Transcript Supplemental Content

JAMA Ophthalmology Journal Club Slides:
TT Clamp vs Standard BLTR
for Trichiasis Surgery
Gower EW, West SK, Harding JC, et al. Trachomatous trichiasis clamp
vs standard bilamellar tarsal rotation instrumentation for trichiasis
surgery. JAMA Ophthalmol. Published online November 9, 2012.
doi:10.1001/jamaophthalmol.2013.910.
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Introduction
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Trachomatous trichiasis (TT) is the leading infectious cause of blindness. It
is the result of years of ocular chlamydial infection, which causes the eyelid
to scar and turn inward such that eyelashes abrade the eye.
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Corrective surgery is performed by surgical technicians with limited
training.
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Postoperative trichiasis is common.
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Previous research shows that surgical factors likely play a role in
postoperative TT and other unfavorable outcomes.
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Objective
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To determine whether a newly designed surgical tool, the TT clamp, could
reduce the rate of unfavorable outcomes occurring within 2 years following
surgery.
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Methods
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Study Design:
– Prospective, randomized, single-masked clinical trial.
– 18 surgeons were randomized to perform surgery with the TT clamp or
standard bilamellar tarsal rotation (BLTR) instrumentation.
– Patients were randomized to surgery with standard BLTR
instrumentation or the TT clamp and were followed up for 2 years
postoperatively.
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Participants: Patients undergoing trichiasis surgery in southern Tanzania.
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Methods
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Data Analysis:
– 3 outcomes were evaluated individually and combined.
– Outcomes included postoperative trichiasis, pyogenic granuloma
formation, and eyelid contour abnormality.
– Generalized linear mixed models were used to evaluate the relative risk
of events between the TT clamp and standard BLTR.
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Limitations:
– Each surgical technician performed only 1 type of surgery. An attempt
was made to match technicians based on surgical skill, but differences
between groups may have existed.
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Results
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1917 individuals were randomized: 957 to TT clamp, 960 to standard BLTR.
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74.4% were female.
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Eyes undergoing surgery: 1671 with TT clamp, 1674 with standard BLTR.
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23.9% of patients were blind in at least 1 eye.
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Baseline characteristics were comparable between groups except TT severity.
The TT clamp group had more severe baseline trichiasis (a risk factor for
recurrence).
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Results
Characteristics of Study Eyes at Last Visita
Overall rates of at least 1
unfavorable outcome were
similar between groups and
higher than is desirable.
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Results
Outcomes in the TT Clamp Group vs the Standard BLTR Group
After adjustment, no differences were seen in
the rate of at least 1 unfavorable outcome.
Granulomas and moderate to severe eyelid
contour abnormalities were less likely in the
TT clamp group, while postoperative TT was
somewhat more common.
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Comment
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Overall rates of at least 1 unfavorable outcome were similar between
groups, but types of outcomes differed between groups.
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Granuloma and eyelid contour abnormalities were more common using
standard BLTR. These findings are consistent with our initial hypothesis:
use of the TT clamp will ensure a single full-thickness incision with less risk
of jagged tissue fragments and beveled incisions, 2 factors believed to be
important for these outcomes.
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Postoperative TT was more common in the TT clamp group. Baseline TT
severity is a predictor of postoperative TT. The approach for suturing with
the TT clamp may have had an effect on the risk of postoperative TT. This
area needs to be investigated further.
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Contact Information
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If you have questions, please contact the corresponding author:
– Emily W. Gower, PhD, Departments of Epidemiology and Prevention and
Ophthalmology, Wake Forest School of Medicine, Wake Forest Health
Sciences, Medical Center Boulevard, Winston-Salem, NC 27157
([email protected]).
Conflict of Interest Disclosures
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None reported.
Funding/Support
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This work was supported by a grant from the Bill and Melinda Gates Foundation.
Helen Keller International provided manpower and funding to assist in screening
and surgery. Beaver-Visitec International Inc provided manpower and materials to
produce the TT clamp at no charge. Drs Gower and West are recipients of awards
from Research to Prevent Blindness.
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