Effect of position of near addition in an asymmetric refractive multifocal intraocular lens on quality of vision

Orientation of the intermediate-vision zone of rotationally asymmetric multifocal intraocular lenses and photic phenomena

PURPOSE

To evaluate the association between the orientation of the intermediate-vision zone and postoperative photic phenomena in eyes implanted with rotationally asymmetric multifocal intraocular lenses with + 1.5 diopters near addition.

STUDY DESIGN

Retrospective comparative case series.

METHODS

We performed the photic phenomena test (PPT) to quantitatively evaluate photic phenomena at 1-3 months after cataract surgery with Lentis Comfort LS-313 MF15 or Lentis Comfort Toric LS-313 MF15T insertion (Oculentis; Santen Pharmaceutical). In cases of bilateral surgeries, only the right eye was included in the analysis. We also conducted a questionnaire survey about the photic phenomena.

RESULTS

The study included 96 eyes from 96 patients. The intermediate-vision zones of 44, 19, 19, and 14 eyes were fixed in the inferior, superior, nasal, and temporal directions, respectively. The measured PPT values for halo, glare, and starburst were equivalent in all the fixed directions. Eighty-four eyes (87.5%) perceived a triangle-shaped halo, and the direction of fixation for the intermediate-vision zone and the extension direction of this photic phenomenon were consistent in 94.0% of the eyes. Less than 10% of the patients responded "moderate" or "severe" for the triangle-shaped halo, glare, and starburst in fixed directions with low frequency in the questionnaire.

CONCLUSION

No qualitative or quantitative difference was found in photic phenomena in eyes implanted with the LS-313 MF15 or the MF15T regardless of the fixation direction. Our study revealed that many patients were aware of a triangle-shaped halo extending in the direction of the intermediate-vision zone.

Latest Development in Extended Depth-of-Focus Intraocular Lenses: An Update

In recent years, there has been an overwhelming influx of different types of intraocular lenses (IOLs) as treatment for presbyopia. The extended depth-of-focus (EDOF) technology creates a single elongated focal point to enhance depth of focus, in contrast to the multiple foci of multifocal (MF) lenses. In this way, the EDOF lenses aim to reduce photic phenomena, glare, and halos, which have been reported in MF IOLs. A potential disadvantage of this is a blur due to decreased retinal image quality when the amount of the aberrations is increased excessively. Multifocality and EDOF characteristics are not exclusive of each other. Frequently, EDOF IOLs are combined with MF optical designs, a bifocal IOL may exhibit EDOF characteristics, likewise an aspheric monofocal IOL or a diffractive or refractive trifocal IOL. Thus, EDOF lenses are commonly subjected to confusion. A wide range of different types of EDOF lenses are available on the market to surgeons. In this practical update, we aim to clarify what is a true EDOF lens, classify the different types of the EDOF lenses based on their optical principle and review their recently reported outcomes. Comprehensive patient examination and selection, combined with knowledge of the most updated options and adequate patient counseling, can avoid dissatisfaction and yield the desired outcomes.

Secondary positioning of rotationally asymmetric refractive multifocal intraocular lens in a patient with glaucoma: A case report

BACKGROUND

Asymmetric multifocal intraocular lenses (IOLs) are now widely used in the modern cataract surgery, providing a good level of visual performance over a range of distances and high postoperative patient satisfaction. We report a case of improved visual quality after shifting the near segment of an asymmetrical multifocal IOL to the superotemporal placement in the dominant eye of a glaucoma patient.

CASE SUMMARY

A 72-year-old woman with bilateral glaucoma underwent phacoemulsification in the dominant eye (left eye) with implantation of an asymmetrical multifocal IOL. Postoperative uncorrected distance visual acuity (UDVA) was 0.0 logMAR (20/20 Snellen) and uncorrected near visual acuity (UNVA) was 0.1 logMAR (20/25 Snellen). Two weeks later, the patient presented to our clinic with decreased vision due to migration of lens epithelial cells to IOL anterior surface and edema of corneal endothelial cells. Anterior capsule polishing and superotemporal placement of near segment [+3.00 diopter (D) addition (add)] of IOL were performed. As a result, UDVA at the first week and first year after reposition was 0.0 logMAR (20/20 Snellen), and compared with 0.3 logMAR (20/40 Snellen) in the first week, the UNVA was improved to 0.0 logMAR (20/20 Snellen) one year after surgery.

