Influence of tilt and decentration of scleral-sutured intraocular lens on ocular higher-order wavefront aberration

Evaluation of Dynamic Intraocular Lens Movement Using Anterior Segment Optical Coherence Tomography Movie Analysis

PURPOSE

To introduce a method to quantitatively assess dynamic intraocular lens (IOL) positioning using anterior segment optical coherence tomography (AS-OCT).

METHODS

This retrospective observational study analyzed 13 eyes with in-the-bag IOL fixation between May and December 2023 at the Ophthalmology Department of The Jikei University School of Medicine Hospital in Tokyo. Using ASOCT imaging during horizontal eye movements, dynamic IOL and iris movement angles were quantitatively assessed, compared with conventional static IOL tilt and decentration, and their interrelations were examined.

RESULTS

Static measurements revealed an average IOL tilt of 4.1 ± 1.3 degrees (range: 1.9 to 5.9 degrees) and decentration of 0.17 ± 0.10 mm (range: 0.02 to 0.38 mm). Dynamic analysis showed IOL movement angles of 2.6 ± 2.1 degrees (range: 0.3 to 7.3 degrees) and iris movement angles of 4.1 ± 3.4 degrees (range: 0.3 to 10.3 degrees). No correlation was found between the dynamic IOL movement angle and static IOL tilt and decentration, with some cases showing discrepancies (Spearman's rank correlation, P > .05). However, a strong positive correlation was observed between the dynamic IOL and iris movement angles (Spearman's rank correlation, R = 0.83, P < .05).

CONCLUSIONS

Although the static IOL tilt and decentration were within normal ranges, significant oscillations in IOL positioning were detected, highlighting the importance of dynamic assessment for evaluating IOL stability during daily activities. This study underscores the potential value of dynamic evaluation of IOL position in routine clinical practice. [J Refract Surg. 2025;41(5):e444-e450.].

Comparison of two different intraocular lenses used in the modified Yamane technique

PURPOSE

To compare AcrySof MA60AC (Alcon Laboratories, Fort Worth, TX, USA) and Sensar AR40e (Johnson and Johnson, Santa Ana, CA, USA) used in Yamane sutureless scleral fixation technique in terms of visual acuity, refractive stability, and complications.

METHODS

A retrospective, cross-sectional study was conducted in Istanbul Başakşehir Çam and Sakura City Hospital. Patients were divided into two groups: The first group consisted of patients with MA60AC lenses, while the second group consisted of patients with AR40e. Aphakic patients who underwent secondary intraocular lens (IOL) implantation and had postoperative minimum 3-month follow-up records were included. Visual acuity, refractive outcomes, perioperative and postoperative complications were recorded.

RESULTS

Forty-nine patients were included in the study. Twenty-two patients were in the first group and 27 patients were in the second group. Age, gender, and follow-up time were similar between groups (P = 0.546, 0.213, and 0.347, respectively). The median lenticular astigmatism value was 0.86 (0.08-2.11) D in group 1 and 0.99 (0.31-2.96) D in group 2 (P = 0.898). There was no significant difference between groups in terms of visual acuity, spherical, cylindrical, and spherical equivalent values (P = 0.752, 0.375, 0.073, and 0.949, respectively). In group 1, a haptic tip fracture and optic-haptic separation were observed perioperatively. Optic-haptic junction separation was observed in one patient in group 1 on postoperative day 1. In group 1, epiretinal membrane development was significantly higher (P = 0.019).

CONCLUSIONS

Both AcrySof MA60AC and Sensar AR40e IOLs via the modified Yamane technique yielded favorable and predictable outcomes. Although statistically insignificant, haptic problems were more common in the first group.

Surgically induced astigmatism in the scleral fixated 'Carlevale' IOL technique

PURPOSE

To evaluate the surgically induced astigmatism over a 6-month follow-up period in patients who underwent scleral IOL fixation using an acrylic single-piece IOL with special haptics designed for sutureless scleral fixation.

METHODS

We conducted a prospective longitudinal study at a single site with a single surgeon. We included patients who received transscleral IOL implantation following the Carlevale technique and were followed up post-operatively for 24 weeks. We measured the patient's refraction at baseline, week 12 and week 24 using the best corrected visual acuity at 4 m (EDTRS chart). We performed corneal tomography at every visit using an anterior segment optical coherence tomography (AS-OCT). We evaluated surgically induced astigmatism (SIA) and refraction during each follow-up visit and compared them to baseline. We then assessed changes in SIA over time.

RESULTS

In total, 27 eyes of 27 patients consisting of 16 female and 11 male individuals were evaluated. The mean patient age was 71 ± 11.7 years, mean axial length was 24.30 ± 1.47 mm (range: 21.4-27.23) and mean white-to-white distance was 12.07 ± 0.40 mm (range: 11.4-12.7). The mean SIA decreased from 1.78 ± 0.96D at week 1 significantly to 0.80 ± 0.55D at week 12 (p < 0.001) and then stayed unchanged around 0.82 ± 0.72D at week 24 (p = 1.0).

CONCLUSIONS

The scleral fixated Carlevale IOL and its implantation procedure were found to result in a predictable SIA of <1D after 24 weeks. However, the axis orientation of the SIA appeared to be random, making it unsuitable for implementation in toric IOL calculations.

Analysis of intraocular lens tilt and decentration after cataract surgery in eyes with high myopia using the anterior segment optical coherence tomography

This retrospective study investigated the degree of intraocular lens (IOL) tilt and decentration after cataract surgery in eyes with varying degrees of myopia using the anterior segment optical coherence tomography (AS-OCT). Eyes of 76 patients were analyzed and divided into three groups: mild myopia (emmetropia to - 1.5 diopter [D], Group 1), moderate myopia (- 1.5 D to - 6.0 D, Group 2), and high myopia (over - 6.0 D, Group 3). Postoperative IOL decentration, tilt, and lens diameter were evaluated using swept-source AS-OCT under mesopic conditions without dilation eyedrop. Postoperative parameters revealed no difference in IOL tilt, but IOL decentration was significantly different among the groups, and the degree of decentration was greater in Group 3 (P = 0.007). Univariable regression analysis indicated that age, sex, preoperative uncorrected distant visual acuity, corrected distant visual acuity, intraocular pressure, spherical equivalent, preoperative anterior chamber depth and lens thickness had no influence on postoperative IOL decentration, but axial length (AL) was significantly related to IOL decentration (P = 0.001). This association was confirmed using multivariable regression analysis, establishing a significant correlation between AL and IOL decentration (P = 0.001) on AS-OCT, showing an increase in IOL decentration associated with increasing AL.

The Surgical Outcomes of Modified Intraocular Lens Suturing with Forceps-Assisted Haptics Extraction: A Clinical and Basic Evaluation

Background/Objectives: Postoperative intraocular lens (IOL) tilt is a risk associated with IOL scleral fixation. However, the cause of IOL tilt during IOL suturing remains unclear. Therefore, this study aimed to evaluate the surgical outcomes of a modified IOL suturing technique and investigate the factors contributing to postoperative IOL tilt and decentration. Methods: We included 25 eyes of 22 patients who underwent IOL suturing between April 2018 and February 2020. A modified IOL suturing technique that decreased the need for intraocular suture manipulation was used. Factors contributing to IOL tilt and decentration were investigated using an intraoperative optical coherence tomography (iOCT) system. Results: The mean postoperative best-corrected visual acuity improved from 0.15 ± 0.45 to -0.02 ± 0.19 (p = 0.02). The mean IOL tilt angle at the last visit after surgery was 1.84 ± 1.28 degrees. The present study reveals that the distance of the scleral puncture site from the corneal limbus had a stronger effect on IOL tilt; meanwhile, the suture position of the haptics had a greater effect on IOL decentration. Conclusions: The modified IOL suturing technique, which avoids intraocular suture handling, had favorable surgical outcomes with improved postoperative visual acuity and controlled IOL tilt and decentration. Accurate surgical techniques and careful measurement of distances during surgery are crucial for preventing postoperative IOL tilt and decentration.

Impact of scleral tunnel length on the position of intraocular lenses in flanged intrascleral haptic fixation

PURPOSE

To investigate the effect of scleral tunnel length on the effective lens position and tilt of the intraocular lens (IOL) in flanged intrascleral haptic fixation (ISHF) using anterior segment optical coherence tomography (AS-OCT).

SETTING

Tertiary institution.

DESIGN

Retrospective case-control study.

METHODS

This study included 55 and 42 eyes that underwent ISHF with 1.0 and 2.0 mm scleral tunnels, respectively. 23 eyes that underwent sutured fixation were used as a control. The anterior chamber depth (ACD), scleral tunnel length, incident angle of haptic, and tilting of optic were analyzed using AS-OCT.

