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

The LISA-PPV Formula: An Ensemble Artificial Intelligence-Based Thick Intraocular Lens Calculation Formula for Vitrectomized Eyes

PURPOSE

To investigate the relationship between effective lens position (ELP) and patient characteristics, and to further develop a new intraocular lens (IOL) calculation formula for cataract patients with previous pars plana vitrectomy (PPV).

DESIGN

Cross-sectional study.

METHODS

A total of 2793 age-related cataract patients (group 1) and 915 post-PPV cataract patients (group 2) who underwent phacoemulsification with IOL implantation were included. The ELP of 2 groups was compared and the association between ELP and patient characteristics was further evaluated using standardized multivariate regression coefficients. An ensemble artificial intelligence-based ELP prediction model was developed using a training set of 810 vitrectomized eyes, and a thick-lens IOL formula (LISA-PPV) was constructed and compared with 7 existing formulas on an external multi-center testing set of 105 eyes.

RESULTS

Compared to eyes with age-related cataract, vitrectomized eyes showed a similar ELP distribution (P = .19), but different standardized coefficients of preoperative biometry for ELP. The standardized coefficients also varied with the type of vitreous tamponade, history of scleral buckling, and ciliary sulcus IOL implantation. The LISA-PPV formula showed the lowest mean and median absolute prediction error (MAE: 0.63 D; MedAE: 0.44 D), and the highest percentages of eyes within ±0.5 D of prediction error (57.14%) in the testing dataset.

CONCLUSIONS

The ELP prediction required optimization specifically for vitrectomized eyes based on their biometric and surgical characteristics. The LISA-PPV formula is a useful and accurate tool for determining IOL power in cataract patients with previous PPV (available at http://ppv-iolcalculator.com/).

Analysis of intraocular lens decentration and tilt after femtosecond laser-assisted cataract surgery using swept-source anterior optical coherence tomography

Objective

To evaluate and compare the magnitude of intraocular lens (IOL) decentration and tilt following conventional and femtosecond laser-assisted cataract surgery (FLACS) using swept-source anterior optical coherence tomography (SS-OCT).

Methods

In this retrospective observational study, we enrolled patients who underwent conventional cataract surgery or FLACS with the implantation of hydrophobic 1-piece monofocal IOL. The magnitude of IOL decentration and tilt were measured using SS-OCT. Visual acuity, intraocular pressure, spherical equivalent, axial length, contrast sensitivity, and satisfaction questionnaire were evaluated before and one-month post-surgery. Additionally, postoperative internal cylinder measurements were obtained using a wavefront aberrometer. Correlation factors between each parameter and IOL decentration or tilt were analyzed.

Results

This study included 100 eyes from 100 patients. Mean IOL decentration and tilt were 0.21 ± 0.13 mm and 5.01 ± 1.49°, respectively. Conventional cataract surgery (versus FLACS, P = 0.001) and male sex (versus female, P = 0.047) were significantly correlated with higher postoperative decentration. Preoperative lens diameter (P < 0.001), preoperative lens tilt (P = 0.007), and preoperative intraocular pressure (P = 0.027) were correlated with higher postoperative tilt. Fifty eyes that underwent FLACS demonstrated mean postoperative decentration of 0.21 ± 0.13 mm and tilt of 4.64 ± 1.48°. Compared with the conventional surgery group, the FLACS group significantly differed in postoperative decentration (0.30 ± 0.12 mm, P < 0.001) but not in tilt (5.03 ± 1.35°, P = 0.173). Postoperative visual acuity did not significantly differ between the two groups.

Conclusion

Patients who underwent FLACS demonstrated better IOL decentration and tilt than those who underwent conventional cataract surgery one-month post-surgery. However, differences in IOL decentration and tilt did not affect postoperative visual acuity.

Observation on the tilt and decentration of multifocal intraocular lens with optic capture in Berger space for pediatric cataract

PURPOSE

This study aimed to observe the tilt and decentration of multifocal intraocular lens (IOL) with optic capture in Berger space within 2 years after pediatric cataract surgery.

METHODS

This is a prospective observational study. The implantation of multifocal IOL (Tecnis ZMB00) with optic capture in Berger space was performed on 33 patients (48 eyes) with pediatric cataract at Qingdao Eye Hospital. Tilt and decentration of IOL was measured using Scheimpflug system (Pentacam) at 1 month and 2 years postoperatively.

