Management of Intraoperative Floppy-iris Syndrome and Small Pupils With Different Mechanical Devices Clinical Trial
— IFISOfficial title:
Methods to Manage Intra-operative Floppy-iris Syndrome and Poor Pupil Dilation in Cataract Surgery: an Exploratory Study
Cataract surgery is one of the most frequently performed surgeries worldwide and
complications are rare. However, there are factors that increase the risk of complications,
such as poor pupil dilation and intra-operative floppy iris syndrome (IFIS). Reasons for a
small pupil size are pseudoexfoliation syndrome (PXF) syndrome, uveitis or synechia and the
use of pilocarpin drops. IFIS is a syndrome usually caused by systemic alpha1-blockers
(foremost tamsulosin) used to treat benign prostatic hyperplasia.1,2 As described by Chang
and Campbell3 IFIS is characterized by billowing of a flaccid iris stroma, a propensity for
iris prolapse towards the phacoemulsification tip as well as towards the incisions and
progressive intra-operative pupil constriction.
Stopping tamsulosin pre-operatively did not show to effectively prevent IFIS.4,5 However, it
is of high importance to identify patients prior to surgery, who are treated with
alpha1-blockers, or patients with a small pupil size and poor pharmacological pupil
dilation. Some methods, such as intracameral injection of phenylephrine is only sufficient
in a few cases 6, and a disadvantage is the risk of a hypertensive episode.7 Another
pharmacological method is the use of atropine drops pre-operatively, but this method did not
show to sufficiently reduce IFIS.4
Different methods were shown to reduce intra-operative problems due to IFIS/small pupil
size:
The use of highly cohesive ophthalmic viscosurgical devices (OVD), also called
viscoadaptives, such as sodium hyaluronate (e.g. AMO Healon5 or Croma Eyefill H.D.) help to
viscodilate the pupil and by resting on the iris during the entire phacoemulsification
procedure reduce the risk of iris prolapsing towards the incisions. This method is more
dependent on a central phacoemulsification technique and low fluidic parameters to allow the
OVD to stay on the iris during the entire procedure.8 In case of a small pupil, pupil
stretching with 2 instruments can be used additively.
Another option to stabilize the pupil size is the use of mechanical pupil expansion devices,
such as
1. Iris retractors - these devices are routinely used to dilate the pupil
intra-operatively. Typically, 4 or 5 iris retractors, also called iris hooks, are
inserted through 4-5 incisions. Usually, the IFIS pupil is very elastic and the risk of
overstretching is small.8
2. Pupil expansion rings, such as the Malyugin ring. This ring is placed on the pupil
margin with an injector through the main incision. It eliminates the need of additional
incisions and saves time.9
Rationale To compare different methods to manage IFIS and poor pupil dilation in cataract
surgery: a pupil expansion ring (Malyugin Ring), iris retractors (iris hooks) and a
viscoadaptive OVD.
| Status | Recruiting |
| Enrollment | 80 |
| Est. completion date | December 2013 |
| Est. primary completion date | July 2013 |
| Accepts healthy volunteers | No |
| Gender | Both |
| Age group | 21 Years and older |
| Eligibility |
Inclusion Criteria: - Age-related cataract - Age 21 and older - written informed consent prior to surgery - Small pupil group: Patients with a pupil size below 4.0 mm after pharmacological dilation with tropicamide 1% and phenylephrine 2.5% gtt as used routinely for pupil dilation, - IFIS group: Patients, who currently are or have been treated with Alpha-adrenergic receptor antagonists (Tamsulosin- i.e. Alna ret.®) Exclusion Criteria: - Pregnancy (pregnancy test will be taken pre-operatively in women of reproductive age) - Traumatic cataract - History of uveitis - Any ophthalmic pathology that could compromise the measurements |
Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Treatment
| Country | Name | City | State |
|---|---|---|---|
| Austria | VIROS- Vienna Institute for Research in Ocular Surgery - Department of Ophthalmology, Hanusch Hospital Vienna | Vienna |
| Lead Sponsor | Collaborator |
|---|---|
| Vienna Institute for Research in Ocular Surgery |
Austria,
| Type | Measure | Description | Time frame | Safety issue |
|---|---|---|---|---|
| Primary | Mean difference in flare (pre-operatively to 1 day post-operatively) between the OVD and the device group | pre-operatively to 1 day postoperatively | No |