Journal of Refractive Surgery

Report 

Multifocal Toric Intraocular Lens Implantation for Forme Fruste and Stable Keratoconus

Margarita Montano, MD; Karla P. López-Dorantes, MD; Arturo Ramirez-Miranda, MD; Enrique O. Graue-Hernández, MD, MSc; Alejandro Navas, MD, MSc

Abstract

PURPOSE:

To describe the results of multifocal toric intraocular lens implantation in two patients (one with forme fruste keratoconus and the other with frank but stable keratoconus).

METHODS:

A 50-year-old woman with forme fruste keratoconus and positive family history of keratoconus and a 42-year-old man with frank keratoconus underwent corneal collagen cross-linking. Uncorrected distance visual acuity was 20/800 in the right eye and 20/400 in the left eye and 20/400 in the right eye and 20/100 in the left eye, respectively. Refractive lens exchange was performed using multifocal toric intraocular lenses in both cases.

RESULTS:

After phacoemulsification, uncorrected distance visual acuity, corrected distance visual acuity, binocular uncorrected distance visual acuity was 20/25 and 20/30 in cases 1 and 2, respectively, and residual refraction was within 0.5 diopters of emmetropia in both cases. Patients were subjectively satisfied.

CONCLUSIONS:

Presbyopic treatment options are scarce for patients with keratoconus and multifocal toric intraocular lenses may be useful in selected cases.

[J Refract Surg. 2014;30(4):282–285.]

From the Department of Cornea and Refractive Surgery, Institute of Ophthalmology “Conde de Valenciana,” Mexico City, Mexico.

The authors have no financial or proprietary interest in the materials presented herein.

AUTHOR CONTRIBUTIONS

Concept and design (AN); data collection (KPL-D, MM); analysis and interpretation of data (AR-M, EOG-H); writing the manuscript (AN, KPL-D, MM); critical revision of the manuscript (AR-M, EOG-H); supervision (AN, EOG-H)

Correspondence: Alejandro Navas, MD, MSc, Department of Cornea and Refractive Surgery, Institute of Ophthalmology “Conde de Valenciana,” Chimalpopoca 14, Col Obrera, Mexico City 06800, Mexico. E-mail: dr.alejandro.navas@gmail.com

Received: December 02, 2013
Accepted: December 18, 2013
Posted Online: April 04, 2014

Abstract

PURPOSE:

To describe the results of multifocal toric intraocular lens implantation in two patients (one with forme fruste keratoconus and the other with frank but stable keratoconus).

METHODS:

A 50-year-old woman with forme fruste keratoconus and positive family history of keratoconus and a 42-year-old man with frank keratoconus underwent corneal collagen cross-linking. Uncorrected distance visual acuity was 20/800 in the right eye and 20/400 in the left eye and 20/400 in the right eye and 20/100 in the left eye, respectively. Refractive lens exchange was performed using multifocal toric intraocular lenses in both cases.

RESULTS:

After phacoemulsification, uncorrected distance visual acuity, corrected distance visual acuity, binocular uncorrected distance visual acuity was 20/25 and 20/30 in cases 1 and 2, respectively, and residual refraction was within 0.5 diopters of emmetropia in both cases. Patients were subjectively satisfied.

CONCLUSIONS:

Presbyopic treatment options are scarce for patients with keratoconus and multifocal toric intraocular lenses may be useful in selected cases.

[J Refract Surg. 2014;30(4):282–285.]

From the Department of Cornea and Refractive Surgery, Institute of Ophthalmology “Conde de Valenciana,” Mexico City, Mexico.

The authors have no financial or proprietary interest in the materials presented herein.

AUTHOR CONTRIBUTIONS

Concept and design (AN); data collection (KPL-D, MM); analysis and interpretation of data (AR-M, EOG-H); writing the manuscript (AN, KPL-D, MM); critical revision of the manuscript (AR-M, EOG-H); supervision (AN, EOG-H)

Correspondence: Alejandro Navas, MD, MSc, Department of Cornea and Refractive Surgery, Institute of Ophthalmology “Conde de Valenciana,” Chimalpopoca 14, Col Obrera, Mexico City 06800, Mexico. E-mail: dr.alejandro.navas@gmail.com

Received: December 02, 2013
Accepted: December 18, 2013
Posted Online: April 04, 2014

There are several treatment options for managing keratoconus.1 Recent studies have shown that toric intraocular lenses can be used to treat keratoconus with encouraging results.2–5 Premature cataract formation has been reported in those with keratoconus.6

Multifocal toric intraocular lenses can provide promising results for patients with astigmatism and presbyopia.7 Presbyopic treatments for keratoconus are limited and often unconsidered. Although multifocal toric intraocular lenses are not usually considered to treat keratoconus, the outcomes should theoretically benefit selected patients.

