High order aberration and straylight evaluation after cataract surgery with implantation of an aspheric, aberration correcting monofocal intraocular lens

Modified femtosecond laser-assisted arcuate keratotomy for managing low corneal astigmatism using trifocal intraocular lens implantation in Chinese cataract patients

To evaluate the visual outcome and astigmatic correction following trifocal intraocular lens (IOL) implantation using the modified femtosecond laser-assisted arcuate keratotomy (FSAK) in Chinese cataract patients with low astigmatism. This retrospective study included consecutive cataract patients with regular corneal astigmatism ranging from 0.75 to 1.5 D who underwent FSAK combined with the trifocal IOL implantation between November 2020 and September 2022. Monocular uncorrected distance visual acuity, uncorrected intermediate visual acuity, uncorrected near visual acuity, and refractive data were collected at the 3-month follow-up. The pre- and post-operative high-order aberrations (HOAs) were recorded. The variation in astigmatism was analyzed using Alpins vector analysis. A total of 27 eyes from 23 patients were analyzed. The monocular uncorrected distance visual acuity (UDVA) (5 m) at the 3-month follow-up was 0.04 ± 0.09 logarithm of the minimum angle of resolution (logMAR), which was significantly improved compared with the preoperative value of 0.95 ± 0.51 logMAR (P <.001). The corneal astigmatism was significantly reduced from 1.24 ± 0.42 D to 0.49 ± 0.34 D (P <.001). The target-induced astigmatism (TIA) was 1.25 ± 0.43 D, the surgically induced astigmatism (SIA) was 1.16 ± 0.52 D, and the difference vector (DV) was 0.5 ± 0.34 D. The magnitude of error (ME) (difference between SIA and TIA) was -0.1 ± 0.41 D, and the correction index (CI) (ratio of SIA to TIA) was 0.93 ± 0.36. The angle of error was 3.92° ± 16.90°. Total HOA was reduced from 0.89 ± 1.11 to 0.41 ± 0.55 (P = 0.184), and the corneal HOA was lowered from 0.17 ± 0.18 to 0.10 ± 0.10 (P = 0.129). Implantation of trifocal IOL following the modified FSAK in Chinese cataract patients exhibited excellent visual efficacy and effectively reduced corneal astigmatism.

Comparison of visual performance with iTrace analyzer following femtosecond laser-assisted cataract surgery with bilateral implantation of two different trifocal intraocular lenses

AIM

To compare the postoperative binocular visual performance with an iTrace analyzer following femtosecond laser-assisted cataract surgery (FLACS) combined with bilateral implantation of two different types of diffractive trifocal intraocular lenses (IOL).

METHODS

During this retrospective observational study, patients who received bilateral FLACS combined with implantation of two different types of diffractive trifocal IOLs were evaluated. According to the IOLs' different types and design, the patients were divided into AT LISA tri839MP group (tri839 group) and AcrySof PanOptix TFNT00 group (TFNT group). Study parameters included preoperative and postoperative uncorrected distance visual acuity (UDVA) at 5 m, uncorrected near visual acuity (UNVA) at 30 cm and 40 cm, uncorrected intermediate visual acuity (UIVA) at 60 cm and 80 cm, postoperative refractive status, objective visual qualities and total high order aberrations (HOAs) postoperatively. The postoperative complications were also recorded.

RESULTS

Totally 56 eyes of 28 patients (tri839 group, n=26; TFNT group, n=30) were included. Preoperative baseline characteristics between groups were not statistically significantly different. UDVA was not significantly different between groups except for 1wk follow-up due to the postoperative corneal edema. TFNT group showed statistically significant better UNIA at 60 cm than tri839 group at the 1wk (0.05±0.19 vs 0.15±0.10 logMAR, P=0.013), 1mo (0.05±0.12 vs 0.15±0.09 logMAR, P=0.001) and 3mo (0.04±0.12 vs 0.15±0.11 logMAR, P=0.001) follow-up, while tri839 group showed statistically significant better UNIA at 80 cm than TFNT group at the 1d (0.14±0.15 vs 0.20±0.14 logMAR, P=0.041) and 1mo (0.09±0.07 vs 0.14±0.10 logMAR, P=0.042) follow-up. Postoperative refractive status showed stable at every visit. Modulated transfer function (MTF) values and strehl ratio (SR) values were improved and HOAs were lower significantly after surgery.

CONCLUSION

FLACS with bilateral implantations of both tri839 and TFNT00 can achieve satisfactory natural whole-course vision, high postoperative refractive stability and good visual quality but without significantly difference. iTrace aberration instrument can accurately evaluate the visual quality under different status.