CONCLUSION

The postoperative inflammatory reaction and lens epithelial cells proliferation were obvious in this glaucoma patient. Capsule polishing and rotation of the lens were beneficial to the patient, which not only enhanced the patient's vision, but also improved the patient's satisfaction. Therefore, glaucoma patients need to be cautious of implanting multifocal IOLs. Placement of a near segment of an asymmetrical multifocal IOL in the dominant eye should be performed on an individual basis.

Binocular visual function after unilateral versus bilateral implantation of segmented refractive multifocal intraocular lenses: a pilot study

PURPOSE

To evaluate binocular visual function after unilateral and bilateral implantation of segmented refractive multifocal intraocular lenses (MIOLs).

METHODS

This prospective comparative pilot study included patients who underwent SBL-3 (Lenstec; + 3.00 D) implantation at Peking University Third Hospital. Patients were divided into two groups (monocular or binocular surgery). Thirty-two patients with emmetropic presbyopic contralateral eyes and 49 patients with bilateral SBL-3 implantation within a week between eyes were included in the unilateral SBL-3 and bilateral groups, respectively. At 3-month follow-up, the main outcomes were binocular uncorrected distant, intermediate, and near visual acuity (UDVA, UIVA, and UNVA). Secondary outcomes included binocular best-corrected visual acuity at all distances, defocus curve, contrast sensitivity, photic phenomena, spectacle independence, patient satisfaction, and National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) score. The essential perceptual phenomena constituting binocular vision, simultaneous perception, fusion, and stereopsis were also evaluated.

RESULTS

Both groups showed similar binocular UDVA and UIVA, but UNVA was significantly better in the bilateral group (0.07 ± 0.07 versus 0.12 ± 0.07, P = 0.008). Better binocular defocus curve at intermediate to near focal points, higher percentage of spectacle independence at near distance, and NEI-VFQ-25 near activity scores were observed in the bilateral group. No significant differences in contrast sensitivity, photic phenomena, overall satisfaction, other NEI-VFQ-25 subscales, fusional amplitude, and stereoacuity were found between groups.

CONCLUSION

Unilateral implantation of segmented refractive MIOL provided desirable distant visual acuity and high patient satisfaction, but inferior intermediate and near visual outcomes compared with bilateral implantation.

New method to improve the quality of vision in cataractous keratoconus eyes

To analyze using optical simulations if the proper use of a segmented intraocular lens (IOL) can improve the visual outcomes compared to the implantation of a spherical monofocal IOL. The wavefront profile of the Mplus (Oculentis) and a monofocal IOLs with the phase transformation introduced by each IOL were calculated using a Hartmann-Shack wavefront sensor. In addition, the wavefront profile of schematic eye models of various keratoconus conditions was obtained and was propagated to the IOLs. The optical performance of such combination was obtained after combining ray tracing and Fourier optics. A pre-clinical validation was also evaluated incorporating clinical data from three different keratoconus eyes of three patients. The implantation of the Mplus IOL can compensate or reduce the overall coma of the eye with keratoconus improving the quality of vision compared with a spherical monofocal IOL due to lower displacements of the retinal image or tilting in keratoconus. All theoretical simulations were confirmed afterwards by mean of a preclinical validation. The use of a standard toric segmented IOL with a proper orientation and selection of the addition can improve the optical quality of the keratoconus eye compared to the use of a monofocal spherical IOL.

Prospective assessment of plate-haptic rotationally asymmetric multifocal toric intraocular lens with near addition of + 1.5 diopters

Background

To prospectively evaluate surgical results following implantation of rotationally asymmetric, plate-haptic, refractive segmented multifocal toric intraocular lenses (IOLs) with near addition of + 1.5 diopters (D) (Lentis Comfort LS-313 MF15T, Oculentis GmbH).

Methods

In 59 eyes of 41 patients, ocular examinations were conducted before and 1 day, 1 week, 1, 3, and 6 months after surgery. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, uncorrected (UIVA) and distance-corrected (DCIVA) intermediate visual acuity at 70 cm, and uncorrected (UNVA) and distance-corrected (DCNVA) near visual acuity at 30 cm were tested. A defocus curve was drawn, and the degree of disturbing photic phenomena were questioned.

Results

The IOL showed excellent rotational stability; the average absolute rotation was 1.66 ± 1.17 degrees from 1 day 1 to 6 months postoperatively, and 98.1 and 100% of eyes yielded rotation of less than 5 and 10 degrees, respectively. Postoperative distance and intermediate visual acuity were highly satisfactory; UDVA, CDVA, UIVA, and DCIVA were about 20/20, 20/16, 20/25, 20/25, respectively. Near visual acuity was suboptimal; UNVA and DCNVA were at approximately 20/60. The defocus curve analysis showed that 20/25 and 20/40 uncorrected visual acuity was attained at as close as 60 and 40 cm, respectively. Contrast sensitivity was within a normal range, and subjective photic phenomena were minimum.

