Intraocular lens centration and stability: efficacy of current technique and technology

Pupil versus 1st Purkinje capsulotomy centration with femtosecond laser: Long term outcomes with a sinusoidal trifocal lens

PURPOSE

To assess the role of femtosecond laser-assisted capsulotomy centration in the long-term intraocular positioning of a multifocal intraocular lens.

DESIGN

Prospective comparative study.

METHODS

A total of 60 eyes of 30 patients underwent femtosecond laser-assisted Refractive Lens Exchange (RLE). For every patient, capsulotomy centration was randomly performed according to pupil centre (PC) in one eye and first Purkinje reflex (FPR) in the other. The intraocular lens (IOL) positioning, visual acuities, spherical equivalent, internal aberrometry and quality of vision were assessed and compared at 3 years' follow-up between groups (PC and FPR).

RESULTS

Intraocular lens positioning showed a statistically significant difference between groups, with a closer centration to the visual axis in the FPR patients (p < 0.001). Internal aberrometry showed higher values in the PC capsulotomy centration group (p < 0.01).

CONCLUSIONS

FPR centered capsulotomy is associated to a closer centration of the IOL to the visual axis.

The Effect on Post-Operative Intraocular Lens Centration by Manual Intraoperative Centration versus Auto-Centration

Introduction

To determine if intraoperative manual centration of the intraocular lens (IOL) during cataract surgery results in better early post-operative centration. It is common practice for cataract surgeons to align intraocular lens centration to the visual axis by manual intraoperative manipulation of the intraocular lens. We aim to compare post-operative intraocular lens centration between intraocular lenses that were allowed spontaneous positioning in the capsular bag and IOLs that were manually centred during implantation.

Materials and Methods

One hundred and twenty-five consecutive eyes that underwent either femtosecond laser-assisted cataract surgery (FLACS) or phacoemulsification and IOL (monofocal/toric/multifocal) implantation by a single surgeon were included. Post-operative IOL centration at 4 weeks was assessed and measured on a slit-lamp by a masked observer.

Results

A total of 17 (13.6%) IOLs were off-centered to some extent at 4 weeks post-operatively. All the decentered IOLs were graded as minimal or mild (<0.5mm) decentration. There was no statistically significant difference in the proportion of decentered IOLs between the manual centration group and non-centration group (p = 0.59).

Conclusion

The final position of the IOL is not dependent on manual centration but rather on the design and symmetry of the IOL, as well as the integrity of the capsular bag.

Rotational stability of a new multicomponent intraocular lens

Purpose

To evaluate the rotational stability of the Precisight multicomponent intraocular lens (MCIOL) following primary implantation and after enhancement procedures.

Patients and methods

Prospective, single-center study of eyes that underwent routine cataract surgery with implantation of a non-toric MCIOL, (Precisight, InfiniteVision, Optics, Strasbourg, France). The axis of the MCIOL was measured with a line bisecting the two dialing holes in the front lens. Intraoperative orientation was determined using a digital surgical guidance system while the postoperative orientation was determined using slit-lamp imaging. Two populations were analyzed: eyes that only underwent cataract surgery (PRIM) and eyes that also underwent enhancement (ENH), consisting of surgical front optic exchange. Both populations had 3 observation visits: first implantation (P-Op); 3 months (3mo) and 6 months (6mo) after primary surgery. The ENH group had an additional fourth visit that corresponded to the enhancement surgery (E-Op). The main outcome measure was mean absolute change in MCIOL orientation (degrees). The effects of axial length (AL) and anterior chamber depth (ACD) on IOL rotational stability were examined.

Results

Thirty-three eyes received MCIOL of which 29 had usable orientation images. Of these, 12 were in the PRIM group and 17 underwent ENH. Regarding the mean absolute rotation, among PRIM eyes, P-Op to 3mo was 3.03±2.45 degrees; P-Op to 6mo, 2.28±1.54 degrees; and 3–6mo, 2.37±1.56 degrees. Among the ENH eyes, P-Op to 3mo was 3.09±1.68; E-Op to 6mo, 2.71±3.30 and P-Op to 6mo, 3.62±3.42. There were no significant differences in the IOL rotation. There were no statistical differences in rotational stability between the ENH and PRIM groups. There was no correlation between IOL rotation and AL or ACD.

