 49.40 ± 4.20, 60.90 ± 7.70 D and -0.96 ± 0.60 to 43.40 ± 3.70, 46.00 ± 4.00, 44.70 ± 3.80, 54.60 ± 6.90, and -0.21 ± 0.60 D, respectively. RMS LOA and HOA, vertical coma, and spherical aberration decreased from 13 ± 3.3 to 8.8 ± 2.7, 4.2 ± 1.7 to 3.3 ± 1.1, -3.5 ± 1.5 to -1.9 ± 1.4, and -0.4 ± 0.5 to 0.07 ± 0.9 µm, respectively. Average maximum flattening was 12.10 ± 1.70 D. Average thinnest pachymetry was 440 ± 54 µm preoperatively and postoperatively this was 431 ± 56 µm postoperatively. Although the postoperative mean pachymetry was lower than the preoperative pachymetry, this was not statistically significant (P > .05). Average follow-up was 12.9 ± 4 months (range: 6 to 18 months). No postoperative complications were encountered except grade 1 and 2 haze in 5 and 3 patients, respectively. This did not affect vision and no patient complained of glare or halos.

Conclusions: CAIRS combined with CXL can be used as a safe and effective treatment for post-LASIK ectasia. It aids in improving quantitative and qualitative vision while avoiding disadvantages of synthetic intracorneal ring segments and deep anterior lamellar keratoplasty. [J Refract Surg. 2025;41(7):e709-e714.].

Purpose: To evaluate the relationship between pupil size and subjective visual quality after implantation of a simultaneous vision intraocular lens (IOL).

Methods: Patients after bilateral implantation of a trifocal, diffractive IOL were prospectively included. Three months postoperatively, subjective refraction, UDVA, and axis deviation were measured. Pupil size was obtained with an infrared-based pupillometer (PupilX; Albomed) in scotopic, mesopic, and photopic conditions. Subjective impairment with optical phenomena was surveyed in different lighting conditions.

Results: Fifty-two patients (mean age: 68 years) were included; 54 eyes received non-toric IOLs and 50 eyes received toric IOLs. Preoperative spherical equivalent (SE) was -0.914 diopters (D) (range: -10.00 to +5.92 D) and SE and lens torus were 20.3 D (range: 9.00 to 32.00 D) and 1.65 D (range: 1.00 to 3.75 D), respectively. Three months postoperatively pupil size was 5.42 mm (range: 2.60 to 7.50 mm) in scotopic, 4.24 mm (range: 2.60 to 6.10 mm) in mesopic, and 3.38 mm (range: 1.20 to 5.60 mm) in photopic conditions, spherical manifest refractive error 0.14 D (range: -0.75 to 1.25 D), SE 0.034 D (range: -1.13 to +1.13 D), and UDVA 20/22.4 (range: 20/63 to 20/12.5). In low light conditions, halos correlated weakly with scotopic (r = 0.268, P = .006) and mesopic (r = 0.298, P = .002) pupil size and double-contour with scotopic pupil size (r = 0.234, P = .018). Glare, starbursts, and blurred vision were not influenced in any condition. Further significant influential factors were postoperative spherical manifest refractive error (P = .014), SE (P = .007) and lens torus (P = .029) for halos and preoperative SE (P = .019), postoperative UDVA (P = .035), and lens SE (P = .023) for double-contour. In multiple regression analysis, lens torus, mesopic pupil size, preoperative SE, and postoperative UDVA remained significant.

Conclusions: Pupil size did not play a major role in disturbance with optical phenomena after implantation of a trifocal diffractive IOL. [J Refract Surg. 2025;41(7):e645-e654.].