Conclusions

The refractive segmented, rotationally asymmetric multifocal toric IOLs with + 1.5 D near addition showed superb rotational stability and highly satisfactory distance and intermediate vision. Contrast sensitivity was high and incidence of photic symptoms was very low.

Trial registration

This study was registered at JAPIC Clinical Trials Information, ID: JapicCTI-183,877, https://www.clinicaltrials.jp/cti-user/trial/Search.jsp (February 5, 2018).

Influence of angle kappa-customized implantation of rotationally asymmetric multifocal intraocular lens on visual quality and patient satisfaction

PURPOSE

To evaluate the visual outcomes and patient satisfaction with angle kappa-customized implantation of SBL-3 (Lenstec, Inc.; +3 D), a rotationally asymmetric multifocal intraocular lens (MIOL).

METHODS

This was a prospective randomized control study. Data from consecutive patients, who underwent bilateral implantation of SBL-3 MIOL from June 2017 to August 2018, were enrolled in the study. One eye of each patient was randomly chosen to receive a horizontal IOL placement (control group), while the other eye received angle kappa-customized placement (design group). The outcomes include uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), defocus curve, contrast sensitivity, quality of vision and patient satisfaction. The follow-up was 3 months.

RESULTS

The study enrolled 80 eyes of 40 patients. There was no significant difference in mean UDVA, UIVA and UNVA between the two groups. The design group showed significantly better visual acuity at -1.50 D of defocus, based on the defocus curve (p = 0.022), and less vertical coma (p = 0.002) than the control group. No significant differences in contrast sensitivity, modulation transfer function, Strehl ratio and patient satisfaction were found between the two groups.

CONCLUSION

Angle kappa-customized implantation of SBL-3 had little impact on visual outcomes and patient satisfaction, except for a moderate impact on intermediate visual acuity.

Pupil influence on the quality of vision in rotationally asymmetric multifocal IOLs with surface-embedded near segment

PURPOSE

To evaluate the influences of preoperative pupil parameters on the visual outcomes of the SBL-3, a rotationally asymmetric multifocal intraocular lens (IOL) with a surface-embedded near segment.

SETTING

Cathedral Eye Clinic, Belfast, Northern Ireland, United Kingdom.

DESIGN

Retrospective comparative case series.

METHODS

Postoperatively, patients divided into 4 groups according to their pupil size as follows: Group A: 2.50 to 2.99 mm, Group B: 3.00 to 3.50 mm, Group C: 3.51 to 4.00 mm, and Group D: 4.01 to 4.50 mm. The uncorrected distance (UDVA), intermediate (UIVA), and near (UNVA) visual acuities, IOL centration and tilt, and quality of vision (QoV) questionnaires were compared between the 4 groups for 18 months postoperatively.

RESULTS

The study comprised 90 patients (180 eyes). The mean preoperative pupil (photopic and mesopic) diameter was 4.3 mm ± 0.3 (SD) and 5.6 ± 1.4 mm, respectively, which decreased to 3.8 ± 0.7 mm and 4.9 ± 1.2 mm, respectively, at 18 months. Eighteen months postoperatively, both photopic and mesopic pupil groups had a statistically significant reduction in size from preoperative levels. No significant differences in UDVA, UIVA, and UNVA were found between the groups (P > .001). Significant differences in the QoV questionnaire day scores and night scores were found between the 4 groups (P < .001).

CONCLUSIONS

The rotationally asymmetric multifocal IOL provided excellent optical performance during 18-months follow-up. The preoperative photopic pupil is an important parameter for consideration of this type of IOL because smaller pupils have a significant negative subjective impact on QoV.

