Authors: Liliana Werner, MD, PhD,1,2 Susan Strenk, PhD,3

1
Pathological Analysis of a Pannu Universal IOL

• Authors Liliana Werner, MD, PhD,1,2 Susan
  Strenk, PhD,3
• Lawrence Strenk, PhD,3 Don Davis, MD,1
• Oliver Yeh,1 Nick Mamalis, MD1
• From the 1) Moran Eye Center, University of
  Utah, Salt Lake City, UT
• 2) Berlin Eye Research Institute, Berlin, Germany
• 3) MRI Research, Inc., Cleveland, OH

-Design details of the MRI used are proprietary
to MRI Research Inc. The other authors have no
financial or proprietary interest in any product
mentioned in this poster. -Supported in part by
a Seed Grant of the University of Utah to Liliana
Werner, MD, PhD, and by grants from Alcon
Laboratories, and the National Eye Institute (
R43EY018518) to Susan and Lawrence Strenk.
2

• In the early 1980s, lenses of a style referred to
  as Universal were designed to be fixated in
  either, the anterior or the posterior chamber.
  One of such lenses was invented by J.S. Pannu
  (Figure 1).1 The flexible loops would allow for
  implantation in eyes of different sizes. The
  rings at the extremities of the loops could be
  used for suturing techniques for fixation of the
  lens in the ciliary sulcus or in the anterior
  chamber.2-3

Figure 1 Figure from the Pannu IOL patent
4,435,855, showing the different sites for
fixation.
3

• We had the opportunity to receive in our
  laboratory a human eye obtained postmortem,
  implanted with a Pannu IOL.
• The aim of our study was to provide clinicians
  with the pathological features of this specimen.
• To the best of our knowledge, this is the only
  report available on long-term effects of this
  lens in the human eye.

4

• Patient 82-year-old Caucasian man, deceased in
  2007.
• Lens implanted Single-piece, open-loop, all-PMMA
  IOL, marketed as Universal style (Pannu lens).
• Manufacturer Unknown.
• Interval implantation/death of donor Unknown.
  However, as this lens is not in use since the
  late 1980s, we assume the interval was
  approximately 20 years.
• Laboratory analyses High-resolution anterior
  segment magnetic resonance imaging (MRI) of the
  enucleated eye gross analyses of the anterior
  segment of the eye from the posterior and
  anterior views gross and light microscopic
  analyses of the lens after explantation and
  histopathological analysis of the donor eye.

5

• MRI examination of the whole eye revealed the
  presence of an IOL with features mostly
  characteristic of a posterior chamber lens, but
  implanted in the anterior chamber with loops
  fixated to the angle. The optic was in a plane
  slightly anterior to the loops, which seemed to
  be pushing onto the iris (Figure 2, arrow). The
  frontal MRI view (Figure 3) showed the loops in a
  counter-clockwise configuration. The lens was
  fairly centered in relation to the pupil.

Figure 2
Figure 3
6

• Gross examination of the anterior segment from
  anterior (Figures 4 and 5) and posterior (Figures
  6 and 7) views showed significant pigmentary
  dispersion, pupil ovalization, and peripheral
  anterior synechia formation. Two surgical
  iridectomies were apparently performed, and there
  were relatively large areas of transillumination
  defects, some of which coincided with the point
  at which the rings at the extremities of the
  loops were in contact with the iris (arrows).

Figure 4
Figure 6
Figure 5
Figure 7
7

• Gross (Figure 8) and light microscopy (Figures
  9, 10, and 11) of the lens revealed the presence
  of iris pigments throughout the surface of the
  lens.
• One of the loops was incarcerated within the iris
  tissue, which remained attached to its surface
  upon explantation (arrows).

Figure 8
Figure 9
Figure 10
Figure 11
8

• Histopathological examination of multiple
  sections obtained from the enucleated eye showed
  that the cornea was thick, with a significant
  attenuation of the corneal endothelium (Figures
  12, and 13 PAS stain). The anterior chamber
  angle exhibited areas of marked enlargement
  (Figure 14 PAS stain), while other areas had
  peripheral anterior synechiae.

Cornea
Cornea
Corneal endothelium
Iris
Figure 12
Figure 13
Figure 14
9

• Histopathological examination of multiple
  sections obtained from the enucleated eye also
  showed significant vacuolization within the
  pigmented epithelium of the iris (Figures 15 and
  16 PAS stain). The basement membrane of the
  ciliary body epithelium was somewhat thick, which
  may indicate long-standing diabetes (Figure 17
  PAS stain arrow).

Iris
Iris
Figure 15
Figure 16
Figure 17
10

• Because the Pannu IOL may still be observed
  clinically on occasion, this report sought to
  present its history and pathological features.
  This case suggests that the IOL may remain
  well-centered over the long term, when implanted
  into the anterior chamber.
• However, gross and histopathological examination
  revealed that the overall design and fixation
  mechanism of the lens caused long-term trauma
  with significant pigmentary dispersion, among
  other issues. Although unknown in this donor,
  development of further complications, such as
  pigmentary glaucoma remains a possibility.

11

• The Pannu Universal IOL has design features
  which are overall those of a posterior chamber
  lens. Interestingly, some surgeons worldwide
  would still implant posterior chamber lenses in
  the anterior chamber in cases lacking capsular
  support,4 despite clinical studies describing
  complications such as loop encapsulation by
  peripheral anterior synechiae, recurrent iritis,
  central loop displacement with corneal
  endothelial touch, progressive endothelial cell
  loss and corneal edema, glaucoma, and cystoid
  macular edema.5
• In conclusion, the Pannu universal IOL has
  probably not been implanted in the US since the
  late 80s. This study shows long-term biologic
  consequences due to its overall design and
  mechanism of fixation. Our findings are relevant,
  considering more recent anecdotal reports of
  implantation of posterior chamber lenses into the
  anterior chamber (cataract_at_lists.ascrs.org).

12

• 1. Pannu JS, inventor. Universal intraocular lens
  and a method of measuring an eye chamber size. US
  patent 4,435,855. March 13, 1984.
• 2. Pannu JS. Technique for fixating a subluxated
  posterior chamber lens. J Cataract Refract Surg
  1988 14688-690.
• 3. Pannu JS. A new suturing technique for ciliary
  sulcus fixation in the absence of posterior
  capsule. Ophthalmic Surg 1988 19751-754.
• 4. Hara T, Hara T. Ten-year results of anterior
  chamber fixation of the posterior chamber
  intraocular lens. Arch Ophthalmol 2004
  1221112-1116.

• 5. Koch DD, Wang L.
  Complications of anterior
  chamber fixation of posterior chamber intraocular
  lenses. Arch Ophthalmol 2006 124606-607 author
  reply.