Phake Intraokularlinsen

Evaluation of phakic intraocular lens power calculation using the new Linz-Homburg-Castrop formula and comparison with four conventional methods

PURPOSE

To evaluate the accuracy of phakic intraocular lens (pIOL) power calculation in a middle European patient cohort.

SETTING

EyeLaser Clinic, Linz, Austria.

DESIGN

Single-center single-surgeon retrospective consecutive case series.

METHODS

Patients were included after uneventful pIOL surgery implanting 91 nontoric and toric Visian implantable collamer lens model V4c. Online Calculation and Ordering System (OCOS) software, JPhakic software, Olsen-Feingold formula, Holladay formula, and Linz-Homburg-Castrop (LHC) formula were compared. When possible, lens constants were optimized for the patient cohort. Data of single eye per patient were included. Outcome measures were mean absolute prediction error, median absolute prediction error, mean prediction error with SD, and median prediction error, as well as the percentage of eyes with an absolute prediction error within limits of 0.25 diopters (D), 0.5 D, 0.75 D, and 1.0 D.

RESULTS

91 eyes of 91 patients were assessed. After application of the Cochran Q test, the Olsen-Feingold formula achieved a significantly lower percentage of eyes within an absolute prediction error of 1.0 D than all other methods.

CONCLUSIONS

In the patient cohort, OCOS software, JPhakic software, and Holladay and LHC formulas showed equal results and can be cross-checked. The LHC formula was not published before. A ready-to-use Excel sheet is available as an addendum.

A Novel Concept of Correcting Presbyopia: First Clinical Results with a Phakic Diffractive Intraocular Lens

Purpose

To evaluate the effect of a novel technique to correct presbyopia. A phakic IOL (presbyopic IPCL; implantable phakic contact lens) with a diffractive optic is implanted and its impact on visual acuity, refraction, patient satisfaction in patients striving for spectacle-independence is evaluated.

Design

Retrospective noncomparative open-label clinical trial.

Methods

Sixteen eyes of 8 patients (average age 47 years) had a presbyopic IPCL implanted in the posterior chamber. The visual acuity on different distances, refractive status, corneal topography, endothelial cell density, anterior chamber depth, white-to-white, mesopic pupil size and intraocular pressure (IOP) were measured before implantation of this novel phakic IOL with diffractive optic and four weeks after surgery.

Results

At follow-up four weeks after surgery, 9 of the 16 eyes were emmetropic and uncorrected distance visual acuity was at least 0.8. Near vision was excellent in all patients without the need to wear reading glasses. There was neither a significant change in IOP nor a significant surgical impact on endothelial cells. Patient satisfaction was high. There was no major complaint of halos or glare.

Conclusion

The presbyopic IPCL can provide the presbyopic patient with good visual acuity and spectacle-independence for far and near distance. We found this novel technique to have a good safety profile during the surgical procedure and our short follow-up period. Further long-term follow-up is mandatory.

[Intraocular pressure after implantation of an ICL with aquaport : Development of intraocular pressure after implantation of an ICL (model V4c) with aquaport without iridotomy]

BACKGROUND AND OBJECTIVE

The latest version of the intraocular lens (ICL V4c) has a central hole (aquaport) that avoids a pupillary block. Due to this laser iridotomy or intraoperative surgical peripheral iridectomy are no longer required. In this study, we examined the intraocular pressure (IOP) after implantation of the ICL with aquaport, with special reference to the development of a possible pupillary block glaucoma.

MATERIAL AND METHODS

This retrospective non-randomized study included 87 eyes from 46 patients (consecutive case series). These patients had the ICL model V4c (without a laser iridotomy or peripheral iridectomy) implanted between January 2013 and October 2014. The preoperative IOP values were compared with the postoperative values 1-2 h, 1 day, 1 week and 1 month after implantation.

RESULTS

The median intraocular pressure was 14 ± 2 mm Hg before implantation of the ICL, palpatory normotensive 1-2 h after implantation, 13 ± 3 mm Hg 1 day after implantation, 15 ± 3 mm Hg 1 week after implantation and 16 ± 4 mm Hg 1 month after implantation (a slight statistically significant increase of the intraocular pressure, p < 0.05). In 2 patients there was a steroid response in both eyes with IOP reaching up to a maximum of 28 mm Hg. There were no peaks of intraocular pressure due to a pupillary block.

CONCLUSION

It is possible to implant the latest ICL V4c with a central hole (Aquaport) without a laser iridotomy or peripheral iridectomy or development of a pupillary block.

[Explantation of two historical posterior chamber phakic intraocular lenses 31 years after implantation]

This article reports the case of a 56-year-old male patient who had undergone implantation of posterior chamber phakic intraocular lenses in 1987 in Russia. The patient presented to this clinic 31 years after the initial surgery with anterior cortical cataracts and initial stages of corneal decompensation in both eyes. Strategic planning and execution of surgical treatment and the further clinical course are portrayed in this report.

Severe pigment dispersion after iris-claw phakic intraocular lens implantation

A 23-year-old female patient presented 3 months after the implantation of an Artisan^® phakic intraocular lens with a severe depigmentation of the iris and peripheral anterior synechiae. Explantation of the intraocular lens and goniosynechialysis were performed. Eleven months after the explantation appearance of the iris significantly improved. There was no loss of lines of corrected distance visual acuity. Severe pigment dispersion after the implantation of an Artisan^® phakic intraocular lens may happen and may require explantation of the lens. Iris depigmentation may improve with time.