One-year clinical evaluation of rotationally asymmetric multifocal intraocular lens with +1.5 diopters near addition

We conducted a one-year prospective, multicenter study to assess clinical outcomes after implantation of segmented, rotationally asymmetric multifocal intraocular lenses (IOLs) with +1.5 diopters (D) near addition. In this phase III clinical trial, 120 eyes of 65 patients undergoing phacoemulsification and implantation of Lentis Comfort LS-313 MF15 (Oculentis GmbH) were included. The ophthalmological examinations were performed before and 1 day, 1 week, 1, 3, 6, 9, and 12 months after surgery. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, uncorrected (UIVA) and distance-corrected (DCIVA) intermediate visual acuity at 70 cm, and uncorrected (UNVA) and distance-corrected (DCNVA) near visual acuity at 30 cm were measured. A defocus curve was obtained and patients were asked about the severity of photic phenomena. Postoperative distance and intermediate visual acuity was excellent, with UDVA, CDVA, UIVA, and DCIVA of approximately 20/20, 20/16, 20/25, 20/25 were attained, respectively. The level of near visual acuity was lower; UNVA and DCNVA remained at around 20/60 and 20/70, respectively. The defocus curve indicated that postoperative uncorrected visual acuity of 20/25 and 20/40 was obtained at as close as 67 cm and 50 cm, respectively. Contrast sensitivity was within the normal range, with a minimal level of subjective symptoms and high patient satisfaction. The rotationally asymmetric multifocal IOLs with +1.5 D near addition provided excellent distance and intermediate vision, but near vision was not enough for reading small prints. Contrast sensitivity was high, with very low incidences of photic phenomena and a high level of patient satisfaction.

Visualization of Light Propagation with Multifocal Intraocular Lenses Using the Ouzo Effect

The number of presbyopia correcting intraocular lenses (IOLs) is increasing and new technologies are constantly emerging with the aim of correcting the loss of accommodation after cataract surgery. Various optical designs have been proposed to implement multifocality or an extended depth of focus (EDOF). Depending on the optical principle of an implanted lens, the visual performance often is deteriorated by superposition of individual image planes and halos of varying intensity. This experimental study presents a concept to visualize the light fields and especially the halos of mono- and multifocal IOLs using the well known alcoholic beverage “ouzo” in order to obtain qualitative data on the imaging characteristics. We conclude that ouzo is a useful, cost effective, and nonpolluting medium for beam visualization and an alternative to fluorescein or milk, which could find an application for educational purposes.

Differences in visual quality with orientation of a rotationally asymmetric bifocal intraocular lens design

PURPOSE

To evaluate visual and perceptual performance for different orientations of a rotationally asymmetric bifocal intraocular lens (IOL) (M-Plus) simulated optically using a simultaneous vision simulator.

SETTING

Instituto de Optica, Madrid, Spain.

DESIGN

Prospective observational study.

METHODS

Perceptual quality and decimal high-contrast visual acuity (HCVA) was measured under cycloplegia for 8 orientations of the asymmetric bifocal IOL phase pattern at far, intermediate, and near distances simulated with a simultaneous vision simulator using face images and tumbling E targets. The preferred orientation at each distance was calculated as the centroid of the data for 8 orientations. The visual Strehl value was calculated using the subjects' ocular aberrations and multifocal pattern at each orientation. Optical predictions were obtained by implementing a differential visual Strehl values-based ideal observer model.

RESULTS

The study comprised 20 subjects (aged 21 to 62 years). Horizontal orientation (near segment at 0 or 180 degrees ± 45 [SD]) was preferred by 14 subjects and by 13 subjects at far and near distances, respectively; 8 subjects showed strong orientation preferences. The mean difference in preferred orientation between far and near was 27 ± 22 degrees. No significant differences in HCVA were observed. Optical predictions correlated strongly and significantly with measurements (far r = 0.71, near r = 0.62; P < .0001). The mean difference between measurement and simulation in the preferred orientation was 28 ± 29 degrees at far and 36 ± 28 degrees at near.

CONCLUSIONS

The perception varied for different orientations of an asymmetric bifocal IOL design tested using a simultaneous vision simulator. Optimum orientation was driven by interactions of the design with the eye's optical aberrations.

FINANCIAL DISCLOSURE

None of the authors has a financial or proprietary interest in any material or method mentioned.

Comparison of the visual performance and quality of vision with combined symmetrical inferonasal near addition versus inferonasal and superotemporal placement of rotationally asymmetric refractive multifocal intraocular lenses

PURPOSE

To compare the postoperative quality of vision between different bilateral placements of near segments of rotationally asymmetric refractive multifocal intraocular lenses (IOLs) and to determine how this affects visual performance.

SETTING

Cathedral Eye Clinic, Belfast, Northern Ireland, United Kingdom.

DESIGN

Retrospective comparative case series.

