Corneal ulcer in a Cambodian eye hospital
Traumatic corneal ulcer is an important cause of bilateral and monocular blindness in the developing world, with estimates of 5% of all blindness being trauma related. Cambodia is likely the poorest country in South East Asia with no national survey of blindness aetiology, although surveys were carried out in the provinces Kandal (1996) and Battambang (1997). Most Cambodians are rice farmers and agricultural work-related corneal trauma is a neglected area of research. This retrospective case-series study in Takeo Eye Hospital in southern Cambodia looked at sex, age, history, surgery and comparative visual acuity of affected eyes between presentation and discharge of 130 patients with a corneal ulcer diagnosis between 21 May and 31 December 2001. Whilst the study cannot shed light on, for example, corneal ulcer aetiology or the relative efficacy of different treatments, it can describe patterns in this particular patient population that may prove useful and indicate areas for further research.
Results: 55% patients were male, 45% female, aged 1-88 yrs. Most were of working age. Of 121 cases, 51% recorded trauma. There were 99 cases with a recorded acuity; 75 presented blind (defined here <3/60); 15 had normal vision (defined here 6/6-6/18). There were 14 fewer blind eyes and 9 more with normal vision at discharge. About a quarter improved in WHO category of visual loss (including 6 from blind to normal), half stayed the same (12 maintained as normal and 58 remained blind); 4 eyes out of 99 deteriorated. 23 of the 24 eyes removed were blind on presentation.
Conclusions: With a rough quarter of the sample showing an improvement of one or more grades and deterioration in only 4%, patients are benefiting as a whole (some individuals dramatically) from their treatment in Takeo Eye Hospital. However, most are arriving with a blind eye and there is need for more research into how to prevent this. There is also a need to discover the extent of under-reporting of corneal ulcer and of monocular blindness with a prospective population-based study. The vast majority of patients were of working age (there were surprisingly few children given the economic environment). Do they present because they need to work but cannot see (most present blind) and not present because they need to work and can still see? Their disability impacts the economy. This study cannot reveal aetiology but it is worth noting that half the patients reported trauma. Trauma and corneal ulceration is largely a cause of monocular blindness although it is an important cause of bilateral blindness as well. Added to a complex aetiology this makes it a difficult area to tackle. It is sad but unsurprising that it is developing countries that suffer most from this silent epidemic.
Table 1. Comparison by visual acuity grading of affected eyes at presentation and at discharge
|Visual Acuity||At presentation||At discharge|
|6/6 – 6/18||15||24|
|< 6/18 – 6/60||7||12|
|< 6/60 – 3/60||2||2|
Table 2. Difference in grade between presentation and discharge as a percentage of sample.