Analyse objective de la qualité de vision en fonction de l’asphéricité post-opératoire d’une chirurgie micro-incisionnelle de la cataracte

Analysis of corneal higher-order aberrations in cataract patients with high myopia

PURPOSE

To evaluate the differences in corneal higher-order aberrations (HOAs) between cataract patients with high axial myopia and normal cataract patients, and to identify the associated factors.

SETTING

Department of Ophthalmology and Vision Science of the Eye and ENT Hospital of Fudan University, Shanghai, China.

DESIGN

Retrospective case series.

METHODS

Corneal aberrations and axial lengths (ALs) were measured using a rotating Scheimpflug camera (Pentacam) and partial coherence interferometry (IOLMaster) in the high myopia group and the control group.

RESULTS

The study comprised 287 patients (520 eyes). There were 194 eyes in the high myopia group and 326 eyes in the control group. The 5 anterior corneal aberrations-vertical coma, vertical trefoil, horizontal coma, oblique trefoil, and primary spherical aberration-in the high myopia group were 0.07 μm ± 0.38 (SD), -0.11 ± 0.23 μm, 0.07 ± 0.28 μm, -0.02 ± 0.18 μm, and 0.39 ± 0.19 μm, respectively. No negative primary spherical aberrations of the total or anterior corneal surface were found in the high myopia group. Differences between the 2 groups were found in terms of central corneal thickness, astigmatism, primary spherical aberration, vertical coma, and oblique trefoil; however, these differences were not consistent between different age subgroups. Higher-order aberrations were correlated with age. Posterior corneal vertical coma was correlated with AL (Pearson correlation = -0.188, P = .047).

CONCLUSIONS

Negative primary spherical aberrations of the anterior or total corneal surface were not found in the high myopia group. Age showed a strong relationship with HOAs. For cataract patients with high myopia, aspheric intraocular lens implantation is recommended.

Early clinical outcome with a new monofocal microincision intraocular lens

The purpose of this study was to evaluate the early visual and refractive outcomes of a new aspheric monofocal microincision intraocular lens (IOL). This retrospective case series included eyes of patients who underwent implantation of a microincision IOL following 1.8 mm manual coaxial microincision cataract surgery and who attended regular postoperative follow-up visits on the first week and first, third, and sixth months. The postoperative uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refraction and predictability, intraoperative and postoperative complications, posterior capsule opacification (PCO), IOL centration, and surgically induced astigmatism (SIA) were evaluated. Sixty-three eyes of 38 patients ranging in age from 51 to 86 were included in the study. The mean preoperative BCVA was 0.52 ± 0.42 logMAR. At the postoperative sixth month, the mean postoperative UCVA and BCVA were 0.12 ± 0.11 and 0.01 ± 0.03 logMAR, respectively. The mean postoperative spherical equivalent refraction (SER) was -0.30 ± 0.49 D. The SER was within ± 1.00 D of the attempted correction in 95.2 % of the eyes. The mean SIA measured with vector analysis was 0.45 ± 0.28 D. Mild PCO was observed in 9 eyes (14.7 %) with none requiring Nd:Yag laser capsulotomy. On centration analysis, the IOL was found to be 0.26 mm on average to the supero-nasal position. The aspheric microincision IOL was safely implanted and provided satisfactory visual and refractive outcomes in the early postoperative period.

Objective optical quality analysis using double-pass technique in pterygium surgery

PURPOSE

To analyze objective optical quality changes after pterygium surgical excision using the Optical Quality Analysis System.

METHODS

Forty eyes with primary pterygium suitable for surgical treatment were included. Uncorrected distance visual acuity, corrected distance visual acuity (CDVA), objective scattering index (OSI), and cutoff frequency of the modulation transfer function (MTFcutoff) were recorded preoperatively and at 1 and 6 months postoperatively. Slit-lamp measurement of pterygium size was performed to classify them: small in group 1 and medium size/large in group 2. A paired comparative study of all data that included preoperative with 1-month results (comparison A), preoperative with 6-month results (comparison B), and 1 month with sixth-month results (comparison C) was performed.

