Two IOL styles prove to be equally
accommodating in comparative trial
NICE - The HumanOptics and CrystaLens IOLs appear to perform equally
well in what may be the first direct comparison of accommodative
lenses, according to a Swiss ophthalmologist.
Thirty-two eyes of cataract patients underwent phacoemulsification
and implantation of the HumanOptics Accommodative® 1CU or the
The accommodative amplitude was almost identical with the two lenses
after three to six months follow-up, Filippo Simona MD said.
The 14 eyes implanted with the CrystaLens achieved 1.33 D of accommodation
while the 18 eyes implanted with HumanOptics IOL achieved 1.36 D
Visual acuity improved in all patients with values between 20/50
and 20/16. Overall the amplitude of accommodation ranged from 0.5
to 1.75 D. Near visual acuity with distance correction ranged from
J10 (0.2) to J1 (0.8).
Eyes implanted with the CrystaLens had a mean distance UCVA of 0.84
and a mean distance BCVA of 0.94. The mean near UCVA was 0.36 and
best corrected near visual acuity was 0.32.
Eyes with the HumanOptics lens had a mean distance UCVA of 0.80
and a mean distance BCVA of 1.01. The mean near UCVA for the group
was 0.48 and 0.34 with distance correction.
Spherical equivalent (SE) was -0.25 D for the CrystaLens and -0.59
D for the HumanOptics IOL, Dr Simona noted.
"The HumanOptics eyes tended to be a little bit more myopic
and therefore had better unaided near visual acuity. We have since
increased the A constant from 119 to 118.5," he added.
Prior to carrying out the implantation procedures, Dr Simona and
his associates measured anterior chamber depth and axial length
using immersion biometry and the IOL master machine.
was uncomplicated in all patients with successful in-the-bag implantation
and good centration of the IOLs.
Dr Simona noted that patients with both lenses appeared to learn
to achieve better accommodation as time went on. Their findings
also suggested that the physiology of accommodation still holds
"In theory the greater the power of the IOL the less it must
move to achieve the same accommodation, but in reality we didn't
find this strong relationship.
"For example, while we have one patient with an IOL of 16 D
power who has an accommodation of 1.75 D, another patient with an
IOL of 23 D has the same 1.75 D of accommodation," he said.
Dr Simona noted that the unanswered questions with the two lenses
include their long-term efficacy and the degree of ametropia in
which they will be useful.
"Our results show that at three months the two types of IOL
are mathematically identical and the mean accommodative power was
1.35 D. Further studies are needed to assess the long-term stability
of this pseudoaccommodation," Dr Simona added.
Both the CrystaLens and the HumanOptics 1CU operate mechanically.
The IOLs have hinged haptics that create accommodation by moving
the lens in response to the ciliary muscles.