Clinical Evaluation of the Use of Sealed Capsule Irrigation With Sodium Chloride During Pediatric Cataract Surgery and IOL Implantation

Dramatic advances have occurred in the treatment of childhood cataracts in the last 10 years.
Intraocular lens implantation (IOL) has been universally accepted as standard of care in
children beyond 2 years of age. Despite advances in cataract surgery in children, PCO
remained a significant complication following pediatric cataract surgery. In addition to
being visually disturbing, it also induces amblyopia in children and if not treated at
earliest, irreversible visual changes may occur. The younger the child, more acute is the
problem: PCO occurs faster and effect of amblyopia is more pronounced. PCO generally requires
second surgical intervention, as closure of the opening made by YAG capsulotomy is very
common after pediatric cataract surgery. Many times, children are not cooperative to sit down
for YAG capsulotomy, and that may also be an additional indication for second surgery for
PCO.

Removal of residual epithelial cells is one of the key factors to avoid the complication of
PCO. Several chemicals have been suggested in experimental settings to remove or kill these
residual lens epithelial cells. However, they are toxic to other ocular structures.
Researchers are searching for a device which can help to selectively kill these lens
epithelial cells. In the long term, this may help to avoid PCO.

Perfect Capsule: Perfect CapsuleTM (Milvella ltd) is a sterile single use ophthalmic
instrument used to perform sealed irrigation of the capsular bag during cataract surgery in
order to facilitate irrigation of the capsule without the irrigation fluid contacting other
ocular structures. The device has the FDA approval via 510(k) in the USA, and is CE marked in
Europe. No specific age limit has been listed for FDA approval. The device (see fig) consists
of a 7 mm diameter head, a 3 mm wide body and a 4 mm wide foot that remains external to the
eye. The head of the device comprises a circumferential vacuum channel connected to a vacuum
syringe via a vacuum tube. The central portion of the head forms a plug with an
irrigation/aspiration (I/A) channel (the body) which extend through the cornea allowing
fluids to be injected into the under surface of the plug and thus into the capsule. The
device has an internal diameter of 5 mm, is molded in medical grade silicone, packaged and
gamma sterilized. It can be easily rolled or folded to pass through the standard corneal
incision into the eye and positioned on the anterior surface of the capsule using standard
ophthalmic instrument.

Concentrated Sodium Chloride: Concentrated Sodium Chloride injection, USP 23.4% (American
Regent Laboratories, Inc., Shirley, NY) is sterile, preservative free, nonpyrogenic solution
of Sodium Chloride in water for injection. Deionised water has been shown to lyse lens
epithelial cells through osmotic flow. Concentrated Sodium Chloride is not currently
indicated for intraocular use and is also expected to affect the corneal endothelium. Use of
Perfect Capsule will help to avoid the contact of Concentrated sodium Chloride to the
endothelial cells.

For the purpose of this study, Concentrated Sodium Chloride for injection will be colored
with minimal fluorescein so that the flow and location of it can be visualized throughout the
procedure. Viscoelastic within the anterior chamber will provide additional protection for
the corneal endothelium.

SCI with Perfect Capsule and Concentrated Sodium Chloride: Perfect CapsuleTM allows for the
empty capsular bag to be irrigated with Concentrated Sodium Chloride. A previous study in
rabbits has shown that toxic solutions can be safely used for SCI. It has also been shown
that the irrigation solution is contained within the capsular bag when SCI is performed in
humans. Dr. Auffarth has presented a summary of the two year Australian study results and one
year European multi-center clinical trial results performing SCI with distilled water in
humans (At American Society of Cataract and Refractive Surgery meeting, 2005). In 44 patients
studied, the system could be used without complication and the endothelial cell count and
corneal pachymetry was not different from the control eyes. Visual acuity development over a
6-12 months period was similar in both groups. Retro-illumination photographs showed a higher
incidence of fibrosis and anterior capsule whitening in the control group compared to the SCI
group. With the currently available IOLs, PCO is not a significant complication in adult eyes
at 1-2 year postoperative period. Long-term results will be needed to detect the difference
(if any) in terms of PCO in adult eyes. In contrast, PCO is a significant problem in
pediatric eyes. It occurs at a much faster rate and during early postoperative period in
children's eyes as compared to adult's eyes. Younger the child at the time of cataract
surgery, more acute is the problem. Thus, it is possible to see the difference in terms of
PCO (if any) with the use of Perfect Capsule in children's eyes during early postoperative
period, as 1 year postoperatively in this study. We are not aware of any published results or
results presented at the meeting showing use of SCI or distilled water in pediatric eyes.

Inclusion Criteria:

- bilateral cataract

- 4 - 18 years of age

- Informed consent from the parents/legal guardian.

Exclusion Criteria:

- traumatic cataract

- fellow eye - visually not significant cataract

- fellow eye surgery not planned during the study enrollment period

- weak or compromised posterior or anterior capsule

- dense posterior capsule plaque

- preexisting posterior capsule defect

- capsulorhexis diameter>5 mm

- radial capsular tears

- defects within the remaining capsular bag

- inability to visualize the entire capsulorhexis

- shallow anterior chamber

- very high vitreous pressure