The purpose of this report is to describe the visual and refractive outcomes of bilateral multifocal toric intraocular lens implantation in two patients with keratoconus.

Case Reports

Case 1

A 50-year-old woman with forme fruste keratoconus and first-degree positive family history for keratoconus was treated 6 months previously with corneal collagen cross-linking. After surgery, uncorrected distance visual acuity was 20/800 in the right eye and 20/400 in the left eye with a refraction of −5.50 −2.25 × 45 in the right eye and −3.25 −1.75 × 165 in the left eye; corrected distance visual acuity for both eyes was 20/25. There was stable refraction for 6 months postoperatively. Scheimpflug images (Pentacam; Oculus Optikgerate GmbH, Wetzlar, Germany) showed forme fruste keratoconus with asymmetric bowties in both eyes. A slight enantiomorphism was also observed between both eyes (Figure 1).

Case 1. Topographic images of the (A) right and (B) left eye and the (C and D) software-suggested axis. (E and F) The final alignment according to the astigmatism axis and the centered multifocal rings of the multifocal toric intraocular lenses. Case 2. (a and b) Topographic axial image of forme frank keratoconus in both eyes and slight enanthomorphism. (c and d) Multifocal toric intraocular lens-alignment software calculations with the suggested position according to the astigmatic axis. Clinical images showing proper alignment of the linear marks according to the desired axis. (e and f) No intraocular lens rotation was found during follow-up. Diffractive intraocular lenses rings were well centered.

Figure 1.

Case 1. Topographic images of the (A) right and (B) left eye and the (C and D) software-suggested axis. (E and F) The final alignment according to the astigmatism axis and the centered multifocal rings of the multifocal toric intraocular lenses. Case 2. (a and b) Topographic axial image of forme frank keratoconus in both eyes and slight enanthomorphism. (c and d) Multifocal toric intraocular lens-alignment software calculations with the suggested position according to the astigmatic axis. Clinical images showing proper alignment of the linear marks according to the desired axis. (e and f) No intraocular lens rotation was found during follow-up. Diffractive intraocular lenses rings were well centered.

Intraocular lens calculations were obtained using interferometry (IOLMaster; Carl Zeiss Meditec, Jena, Germany), Scheimpflug images, and SRK-II formula for emmetropia using multifocal toric intraocular lens calculator software. The SND1T4 multifocal toric intraocular lens model (Alcon Laboratories, Inc., Fort Worth, TX) was suggested for both eyes (Figure 1). A Mendez degree gauge (Asico, LLC, Westmont, IL) was used to make axis marks at 124° and 59°. Under topical anesthesia, a 2.8-mm clear corneal incision at 140° was made. During refractive lens exchange, a slight anterior capsule tear occurred in the right eye without any other eventualities. Toric intraocular lenses were aligned according to the marks (Figure 1). Intraocular lens powers were +13.0 diopters (D) (cylinder: 2.25 D) at 124° and +14.0 D (cylinder: 2.25 D) at 59°.

At the 1-year follow-up, uncorrected distance visual acuity was 20/30 and corrected distance visual acuity was 20/25 in both eyes, binocular uncorrected distance visual acuity was 20/25, and refraction of plano was −0.50 × 105 in the right eye and −0.25 −0.50 × 85 in the left eye. A mild misalignment was found in the right eye. No lens rotation was observed and uncorrected near visual acuity was Jaeger 2. Postoperative Wavefront Aberration Supported Cornea Ablation (WASCA) aberrometer analysis (Shack-Hartmann; Carl Zeiss Meditec) reported total aberrations root mean square of 0.49 and 0.41 μm and higher-order aberrations root mean square of 0.20 and 0.19 μm for the right and left eye, respectively. Scotopic pupil diameter was 3.75 mm in the right eye and 3.72 mm in the left eye. The patient was subjectively satisfied without nighttime visual disturbances.

Case 2

A 42-year-old man treated with spectacles since age 15 years was diagnosed as having keratoconus. Uncorrected distance visual acuity was 20/400 in the right eye and 20/100 in the left eye. Refraction was −10.25 −5.00 × 25 in the right eye and − 3.50 −6.00 × 140 in the left eye. Corrected distance visual acuity was 20/40 for both eyes. There was stable refraction for 1 year postoperatively. Topographic images (Orbscan II; Bausch & Lomb, Rochester, NY) showed forme frank keratoconus (Figures 1a–1b).

