Modified Instrumentation for Surgery to Correct Trichiasis
Summary
Trachoma, an ocular infection caused by C. trachomatis, is the second leading infectious cause of blindness worldwide. Years of repeated infection with C. trachomatis cause the eyelid to scar and contract and ultimately to rotate inward such that the eyelashes rub against the eyeball and abrade the cornea (trichiasis). The World Health Organization (WHO) has endorsed a multi-faceted strategy to combat trachoma which includes surgery to repair lids distorted by trachoma (trichiasis) in imminent danger of vision loss. Current evidence suggests that long-term success rates of trichiasis surgery are less than optimal due to variation in surgical technique. Previous research by this study team has demonstrated that shorter incisions have a higher rate of trichiasis recurrence. In addition, observations by this team's oculoplastic surgeon have led to the hypothesis that granuloma formation and lid contour abnormalities may result from current surgical practices. The objective of this study is to compare outcomes of trichiasis surgeries performed with the newly developed trachomatous trichiasis (TT) clamp versus surgeries following standard technique (bilamellar tarsal rotation procedure or BTRP).
Description
Field observations in 2005 by this study's PI and oculoplastic surgeon revealed some significant departures from current trichiasis surgery procedure (bilamellar tarsal rotation procedure or BTRP), as described in the WHO manual, "Trichiasis Surgery for Trachoma-the Bilamellar Tarsal Rotation Procedure". These procedural departures were felt to contribute to adverse outcomes, including trichiasis recurrence, granuloma formation and lid contour abnormalities. This study team developed a new surgical tool, the TT clamp, to help improve surgical outcomes following BTRP.
A randomized, single-masked clinical trial will be implemented in the Mtwara region in Tanzania. Study participants will be randomized on a 1:1 basis to surgery with the TT clamp or to surgery with standard BTR equipment. All surgeries will take place at surgical centers in Mtwara and Lindi over an 8-month period.
Baseline assessment for severity of trichiasis and other predictors of surgical failure will be carried out prior to surgery. Follow-up is planned at 2 weeks (for suture removal), 6 weeks, 12 months, and 24 months post-surgery. At each follow-up visit participants will be assessed for evidence of unfavorable outcomes, including trichiasis recurrence, granuloma formation, and lid contour abnormalities. All outcomes will be assessed clinically by a trained observer who is masked to intervention status.
Study Design
Allocation: Randomized, Control: Active Control, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Treatment
Conditions
Trachoma
Intervention
TT Clamp, Standard BTRP Technique
Location
Johns Hopkins University
Baltimore
Maryland
United States
21205
Status
Active, not recruiting
Source
Johns Hopkins University
Results (where available)
Links
- Source: http://clinicaltrials.gov/show/NCT00886015
- Information obtained from ClinicalTrials.gov on July 15, 2010
Medical and Biotech [MESH] Definitions
Patch-clamp Techniques
An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.
Colorimetry
Any technique by which an unknown color is evaluated in terms of standard colors. The technique may be visual, photoelectric, or indirect by means of spectrophotometry. It is used in chemistry and physics. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Glucose Clamp Technique
Maintenance of a constant blood glucose level by perfusion or infusion with glucose or insulin. It is used for the study of metabolic rates (e.g., in glucose, lipid, amino acid metabolism) at constant glucose concentration.
Conjunctivitis, Inclusion
An infection of the eyes characterized by the presence in conjunctival epithelial cells of inclusion bodies indistinguishable from those of trachoma. It is acquired by infants during birth and by adults from swimming pools. The etiological agent is CHLAMYDIA TRACHOMATIS whose natural habitat appears to be the genito-urinary tract. Inclusion conjunctivitis is a less severe disease than trachoma and usually clears up spontaneously.
Reverse Transcriptase Polymerase Chain Reaction
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
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