RESULTS

The mean postoperative ACD, vertical tilt angle, and spherical equivalent of the 1.0 mm were 5.27 ± 0.39 mm, 6.04 ± 4.87 degrees, and 0.38 ± 1.03 diopters, respectively. The ACD and vertical tilt angle of the 1.0 mm were larger than those of the others ( P < .001 and P < .05, respectively), and the postoperative spherical equivalent was more hyperopic ( P < .05). The 2.0 mm exhibited a lower frequency of tilting greater than 7 degrees. The intereye difference in ACD between in-the-bag fixation and ISHF of the 1.0 mm tunnel was significantly greater than that in the 2.0 mm tunnel ( P < .05). The 1.0 mm tunnel had a significantly larger incident angle and a longer tunnel length ( P < .001, respectively) and showed a greater difference in the tunnel length on both sides ( P < .05).

CONCLUSIONS

A shorter tunnel yielded a more unstable IOL position, greater variation in angle and tunnel length, and longer ACD during ISHF. An exact 2.0 mm tunnel must be created on both sides to achieve a stable and predictable IOL position.

Prediction of low-addition segmented refractive intraocular lens position and deviation using anterior-segment optical coherence tomography

This study aimed to develop and analyze the accuracy of predictive formulae for postoperative anterior chamber depth, tilt, and decentration of low-added-segment refractive intraocular lenses. This single-center, retrospective, observational study included the right eyes of 96 patients (mean age: 72.43 ± 6.58 years), who underwent a cataract surgery with implantation of a low-added segmented refractive intraocular lens at the Medical University Hospital between July 2019 and January 2021, and were followed up for more than 1 month postoperatively. The participants were divided into an estimation group to create a prediction formula and a validation group to verify the accuracy of the formula. Anterior segment optical coherence tomography (CASIA 2, Tomey Corporation, Japan) and swept-source optical coherence tomography biometry (IOL Master 700, Carl Zeiss Meditec AG) were used to measure the anterior ocular components. A predictive formula was devised for postoperative anterior chamber depth, intraocular lens tilt, and intraocular lens decentration (p <0.01) in the estimation group. A significant positive correlation was observed between the estimated values calculated using the prediction formula and the measured values for postoperative anterior chamber depth (r = 0.792), amount of intraocular lens tilt (r = 0.610), direction of intraocular lens tilt (r = 0.668), and amount of intraocular lens decentration (r = 0.431) (p < 0.01) in the validation group. In conclusion, our findings reveal that predicting the position of the low-added segmented refractive intraocular lens enables the prognosis of postoperative refractive values with a greater accuracy in determining the intraocular lens adaptation.

Clinical and Anatomic Outcomes of 3-Piece Poly(methyl methacrylate) Intraocular Lens Rescue and Needle-Assisted Transconjunctival Intrascleral Lens Fixation

Purpose: To report the clinical and anatomic outcomes of a single-stage rescue and sutureless 30-gauge needle-assisted transconjunctival intrascleral fixation of dislocated 3-piece rigid poly(methyl methacrylate) (PMMA) intraocular lenses (IOLs). Methods: This retrospective noncomparative single-surgeon interventional study comprised eyes that had concurrent 23- or 25-gauge pars plana vitrectomy and IOL rescue with sutureless transconjunctival needle-assisted flanged haptic intrascleral fixation. Lamellar scleral dissection for haptic fixation was performed 3 mm posterior to the surgical limbus with 30-gauge needles. Primary endpoints included visual acuity (VA), IOL tilt measured with ultrasound biomicroscopy (UBM), and postoperative complications. Results: The study evaluated 25 eyes of 24 patients. The IOL was successfully refixated in 24 of the 25 eyes. The mean preoperative logMAR VA of 1.21 ± 0.79 SD (median 1.3; Snellen equivalent 20/400) improved to 0.28 ± 0.35 (median 0.14; Snellen equivalent 20/30) postoperatively (P < .0001). The mean IOL tilt measured by UBM (n = 7) was 3.79 ± 3.60 degrees. The mean postoperative follow-up was 348 ± 284 days (range, 7-979 days). Postoperative complications included self-clearing vitreous hemorrhage (n = 9), retinal detachment (RD) (n = 1), cystoid macular edema (n = 3), and corneal edema (n = 3). Three eyes (13%) required additional surgery, 1 for RD and 2 for delayed haptic slippage and secondary IOL tilt causing irregular astigmatism. Conclusions: Intrascleral needle-assisted fixation of dislocated or mobile 3-piece PMMA IOLs is an effective, safe method to restore VA.

Usefulness of intraoperative optical coherence tomography to minimize the intraocular lens tilt during the intrascleral fixation: a clinical and experimental evaluation

To report the usefulness of intraoperative real-time adjustment of intraocular lens (IOL) tilt during the intrascleral fixation with intraoperative optical coherence tomography (iOCT) as a clinical evaluation and investigate the factors contributing to IOL tilt using iOCT as an experimental evaluation. Retrospective cohort study and experimental research. As a clinical evaluation, the medical records of 43 eyes of 41 patients who underwent intrascleral IOL fixation combined with real-time iOCT observation were retrospectively reviewed. As an experimental evaluation, in order to investigate the factors contributing to IOL tilt, the four experiments were performed using iOCT. The mean IOL tilt angle (°) at the end of surgery and 3 months after surgery were 1.81 ± 1.15 and 2.10 ± 1.66, respectively (p = 0.46). No apparent intra- or postoperative complications occurred during the follow-up period. The experimental evaluation indicated that the IOL tilt was influenced by the insertion angle of the haptic in the vertical direction. The mean IOL tilt angle (°) was 1.94 ± 0.09, 4.67 ± 0.11, 8.90 ± 0.11, and 15.78 ± 0.85 when the insertion angle of the haptic was 0°, 10°, 27.5°, and 45° in the vertical direction, respectively (p < 0.01). Clinical and experimental IOL tilt assessment using iOCT is interactively useful for better quality surgery and better postoperative outcome.

Influence of decentration of plate-haptic toric intraocular lens on postoperative visual quality

BACKGROUND

To evaluate the influence of decentration of plate-haptic toric intraocular lens (IOLs) on visual quality.

METHODS

This study enrolled 78 eyes of 78 patients. Patients in group A were implanted with toric IOLs, and patients in group B were implanted with monofocal IOLs. All patients were divided into group A1 and B1 (decentration below 0.3 mm) and group A2 and B2 (decentration above 0.3 mm). The uncorrected distance visual acuity (UDVA), best corrected visual acuity (BCVA), modulation transfer function cutoff (MTF cutoff), objective scatter index (OSI), strehl ratio (SR), optical interference and patients' satisfaction were measured in different pupils at three months postoperatively. The associations between decentration and visual quality were analyzed by Spearman correlation.

RESULTS

There were no significant differences in UDVA, BCVA, MTF cutoff, OSI, SR, optical interference and patients' satisfaction among subgroups. The differences in decentration between groups A and B were not statistically significant. In group A2, the total higher order aberrations (tHOAs) at pupil sizes of 3 mm (P = 0.046), 5 mm (P = 0.014), spherical aberrations at pupil sizes of 3 mm (P = 0.011), 4 mm (P = 0.014), 5 mm (P = 0.000), secondary astigmatism at pupil sizes of 3 mm (P = 0.002), 4 mm (P = 0.005) were higher than in group B2. Compared to group A1, group A2 had higher spherical aberrations at pupil sizes of 4 mm (P = 0.042), 5 mm (P = 0.001), 6 mm (P = 0.038), secondary astigmatism at pupil sizes of 3 mm (P = 0.013), 4 mm (P = 0.005), 6 mm (P = 0.013). Group B2 has higher coma and secondary astigmatism than group B1 at 6-mm pupil (P = 0.014, P = 0.045). Significant positive correlations were found between spherical aberrations and the decentration of group A1 and A2 at 6-mm pupils.

CONCLUSION

The decentration above 0.3 mm negatively affected visual quality due to increased tHOAs, spherical aberrations, coma and secondary astigmatism aberrations, the influence become larger with increasing pupil diameter. And toric IOLs are more affected by decentration than monofocal IOLs.

Refractive outcome and lens power calculation after intrascleral intraocular lens fixation: a comparison of three-piece and one-piece intrascleral fixation technique

PURPOSE

To evaluate the refractive prediction error of common intraocular lens (IOL) power calculation formulae in patients who underwent intrascleral IOL fixation using two different techniques.

