A comparison of the astigmatic results with a multifocal toric IOL (M-flex-T, Rayner) and a non-toric model (M-flex, Rayner)
combined with a limbal relaxing incision (LRI) showed that the uncorrected and distance visual acuity results were similar.
The toric IOL was more effective for treating higher amounts of astigmatism. The contrast sensitivity results and rotational
stability also were good. Dr Oliver Findl, MBA, presented his results during the annual meeting of the American Society of
Cataract and Refractive Surgery.
Astigmatism is a common occurrence in the general population, and 30% of the population can have 1 D or more of astigmatism.
In addition, the visual function can decrease substantially, especially with multifocal IOLs, said Dr Findl, chairman, Department
of Ophthalmology, Hanusch Hospital, Vienna, Austria, and consultant ophthalmic surgeon, Moorfields Eye Hospital, London.
To improve vision in these patients the intraoperative options include toric IOL, LRIs, clear corneal incisions and, potentially,
corneal laser surgery. Each of these options has advantages and disadvantages. The outcomes with LRIs are not as stable longterm
and are less predictable than those of the toric IOLs; however, the rotational stability of these IOLs is a safety issue,
although most are stable. The flip side of the coin shows that LRIs are cheaper than IOLs and do not require preoperative
ordering as IOLs do, he noted.
Dr Findl and his colleagues evaluated the refractive multifocal IOL with a 3 D near add on the lens plane; the IOL is available
in two sizes depending on the IOL power. The investigators conducted a randomized, controlled, contralateral eye study that
included 60 eyes of 30 patients with corneal astigmatism ranging from 1 to 2.5 D bilaterally. The multifocal toric IOL was
implanted into one eye of a patient, and an LRI was created in the fellow eye with a 600 Ám steel blade using the Donnenfeld
nomogram followed by implantation of the same nontoric IOL.
The purpose of the study was to compare the level of refractive astigmatism after surgery between the two eyes of each patient.
Other outcome measures were the corrected near and distance visual acuities, the rotational stability 1 hour and 1 and 3 months
postoperatively, and the results of glare and contrast sensitivity measurements under photopic and mesopic conditions.
The patients were asked to fill out a questionnaire that included 17 questions regarding patient satisfaction.
There were no differences between the two eyes in the preoperative astigmatism, and the astigmatism was evenly distributed
between 1 and 2.5 D.
The mean refractive astigmatism with the toric IOL was 0.4 D 3 months after implantation, which was less than the 0.8 D in
the eyes treated with an LRI and multifocal IOL, Dr Findl said.
The uncorrected distance and near visual acuities were similar in both groups, but there was a trend toward slightly better,
although not significant, results in the eyes with the toric IOL. There were also no differences between the toric and non-toric
groups in contrast sensitivity under mesopic and photopic conditions.
The rotational stability was very good, according to Dr Findl, at 2.9░ on average, which agrees with results determined with
other IOLs. This was evaluated using a dedicated retroillumination photography system that has been shown to have an accuracy
The questionnaire results showed that 95% of patients needed spectacles for some visual tasks, especially for periods of long-term
reading. Most patients, however, could perform tasks throughout the day without using glasses, Dr Findl added.
No patients reported symptoms of dry eye, which is a potential problem with LRIs. Glare and halos developed in 41% and 35%,
respectively. No explantations were performed and patients expressed satisfaction with the outcomes.
"The toric IOL was a bit more effective for addressing moderate corneal astigmatism from 1 to 2.5 D, especially in the subgroup
of patients with 2 D and more of astigmatism," Dr Findl concluded. "The uncorrected distance and near visual acuities were
similar with both treatments. The rotational stability was excellent. The patient satisfaction was good."