Conclusion

Precisight appears to be rotationally stable. The enhancement procedure does not affect rotational stability.

Clinical outcomes and rotational stability of a 4-haptic toric intraocular lens in myopic eyes

PURPOSE

To evaluate the refractive outcomes and rotational stability of a 4-haptic toric intraocular lens (IOL) in myopic eyes and the correlations between IOL rotation and refractive sphere, axial length (AL), and white-to-white (WTW) diameter.

SETTING

Eye Clinic, Careggi Hospital, Florence, Italy.

DESIGN

Prospective case series.

METHODS

Phacoemulsification cataract extraction and implantation of an AT Torbi 709M IOL were performed. Corneal astigmatism was 1.50 diopters (D) or greater and the AL between 25.0 mm and 27.0 mm in all eyes. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, and IOL axis were evaluated preoperatively and postoperatively up to 6 months.

RESULTS

The study enrolled 20 eyes (20 patients). The UDVA and CDVA improved significantly postoperatively (P<.001). The mean refractive spherical equivalent decreased significantly from -7.10 D±1.78 (SD) preoperatively to -0.55±0.25 D 1 day postoperatively (P<.001) and remained stable thereafter. Vector analysis showed that 90% and 85% of the eyes were within ±0.25 D for J0 and J45, respectively. At 3 months and 6 months, the mean IOL rotation was 2.66±1.53 degrees and 3.00±1.69 degrees, respectively (P<.001), with 95% of eyes and 90% of eyes, respectively, within ±5 degrees. A positive correlation was found between IOL rotation and preoperative sphere; none was found with AL and WTW.

CONCLUSIONS

Implantation of the 4-haptic toric IOL in myopic eyes was effective and safe. The IOL showed no significant rotation over the 6-month follow-up.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Capsular block syndrome: a case report and literature review

PURPOSE

To report the case of a patient who developed late capsular block syndrome and to review the current literature regarding this complication of phacoemulsification procedures.

METHODS

The literature was reviewed to summarize the diagnosis, classification, use of diagnostic aids, and the current treatments for this complication.

RESULTS

A 69-year-old patient complained of decreased visual acuity 11 months after undergoing phacoemulsification. She was found to have a secondary myopization. Anterior segment ultrabiomicroscopy confirmed the diagnosis of capsular block syndrome. The patient underwent neodymium-doped yttrium aluminum garnet (Nd:YAG) laser posterior capsulotomy, which resulted in complete resolution of her symptoms.

CONCLUSION

CAPSULAR BLOCK SYNDROME IS A FAIRLY RARE COMPLICATION OF PHACOEMULSIFICATION PROCEDURES THAT, DEPENDING PRIMARILY ON THE TIMING OF ITS OCCURRENCE FOLLOWING SURGERY, CAN DEVELOP INTO ONE OF THE THREE FOLLOWING POSSIBLE CLINICAL SCENARIOS: intraoperatory, early postoperatory, and late postoperatory. In this patient, Nd:YAG laser capsulotomy was shown to be a safe and effective treatment option for this type of complication.

Coaxially sighted intraocular lens light reflex for centration of the multifocal single piece intraocular lens

Centration of multifocal Intraocular lenses (IOL) may be critical to ensure optimal function and prevent untoward side effects. Pharmacologic pupillary dilation and constriction may shift the physiologic location of the pupillary center rendering intraoperative positioning of multifocal IOL challenging. Similarly, the anterior capsular center is difficult to pinpoint and may not correspond to either the visual axis or the pupillary center. The visual axis is the only landmark that can be consistently identified prior, during and after cataract surgery. Centering diffractive multifocal IOL on the visual axis may allow more consistent placement and better outcome measures. In the following, we describe a simple technique to center multifocal single piece acrylic IOLs on the visual axis.