METHODS

This is a prospective, randomized, longitudinal, single-site, single-surgeon study. Patients who underwent intrascleral IOL implantation using the Yamane or the Carlevale technique were followed up for a period of six months postoperatively. Refraction was measured using the best-corrected visual acuity at 4 m (EDTRS chart). Lens decentration, tilt and effective lens position (ELP) were assessed using an anterior segment optical coherence tomography (AS-OCT). The prediction error (PE) and the absolute error (AE) were evaluated for the SRK/T, Hollayday1 and Hoffer Q formula. Subsequently, correlations between the PE and axial length, keratometry, white to white and ELP were assessed.

RESULTS

In total, 53 eyes of 53 patients were included in the study. Twenty-four eyes of 24 patients were in the Yamane group (YG) and 29 eyes of 29 patients were in the Carlevale group (CG). In the YG, the Holladay 1 and Hoffer Q formulae resulted in a hyperopic PE (0.02 ± 0.56 D, and 0.13 ± 0.64 D, respectively) while in the SRK/T formula the PE was slightly myopic (- 0.16 ± 0.56 D). In the CG, SRK/T and Holladay 1 formulae led to a myopic PE (- 0.1 ± 0.80 D and - 0.04 ± 0.74 D, respectively), Hoffer Q to a hyperopic PE (0.04 ± 0.75 D). There was no difference between the PE of the same formulae across both groups (P > 0.05). In both groups the AE differed significantly from zero in each evaluated formula. The AE error was within ± 0.50 D in 45%-71% and was within ± 1.00 D in 72%-92% of eyes depending on the formula and surgical method used. No significant differences were found between formulae within and across groups (P > 0.05). Intraocular lens tilt was lower in the CG (6.45 ± 2.03°) compared to the YG (7.67 ± 3.70°) (P < 0.001). Lens decentration was higher in the YG (0.57 ± 0.37 mm) than in the CG (0.38 ± 0.21 mm), though the difference was not statistically significant (P = 0.9996).

CONCLUSIONS

Refractive predictability was similar in both groups. IOL tilt was better in the CG, however this did not influence the refractive predictability. Though not significant, Holladay 1 formula seemed to be more probable than the SRK/T and Hoffer Q formulae. However, significant outliers were observed in all three different formulae and therefore remain a challenging task in secondary fixated IOLs.

Changes in Corneal High Order Aberrations and Anterior Chamber Parameters Following Scleral Fixated Intraocular Lens Implantation

BACKGROUND

To evaluate the change in corneal high order aberrations (HOAs) and anterior chamber parameters following scleral fixation in aphakic patients using the Scheimpflug camera system.

METHODS

This retrospective study included patients who were aphakic after phacoemulsification surgery and underwent scleral-fixed intraocular lens (SF-IOL) implantation with Z suture technique between 2010 and 2022. Preoperative and postoperative best corrected visual acuity (BCVA), anterior segment parameters and corneal aberrations were evaluated with a combined Scheimpflug-Placido disc corneal topography device (Sirius Costruzione Strumenti Oftalmici, Florence, Italy). The following values were recorded: Simulated keratometry (SimK), flat meridian (K1), steep meridian (K2), iridocorneal angle (ICA), temporal anterior chamber angle (T-ACA), nasal anterior chamber angle (N-ACA), horizontal anterior chamber diameter (HACD), anterior chamber volume (ACV), corneal volume (CV), total Root Mean Square (RMS), high order aberrations (HOAs), spherical aberration, coma, trefoil, quadrifoil, and secondary astigmatism.

RESULTS

The study included 31 eyes of 31 patients (mean age: 63.00±19.41 years, 17 males/14 females). Postoperative BCVA was better than preoperative BCVA (p=0.012). Postoperatively, there was a statistically significant increase in ACV and CV values and a statistically significant decrease in K2 (p=0.009, p=0.032, p=0.015). Preoperative T-ACA and preoperative and postoperative ACV were negatively correlated with postoperative intraocular pressure (r=-0.427 p=0.033, r=-0.406 p=0.032 and r=-0.561 p=0.001). There were statistically significant postoperative increases in corneal RMS, trefoil and HOAs for 3 mm pupil diameter (p=0.0177, p=0.001, p=0.031) and in corneal RMS, trefoil and quadrifoil aberrations for 6 mm pupil diameter (p=0.033, p=0.001, p=0.001).

CONCLUSIONS

In conclusion, SF-IOL implantation with Z-suture technique used for visual rehabilitation of aphakic patients may affect visual quality by increasing corneal HOAs while improving visual acuity.

A comparative study of transscleral sutured intraocular lens fixation and sutureless flanged intraocular lens fixation

BACKGROUND

To compare the intraocular lens (IOL) tilt and decentration and visual outcomes of transscleral sutured IOL fixation and sutureless flanged IOL fixation. To investigate the influence of IOL tilt and decentration on internal higher-order aberrations (HOAs) in these two techniques.

METHODS

Patients who received transscleral sutured or sutureless flanged IOL fixation procedures were included in this prospective, non-randomized, comparative study. Corrected distance visual acuity (CDVA) was measured at baseline and at every postoperative visit for 12 months. IOL tilt and decentration were measured using a second-generation anterior segment optical coherence tomography (Casia2) and internal HOAs were measured using iTrace Visual Function Analyzer at 3 months postoperatively.

RESULTS

The study included 27 eyes from the transscleral sutured IOL fixation group and 26 eyes from the sutureless flanged IOL fixation group. There was no significant difference in CDVA between the two groups at all time points. The two groups did not differ in refractive difference from the predicted value, corneal endothelial cell loss, IOL tilt, IOL decentration, internal astigmatism or internal HOAs. Vertical IOL decentration significantly correlated with total internal optical aberration (r = 0.288, P = 0.036), total internal HOA (r = 0.440, P = 0.001), internal coma (r = 0.348, P = 0.001), vertical internal coma (r = 0.388, P = 0.004), average height of modulation transfer function (r = - 0.364, P = 0.007) and Strehl ratio (r = - 0.297, P = 0.031). Horizontal IOL decentration significantly correlated with horizontal internal coma (r = 0.312, P = 0.023).

CONCLUSIONS

Transscleral sutured IOL fixation and sutureless flanged IOL fixation had similar IOL positions and visual outcomes. IOL decentrations correlated with internal HOAs and thus should be avoided.

Effects of tilt and decentration of Visian Implantable Collamer Lens (ICL V4c) on visual quality: an observational study

Background

The central hole of the Visian Implantable Collamer Lens (ICL V4c) provides a reference to observe its tilt or decentration. This study aimed to investigate the tilt and decentration effects of ICL V4c on visual quality after implantation.

Methods

A total of 135 eyes from 69 patients who underwent ICL V4c implantation were included in this study. Evaluation of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and aberrations were performed 6-months postoperatively. The anterior segment parameters were collected using CASIA2 anterior segment-optical coherence tomography, tilt and decentration of ICL V4c were analyzed using MATLAB software. All patients received questionnaires to investigate the visual quality postoperatively.

Results

The safety and effectiveness were 1.18 ± 0.17 and 1.11 ± 0.18, respectively. No significant changes were observed regarding higher-order and spherical aberrations after the operation; however, coma and trefoil significantly increased compared to preoperative values. The average total decentration and tilt was 0.21 ± 0.12 mm and 2.54 ± 1.00°, respectively. Horizontal, vertical, and total values of tilt and decentration were not significantly associated with postoperative CDVA, UDVA, and aberrations. The most common visual symptom was halo, and 97.04% of patients had a satisfaction score ≥ 8. The total or horizontal tilt was significantly positively correlated with the frequency, severity, and bothersome scores from the questionnaires.

Conclusions

ICL V4c implantation can obtain high visual quality and patient satisfaction. Although the degree of tilt and decentration after ICL V4c implantation was small, a positive effect on subjective visual quality was observed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02499-4.

A Comparison of Visual Quality and Contrast Sensitivity between Patients with Scleral-Fixated and In-Bag Intraocular Lenses

Purpose: To analyze visual quality and contrast sensitivity in patients after intraocular lens (IOL) implantation with sutured scleral fixation. Setting: Chang Gung Memorial Hospital, Taoyuan, Taiwan. Design: Retrospective observational study. Methods: Data on the refractive outcome, visual acuity, and subjective visual symptoms in patients with scleral-fixated or in-bag IOL implantation were collected from September 2019 to March 2020. We also investigated patients’ postoperative higher-order aberrations (HOAs) and dysphotopsia using a wavefront aberrometer and glaretester, respectively. The following values were compared: corrected distance visual acuity, spherical equivalent, root mean square values for aberrations, and contrast sensitivity. Results: A total of 23 eyes implanted with scleral-fixated IOL and 74 eyes with in-bag IOL were studied. The mean postoperative spherical equivalent and logarithm of the minimum angle of resolution after scleral fixation were −1.09 ± 3.32 D and 0.20 ± 0.17, respectively. The ocular HOAs were higher in the scleral-fixation group than in the in-bag group (p = 0.001). Contrast sensitivity was negatively associated with age, and it was similar between the two groups after controlling for the age effect. Conclusions: Ocular HOAs and refractive errors were higher in the scleral-fixation group than in the in-bag group. However, no significant difference was noted in contrast sensitivity between advanced scleral fixation and in-bag IOL implantation.

