Toric intraocular lens implantation - atypical cases

Abstract

Objective: To describe the results of toric intraocular lens (IOL) implantation in three atypical cases (four eyes) with cataract and corneal astigmatism: one with bilateral keratoconus, one with pellucid marginal degeneration and one with buphthalmos due to congenital glaucoma. Methods: Three patients (four eyes) with corneal astigmatism (one with bilateral keratoconus, one with pellucid marginal degeneration and one with buphthalmos due to congenital glaucoma) underwent cataract surgery by standard phacoemulsification and the implantation of toric IOLs in the capsular bag. The presence of corneal astigmatism was identified by automated keratometry and confirmed by Scheimpflug-based corneal tomography. The toric IOL implanted in all cases was a single-piece AcrySof Toric IOL (Alcon Laboratories, Inc.). Postoperative visual acuity, the reduction in the refractive astigmatism, the spherical equivalent (SE) and the rotational stability of the toric IOL were recorded for all the patients. Results: Visual acuity increased and the refractive astigmatism decreased in all cases. In Case 1, the right eye achieved a postoperative uncorrected visual acuity (UCVA) of 20/ 20, a decrease in the refractive astigmatism from -3 DCyl to -0.75 DCyl and a spherical equivalent (SE) of -0.25. The left eye presented with a best-corrected visual acuity (BCVA) of 20/ 20, a decrease in the refractive astigmatism from -1.50 DCyl to -1.25 DCyl and a SE of -0.25. In Case 2, the postoperative UCVA was 20/ 20, with a decrease in the refractive astigmatism from -5.5 DCyl to -1 DCyl and a SE for the right eye of 0.00 D. In Case 3, the postoperative BCVA was 20/ 20, with a decrease in the refractive astigmatism from -4.75 DCyl to -1.50 DCyl and a SE of +1.25. No misalignment of the axis of the toric IOL was observed in any patient at subsequent follow-ups. The postoperative visual acuity was satisfactory for all the patients. Conclusions: Toric intraocular lenses can be an effective option for implantation in patients with cataract and corneal astigmatism in atypical situations such as mild to moderate keratoconus, pellucid marginal degeneration and buphthalmos due to congenital glaucoma. Predicting the refractive outcome is difficult in atypical cases and the surgeon should have accuracy and consistency in the preoperative measurements, for achieving satisfactory postoperative results.

Keywords: astigmatism; buphthalmos; cataract; congenital glaucoma; keratoconus; pellucid marginal degeneration; phacoemulsification; toric intraocular lens.

Fig. 1

Scheimpflug Corneal Tomography Sagittal Curvature Map of the right eye showing oblique astigmatism with an “asymmetric bow tie” pattern (Case 1)

Fig. 2

Scheimpflug Corneal Tomography Sagittal Curvature Map of the left eye showing irregular astigmatism and a pattern of “asymmetric bowtie with skewed radial axis” (Case 1)

Fig. 3

Belin/ Ambrosio Enhanced Ectasia analysis showing an ectatic aspect of the cornea in the right eye (Case 1)

Fig. 4

Belin/ Ambrosio Enhanced Ectasia analysis showing an ectatic aspect of the cornea in the left eye (Case 1)

Fig. 5

Corneal topography of the right eye showing an aspect of Pellucid Marginal Degeneration (Case 2)

Fig. 6

Scheimpflug Corneal Tomography of the right eye showing inferior steepening of the cornea (Case 2)

Fig. 7

Belin/ Ambrosio Enhanced Ectasia analysis of the right eye showing ectatic changes in the right eye (Case 2)

Fig. 8

Scheimpflug Corneal Tomography of the left eye showing highly irregular astigmatism (Case 2)

Fig. 9

Belin/ Ambrosio Enhanced Ectasia analysis of the left eye (Case 2)

Fig. 10

Corneal Topography of the Right Eye Showing regular corneal astigmatism with a “Symmetric bowtie” aspect (Case 3)

Fig. 11

Scheimpflug Corneal Tomography of the right eye (Case 3)

Fig. 12

Scheimpflug Corneal Tomography of the right eye (Case 3)

Fig. 13

Right eye vertical corneal diameter of 13 mm as measured by calipers (Case 3)

Fig. 14

Right eye horizontal corneal diameter of 15 mm as measured by calipers (Case 3)