Long-Term Evaluation of Visual Outcomes and Patient Satisfaction after Binocular Implantation of a Bioanalogic Lens

Purpose

Long-term evaluation of the visual refractive outcomes and the quality of life after implantation of the WIOL-CF (Medicem, Czech Republic) in both eyes.

Design

retrospective, nonrandomized noncomparative case series.

Methods

50 eyes of 25 patients, including 11 women (44%) and 14 men (56%). The age range of the patients was 38 to 77 years (mean age 55.48 ± 10.97 years). All patients underwent bilateral implantation of the WIOL-CF. Exclusion criteria were previous ocular surgeries except for cataract surgery and refractive lens exchange, irregular corneal astigmatism of >1.0 diopter, and ocular pathologies or corneal abnormalities. Postoperative examinations were performed at 14 days and 3, 6, 12 months of surgery; the last follow-up was between 24 and 36 months after the procedure. All exams included manifest refraction, monocular uncorrected visual acuity (UCVA) and distance-corrected visual acuity (DCVA) in 5 m (Snellen), monocular uncorrected visual acuity in 70 cm and 40 cm (Jeager) and binocular UCVA, DCVA in 5 m, 70 cm, and 40 cm, binocular contrast sensitivity (CS) under photopic conditions, binocular defocus curves, high-order aberrations, quality-of-vision VF-14 questionnaire, and spectacle independence.

Results

Significant improvement in monocular visual acuity at all distances was demonstrated; the mean postoperative spherical equivalent was 0.32 ± 0.45D. The postoperative means of binocular distance UCVA and BCVA were also improved (p < .001) and so were the mean uncorrected intermediate VA (2.053 ± 1.268) and near uncorrected VA (2.737 ± 1.447). There was a significant improvement in contrast sensitivity at all spatial frequencies and higher-order aberration, compared to preoperative results.

Conclusions

The evaluation of a WIOL-CF showed good distance, intermediate, and near visual acuity. Contrast sensitivity increased after surgery in all spatial frequencies. Patient satisfaction was high despite some optical phenomena. The rate of postoperative spectacle independence also turned out high. Financial Disclosure. No author has a financial or proprietary interest in any material or method mentioned.

Iterative-Trained Semi-Blind Deconvolution Algorithm to Compensate Straylight in Retinal Images

The optical quality of an image depends on both the optical properties of the imaging system and the physical properties of the medium in which the light travels from the object to the final imaging sensor. The analysis of the point spread function of the optical system is an objective way to quantify the image degradation. In retinal imaging, the presence of corneal or cristalline lens opacifications spread the light at wide angular distributions. If the mathematical operator that degrades the image is known, the image can be restored through deconvolution methods. In the particular case of retinal imaging, this operator may be unknown (or partially) due to the presence of cataracts, corneal edema, or vitreous opacification. In those cases, blind deconvolution theory provides useful results to restore important spatial information of the image. In this work, a new semi-blind deconvolution method has been developed by training an iterative process with the Glare Spread Function kernel based on the Richardson-Lucy deconvolution algorithm to compensate a veiling glare effect in retinal images due to intraocular straylight. The method was first tested with simulated retinal images generated from a straylight eye model and applied to a real retinal image dataset composed of healthy subjects and patients with glaucoma and diabetic retinopathy. Results showed the capacity of the algorithm to detect and compensate the veiling glare degradation and improving the image sharpness up to 1000% in the case of healthy subjects and up to 700% in the pathological retinal images. This image quality improvement allows performing image segmentation processing with restored hidden spatial information after deconvolution.

Personalized aspheric intraocular lens implantation based on corneal spherical aberration: a review

With the evolution of cataract surgery from visual rehabilitation to refractive surgery, aspheric intraocular lenses (IOLs) are being increasingly used in the field of ophthalmology. This increased use can be attributed to negative or zero spherical aberrations with unique optical designs, which counteract some of the positive spherical aberrations of the cornea. These alterations reduce the total spherical aberration of human eyes and improve the visual acuity in patients with cataract postoperatively. At present, various types of aspheric IOLs are used worldwide. Although the implantation of aspheric IOL is beneficial to the patients who need correction of spherical aberrations, much controversy is still associated with ocular residual spherical aberrations that facilitate the best visual quality for patients postoperatively. In order to provide reference for future clinical work and scientific research, this report reviews the relationship between the ocular residual spherical aberration of human eyes and visual quality.

Short-term change in higher-order aberrations after mitomycin-C-augmented trabeculectomy

PURPOSE

To investigate the changes in ocular higher-order aberrations (HOA) after trabeculectomy using mitomycin-C (MMC).