Intrascleral Intraocular Lens Fixation Preserving the Lens Capsule in Cases of Cataract with Insufficient Zonular Support

Purpose

To report our modified simple technique for optic capture and the clinical results of intrascleral IOL fixation preserving the lens capsule, without vitrectomy, in cases of cataract with insufficient zonular support to stabilize the intraocular lens (IOL).

Patients and Methods

In 37 eyes of 25 patients with phacodonesis and two or more risk factors for progressive zonular insufficiency, we inserted a CTR to support the capsule and zonules during cataract surgery and IOL fixation; an optic was inserted into the lens capsule, and a haptic was fixed in the scleral tunnel without vitrectomy. In all cases, anterior or total vitrectomy was not needed.

Results

The postoperative mean (± standard deviation) tilt and decentration of the implanted IOL did not change from 6 to 12 months (6.77 ± 3.15° to 6.33 ± 3.38° and 0.60 ± 0.30 to 0.61 ± 0.35 mm, respectively). We encountered no late IOL dislocation and no retinal complications, including retinal breaks or cystoid macular oedema, postoperatively (follow-up = 21.1 ± 5.2 months).

Conclusion

Our modified techniques preclude the need for vitrectomy. If the lens capsule can be preserved using a CTR, our modified technique can be used to stabilize IOL.

Influence of Overhanging Bleb on Corneal Higher-Order Aberrations after Trabeculectomy

Recent advances in ocular aberrometry have revealed that ocular surgery increases ocular and corneal higher-order aberrations. This retrospective single-center study aimed to examine the effects of the overhanging bleb on corneal higher-order aberrations using a wavefront analyzer. We included 61 eyes from 50 patients with overhanging bleb after trabeculectomy with a fornix-based conjunctival flap using mitomycin C (overhanging bleb group) and 65 eyes from 54 glaucoma patients with no history of glaucoma surgery (control group). Corneal higher-order aberrations (total higher-order aberrations, coma aberrations, coma-like aberrations, spherical aberrations, and spherical-like aberrations) on a 4 mm pupil diameter were measured using the TOPCON KR-1W wavefront analyzer. Corneal coma aberrations were higher in the overhanging bleb group than in the control group (0.16 ± 0.13 μm and 0.10 ± 0.05 μm, respectively; p = 0.042). Corneal coma-like aberrations were also higher in the overhanging bleb group than in the control group (0.31 ± 0.32 μm and 0.16 ± 0.09 μm, respectively; p = 0.022). With an increasing ratio of cornea covered by the bleb to the entire cornea, all corneal higher-order aberrations increased except for corneal coma-like aberrations. Overhanging bleb after trabeculectomy with a fornix-based conjunctival flap using mitomycin C and its size influenced corneal higher-order aberrations.

Simulations of Decentration and Tilt of a Supplementary Sulcus-Fixated Intraocular Lens in a Polypseudophakic Combination Using Ray-Tracing Software

This study aimed to assess image quality after the tilt and decentration of supplementary intraocular lenses (IOLs) in a two-lens configuration. One was designed for sulcus fixation with a nominal power range of 1D–10D and was combined with a capsular fixation 20D IOL. The optical performance of a ray-tracing model was tested under IOL misalignment through the area under the modulation transfer function (MTFa) and wave aberrations. Tilting by 10° resulted in a 4% reduction of the MTFa for a 10D IOL as compared to 9% for the 20D lens. The two models demonstrated good tolerance to a 1 mm decentration; as for the 10D sulcus-fixated lens, the MTFa loss was 2%, and 4% for the capsular fixation lens. Coma and astigmatism increased three- and four-fold, respectively, after a 10° tilt compared to the aberration level induced by the 1 mm decentration. Both analyses showed a trend towards a lower MTF impact and fewer optical errors with decreasing nominal power. In conclusion, when misaligned, low-power sulcus-fixated IOLs might retain their good optical quality. An extreme tilt of 10° has a more detrimental effect on the IOL performance than a 1 mm decentration. The proper alignment of a high-power capsular fixation lens is important in achieving a desirable postoperative outcome.

In vivo evaluation of a 1-piece foldable sutureless intrascleral fixation intraocular lens using ultrasound biomicroscopy and anterior segment OCT

PURPOSE

To evaluate the optic plate and haptics of a specially designed sutureless intrascleral-fixated intraocular lens (IOL) using ultrasound biomicroscopy and anterior segment optical coherence tomography (AS-OCT).

SETTING

Department of Ophthalmology, San Marino Hospital, Republic of San Marino.

DESIGN

Retrospective observational case series.

METHODS

Eyes that underwent intrascleral fixation with IOL implantation (Carlevale) were included. Preoperative and postoperative refractive outcomes were reported. Optic plate tilt and haptics position were assessed with ultrasound biomicroscopy, whereas intrascleral plug depth and conformation were evaluated with AS-OCT.

RESULTS

The study comprised 10 aphakic eyes. Postoperative visual acuity improved in all patients. At postoperative month 3, 3 eyes (30%) had a vertical tilt of more than 100 μm, whereas no horizontal tilt was observed in any patient. The mean vertical intraocular tilt was 0.19 ± 0.22 mm. Of 20 haptics, 13 (65%) passed through the ciliary sulcus, 4 (20%) posterior to the ciliary body, and 3 (15%) through the ciliary body. AS-OCT scans showed a mean intrascleral plug depth of 247.20 ± 62.82 μm in the nasal sector and 265.50 ± 30.11 μm in the temporal sector, with adequate integration of the T-shaped plugs in the scleral tissue.

CONCLUSIONS

This secondary IOL showed good intraocular stability and safe haptics fixation, making it suitable for the intrascleral fixation technique. The specific foldable design results in a low predisposition to optic plate tilt and haptic torsion. In long eyes, the sulcus-to-sulcus distance should be carefully evaluated preoperatively because the flexible structure of the IOL could be subjected to excessive stretching.

Prospective comparison of apex-centered vs standard pupil-centered femtosecond laser-assisted capsulotomy in cataract surgery

PURPOSE

To compare the lens tilt after apex-centered capsulotomy with standard pupil-centered capsulotomy.

SETTING

Clinical practice.

DESIGN

Prospective, randomized, investigator-masked trial.

METHODS

This prospective, randomized, investigator masked study included 40 patients with age-related cataract scheduled for femtosecond laser-assisted cataract surgery (FLACS) in both eyes. The main outcome was the tilt of the intraocular lens (IOL), measured with the IOLMaster 700.

RESULTS

The study enrolled 80 eyes of 40 patients. The mean distance from the center of the apex-centered capsulotomy to the pupil-centered capsulotomy was 175.8 ± 97.2 μm. The amount of IOL tilt was not significantly reduced with the new technique (P > .05). Tilt orientation was more stable in eyes treated with apex-centered capsulotomy.

CONCLUSIONS

Centration of the capsulotomy on the lens apex in FLACS does not influence the amount of IOL tilt but the orientation stability. The clinical importance of this finding has to be further elucidated.

Characteristics and Risk Factors of Intraocular Lens Tilt and Decentration of Phacoemulsification After Pars Plana Vitrectomy

Purpose

The purpose of this study was to investigate the characteristics and risk factors of intraocular lens (IOL) tilt and decentration of phacoemulsification after pars plana vitrectomy (PPV) using swept-source optical coherence tomography (SS-OCT).

Methods

One hundred four eyes with prior PPV and 104 eyes without PPV undergoing uneventful cataract surgery were enrolled in this study. IOL tilt and decentration were measured by SS-OCT (CASIA2) 3 months postoperatively.

Results

The mean IOL tilt and decentration were greater in the PPV group (5.36 ± 2.50 degrees and 0.27 ± 0.17 mm, respectively) than in the non-PPV group (4.54 ± 1.46 degrees, P = 0.005; 0.19 ± 0.12 mm, P < 0.001, respectively). Multiple logistic regression showed that silicone oil (SO) tamponade (odds ratio [OR] = 5.659, P = 0.021) and hydrophilic IOL (OR = 5.309, P = 0.022) were associated with IOL tilt over 7 degrees, and diabetes mellitus (DM; OR = 5.544, P = 0.033) was associated with IOL decentration over 0.4 mm. Duration of SO tamponade was positively correlated with IOL tilt (P = 0.014) and decentration (P < 0.001). The internal total higher-order aberration, coma, trefoil, and secondary astigmatism in the PPV group were higher than in the non-PPV group, and positively correlated with IOL tilt (P < 0.05).

