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

Improving Effective Lens Position Prediction for Transscleral Fixation of Intraocular Lens Among Congenital Ectopia Lentis Patients

PURPOSE

To introduce a method of predicting effective lens position (ELP) among congenital ectopia lentis (CEL) patients undergoing transscleral fixation of intraocular lens (IOL), and evaluate its effect on improving refractive outcome by utilizing the Sanders-Retzlaff-Kraff / theoretical (SRK/T) formula.

DESIGN

Retrospective cross-sectional study.

METHODS

A training set (93 eyes) and validation set (25 eyes) was included. Z value as the distance between the iris plane and a hypothetic postoperative IOL position was introduced in this study. The Z-modified ELP consisted of corneal height (Ch) and Z (ELP = Ch + Z), and Ch was calculated by keratometry (Km) and white-to-white (WTW). The value of Z was identified by linear regression formula with the involvement of axial length (AL), Km, WTW, age, and gender. The comparison of mean (MAE) and mediate absolute error (MedAE) among Z-modified SRK/T formula, SRK/T, Holladay I, and Hoffer Q formula was performed to evaluate the performance of Z-modified SRK/T formula.

RESULTS

Z value was associated with AL, K, WTW, and age (Z = offset + 15.1093 × lg (AL) + 0.0953899 × Km - 0.3910268 × WTW + 0.0164197 × Age - 19.34804). The Z-modified ELP has good accuracy with no difference to back-calculated ELP. The accuracy of Z-modified SRK/T formula was better than other formulas (P < .001) as the MAE was 0.24 ± 0.19 diopter (D) and MedAE was 0.22 D (95% CI: 0.01-0.57 D). Sixty-four percent of eyes had a refractive error smaller than ±0.25 D, and none of the subjects had a prediction error greater than ±0.75 D.

CONCLUSIONS

ELP of CEL can be accurately predicted by AL, Km, WTW, and age. Z-modified SRK/T formula improved on the current formula by improving predicting accuracy of ELP and may serve as a promising formula for CEL patients with transscleral fixation of IOL.

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.

RISK FACTORS FOR PUPILLARY OPTIC CAPTURE FOLLOWING SUTURELESS FLANGED INTRAOCULAR LENS FIXATION FOR INTRAOCULAR LENS DISLOCATION

PURPOSE

To identify risk factors for pupillary optic capture after sutureless flanged intraocular lens (IOL) fixation for IOL dislocation.

METHODS

This retrospective comparative study enrolled consecutive patients who underwent flanged IOL fixation using 25-gauge pars plana vitrectomy. One hundred twenty-six eyes (126 patients) were divided into two groups according to the presence or absence of pupillary optic capture. A swept-source anterior segment optical coherence tomography and a rotating Scheimpflug camera were used to analyze and compare surgical parameters, including axial length, anterior chamber depth, differences in scleral tunnel angle and length, and IOL tilt and decentration, between the two groups.

RESULTS

Compared with the nonpupillary optic capture group (106 eyes, 84.1%), the pupillary optic capture group (20 eyes, 15.9%) had larger differences in the nasal and temporal scleral tunnel angles and larger horizontal tilt (P < 0.05). Multivariate regression analysis demonstrated that these factors correlated with the occurrence of pupillary optic capture (P < 0.05).

CONCLUSION

To prevent pupillary optic capture after flanged IOL fixation, surgeons should avoid asymmetry in the angles of the nasal and temporal scleral tunnels, which causes horizontal IOL tilt and subsequent pupillary capture.

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.

Early Clinical Outcomes of Intrascleral Fixation Using an Intraocular Lens with Hook-Shaped Haptics

Purpose

In this study, we aimed to report on the early results of intrascleral intraocular lens (IOL) fixation using a hook-shaped haptic IOL (hsh-IOL).

Patients and Methods

We enrolled 27 consecutive eyes of 27 patients (mean age, 74±11.4 years) who underwent intrascleral IOL fixation with an hsh-IOL and were followed-up for 3 months postoperatively. The reasons for surgery included insufficient capsular support, including IOL dislocation, aphakia, or dislocated crystalline lens. The haptic of the hsh-IOL was externalized from the eye using forceps, and the hook was buried in the scleral tunnel. We investigated the preoperative and 3-month postoperative corrected visual acuity (VA), intraocular pressure (IOP), corneal endothelial cell density, refractive prediction error, postoperative intraocular astigmatism, surgically induced astigmatism, and intraoperative and postoperative complications.

Results

The mean postoperative corrected VA (logMAR, 0.083±0.18) was significantly better than the mean preoperative value (0.42±0.60, p=0.0007). The 3-month postoperative mean absolute prediction error was 1.00±0.96 D. The mean IOL-induced astigmatism was 0.95±0.70 D. Further, the mean postoperative corneal endothelial cell count (2036±644 cells/mm²) was significantly lower than the preoperative value (2316±527 cells/mm²) (p=0.009). No patient had a 1-month postoperative IOP <5 mmHg or >25 mmHg. There were no intraoperative or vision-threatening complications, such as retinal detachment, endophthalmitis, or IOL dislocation, due to postoperative haptics misalignment.

Conclusion

Intrascleral IOL fixation using hsh-IOL is an effective option for eyes with insufficient capsular support.