Modified Instrumentation for Surgery to Correct Trichiasis

Partnership for the Rapid Elimination of Trachoma (PRET) Clinical Trial of Evaluation of Modified Instrumentation for Surgery to Correct Trichiasis

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 BLTR).

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 BLTR. 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 BLTR 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.

A pyogenic granuloma was defined as a sessile growth of 2 mm or more in diameter on the tarsal conjunctiva.

At least 1 unfavorable outcome, including mild, moderate, or severe trichiasis; granuloma; or mild, moderate, or severe eyelid contour abnormality

Number of Eyelids With Normal or Mild Eyelid Contour Abnormalities vs Moderate or Severe Eyelid Contour Abnormalities

Eyelid contour abnormalities (ECA) were graded by photographs of the eyes. In the primary outcome measure, normal eyes and mild eyelid contour abnormalities are considered together, and moderate or severe eyelid contour abnormalities are considered together. ECA severity is defined as follows: Mild: Vertical deviation from the natural contour < 1 mm in height (less than half the pupil height in daylight) and affecting < 1/3 of horizontal eyelid length; Moderate: Vertical deviation from the natural contour 1-2 mm in height (about the pupil height in daylight) or affecting 1/3-2/3 of horizontal eyelid length; Severe: Vertical deviation from the natural contour > 2 mm in height (more than the pupil height in daylight) or a defect > 2/3 of the horizontal eyelid length

Eyelid contour abnormalities (ECA) were graded by photographs of the eyes. ECA severity is defined as follows: Mild: Vertical deviation from the natural contour < 1 mm in height (less than half the pupil height in daylight) and affecting < 1/3 of horizontal eyelid length; Moderate: Vertical deviation from the natural contour 1-2 mm in height (about the pupil height in daylight) or affecting 1/3-2/3 of horizontal eyelid length; Severe: Vertical deviation from the natural contour > 2 mm in height (more than the pupil height in daylight) or a defect > 2/3 of the horizontal eyelid length

Trichiasis is generally defined as 1 or more eyelashes touching globe in primary position. Classifications of trichiasis severity are as follows: Mild: 1-4 Eyelashes touching globe, no epilation OR 1-10 Eyelashes epilated, no eyelashes touching globe; Moderate: 5-9 Eyelashes touching globe, no epilation OR 1-4 Eyelashes touching globe and 1-10 eyelashes epilated; Severe: 5-9 Eyelashes touching globe and 1-10 eyelashes epilated OR 10 Eyelashes touching globe, regardless of epilation status OR 11-20 Eyelashes epilated, regardless of eyelashes touching globe OR Entire eyelid epilated, regardless of eyelashes touching globe

Inclusion Criteria: Presence of upper lid trichiasis: defined by at least one eyelash touching the globe of the eye or evidence of epilation No previous report of trichiasis surgery in at least one eye with trichiasis: eyes with prior surgery are already at high risk due to the prior surgery, and their inclusion may decrease our ability to clearly evaluate our primary outcome if unilateral surgery has been performed previously, only the eye without prior history of surgery will be in the study, even if both eyes require surgery Age 18 or older (in order to provide consent as an adult): the vast majority of trichiasis patients are aged 18 or older At time of enrollment, subjects must state their intention to remain in the area for two years to facilitate study follow-up Exclusion Criteria: Absence of upper lid trichiasis Prior trichiasis surgery on both eyes Age 18 or younger Subjects who are transiently in the area

Deidentified data will be provided to investigators through application to the data committee at Johns Hopkins University.

Gower EW, Munoz B, Rajak S, Habtamu E, West SK, Merbs SL, Harding JC, Alemayehu W, Callahan EK, Emerson PM, Gebre T, Burton MJ. Pre-operative trichiatic eyelash pattern predicts post-operative trachomatous trichiasis. PLoS Negl Trop Dis. 2019 Oct 7;13(10):e0007637. doi: 10.1371/journal.pntd.0007637. eCollection 2019 Oct.

Gower EW, West SK, Harding JC, Cassard SD, Munoz BE, Othman MS, Kello AB, Merbs SL. Trachomatous trichiasis clamp vs standard bilamellar tarsal rotation instrumentation for trichiasis surgery: results of a randomized clinical trial. JAMA Ophthalmol. 2013 Mar;131(3):294-301. doi: 10.1001/jamaophthalmol.2013.910.