Conclusions

Patients with prior vitrectomy had greater IOL tilt and decentration than the non-PPV group. Longer duration of SO tamponade, hydrophilic IOL, as well as DM were the risk factors of greater IOL tilt and decentration in patients with prior PPV.

Translational Relevance

Optically sophisticated designed IOLs should be used cautiously in vitrectomized eyes.

Stability of Various Types of Aspheric Intraocular Lenses After Implantation: A One-Year Retrospective Study

Objective

The aim of the present study was to evaluate the stability of four different types of aspheric intraocular lenses (IOLs) after implantation.

Methods

This retrospective study included 124 eyes implanted with four different types of aspheric IOLs including a one-piece four-loop fixed hydrophilic acrylic IOL, a one-piece flat fixed acrylic IOL, a one-piece two-loop fixed acrylic IOL, and a three-piece two-loop fixed silicone IOL. IOL decentration, tilt, and ocular coma-like aberration (coma) at one-week, one-month, three-month, and one-year time points were evaluated postoperatively.

Results

IOL decentration, tilt, and coma in the AO, 36A, IQ, and KS-AiN implantation groups were statistically significantly different one week and one year postoperatively (p < 0.01). There were significant differences between each of the pairs of groups (p < 0.01), except for coma between the AO and 36A implantation groups one week postoperatively (p > 0.05). When comparing the different time points (ie, one week, one month, three months, and one year postoperatively), IOL decentration, tilt, and coma were significantly different in each group (p < 0.05). IOL decentration, tilt, and coma in each group increased over the period from one week to one year postoperatively. A positive linear correlation was observed between IOL decentration or tilt and coma one year postoperatively (p < 0.01).

Conclusion

One-piece multi-point fixed acrylic IOLs demonstrate better stability when compared with three-piece two-point fixed silicone IOLs. IOL decentration, tilt, and coma increase gradually over time. Ocular coma-like aberrations are influenced by the stability of IOLs.

Comparison of Clinical Outcomes Between Intracapsular Implantation and Intrascleral Fixation Using the Same Model of Intraocular Lens

Purpose

To compare the clinical outcomes of intrascleral intraocular lens (IOL) fixation surgery with those of intracapsular IOL implantation in conventional cataract surgery.

Patients and Methods

Twenty-one eyes of 21 consecutive patients who underwent intrascleral IOL fixation (SF group) and 21 eyes of 21 patients who underwent IOL intracapsular implantation during cataract surgery (IN group) were retrospectively enrolled. For both groups, the same model of IOL was used in all cases. For all cases in the SF group, Yamane’s double-needle technique was performed.

Results

The mean corrected visual acuity (logMAR) after surgery was significantly better in the IN than in the SF group (−0.063 ± 0.12 vs 0.05 ± 0.14; p = 0.0083). The mean anterior chamber depth after surgery was significantly smaller in the IN than in the SF group (4.65 ± 0.23 mm vs 4.98 ± 0.61 mm; p = 0.0231). The amounts of tilt and decentration were also significantly smaller in the IN group (5.21°± 1.47° and 0.22 ± 0.13 mm, respectively, vs 8.8° ± 3.9° and 0.52 ± 0.35 mm, respectively; p = 0.0003 and p = 0.0007). The mean absolute refractive prediction error was significantly smaller in the IN than in the SF group (0.22 ± 0.17 D vs 0.86 ± 0.59 D; p = 0.0002).

Conclusion

The intrascleral IOL fixation surgery proved to be highly effective. However, its clinical outcomes were slightly inferior to those of IOL intracapsular implantation, and further improvement of this surgical technique may be needed.

Influence of sclerotomy size on intraocular lens tilt after intrascleral intraocular lens fixation

PURPOSE

To determine whether differences in sclerotomy size during intrascleral intraocular lens (IOL) fixation influence IOL tilt and visual acuity after surgery.

SETTING

University of Fukui Hospital and Japanese Red Cross Fukui Hospital, Japan.

DESIGN

Retrospective case series.

METHODS

The study reviewed the records of patients who had intrascleral IOL fixation with transconjunctival 25-gauge pars plana vitrectomy and a follow-up longer than 6 months. The preoperative and postoperative visual outcomes, degree of IOL tilt, and intraoperative and postoperative complications were statistically compared between the sclerotomy groups.

RESULTS

The study included 65 eyes (60 patients). Postoperatively, the maximum degree of IOL tilt was significantly smaller in the 24-gauge sclerotomy group than in the 30-gauge sclerotomy group (P = .003). The degree of IOL tilt was significantly correlated with the amount of postoperative IOL astigmatism (total astigmatism - corneal astigmatism) (P = .0001, R² = 0.23). There were no statistically significant differences in the preoperative or postoperative corrected distance visual acuity (CDVA) or the complication rate between the sclerotomy groups.

CONCLUSION

A smaller sclerotomy for intrascleral IOL fixation was associated with greater IOL tilt and IOL astigmatism after surgery; however, this did not clinically or significantly affect the postoperative CDVA.

Optical coherence tomography-based deep learning algorithm for quantification of the location of the intraocular lens

Background

Cataract surgery has been recently developed from sight rehabilitating surgery to accurate refractive surgery. The precise concentration of intraocular lens (IOL) is crucial for postoperative high visual quanlity. The three-dimentional (3D) images of ocular anterior segment captured by optial coherence tomography (OCT) make it possible to evaluate the IOL position in 3D space, which provide insights into factors relavant to the visual quanlity and better design of new functional IOL. The deep learning algorithm potentially quantify the IOL position in an objective and efficient way.

Methods

The region-based fully convolutional network (R-FCN) was used to recogonize and delineate the IOL configuration in 3D OCT images. Scleral spur was identified automatically. Then the tilt angle of the IOL relative to the scleral spur plane along with its decentration with respect to the pupil were calculated. Repeatability and reliability of the method was evaluated by the intraclass correlation coefficient.

Results

After improvement, the R-FCN network recognition efficiency of IOL configuration reached 0.910. The ICC of reliability and repeatability of the method is 0.867 and 0.901. The average tilt angle of the IOL relative to scleral spur is located in 1.65±1.00 degrees. The offsets dx and dy occurring in the early X and Y directions of the IOL are 0.29±0.22 and 0.33±0.24 mm, respectively. The IOL offset distance is 0.44±0.33 mm.

Conclusions

We proposed a practical method to quantify the IOL postion in 3D space based on OCT images and assisted by an algorithm.

Impact of vitrectomy and air tamponade on aspheric intraocular lens tilt and decentration and ocular higher-order aberrations: phacovitrectomy versus cataract surgery

PURPOSE

To evaluate the impact of vitrectomy and air tamponade on aspheric intraocular lens (IOL) tilt and decentration and postoperative internal higher-order aberrations (HOAs) in combined cataract surgery and vitrectomy (phacovitrectomy).

STUDY DESIGN

Prospective comparative observational study.

METHODS

Forty-five eyes that underwent phacovitrectomy using aspheric IOLs and 18 eyes that only underwent cataract surgery also using aspheric IOLs were prospectively evaluated. The subjects were divided into three groups: phacovitrectomy without fluid-air exchange (F/Ax) or with F/Ax and cataract surgery alone (Groups A, B, and C, respectively) Surgery-induced changes in lens tilt and decentration and internal HOAs were compared between each pair of groups. Subgroup analysis was conducted for cases with largely tilted (> 7°) or decentered (> 0.40 mm) IOLs 1 month postoperatively.

RESULTS

Surgery-induced changes in lens tilt in Group B were significantly more pronounced than those in Group C at 1 week, 1 month, and 3 months postoperatively (P = 0.007, 0.009, and 0.043, respectively), while there was no significant difference in surgery-induced changes in lens decentration among the groups. IOLs in Group B were tilted and decentered toward the inferonasal direction. In contrast, there was no significant difference in internal HOAs among the groups at any postoperative visit. Only Group B included cases with largely decentered IOLs, and the internal total HOAs in these cases were significantly larger than those in the others (P = 0.015).

CONCLUSION

Although largely decentered IOLs were occasionally found in Group B, aspheric IOLs could be effectively used in phacovitrectomy.

Effects of capsular tension ring on surgical outcomes of premium intraocular lens in patients with suspected zonular weakness

Purpose

To assess the influence of capsular tension ring (CTR) on surgical outcomes of toric and multifocal intraocular lenses (IOLs) in eyes at high risk of zonular instability.