METHODS

The study enrolled consecutive patients having refractive lens exchange and implantation of rotationally asymmetric multifocal IOLs. Group 1 received bilateral SBL-3 IOLs and Group 2 received bilateral Lentis Mplus LS-312 MF30 IOLs, with the near segments placed inferonasally in each group. Group 3 received a Lentis Mplus LS-312 MF20 IOL in the dominant eye with the near segment positioned superotemporal and a Lenstec SBL-3 IOL positioned inferonasally in the fellow eye. Binocular uncorrected (UDVA) and corrected distance visual acuities, binocular uncorrected near (UNVA) and intermediate (UIVA) visual acuities, binocular distance-corrected near and intermediate visual acuities, and quality of vision were evaluated over 3 months postoperatively.

RESULTS

The study enrolled 180 patients (360 eyes). There was no significant difference between the groups in binocular UDVA, UIVA, and UNVA; however, there was a significant difference between the groups in quality of vision (P ≤ .001). Group 3 had significantly better overall quality of vision.

CONCLUSION

When implanting rotationally asymmetric multifocal IOLs, a combination of superotemporal placement of the near segment (+2.00 diopter [D] addition [add]) in the dominant eye with inferonasal placement of the near segment (+3.00 D add) in the fellow eye yielded consistent, high overall quality of vision and uncorrected visual acuity.

FINANCIAL DISCLOSURE

None of the authors has a financial or proprietary interest in any material or method mentioned.

Visual Outcomes After Implantation of a Segmental Refractive Multifocal Intraocular Lens Following Cataract Surgery

PURPOSE

To evaluate visual outcomes, with particular attention to intermediate visual acuity (VA), of a segmental refractive multifocal intraocular lens (IOL) with optimized depth of focus (DoF).

DESIGN

Prospective, nonrandomized, noncomparative case series.

METHODS

Setting: Department of Ophthalmology, Goethe University, Frankfurt/Germany. Patient or Study Population: Fifty eyes (25 patients) were included. Inclusion criteria were bilateral cataract, age > 45 years, corneal astigmatism ≤ 0.75 diopter (D) postoperatively, pupil size 3-6 mm (mesopic), and center shift < 1 mm (Pentacam). Exclusion criteria were ocular surgeries, amblyopia, or potential postoperative distance-corrected VA (DCVA) > 0.3 logMAR. Intervention or Observation: Uncorrected (UCVA) and DCVA in 4 m, 80 cm, 40 cm; contrast sensitivity (CS); reading skills; defocus curve; and questionnaire on optical quality (OQ) and spectacle independence were assessed after 3 months.

MAIN OUTCOME MEASURES

UCVA and DCVA in 4 m, 80 cm, 40 cm; defocus curve.

RESULTS

UCVA was 0.05 ± 0.122 logMAR at 4 m, 0.18 ± 0.164 logMAR at 80 cm, and 0.16 ± 0.140 logMAR at 40 cm. Defocus curve testing showed, respectively, a flat monocular and binocular VA range from 0.00 to -2.00 D (-0.03 to 0.11 logMAR, -0.05 to 0.05 logMAR). Median CS under photopic and mesopic conditions without and with glare was 1.81 logCS, 1.65 logCS, 1.52 logCS, and 1.14 logCS, respectively. Reading speed at 40 cm showed a reading acuity of 0.100 logRAD with 94 words/minute.

CONCLUSION

This segmental multifocal IOL provides good VA at all distances (<0.20 logMAR), particularly providing good intermediate visual acuity and DoF. It showed good reading skills, OQ, and CS and high spectacle independence.

Rotationally asymmetric multifocal intraocular lenses: preoperative considerations and postoperative outcomes

PURPOSE OF REVIEW

The manuscript presents a review of recently published studies reporting objective and subjective outcomes and preoperative considerations of asymmetrical multifocal intraocular lenses (IOLs).

RECENT FINDINGS

Current publications suggest that asymmetrical multifocal IOLs provide good, distance, intermediate and near vision for cataract and clear lens extraction patients. The contrast sensitivity achieved is similar to monofocal IOLs. Photopic phenomenon such as glare and halos has been reduced through the use of these IOLs leading to better patient satisfaction. Centration plays a critical role and the lack of a gold standard assessment tool has led to a minority of patients experiencing lower quality of vision and side-effects such as glare and hazy vision. The frequency of dissatisfied patients can be minimized by appropriate patient selection. This is achieved by assessing pupil parameters which guides the surgeon to align the IOL accordingly.

SUMMARY

Asymmetric multifocal IOLs provide the surgeon with an IOL that achieves excellent visual and refractive outcomes enabling patients to see clearly at a range of distances. Subjectively patients report low levels of photopic phenomena and high levels of spectacle independence resulting in high overall patient satisfaction.