CATARACT/ IOL |
When seeing is better than believing by Matt Young EyeWorld Contributing Editor |
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 This patient has anterior basement membrane dystrophy (ABMD) changes in the epithelium,
which is viewed here with a slit lamp. The slit lamp still is
a very useful tool even in an age of new advances in imaging
technology Source: Christopher Rapuano, M.D.
Ophthalmologists know posterior capsule rupture can occur
after nonpenetrating ocular injury. Their knowledge of this problem could
be further enhanced by Scheimpflug imaging, which was used recently in
just such a case for possibly the first time to visualize and quantify
the posterior capsule rupture size. “When TPCR [traumatic posterior capsule rupture] occurs, the extent
of rupture, amount of residual nucleus and cortex, and presence or absence
of vitreous prolapse in the anterior chamber are all variable factors which
can be documented with Scheimpflug imaging,” according to Dilraj Grewal,
M.D., Bascom Palmer Eye Institute, Palm Beach Gardens, Fla. Dr. Grewal reported
these findings in the May-June 2008 issue of the European Journal of Ophthalmology.
An in-depth look
Dr. Grewal analyzed an 11-year-old boy two days after blunt trauma occurred
to the left eye. It was caused by a slingshot. BCVA was 20/20 in the right
eye and 20/400 in the affected left eye. “Slit lamp biomicroscopy revealed a Vossius ring traumatic cataract,
traumatic posterior capsular rupture (TPCR) with bulging out of lens cortex,” Dr.
Grewal reported. “Gonioscopy revealed a 360-degree angle recession.
It was a closed globe injury, Type B, Grade 3, Zone 3 RAPD negative.” Further, Scheimpflug imaging (Pentacam 70700, Oculus, Wetzlar, Germany) was
used. According to the manufacturers: “The Pentacam is a rotating Scheimpflug
camera which captures Scheimpflug images of the anterior eye segment. The
Scheimpflug technique provides sharp and crisp images that include information
from the anterior corneal surface to the posterior crystalline [capsule].
The key advantages of the rotating imaging process are the precise measurement
of the central cornea, the correction of eye movements, the easy fixation
for the patients and the extremely short examination time.” The Pentacam
could be used by corneal refractive surgeons and cataract surgeons. It could
be used in examinations from general screenings to glaucoma screenings, providing
the following: anterior and posterior corneal topography and elevation maps,
corneal pachymetry, 3D-chamber analyzing, lens density, tomography, and improved
IOL-calculation. In this case, it was used to further analyze posterior capsule
rupture. “Traumatic cataract in region of TPCR was evidenced by increased lens
density at cortex-vitreous interface,” Dr. Grewal noted. Scheimpflug imaging showed posterior pseudo-lenticonus, or lens material
bulging through the posterior capsule rupture. It was able to measure the
size of the posterior capsule opening, which was 5920 microns x 3880 microns
preoperatively.
After surgery, it was able to visualize a well-centered IOL, “increased
density along the short axis of TPCR,” and “increased density
along the long axis of TPCR,” Dr. Grewal reported. The posterior capsule opening postoperatively measured 4840 microns x 3970
microns, as determined by Scheimpflug imaging. After phacoemulsification
with and IOL implant was carried out, BCVA reached 20/20 in the affected
eye. “I think that’s really a great use of technology,” said
Mark Packer, M.D., clinical associate professor of ophthalmology, Casey Eye
Institute, Oregon Health & Science University, Portland, Ore., in reference
to Scheimpflug imaging for analyzing a posterior capsule rupture. Nonetheless, he doesn’t consider it to be an essential technology moving
forward to help diagnose and treat posterior capsule rupture. “This could be done at the slit lamp,” he said. “You could
just use a slit lamp and make the same diagnosis. It’s just an optical
measurement technique.” He added, “ I have thought about [Scheimpflug
imaging] as a very expensive slit lamp.” Nonetheless, Dr. Packer said, Scheimpflug imaging does add an element of
precision. “You could grade cataracts this way and correlate them with
effective phaco time,” he said. He wondered, however, about the patient’s age in this case, suggesting
that very young children could have trouble sitting still for image taking.
There are other technologies in play that also are elucidating ocular problems
like never before. Ultrasound, for instance, could help analyze a posterior
cataract, he said. Nonetheless, the use of Scheimpflug imaging to examine posterior capsule
rupture demonstrates the versatility of this technology, and “how inventive
surgeons can be,” Dr. Packer said.
Clearly, in this case study, Scheimpflug imaging was used in addition to
slit lamp biomicroscopy and gonioscopy rather than in place of these devices. For the moment, Scheimpflug imaging—at least for analyzing posterior
capsule rupture—appears to be an additional help, rather than a replacement
technology. Editors’ note:
Dr. Grewal has no financial interests related to this study. Dr.
Packer has no financial interests related to his comments. Contact
information: Grewal: Dilraj@gmail.com Packer: 541-687-2110 , mpacker@finemd.com |
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