Methods

Fifty-five eyes of 43 patients who had undergone phacoemulsification and IOL implantation were included in the analysis. They had some risk of zonular weakness, such as pseudoexfoliation, shallow anterior chamber, high myopia, and phacodonesis, or were judged to have unstable zonules during surgery. Toric IOL was implanted in 9 eyes with CTR and 22 eyes without CTR, while multifocal IOL was used in 9 eyes with CTR and 15 eyes without CTR. Manifest refraction, refractive astigmatism, visual acuity, and degree of IOL decentration and tilt measured using swept-source anterior segment optical coherence tomography were analyzed. Axis misalignment of toric IOLs were also evaluated.

Results

In toric IOLs, co-implantation of CTR significantly reduced decentration and axis misalignment of IOL, resulting in better uncorrected and corrected visual acuity after surgery. In multifocal IOLs, combined use of CTR significantly prevented IOL tilt, leading to better intermediate visual acuity. Spherical equivalent and residual astigmatism were not significantly affected by the use of CTR.

Conclusions

CTR reduces decentration and axis misalignment of toric IOL and tilt of multifocal IOL, achieving improvement of postoperative visual function in eyes with suspected zonular instability.

Transscleral sutureless intraocular lens versus retropupillary iris-claw lens fixation for paediatric aphakia without capsular support: a randomized study

PURPOSE

To compare results of sutureless transscleral intraocular lens (IOL) fixation to retropupillary iris-claw lens implantation in cases of paediatric aphakia without capsular support.

METHODS

Thirty eyes of children with insufficient capsular support for IOL implantation were randomized to undergo sutureless transscleral IOL fixation or iris-claw lens fixation. The primary outcome was best-corrected visual acuity (BCVA). Secondary outcomes included operative time, astigmatism, central corneal thickness, endothelial cell count (ECC), IOL decentration and tilt, central foveal thickness and complications.

RESULTS

There was a significant improvement in BCVA at all follow-up visits, with no significant difference between both groups. 53.3% in the transscleral-fixated IOL group and 80% in the iris-claw IOL group had a final BCVA ≥0.3. The operative time was significantly shorter in the iris-claw IOL group (p = 0.001). IOL decentration and tilt were higher in the transscleral-fixated IOL group, but the difference was not significant. The ECC was reduced by 14.6% in the transscleral-fixated IOL group and 11% in the iris-claw group at 6 months, with no significant difference between both groups (p = 0.5). In the transscleral-fixated IOL group, two eyes developed ocular hypertension and two eyes had IOL decentration, while in the iris-claw IOL group, 1 eye developed glaucoma, three eyes had haptic disenclavation, and one eye had retinal detachment.

CONCLUSION

Both techniques yielded a comparable visual outcome. Retropupillary iris-claw lens fixation is a shorter procedure and technically easier than sutureless transscleral fixation, but the risk of disenclavation should be considered especially in younger age groups. Scleral fixation is the only option in case of severe iris damage, but may be associated with more endothelial cell loss.

Multifocal Intraocular Lenses Implantation in Presbyopia Correction. Literature Review

Reduced dependence on glasses is an increasingly common expectation among those who want to take advantage of new surgical opportunities, especially for patients who lead an active lifestyle. Currently, due to the increase in the duration of active life in people over 40, there is a need for effective correction of presbyopia. Multifocal intraocular lenses are increasingly used in the treatment of presbyopia. After implantation of multifocal intraocular lenses most patients have no need for spectacle or contact vision. However, complications can affect the patient’s quality of life and level of satisfaction. The most common complications of multifocal correction are blurred vision and the presence of optical phenomena (“halo” and “glare”), associated with residual ametropia, clouding of the posterior capsule, large pupil size, anomalies of the wave front, dry eye and lens decentration. The main reasons for this are the failure to attempt to neuroadapt a patient, the dislocation of the lens, the residual refractive error and the clouding of the lens. The review presents the main features of various models of multifocal intraocular lenses, their implantation techniques, associated complications and methods for their correction. The development of multifocal correction of presbyopia and ametropia seems to be a promising direction in ophthalmic surgery.

Ocular adhesives: Design, chemistry, crosslinking mechanisms, and applications

Closure of ocular wounds after an accident or surgery is typically performed by suturing, which is associated with numerous potential complications, including suture breakage, inflammation, secondary neovascularization, erosion to the surface and secondary infection, and astigmatism; for example, more than half of post-corneal transplant infections are due to suture related complications. Tissue adhesives provide promising substitutes for sutures in ophthalmic surgery. Ocular adhesives are not only intended to address the shortcomings of sutures, but also designed to be easy to use, and can potentially minimize post-operative complications. Herein, recent progress in the design, synthesis, and application of ocular adhesives, along with their advantages, limitations, and potential are discussed. This review covers two main classes of ocular adhesives: (1) synthetic adhesives based on cyanoacrylates, polyethylene glycol (PEG), and other synthetic polymers, and (2) adhesives based on naturally derived polymers, such as proteins and polysaccharides. In addition, different technologies to cover and protect ocular wounds such as contact bandage lenses, contact lenses coupled with novel technologies, and decellularized corneas are discussed. Continued advances in this area can help improve both patient satisfaction and clinical outcomes.

Effect of trabeculectomy on ocular higher-order aberrations in patients with open angle glaucoma

OBJECTIVE:

The aim of this study was to evaluate the effect of trabeculectomy on ocular higher-order aberrations following surgery in a group of patients with open angle glaucoma.

METHODS:

In this prospective study, patients with primary open angle glaucoma underwent wavefront aberrometry before trabeculectomy with mitomycin-C. Coma-like, spherical-like, and total ocular higher-order aberrations were measured as root mean square values. The measurements were repeated 1 month and 3 months after the procedure.

RESULTS:

A total of 20 eyes from 20 patients were examined. There was a significant decrease in intraocular pressure following surgery at 1 month and 3 months postoperatively. However, there was no statistically significant change in the spherical equivalent of the eyes. One month after surgery, a significant change in coma-like, spherical-like, and total higher-order aberrations of the eyes was observed. However, the repeated measurements performed 3 months after procedure revealed no significant difference compared to the baseline values.

CONCLUSION:

Ocular higher-order aberrations increased 1 month following trabeculectomy surgery. However, this effect seems to be transient, as the values returned to the preoperative measurement 3 months after the procedure.

Keratoprosthesis Decentration and Tilt Results in Degradation in Image Quality

PURPOSE

To study the effect of decentration and tilt of the type I Boston keratoprosthesis (KPro) on image quality in both aphakic and pseudophakic eyes.

METHODS

An optical ray-tracing program was used to simulate the image projected onto the retina in an eye with a perfectly centered KPro, and in eyes with varying degrees of KPro decentration and tilt. Decentration was modeled along a typical white-to-white distance of 12.0 mm, and the corresponding tilt was calculated assuming a radius of curvature of 8.0 mm, the radius of curvature of the backplate of the KPro. Both aphakic and pseudophakic eyes were simulated, and the corresponding modulation transfer function curves, point spread functions, and astigmatism were analyzed.

RESULTS

The perfectly centered KPro produced a high-quality image with no induced astigmatism. Increasing decentration beyond approximately 0.5 mm resulted in poorer image quality with a more pronounced effect in the presence of an intraocular lens. Using models of the normal eye as a threshold, image degradation due to decentration becomes clinically significant at approximately 1.4 mm and 0.9 mm for the aphakic and pseudophakic cases, respectively. Astigmatism introduced by decentration is approximately 0.25 D cylinders at those thresholds.

CONCLUSIONS

Decentration of up to 0.5 mm had no significant impact on image quality and an attempt at good intraoperative centration of the KPro within this range is important. Conversely, decentration of 0.9 mm or more during surgical implantation can result in significant degradation in retinal image quality including astigmatism. The effect is greater in the pseudophakic eye.

Comparison of long-term decentration and tilt in two types of multifocal intraocular lenses with OPD-Scan III aberrometer

PURPOSE

To compare the long-term decentration and tilt in two multifocal intraocular lenses (MfIOLs) with an OPD-Scan III aberrometer.

METHODS

Eighty cataract patients who underwent uneventful MfIOL implantation (42 with AcrySof® IQ ReSTOR® SN6AD1 and 38 with AMO Tecnis® ZMB00) were enrolled. At 1 year after surgery, a postoperative visual acuity evaluation included the measurement of uncorrected distance visual acuity, corrected distance visual acuity, distance-corrected near visual acuity, and distance-corrected intermediate visual acuity. OPD-Scan III aberrometer was used to collect the decentration, tilt, and high-order aberration (HOA) data. Significance was tested with Student's t test, Mann-Whitney U test, paired t test, and χ² test RESULTS: The average intraocular tilt was lower in the SN6AD1 group than in the ZMB00 group, whereas the average decentration of the two groups did not differ significantly. The mean total ocular HOAs, ocular trefoil, total internal HOAs, and spherical aberrations were significantly lower in the SN6AD1 group than in the ZMB00 group. In both the SN6AD1 and ZMB00 groups, the intraocular tilt was directly proportional to the total ocular HOAs, coma, and spherical aberration. However, there was no significant correlation between decentration and any type of HOA in SN6AD1 group, whereas decentration correlated positively with total ocular HOAs, coma, and spherical aberration in ZMB00 group.

