RESIDENT'S REVIEW

My First Alcon Toric Experience

By Farhan A. Irshad, MD, Tulane Ophthalmology

A 57-year-old female presented complaining of increased glare and halos and difficulty seeing, especially at night. She said her vision was becoming increasingly cloudy and colors seemed to be fading. Her eyeglass prescriptions were changing more frequently and her spectacles were very costly due to combined astigmatism and extreme near-sightedness.

Her best-corrected vision was 20/50 in each eye with a refraction of −19.00 +4.00 x 105 OD and −12.75 +5.25 x 096 OS.

Patient Exam

The anterior segment was unremarkable except for cataracts in each eye. The dilated fundus examination revealed changes consistent with high myopia. Her corneal topography confirmed a significant amount of regular with-the-rule corneal astigmatism in each eye. The unusual and asymmetric axial length of her eyes (27.10 mm OD and 26.06 mm OS) was confirmed by immersion A-scan biometry as well as with the IOL Master (Carl Zeiss Meditec).

I advised the patient that we could implant an artificial lens in her eye to tackle most of her near-sightedness but because of the unusual length of her eyes, we could not be sure about the exact lens power calculation. I further explained that even after surgery, she would need eyeglasses because of her high level of astigmatism.

Surgery and Outcome

I had learned about toric IOLs at the last AAO meeting, including a recent study concluding that toric lenses can lead to an improved quality of life coupled with cost savings on contact lenses and spectacles.

Toric lenses usually correct up to 2.0 to 2.5D of astigmatism but our patient had almost double this in each eye. Although we would not be able to fully address her unusually high cylindrical power simply with a toric IOL, we wanted to go ahead and try our best.

Measurements were done three different times at two different institutions in order to obtain the most accurate measurements possible for her unusual refraction.

The surgery was very challenging. She had a very deep anterior chamber that made completion of the anterior capsulorhexis difficult. Her cataract extraction was also complicated by poor dilation. Since the alignment marks on the toric IOL could not be visualized because of poor intra-operative dilation, several iris hooks were employed to better visualize the final lens alignment with the pre-op placed marks on the steep axis.

We were able to successfully implant the toric lens in the right eye and she was 20/20-2 1-day post-op, completely uncorrected. She was extremely happy. We had anticipated the need to make additional corrections, but as our representative explained, even if you correct half of the astigmatism, it can make a significant overall difference to the patient.

The patient returned without her eyeglasses, saying she was thrilled with the improved brightness of colors and her new crisp, clear vision.

We told her we would take the same approach to her left eye but wanted her to have realistic expectations about her results. We followed the same game plan, using what we learned on her right eye as a guide. She was 20/25 1-day post-op.

This case was unusual because of the patient's deep anterior chamber and some trampolining of her posterior capsule combined with issues of poor intra-op dilation. But with planning and patience, the outcomes were excellent. After about 10 weeks, the patient's vision has remained stable—she is 20/20 OU uncorrected and her final refraction is plano +0.50 x 100 OD and −0.50 +0.50 x 080 OS.

Despite her unusually long and asymmetric eyes and very high corneal astigmatism, I was able to achieve success with careful planning and persistence in this combined cataract and refractive surgery. Our patient can now see better than ever before. nMD

Dr. Irshad is a fellow in Cornea and Anterior Segment at the Tulane School Of Medicine, Ophthalmology Program in New Orleans, La.