Download Excellent visual outcomes for ICL, but cataract formation

Excellent visual outcomes for ICL, but cataract
formation still a problem
Dermot McGrath
in Lisbon
LONGTERM clinical experience
with the Implantable Contact
Lens (Visian ICL, Staar Surgical)
demonstrates consistently high
rates of refractive success and
patient satisfaction, but these
benefits must be balanced with
the possibility of eventual surgery
for ICL-induced cataract,
according to a number of
researchers at the XXIII
Congress of the ESCRS.
“This foldable, posterior
chamber, phakic IOL performs
well in terms of safety, efficacy
and predictability for moderate
to high myopia, but there remains
a concern in the long term due
to the relatively high incidence of
anterior subcapsular cataract
found with this type of lens,” said
Philippe Othenin-Girard MD.
Dr Othenin-Girard, University
Eye Hospital, Lausanne,
“This foldable,
posterior
chamber, phakic
IOL performs well
in terms of safety,
efficacy and
predictability for
moderate to high
myopia, but
there remains a
concern in the
long-term.”
Switzerland, noted that the ICL
can be implanted through a small
incision, offers an excellent range
of correction, and typically results
in very good uncorrected acuity.
Along with his co-researchers
Drs Nguyen, Titzé, Bornet and
Gonvers, Dr Othenin-Girard
implanted 149 ICLs in 87 patients
between April 1998 and August
2005. The final study data
included 136 eyes of 82 patients
with a mean age of 38 years,
ranging from 16 to 65 years.
Mean follow-up was 50 months
with a range of 12 to 86 months.
The mean preoperative spherical
equivalent was –13.1 D, and the
mean lens power was –16.3 D.
Of 73 patients who were
targeted for emmetropia, the
mean preoperative spherical
equivalent was –11.7 D (range
–7.3 D to –17.8 D).
Three generations of the Staar
ICL were implanted over the
course of the study, the majority
of which were the latest model,
the V4.The V4 is said to have
improved vaulting to reduce the
possibility of contact with the
crystalline lens.
Good predictability and safety
Predictability was excellent, noted
Dr Nguyen, who presented the
visual acuity data. For the 73 eyes
targeted for emmetropia, the
mean final SE was –0.69 D (range
+1.25D to –4.88 D). Some 78% of
eyes were within 1.0 D of
intended refraction, with 44%
within 0.5 D.
The data for safety were
similarly encouraging. Some 72%
of eyes gained one or more lines
of best-corrected visual acuity,
22.5% remained stable and 5.6%
lost one or two lines. Of the
group that was targeted for
emmetropia, uncorrected visual
acuity was 0.5 or better in 77% of
the eyes and 1.0 or better in 26%.
The results for intraocular
pressure showed that 52 eyes had
a higher postoperative IOP, 21
eyes remained stable and 63 eyes
recorded a lower IOP, although
the differences were not
statistically significant. Dr Nguyen
also noted that there was no
demonstrable correlation
between an increase in IOP and
the degree of vaulting.
Complications associated with
the procedure included two acute
symptomatic vitreous
detachments that occurred in the
first week after Nd:Yag laser
iridotomy. One of these led to
rhegmatogenous retinal
detachment three weeks after
ICL implantation.The other
patient complained of acute
floaters and underwent a
vitrectomy before ICL
implantation.
Intraoperative complications
included two ICLs that had to be
second, a clear lens three months
after the surgery in order to
exclude the possibility of a
peroperative iatrogenic cataract.
He said that between 2003 and
2005, the rate of ICL-induced
subcapsular opacities progressed
from 26% to 30%, necessitating
six new phacoemulsifications. No
subcapsular opacities were
observed before the one-year
follow-up point.
Dr Othenin-Girard stressed
that age played a role in the
incidence of subcapsular
opacities.
“It is clear that the number of
cataracts increases with age,
“It is clear that the number of
cataracts increases with age, 17.4% of
the patients aged between 31 and 40
years developed a cataract, more than
44% between 41 and 50 years and 42%
between 51 and 64 years.”
removed and replaced during
surgery – one because of a 180degree rotation of the ICL, and
the other because a plate of the
ICL had completely folded on
itself. Postoperative complications
included six cases of peripheral
bulging of the plates, six cases of
late ocular hypertension, four
cases of asymptomatic late retinal
tears, and four cases of excessive
vaulting, one which required a
surgical reposition eight months
after surgery.
Subcapsular opacities
Focusing on the persistent
problems of cataract formation
associated with the ICL, Dr
Othenin-Girard said that two
main conditions needed to be
satisfied for the development of
an ICL-induced cataract: first, the
presence of characteristic
anterior subscapsular opacity and
17.4% of the patients aged
between 31 and 40 years
developed a cataract, more than
44% between 41 and 50 years
and 42% between 51 and 64
years. There was also a
correlation between the
incidence of cataract and higher
lens power.”
Examination of peripheral
vaulting by Scheimpflug
photography confirmed the
research team’s previous finding
that total vaulting completely
prevents cataract formation.
Dr Othenin-Girard said that no
ICL-induced cataracts had been
observed before a follow-up of
one year and that the number of
cataracts had slowly increased
thereafter, with a progressive
density of opacities. He said that
the typical subcapsular cataract is
related to the age of the patient,
the central vaulting and the ICL
power value.
“Total vaulting protects the
lens against cataract, however
only a minority of eyes have this
complete vaulting. No matter
what technology is used to
measure the sulcus diameter, a
precise total vaulting
predictability cannot be actually
achieved. We have therefore
restricted our ICL indication to
myopia over –9.0 D and for
patients older than 40 years of
age to reduce the risk of ICLinduced cataract in young
patients, even if the risk is agerelated,” he said.
Philippe Othenin–Girard MD
[email protected]
Good vaulting essential
Exploring further the relationship
between IOL vaulting and
cataract development, Dr
Othenin-Girard noted that all
examinations were performed
with Scheimpflug photography
and a mean central vaulting had
been calculated based on 10
values per eye. Analysis showed a
significant difference between the
clear lens group and the cataract
group in terms of central
vaulting, with a higher mean vault
value in the clear lens group.
EuroTimes March 2006