CONCLUSION

Both MfIOLs significantly improve the visual acuity of the patients. However, tilt was lower in the SN6AD1 group than in the ZMB00 group 1 year after surgery, which provide fewer HOAs and better visual quality.

Tilt, Decentration, and Internal Higher-Order Aberrations of Sutured Posterior-Chamber Intraocular Lenses in Patients with Open Globe Injuries

Purpose

To evaluate the tilt, decentration, and internal higher-order aberrations (HOAs) of sutured posterior-chamber intraocular lenses (IOLs) in patients with open globe injuries.

Methods

46 consecutive patients (47 eyes) who underwent transsclerally sutured IOL implantation were enrolled in this prospective cohort study. Nineteen eyes had a history of open globe injury. The tilt and decentration of the IOLs and the visual quality were measured 1 month after surgery.

Results

The horizontal tilt and decentration of the IOLs in the open-globe-injury group were significantly higher than those in the control group (both P < 0.05). In the open-globe-injury group, the horizontal decentration was significantly greater in the limbus-sclera-involved group (n = 11) than in the only-cornea-involved group (n = 8, P = 0.040). The internal coma, 3rd-order, and total HOA values at pupil sizes of 4 mm (P = 0.006) and 6 mm (P = 0.013) were significantly higher in the open-globe-injury group than in the controls. Consequently, the optical quality data for the modulation transfer function and the Strehl ratio (all P < 0.05) were significantly poorer in the open-globe-injury group.

Conclusions

Open globe injuries damage the structural integrity of the eyeball, resulting in more-misaligned sutured IOLs and poorer visual quality.

Interaction between Corneal and Internal Ocular Aberrations Induced by Orthokeratology and Its Influential Factors

Purpose

To investigate the interaction between corneal, internal, and total wavefront aberrations (WAs) and their influential factors during orthokeratology (OK) treatment in Chinese adolescents.

Methods

Thirty teenagers (n = 30 eyes) were enrolled in the study; spherical equivalent refraction (SE), corneal curvature radius (CCR), central corneal thickness (CCT), WAs, and the difference in limbal transverse diameter and OK lens diameter (ΔLLD) were detected before and after one-month OK treatment. Every component of WAs was measured simultaneously by iTrace aberrometer. The influential factors of OK-induced WAs were analyzed.

Results

SE and CCT decreased while CCR increased significantly (P < 0.01). Higher-order aberrations (HOAs), Spherical aberrations (SAs), and coma increased significantly (P < 0.01). Corneal horizontal coma (Z3¹-C) and corneal spherical aberrations (Z4⁰-C) increased (P < 0.01). The HOAs, coma, SAs, Z3¹-C, Z3¹-T, Z4⁰-C, and Z4⁰-T were positively correlated with SE and CCR (P < 0.01). Z3⁻¹-C showed negative correlations with (ΔLLD) and positive correlations with SE (P < 0.05).

Conclusions

The increase in OK-induced HOAs is mainly attributed to Z3¹ and Z4⁰ of cornea. Z3⁻¹ in the internal component showed a compensative effect on the corneal vertical coma. The degree of myopic correction and increase in CCR may be the essential influential factors of the increase in Z3¹ and Z4⁰. The appropriate size of the OK lens may be helpful to decrease OK-induced vertical coma.

Effects of optical diameter of intraocular lenses with intrascleral fixation on higher-order aberrations

Background

Intrascleral fixation of an intraocular lens (IOL) is used in eyes that lack capsular support. The aim of the study is to determine whether a larger optical diameter IOL will decrease the higher-order aberrations (HOAs) when the haptics are extended for intrascleral fixation than a smaller diameter IOL.

Methods

Three-piece acrylic IOLs with 6.0 mm optics (X-60, VA-60BBR) and 7.0 mm optics (X-70, VA-70 AD) were fixed at lengths of 13, 14, 15, 16, or 17 mm. A wavefront analyzer was used to measure the HOAs within the central 3.0 and 5.2 mm optic diameter.

Results

The astigmatic aberration within the central 5.2 mm was greater than that within the central 3.0 mm for all IOLs. The HOAs increased significantly with an extension of the IOLs with both optical diameters (P < 0.001). The coma aberration within the central 5.2 mm was greater than that within the central 3.0 mm but it did not increase with an extension of the haptics. The astigmatic aberration of the X-60 IOL was significantly greater than that of the X-70 only at an extension of 17 mm. The astigmatic aberration of the VA-70 AD was not significantly different from that of the VA-60BBR. The cylindrical power changed from 0.047 D in the X-60 to 0.118 D in the VA-70 AD when the IOLs were extended from 13 to 17 mm.

Conclusion

When three-piece IOLs are highly extended for intrascleral fixation, the astigmatic aberration increases significantly. However, IOLs with 7 mm optics do not have less astigmatic and coma aberrations than IOLs with 6 mm optics.

Sulcus Fixation of Foldable Intraocular Lenses Guided by Ultrasound Biomicroscopy

Background. To evaluate the clinical efficacy of suture fixation of foldable intraocular lens (IOL) in ciliary sulcus guided by ultrasound biomicroscopy (UBM). Methods. Thirty-five eyes of 32 cases needing suture fixation of foldable IOL in ciliary sulcus in our hospital were collected and divided into two groups: group A and group B. In group A, UBM was performed on 19 eyes of 17 cases before surgery to locate the projection position of ciliary sulcus in iris surface. In group B, the traditional sulcus fixation of IOL was performed on 16 eyes of 15 cases. The inserting position of needles, the haptics position of IOL and the IOL tilt, and decentration were observed by UBM examination 3 months after the surgery. Meanwhile, the vision and contrast sensitivity were analysed. Results. The differences in inserting position of the needle, the IOL tilt and decentration, the ratio of IOL haptics in sulcus, and uncorrected visual acuity were statistically significant (P < 0.05). The differences in best corrected visual acuity (BCVA) and contrast sensitivity were not statistically significant (P > 0.05). Conclusions. Sulcus fixation of foldable IOL aided by UBM can increase the accuracy of IOL haptics implanted into ciliary sulcus and reduce the IOL tilt and decentration.

Dynamic changes of optical aberrations during restoration of optical properties of hydrophobic acrylic intraocular lens ejected through cartridge

AIM

To evaluate the effect of temperature on the restoration of the optical properties of hydrophobic acrylic intraocular lenses (IOLs) after ejection through a cartridge into a temperature-controlled water chamber.

METHODS

Acrylic IOLs (SA60AT; iSert 251; W-60; X-70; and VA-70AD) were loaded into a cartridge with viscoelastic material and ejected into a water chamber at 24°C or 34°C. A wavefront analyser was used to measure the spherical and cylindrical powers, and the higher-order aberrations of the optics of the IOLs. The time to restore the cylindrical power to within 0.1 dioptres of the baseline power was determined.

RESULTS

Surface irregularities of the IOLs after ejection were detected in the dioptric power maps but not in the higher-order aberration maps. The cylindrical power and the astigmatic and coma aberrations recovered immediately at 34°C but were delayed at 24°C. The restoration time of all IOLs at 24°C was significantly longer than that at 34°C (p<0.05).

CONCLUSIONS

The dioptric power maps determined by the wavefront analyser can detect and follow the restoration of the optical properties of hydrophobic acrylic IOLs immediately after ejection. The restoration time was dependent on the temperature of the water chamber.

Multiple methods of surgical treatment combined with primary IOL implantation on traumatic lens subluxation/dislocation in patients with secondary glaucoma

AIM

To describe clinical findings and complications from cases of traumatic lens subluxation/dislocation in patients with secondary glaucoma, and discuss the multiple treating methods of operation combined with primary intraocular lens (IOL) implantation.

METHODS

Non-comparative retrospective observational case series.

PARTICIPANTS

30 cases (30 eyes) of lens subluxation/dislocation in patients with secondary glaucoma were investigated which accepted the surgical treatment by author in the Ophthalmology of Xi'an No.4 Hospital from 2007 to 2011. According to the different situations of lens subluxation/dislocation, various surgical procedures were performed such as crystalline lens phacoemulsification, crystalline lens phacoemulsification combined anterior vitrectomy, intracapsular cataract extraction combined anterior vitrectomy, lensectomy combined anterior vitrectomy though peripheral transparent cornea incision, pars plana lensectomy combined pars plana vitrectomy, and intravitreal cavity crystalline lens phacofragmentation combined pars plana vitrectomy. And whether to implement trabeculectomy depended on the different situations of secondary glaucoma. The posterior chamber intraocular lenses (PC-IOLs) were implanted in the capsular-bag or trassclerally sutured in the sulus decided by whether the capsular were present.

