Report of the 4th Global Scientific Meeting on Trachoma, Geneva, 27–29 November 2018

Overview

The 4th Global Scientific Meeting on Trachoma:
1. Recommended that the World Health Organization not change the existing trachomatous
inflammation—follicular elimination prevalence threshold [paragraph 2.8];
2. Requested the global trachoma programme to continue to investigate, in national programmes,
the role of alternative technical indicators of elimination of trachoma as a public health problem
[paragraph 2.8];
3. Recommended that the definition of trachomatous trichiasis be changed to “at least one eyelash
from the upper eyelid touches the eyeball, or evidence of recent epilation of in-turned eyelashes
from the upper eyelid”. (The change here is the exclusion of trichiasis that affects only the lower
eyelid.) [paragraph 3.8];
4. Noted that in circumstances where there is evidence of upper eyelid trichiasis with little or no
evidence of current or past active trachoma, cases of trichiasis should be assessed (by
clinicians with appropriate training and expertise) for alternative aetiologies. This may take into
account evidence such as trachomatous scarring of the conjunctiva, superior pannus, Herbert’s
pits and entropion, in order to determine whether upper eyelid trichiasis is due to trachoma or
not [paragraph 3.9];
5. Recommended that trichiasis surgeons target a cumulative incidence of post-operative
trachomatous trichiasis of < 10% by six months for cases that had minor trachomatous trichiasis
(≤ 5 eyelashes touching the eyeball) pre-operatively, and < 20% by six months for cases that
had major trachomatous trichiasis (> 5 eyelashes touching the eyeball) pre-operatively
[paragraph 4.10];
6. Recommended that in order to improve the outcomes of trachomatous trichiasis surgery,
Trichiasis surgery for trachoma (1) be revised to include: (i) a section on day one assessment,
by the operating surgeon, for under- and over-correction, with instructions on how these
conditions should be managed; and (ii) guidance on undertaking audits of trichiasis surgery
outcomes at 6 months [paragraph 4.11]; and
7. Agreed that to assess whether the elimination prevalence target for trachomatous trichiasis has
been reached, national programmes may use: (i) population-based prevalence surveys
powered at evaluation-unit level (i.e. populations of 100 000–250 000 people); (ii) house-tohouse case searches (which could be integrated with other public health activities); or (iii)a
combination of data from multiple adjacent evaluation units. Professional statistical advice
should be sought on how best to combine data from multiple evaluation units, with guidance
subsequently given to national programmes and their partners [paragraph 5.4].