As the lead­ing cause of ir­re­versible blind­ness in the world, glau­co­ma re­mains a dev­as­tat­ing af­flic­tion of our times, and is grow­ing in the num­ber of peo­ple who are af­fect­ed.

The World Health Or­gan­i­sa­tion (WHO) es­ti­mates in 2014 that 4.5 mil­lion peo­ple glob­al­ly are blind due to glau­co­ma and that this num­ber is es­ti­mat­ed to rise to 11.2 mil­lion by this year 2020.

Here in T&T, the three most com­mon con­di­tions be­ing seen at the pub­lic health eye clin­ics, which if un­treat­ed can lead to vi­sion im­pair­ment and blind­ness, are glau­co­ma, di­a­betes and cataracts, with glau­co­ma ac­count­ing for about 65 per cent of these pa­tients. Pre­ven­tion and ear­ly treat­ment of glau­co­ma are key as­pects in com­bat­ing this dis­ease. There is no cure for glau­co­ma, and vi­sion loss is ir­re­versible. How­ev­er, med­ica­tion or surgery (tra­di­tion­al or laser) can halt or slow fur­ther vi­sion loss. Ear­ly de­tec­tion is es­sen­tial to lim­it­ing vi­su­al im­pair­ment and pre­vent­ing the pro­gres­sion to­wards se­vere vi­su­al hand­i­cap or blind­ness.

Glau­co­ma is a group of eye dis­eases that cause pro­gres­sive dam­age of the op­tic nerve at the point where it leaves the eye to car­ry vi­su­al in­for­ma­tion to the brain. If left un­treat­ed, most types of glau­co­ma progress (with­out warn­ing nor ob­vi­ous symp­toms to the pa­tient) to­wards grad­u­al­ly wors­en­ing vi­su­al dam­age and may lead to blind­ness.

Once in­curred, vi­su­al dam­age is most­ly ir­re­versible, and this has led to glau­co­ma be­ing de­scribed as the “silent blind­ing dis­ease” or the “sneak thief of sight.” It is note­wor­thy that due to the silent pro­gres­sion of the dis­ease—at least in its ear­ly—up to 50 per cent of af­fect­ed peo­ple in the de­vel­oped coun­tries are not even aware of hav­ing glau­co­ma. This num­ber may rise to 90 per cent in un­der­de­vel­oped parts of the world.

Some forms of glau­co­ma may oc­cur at birth (“con­gen­i­tal”) or dur­ing in­fan­cy and child­hood. In most cas­es how­ev­er, glau­co­ma ap­pears af­ter the 4th decade of life, and its fre­quen­cy in­creas­es with age. There is no clear­ly es­tab­lished dif­fer­ence in glau­co­ma in­ci­dence be­tween men and women. The vast ma­jor­i­ty is “pri­ma­ry”, ie they oc­cur with­out a known cause. It was once be­lieved that the cause of most or all glau­co­ma was high pres­sure with­in the eye (known as in­traoc­u­lar pres­sure—some­times ab­bre­vi­at­ed as IOP). It is now es­tab­lished how­ev­er, that even peo­ple with­out an ab­nor­mal­ly high IOP may suf­fer from glau­co­ma. In­traoc­u­lar pres­sure is con­sid­ered there­fore to­day as a “risk fac­tor” for glau­co­ma, to­geth­er with oth­er fac­tors such as racial an­ces­try, fam­i­ly his­to­ry, high my­opia (near­sight­ed­ness) and age. Some peo­ple have a high­er than nor­mal risk of get­ting glau­co­ma.

This in­cludes peo­ple who:

-are over age 40

-have fam­i­ly mem­bers with glau­co­ma

- of African, His­pan­ic, or Asian her­itage

-have high eye pres­sure

-far­sight­ed or near­sight­ed

-have had an eye in­jury

-use long-term steroid med­ica­tions

-have corneas that are thin in the cen­tre

-have thin­ning of the op­tic nerve

-have di­a­betes, mi­graines, high blood pres­sure, poor blood cir­cu­la­tion or oth­er health prob­lems af­fect­ing the whole body

The on­ly sure way to di­ag­nose glau­co­ma is with a com­plete eye ex­am. A glau­co­ma screen­ing that on­ly checks eye pres­sure is not enough to find glau­co­ma. Thus, all cit­i­zens should take re­spon­si­bil­i­ty for his or her own health and make pre­ven­tive health­care a part of your fam­i­ly’s life.

Vis­it your oph­thal­mol­o­gist or join the free oph­thal­mol­o­gy (eye) clin­ics of­fered at the fol­low­ing pub­lic health in­sti­tu­tions where a wide range of vi­sion and eye care ser­vices, in­clu­sive of surgery, are of­fered if re­ferred from your lo­cal health cen­tre. Once ap­pro­pri­ate­ly re­ferred, these fa­cil­i­ties can be ac­cessed at the fol­low­ing in­tu­itions:

The Port-of-Spain Gen­er­al Hos­pi­tal

The Er­ic Williams Med­ical Sci­ences Com­plex;

The San­gre Grande Hos­pi­tal;

The San Fer­nan­do Gen­er­al Hos­pi­tal.

It is a com­mon ob­ser­va­tion though, that many of these pub­lic clin­ics are flood­ed with pa­tients and the wait­ing list is quite long. Whether this is an in­di­ca­tion of a high in­ci­dence and preva­lence of the dis­ease, he in­di­cat­ed that this is true to some ex­tent, as con­di­tions of the eye like glau­co­ma and cataract are in­deed quite com­mon.

In fact, glau­co­ma is the lead­ing cause of ir­re­versible blind­ness in T&T, es­pe­cial­ly among el­der­ly pa­tients. There are al­so oth­er fac­tors at play where glau­co­ma is con­cerned in T&T be­cause, un­like oth­er places in the world, there are pa­tients pre­sent­ing at younger age groups. This is at­trib­uted to the high­er num­bers of peo­ple of African de­scent in our pop­u­la­tion as well as en­vi­ron­men­tal fac­tors that seem to con­tribute to a high­er in­ci­dence and preva­lence of glau­co­ma in the South Amer­i­can re­gion.

Oth­er ge­net­ic fac­tors are at play in our pop­u­la­tion as well as oth­er uniden­ti­fied fac­tors that can on­ly be un­earthed with fur­ther re­search.

Dr Visham Bhimull

Fam­i­ly Physi­cian MBBS (UWI)

Diplo­ma in Fam­i­ly Med­i­cine (UWI)