RESULTS

All the multifocal IOLs were successfully implanted in Berger space with optic capture and no visually significant complications were detected during the follow-up. The mean tilt of IOLs was 2.779° ± 0.950° in the vertical plane and 2.399° ± 0.898° in the horizontal plane at 1 month postoperatively, and the mean length of the decentration was 0.207 ± 0.081 mm in vertical plane and 0.211 ± 0.090 mm in the horizontal plane. Compared with 1 month after surgery, the angle of tilt decreased by a mean of 0.192° and decentration increased by a mean of 0.014 mm at the vertical meridian at 2 years postoperatively (P = 0.37 and P = 0.27, respectively), meanwhile, tilt increased by 0.265° and decentration increased by 0.012 mm at the horizontal meridian (P = 0.11 and P = 0.22, respectively).

CONCLUSIONS

The follow-up results suggest the tilt and decentration of multifocal IOL implantation with optic capture in Berger space remain stable in an acceptable range within 2 years after cataract surgery in children above the age of 5.

TRIAL REGISTRATION

The study was approved by the Ethics Committee of Qingdao Eye Hospital, and registered on Chinese Clinical Trial Registry (ChiCTR identifier: 1900023155).

Outcomes of Secondary Intracapsular Intraocular Lens Implantation in Patients following Rhegmatogenous Retinal Detachment

This study reports the outcomes of a secondary IOL implantation technique in patients that suffered from rhegmatogenous retinal detachment combined with a cataract, which included reopening the capsular bag, enabling secondary intracapsular intraocular lens (IOL) implantation. We included consecutive cases with rhegmatogenous retinal detachment (RRD) treated with vitrectomy and silicone oil tamponade, and subsequent secondary IOL implantation during silicone oil removal between September 2019 and June 2022. Demographics, pre- and postoperative clinical data, and complications were collected. Visual and refractive outcomes and IOL position were evaluated. Thirty eyes were included and followed up for a mean of 24.2 ± 5.06 months. Compared with the preoperative values, no significant changes were observed in the intraocular pressure (p = 0.170) and endothelial cell density (p = 0.336); however, the best-corrected visual acuity (Snellen: 20/83 vs. 20/38; logMAR: 0.66 ± 0.23 vs. 0.37 ± 0.32; p < 0.001) and spherical equivalent (p < 0.001) improved significantly. The mean prediction error (ME) was -0.45 ± 0.68 D (-1.9-0.54 D), and the mean absolute prediction error (MAE) was 0.62 ± 0.52 D (0.01-1.9 D). The macula-on subgroup demonstrated significantly better refractive outcomes than the macula-off subgroup (ME, p = 0.046; MAE, p = 0.008). The IOL was well positioned, with a mean horizontal and vertical tilt and decentration of 0.53 ± 0.49° and 0.21 ± 0.16 mm, and 0.54 ± 0.45° and 0.22 ± 0.16 mm, respectively. Secondary intracapsular IOL implantation provided a good and stable IOL position and satisfactory refractive outcomes, and is a feasible treatment option for patients with RRD.

Optic inversion of scleral-fixated intraocular lens after vitrectomy with fluid-air exchange: case series and review of the literature

Lens dislocation is a significant complication after cataract surgery. Scleral fixation of 3-piece intraocular lens provides favorable visual outcome and can spare patients the need for lens exchange. Two patients presented with dislocated 3-piece lenses implanted over 10 years earlier. Both patients underwent pars plana vitrectomy and dropped lens rescue with scleral fixation. Postoperatively, the lens optic was found flipped nearly 90° at the optic-haptic junctions secondary to fluid-air exchange performed during vitrectomy. Both patients underwent intraocular lens exchange with a four point sclera fixated lens. Our study found that air tamponade is better avoided during rescue of old dislocated 3-piece lens implants. Intraocular lens exchange is preferred, when possible, to avoid complications associated with old dislocated lenses. Larger studies are needed to determine the effect of time on dislocated lens implants materials.

Choice of intraocular lens calculation formula for cataract patients with prior pars plana vitrectomy

PURPOSE

To determine the optimal intraocular lens (IOL) calculation formula for vitrectomized eyes with diverse surgical and biometric characteristics.

SETTING

Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.

DESIGN

Retrospective consecutive case series study.

METHODS

This study included 974 vitrectomized eyes (974 patients) scheduled for phacoemulsification with IOL implantation. 11 formulas were evaluated: Barrett Universal II (BUII), Emmetropia Verifying Optical, Hoffer-QST, Kane, Ladas Super Formula, Pearl-DGS, Radial Basis Function (RBF), Haigis, HofferQ, Holladay1, and SRK/T. Risk factors for prediction error (PE) exceeding 1 diopter (D) were determined using multiple logistic regression. Subgroup analyses were performed based on surgical history and biometric parameters.