MAIN OUTCOME MEASURES

visual acuity, intraocular pressure, the situation of intraocular lens and complications after the operations.

RESULTS

The follow-up time was 11-36mo (21.4±7.13). Postoperative visual acuity of all eyes were improved; 28 cases maintained IOP below 21 mm Hg; 2 cases had slightly IOL subluxation, 4 cases had slightly tilted lens optical area; 1 case had postoperative choroidal detachment; 4 cases had postoperative corneal edema more than 1wk, but eventually recovered transparent; 2 cases had mild postoperative vitreous hemorrhage, and absorbed 4wk later. There was no postoperative retinal detachment, IOL dislocation, and endophthalmitis.

CONCLUSION

To take early treatment of traumatic lens subluxation/dislocation in patients with secondary glaucoma by individual surgical plan based on the different eye conditions would be safe and effective, which can effectively control the intraocular pressure and restore some vision.

Registration tolerance of a custom correction to maintain visual acuity

PURPOSE

To present a predictive model of the registration tolerance for wavefront-guided correction to maintain acuity within fixed limits and demonstrate the potential utility using two typical keratoconic eyes.

METHODS

Change in log visual Strehl was plotted as a function of translation error for a series of rotations of a wavefront-guided correction. Contour lines were added at Δlog visual Strehl levels predicted to induce one- and two-line losses of logMAR visual acuity. The model was validated by regressing measured acuity loss from subjects viewing acuity charts that were degraded by the residual wavefront error resulting from the movement of wavefront-guided correction against the model's predicted acuity.

RESULTS

The model's predicted change in acuity can be substituted for measured change in acuity (R² = 0.91) within measurement error (±0.1 logMAR). Translation and/or rotation of a wavefront-guided correction induced asymmetric optical tolerance to movement. Induced errors depended on the wavefront error being corrected, the wavefront-guided correction design, and the amount of registration error.

CONCLUSIONS

Change in log visual Strehl can be used to determine the registration tolerance necessary to keep the variation in acuity within user-defined limits. This tolerance is unique for each wavefront error and wavefront-guided correction design.

Anterior chamber angle evaluation with ultrasound biomicroscopy and optical coherence tomography in eyes implanted with a Crystalens

This study employs optical coherence tomography (OCT) and ultrasound biomicroscopy (UBM) imaging as well as optical aberrometry to examine correlations between the anterior chamber angle aperture and visual acuity for near vision as well as coma along the horizontal and vertical axes in eyes implanted with an accommodative intraocular lens (Crystalens). A retrospective comparative consecutive case series of 22 eyes of 11 patients (5 males) uneventfully implanted with a Crystalens. Eyes with signs of posterior capsular opacification were excluded. All eyes were examined with 40 MHz UBM (Ellex Eyecubed) and spectral-domain OCT (Zeiss Visante). The angle aperture along the horizontal and vertical meridians was recorded based on the software of the systems. The coma root mean square (RMS) scores for the horizontal and vertical meridians were also recorded with the iTrace aberrometer. The anterior chamber angle was significantly wider along the horizontal axis compared with the vertical axis by UBM (46.37° and 44.20°, respectively) and by OCT (46.79° and 43.58°, respectively) (p = 0.02 in both cases, paired-samples t test). The correlations between the logMAR-converted Jaeger near vision score and the horizontal or vertical angle apertures was not statistically significant. Horizontal coma RMS was significantly inversely correlated with the horizontal angle aperture (r = -0.45, p = 0.03 and r = -0.39, p = 0.04 by OCT and UBM, respectively). Measurement of the horizontal angle aperture by the modalities used may represent an anatomical and clinical predictor of the optical aberrations induced by the Crystalens.

Multifocal IOL Implant with or without Capsular Tension Ring: Study of Wavefront Error and Visual Performance

Purpose

To evaluate visual performance and wavefront error after multifocal intraocular lens (MIOL) implant with or without capsular tension ring (CTR).

Methods

Sixty eyes of 60 candidates for phacoemulsification and MIOL implantation were included in the study and were randomly divided into 2 groups. Thirty eyes (group 1) were implanted with the AcrySof ReSTOR® SN60D3 MIOL and Corneal® ACPI 11 CTR and 30 eyes (group 2) received the same MIOL with no CTR.

Results

Twenty days and at 360 days after surgery, the uncorrected and corrected distance visual acuity at high and low contrast were not significantly different between the 2 groups. The root mean square (RMS) of ocular and internal wavefront error was significantly different in the 2 groups early after surgery and did not modify significantly over the 1-year follow-up period. The RMS of total and internal high-order aberrations and ocular and internal trefoil and coma aberrations were significantly lower in group 1 compared to group 2 (p<0.05). Ocular, corneal, internal modulation transfer function at high and low spatial frequencies and ocular, corneal, internal Strehl ratio were not significantly different between the groups. The IOL decentration and tilt were higher in group 1 compared to group 2.

Conclusions

ReSTOR MIOL was effective in improving visual performance and provided a good quality of vision due to a significant reduction of high-order spherical aberration. The implant of CTR additionally reduced the ocular wavefront error related to a reduction of third-order aberration related to better IOL position.

IOL tilt and decentration estimation from 3 dimensional reconstruction of OCT image

Purpose

To evaluate intraocular lens (IOL) tilt and decentration by anterior segment optical coherence tomography (AS-OCT) using 3-dimensional (3D) reconstruction method.

Design

Prospective observational case series.

Participants

Thirty-nine patients (39 eyes) were included.

Methods

The IOL positions of all eyes were examined by AS-OCT. Images were obtained in 4 axes (0–180 degrees, 45–225 degrees, 90–270 degrees, and 135–315 degrees) using the quadrant-scan model. The cross-sectional images were analyzed with MATLAB software.

Main Outcome Measures

The angle (θ) between the reference pupillary plane and the IOL plane, the distances between the center points of the pupil circle and the IOL on the x-axis (dx) and y-axis (dy) and the spatial distance (ds) were calculated after 3D-reconstruction.

Results

The mean angle (θ) between the pupillary plane and the IOL plane was 2.94±0.99 degrees. The mean IOL decentration of dx and dy was 0.32±0.26 mm and 0.40±0.27 mm, respectively. The ds of the IOL decentration was 0.56±0.31 mm. There was no significant correlation between the ocular residual astigmatism (ORA) and the tilted angle or the decentration distance. There was a significant correlation between the ORA and total astigmatism (r = 0.742, P<0.001). There was no significant correlation between the postoperative best corrected visual acuity (BCVA) and the ORA (r = 0.156; P = 0.344), total astigmatism (r = 0.012; P = 0.942), tilted angle (θ; r = 0.172; P = 0.295) or decentration distance (dx: r = 0.191, P = 0.244; dy: r = 0.253, P = 0.121; ds: r = 0.298, P = 0.065).

Conclusions

AS-OCT can be used as an alternative for the analysis of IOL tilt and decentration using 3D-reconstruction.

Effect of trabeculectomy on ocular and corneal higher order aberrations

PURPOSE

To examine the effect of trabeculectomy on ocular and corneal higher order wavefront aberrations.

METHODS

Trabeculectomy with a limbal-based conjunctival flap was performed in 13 patients (13 eyes). Ocular and corneal higher order aberrations were measured using a wavefront analyzer before and after surgery. The higher order aberrations for a 4-mm pupil diameter were expanded into Zernike's polynomials. Coma aberration, spherical aberration, and total higher order aberrations were evaluated as root mean square values.

RESULTS

Mean intraocular pressure was significantly reduced from 15.5 ± 3.1 mmHg preoperatively to 7.5 ± 3.5 and 7.2 ± 4.4 mmHg at 1 and 3 months after surgery, respectively. The mean spherical equivalent refractive error was not changed by the surgery. Mean vector powers for surgically induced refractive changes at 1 and 3 months postoperatively were 1.29 ± 0.69 and 1.30 ± 0.89 diopters, respectively. Corneal coma-like, spherical-like, and total higher order aberrations were not significantly changed by surgery. Trabeculectomy significantly increased ocular coma-like (P = 0.0021) and total (P = 0.0019) higher-order aberrations at 1 month, but not at 3 months postoperatively.

CONCLUSION

Ocular coma-like and total aberrations were significantly increased at 1 month after trabeculectomy with a limbal-based conjunctival flap, but they had returned to normal levels by 3 months.