Intraocular lens power was obtained using intraocular lens calculator software (Z CALC; Carl Zeiss Meditec) (Figures 1c–1d). Reference marks were made at the 112° and 58° axes. Under topical anesthesia, phacoemulsification was performed without complications. Multifocal toric intraocular lenses (AT LISA toric 909M; Carl Zeiss Meditec) were aligned and centered according to the marks (Figures 1E–1F). Intraocular lens powers were −9.00 D (cylinder: 11.00 D) at 112° and +6.50 D (cylinder: 8.00 D) at 58°; when the cylindrical power increased, the spherical power of the intraocular lens decreased in contrast to other multifocal toric intraocular lens models.

At the 3-month follow-up, uncorrected distance visual acuity was 20/30 and corrected distance visual acuity was 20/25 in both eyes, binocular uncorrected distance visual acuity was 20/30, and the spherical equivalent was +0.50. No misalignment or intraocular lens rotation was found in either eye. Uncorrected near visual acuity was Jaeger 1. Postoperative WASCA aberrometer analysis reported total aberrations root mean square of 0.71 and 1.00 μm and higher-order aberrations root mean square of 0.47 and 0.42 μm for the right and left eye, respectively (Figure 2). Scotopic pupil diameter was 5.02 and 5.21 mm for the right and left eye, respectively. The patient was subjectively satisfied being spectacle independent and without night vision impairment.

Superimposed dual Scheimpflug images (Galilei dual-Scheimpflug analyzer; Ziemer Group, Port, Switzerland) showing matching topography with clinical images of the multifocal toric intraocular lenses: (A) linear marks of the right eye for case 2 and (B) three dot marks of the left eye for case 1. Aberrometer analysis demonstrated a decrease in total aberrations and improvement in the simulated vision of the left eye (C) preoperatively versus (D) postoperatively for case 2.

Figure 2.

Superimposed dual Scheimpflug images (Galilei dual-Scheimpflug analyzer; Ziemer Group, Port, Switzerland) showing matching topography with clinical images of the multifocal toric intraocular lenses: (A) linear marks of the right eye for case 2 and (B) three dot marks of the left eye for case 1. Aberrometer analysis demonstrated a decrease in total aberrations and improvement in the simulated vision of the left eye (C) preoperatively versus (D) postoperatively for case 2.

Discussion

Treatment options for keratoconus are varied and keratoconus cases tend to develop cataracts sooner than others.6 Our findings suggest that a multifocal toric intraocular lens could provide optimum outcomes including achieving spectacle independence and correction to a satisfactory level (20/40 or better), such as in these two cases.

It is important to note that these cases were previously managed with only spectacles. Rigid contact lens wearers or those who have already had surgery should perhaps not use multifocal toric intraocular lenses. Corneal cross-linking has improved keratoconus stability.8 However, its use for treating older patients is still controversial and debatable. Although keratoconus progression may cease after five decades of life, we performed corneal cross-linking in the first case due to family history and the higher precision required by the multifocal toric intraocular lens implantation. In the second case, we avoided corneal cross-linking due to well-documented keratoconus stability.

Although toric intraocular lenses have been used with good results,2–5 presbyopic treatment options are limited for patients with ectatic corneas. Theoretically, the multifocal toric intraocular lens models we implanted do not generate significant higher-order aberrations.7,9 Patients with keratoconus tend to have vertical coma instead of other higher-order aberrations.10 After performing multifocal toric intraocular lens implantation in these cases, higher-order and total aberrations remained low and improved postoperatively.

Key factors of toric intraocular lens implantation for keratoconus include stability (often hard to prove and demonstrate), “refractability” or the capacity to improve corrected distance visual acuity with phoropter (not possible in patients with dense cataracts), a not-so-irregular astigmatism (could be asymmetric, but needs to be the most orthogonally), and a topographic or tomographic identifiable axis to properly align the toric intraocular lens.2,4,5 In addition, relative enanthiomorphism (ie, chirality) between eyes needs to be present to obtain favorable results. In addition, for multifocal toric implantation, relative enanthiomorphism (ie, chirality) between eyes is preferred to obtain favorable results due to binocularity.

Although the risk of keratoconus progression may exist, multifocal toric intraocular lens implantation should be considered for selected cases of stable, nonprogressive, and mild to moderate keratoconus because it could offer desirable outcomes and spectacle independence.

References

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10.3928/1081597X-20140320-08

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