RESULTS

The risk of hyperopic PE (>1 D) was higher in patients with silicone oil tamponade (odds ratio [OR], 1.82) and longer axial length (AL) (OR, 1.55), while patients with previous scleral buckling (OR, 2.43) or ciliary sulcus IOL implantation (OR, 6.65) were more susceptible to myopic PE (<-1 D). The Kane formula had the highest overall prediction accuracy, and also the best in silicone oil-filled eyes and the flat cornea subgroup. The BUII and RBF displayed the optimal performance in eyes with previous scleral buckle and steep cornea, respectively. In eyes with an AL ≥ 26 mm, the Holladay1 with the nonlinear version of the Wang-Koch AL adjustment (Holladay1-WKn) showed the lowest absolute PE and highest percentage within ± 1.0 D of PE.

CONCLUSIONS

The Kane achieved the highest overall prediction accuracy in vitrectomized eyes. The optimal formula for eyes with previous scleral buckle, steep cornea, or long AL was BUII, RBF, and Holladay1-WKn, respectively.

Flapless and Conjunctiva-Sparing Technique for Transscleral Fixation of Intraocular Lens to Correct Refractive Errors in Eyes without Adequate Capsular Support

Purpose

To evaluate refractive outcomes, intraocular lens (IOL) power calculation, and IOL position following a novel conjunctiva-sparing transscleral fixation technique.

Methods

Forty-one eyes of 40 patients managed with a flapless transscleral-sutured technique were included. Preoperative and postoperative refractive errors (spherical equivalents, SE) were compared. IOL position was assessed on the Scheimpflug images. IOL power was calculated by SRK/T, Holladay 1, and Hoffer Q formulas.

Results

The mean age was 57.39 ± 14.83 years (range: 26 to 79 years), and the mean follow-up was 7.46 ± 6.42 months (range: 1 to 24 months). Surgical indications were aphakia (n = 14), subluxated lenses (n = 3), and IOL dislocation (n = 24). The SE was 4.50 ± 6.38 diopter (D) (range: -3.75 to 13.75 D) preoperatively and -1.68 ± 1.57 D (range: -5.50 to 1.13 D) postoperatively (P < 0.001). The mean tilt angle and decentration were 2.90° ± 1.93° (range: 0.39° to 9.10°) and 0.23 ± 0.19 mm (range: 0.02 to 0.94 mm) vertically, and 1.75° ± 1.41° (range: 0.24° to 7.65°) and 0.18 ± 0.19 mm (range: 0.02 to 1.06 mm) horizontally, which were clinically insignificant. All three IOL formulas produced myopic errors (range: -0.29 to -0.50 D). The SRK/T had the lowest median absolute error (0.55 D), followed by the Holladay 1 (0.70 D) and the Hoffer Q (0.74 D). The three formulas had the same percentage of prediction errors (PEs) within ±0.5 D (43.48%), while the Hoffer Q had the highest percentage of PEs within ±1.0 D (82.61%).

Conclusion

The present technique can serve as an alternative approach for transscleral IOL fixation and refractive correction in eyes with compromised capsular support, ensuring the stability of IOLs and reasonable IOL power calculation accuracy.

Predicting the risk of clinically significant intraocular lens tilt and decentration in vitrectomized eyes

PURPOSE

To identify predictors and develop a prognostic nomogram for clinically significant intraocular lens (IOL) tilt and decentration in vitrectomized eyes.

SETTING

Zhongshan ophthalmic center, Guangzhou, China.

DESIGN

Prospective observational study.

METHODS

Patients with previous pars plana vitrectomy who underwent phacoemulsification with IOL implantation were enrolled in this study. The tilt and decentration of the lens and IOL were assessed by a swept-source anterior segment optical coherence tomography (CASIA2). Multiple logistic regression analysis and prognostic nomogram models were used to explore factors associated with clinically significant IOL tilt and decentration (defined as tilt ≥7 degrees and decentration ≥0.4 mm).

RESULTS

375 patients (375 eyes) with a mean age of 56.1 ± 9.81 years were included. Lens tilt (odds ratio [OR] = 1.44), lens decentration (OR = 1.74), lens diameter (OR = 0.49), and hydrophilic IOL (OR = 2.36) were associated with IOL tilt over 7 degrees (all P &amp;lt; .05). Lens tilt (OR = 1.24), lens decentration (OR = 2.30), and incomplete capsulorhexis-IOL overlap (OR = 2.44) increased the risk of IOL decentration over 0.4 mm (all P &amp;lt; .05). Preoperative lens tilt together with lens decentration was identified as the strongest predictor of incident clinically significant IOL tilt (area under the curve [AUC] = 0.82, 95% CI, 0.76-0.88) and decentration (AUC: 0.84, 95% CI, 0.78-0.89), and the nomogram was constructed accordingly.

CONCLUSIONS

The tilt and decentration of the crystalline lens, hydrophilic IOL, and incomplete capsulorhexis-IOL overlap were risk factors for clinically significant IOL misalignment. Clinicians could use a prognostic nomogram model based on the preoperative lens position to make a strategy for higher-risk patients.