RESULTS

In global analysis, uncorrected distance visual acuity and OSI showed significant changes in comparison A, all parameters in comparison B, and CDVA, OSI, and MTFcutoff in comparison C. When subdividing into groups, in group 1, there was significant improvement between preoperative uncorrected distance visual acuity value and those at 1 and 6 months. Significant improvement in CDVA, OSI, and MTFcutoff values were observed in comparisons B and C. In group 2, MTFcutoff values significantly improved in comparisons B and C. The comparison of mean values between each group at each evaluation showed a lower value for MTFcutoff at 1 month after surgery. A comparative analysis of the evolution between both groups based on pterygium size did not reveal significant differences.

CONCLUSIONS

Pterygium can undermine visual quality, and its excision provides significant improvement even at 6 months after surgery. Optical Quality Analysis System proved useful for postoperative outcomes.

[Use of "mix-and-match" aspheric intraocular lenses in cataract surgery to enhance depth of field and stereoscopic performance]

INTRODUCTION

One of the remaining challenges in cataract surgery is to compensate for lost accommodative function. The purpose of our study is to evaluate reading ability with a combination of two different aspheric intraocular lenses.

PATIENTS AND METHODS

This retrospective study included 40 eyes (20 patients). The control group (28 eyes, 14 patients) received two negative aspheric intraocular lenses (Acrismart 36A(®), Carl Zeiss Meditec), while the aspheric-optimized group (12 eyes, six patients) received an AcriSmart 36A(®) in the dominant eye and a zero-aspheric intraocular lens (Acrismart 46 LC(®), Carl Zeiss Meditec) in the fellow eye. Patients with corneal asphericity between 0.15 and 0.30 μm and a bilateral monocular postoperative visual acuity of at least 20/20 were eligible for inclusion. Uncorrected and best corrected visual acuity was measured for near, intermediate and distance vision. Corneal and total higher-order aberrations, monocular and binocular defocus curve, and stereoscopic performance were assessed.

RESULTS

Postoperative spherical equivalent and best corrected distance visual acuity were not significantly different between the two groups (P=0.11 and P=0.82 respectively). However, the aspheric-optimized group (36A(®)/46 LC(®)) exhibited better near and intermediate visual acuity (P<0.05), and better stereoscopic vision (P=0.027).

DISCUSSION

The depth of field results in pseudophakes implanted with "mix-and-match" aspheric lenses demonstrates that the binocular combination of two different aspheric profiles seems to improve near vision without affecting stereoscopic vision.

[Refractive precision and objective quality of vision after toric lens implantation in cataract surgery]

PURPOSE

To study efficacy and predictability of toric IOL implantation for correction of preoperative corneal astigmatism by analysing spherocylindrical refractive precision and objective quality of vision.

PATIENTS AND METHODS

Prospective study of 13 eyes undergoing micro-incisional cataract surgery through a 1.8mm corneal incision with toric IOL implantation (Lentis L313T(®), Oculentis) to treat over one D of preoperative corneal astigmatism. Preoperative evaluation included keratometry, subjective refraction, and total and corneal aberrometry (KR-1(®), Topcon). Six months postoperatively, measurements included slit lamp photography, documenting IOL rotation, tilt or decentration, uncorrected visual acuity, best-corrected visual acuity and objective quality of vision measurement (OQAS(®) Visiometrics, Spain).

RESULTS

Postoperatively, mean uncorrected distance visual acuity was 8.33/10 ± 1.91 (0.09 ± 0.11 LogMar). Mean postoperative refractive sphere was 0.13 ± 0.73 diopters. Mean refractive astigmatism was -0.66 ± 0.56 diopters with corneal astigmatism of 2.17 ± 0.68 diopters. Mean IOL rotation was 4.4° ± 3.6° (range 0° to 10°).

DISCUSSION

Mean rotation of this IOL at 6 months was less than 5°, demonstrating stability of the optic within the capsular bag. Objective quality of vision measurements were consistent with subjective uncorrected visual acuity.

CONCLUSION

Implantation of the L313T(®) IOL is safe and effective for correction of corneal astigmatism in 1.8mm micro-incisional cataract surgery.