METHODS

We retrospectively reviewed data for 63 eyes from 63 glaucoma patients who had undergone MMC augmented trabeculectomy. We measured intraocular pressure (IOP), refractive errors, anterior chamber depth (ACD), and HOA before surgery and 1, 2, and 4 weeks postoperatively. The patients were divided into two groups on the basis of preoperative lens status: phakic and pseudophakic group. We used a paired t test to compare preoperative and postoperative HOA values. Regression analysis was used to compare higher-order total (HOT) change and factors including ACD and age.

RESULTS

For entire eye aberrations, coma-like and total HOT were significantly increased postoperatively at 1 week (P = 0.029, P = 0.005, respectively), but not after 2 or 4 weeks in the phakic group and were not significant at any time in the pseudophakic group. Corneal HOA were significantly increased postoperatively after 1, 2 weeks, but not after 4 weeks in the phakic group and were not significant in the pseudophakic group. For internal optics aberrations, HOA were significantly increased postoperatively at 1, 2, and 4 weeks in the phakic group, but were not significant at any time in the pseudophakic group. However, HOT aberration change showed no correlation with age, ACD, IOP change in either group.

CONCLUSION

Following trabeculectomy, HOA changes were significantly increased postoperatively at 1, 2 weeks in the phakic group. Therefore, visual complaint-related HOA changes after trabeculectomy may be more profound in phakic patients.

Evaluation of visual quality of spherical and aspherical intraocular lenses by Optical Quality Analysis System

AIM

To evaluate the impact of spherical and aspherical intraocular lenses on the postoperative visual quality of age-related cataract patients using Optical Quality Analysis System (OQAS).

METHODS

Seventy-four eyes with age-related cataracts were randomly divided into spherical and aspherical lens implantation groups. Best-corrected visual acuity (BCVA) was measured preoperatively, one day, one week, two weeks, one month and two months after surgery. A biometric systems analysis using the OQAS objective scattering index (OSI) was performed.

RESULTS

There were no significant differences in visual acuity (P>0.05) before and after spherical and aspheric lens implantation. There was a negative linear correction between the OSI value and BCVA (r=-0.634, P=0.000), and positive corrections between the OSI value and the lens LOCUS III value of nucleus color (NC), nucleus opacity (NO), cortex (C) and posterior lens capsular (P) (r=0.704, P=0.000; r=0.514, P=0.000; r=0.276, P=0.020; r=0.417, P=0.000, respectively). OSI values of spherical vs aspherical lenses were 11.5±3.6 vs 11.8±3.4, 4.1±0.9 vs 3.3±0.8, 3.5±0.9 vs 2.7±0.7, 3.3±0.8 vs 2.6±0.7, 3.2±0.7 vs 2.5±0.8, and 3.2±0.8 vs 2.5±0.8 before and 1d, 1, 2wk, 1 and 2mo after surgery, respectively. All time points varied significantly (P<0.01) between the two groups.

CONCLUSION

Aspherical IOLs does not significantly affect visual acuity compared with spherical IOLs. The OSI value, was significantly lower in the aspherical lens group compared with the spherical lens. This study shows that objective visual quality of aspheric IOLs is better than that of the spherical lens by means of OQAS biological measurement method.

In vitro comparative optical bench analysis of a spherical and aspheric optic design of the same IOL model

Background

To analyse objective optical properties of the spherical and aspheric design of the same intraocular lens (IOL) model using optical bench analysis.

Methods

This study entailed a comparative analysis of 10 spherical C-flex 570 C and 10 aspheric C-flex 970 C IOLs (Rayner Intraocular Lenses Ltd., Hove, UK) of 26 diopters [D] using an optical bench (OptiSpheric, Trioptics, Germany). In all lenses, we evaluated the modulation transfer function (MTF) at 50 lp/mm and 100 lp/mm and the Strehl Ratio using a 3-mm (photopic) and 4.5-mm (mesopic) aperture.

Results

At 50 lp/mm, the MTF values were 0.713/0.805 (C-flex 570 C/C-flex 970 C) for a 3-mm aperture and 0.294/0.591 for a 4.5-mm aperture. At 100 lp/mm, the MTF values were 0.524/0.634 for a 3-mm aperture and 0.198/0.344 for a 4.5-mm aperture. The Strehl Ratio was 0.806/0.925 and 0.237/0.479 for a 3-mm and 4.5-mm aperture respectively. A Mann–Whitney U test revealed all intergroup differences to be statistically significant (p < 0.01).

Conclusion

The aspheric IOL design achieved higher MTF values than the spherical design of the same IOL for both apertures. Moreover, the differences between the two designs of the IOL were more prominent for larger apertures. This suggests that the evaluated IOL provides enhanced optical quality to patients with larger pupils or working under mesopic conditions.