Couching and cataract extraction a clinic based study in northern Nigeria
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Couching is a common procedure for the treatment of blinding cataract in Northern Nigeria and also elsewhere in West Africa. Traditional beliefs, sometimes good results, the scarcity of surgical facilities and low costs help to sustain this procedure and practice. In this part of Africa the number of ophthalmologists is less than one per million population.
An extensive network of couchers, mainly nomadic Fulani, perform couching in villages and at the home of the patient. Two methods of couching are reported:
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The ‘sharp’ method: the eye is perforated and the lens is pushed backwards by a sharp instrument, for example a long thorn.
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The ‘blunt’ method: the lens is pushed backwards into the vitreous, either by massage or possibly by a ‘magic drop’ which may cause zonulysis (personal communication: W Schrader). In the blunt method the eye is not perforated and this procedure is assumed to be safer.
Mangu Leprosy and Rehabilitation Centre is a Mission hospital in Plateau State, Northern Nigeria. The eye clinic sees about 3200 new patients each year. Outreach programmes are attended by 1600 patients per year. We reviewed the results of couching and cataract surgery in patients presenting to the eye clinic and during outreach work during one dry season.
Methods
During the months of October 1995 and March 1996 the first author (M.G.) studied patients presenting at the clinic or during outreach, who had either undergone couching or who had been operated on elsewhere for cataract. Patients were asked how long ago the procedure took place, by whom it was performed, where it was done, the costs, the method (‘sharp’ or ‘blunt’), and the reason for presenting at the clinic.
Examination consisted of the following: visual acuity by E chart with and without +10 dioptre sphere spectacles, anterior segment inspection with a torch and headband loupe, red reflex and fundus details with a direct ophthalmoscope and intraocular pressure (IOP) measurements with a Schiotz tonometer.
Results
Twenty-four patients had undergone couching (28 couched eyes) and 21 patients had undergone cataract extraction (26 aphakic eyes). (The cataract surgical technique used was ‘intracapsular’ in 21 operations; ‘extracapsular’ in 3 operations; and unknown in 2 operations. Intraocular lens implants were not used).
Twelve (43%) of the couched eyes had a visual acuity (VA) of ³ 3/60 and 24 (92%) of the operated eyes had a VA of ³ 3/60. Four couched eyes had a VA of ³ 6/18, with aphakic correction, compared to 9 (35%) operated eyes. Two patients were incurably blind after couching of both eyes. In total 6 eyes (21%) had no perception of light after couching. One patient (two eyes) was blind after cataract extraction (Table 1).
The ‘sharp’ method of couching was said to have been used in 18 (64%) eyes. Only 6 of these eyes (33%) had a VA of ³ 3/60. The ‘blunt’ method was reported to have been used in 5 eyes (18%). Four of these eyes (80%) had a VA of ³ 3/60. In 5 eyes the method was unknown, of which 2 eyes had a VA of ³ 3/60. No point of entry could be seen in any of these cases.
The main cause of blindness in couched eyes was phacogenic uveitis (6), followed by endophthalmitis (3) and ‘subluxated lenses’ (2). One aphakic patient was blind due to bilateral macular degeneration, not related to surgery (Table 2). Complications seemed to occur immediately following couching in this series.
Seven (25%) couched eyes had elevated IOPs (³ 25mmHg) and 2 couched eyes had hypotonia. IOP was ‘normal’ in 22 (85%) of operated eyes (4 eyes were not measured) (Table 3).
Most couched patients presented because of poor vision (12) or severe pains (7). Three successfully couched patients presented for surgery on their second eye.
The main reason for operated patients to present was for aphakic spectacles (6) or surgery for the second eye (4) (Table 4).
Twenty (71%) of the eyes had been treated by Fulani couchers. Some couchers had travelled from as far as Mali and Benin. Twelve (43%) of the couched eyes were seen during outreach, compared with 4 (15%) of the operated eyes, suggesting that couching is more often performed in remote villages.
Twenty (71%) of the eyes had been couched and 11 (42%) of eyes had been operated on within the last 2 years. Costs in these recently couched eyes varied from N.80 (US $1) plus one chicken to N.4,740 (US $60). Costs in recently operated eyes varied from free to N.4,000 (US $50) (Table 5). Couching was generally cheaper than surgery and apparently subject to intense negotiating. The going rate for cataract surgery in Mission hospitals is at present N.2,000 (US $25) plus N.500 (US $6.25) for aphakic spectacles.
Table 1. Visual acuity (no. of eyes) after couching and cataract extraction
|
Visual Acuity |
Couched (%) |
Cataract Extraction (%) |
|---|---|---|
|
6/18 or better |
4 (14.3) |
9 (34.6) |
|
less than 6/18 to 6/60 |
4 (14.3) |
13 (50) |
|
less than 6/60 to 3/60 |
4 (14.3) |
2 (7.7) |
|
less than 3/60 |
16 (57.1) |
2 (7.7) |
|
Total |
28 (100) |
26 (100) |
Table 2. Causes of blindness (no. of eyes) after couching and cataract extraction
|
Cause of Blindness |
Couched |
Cataract Extraction |
|---|---|---|
|
phacogenic uveitis |
6 |
– |
|
hypopyon/endophthalmitis |
3 |
– |
|
‘sub-luxated lens’ |
2 |
– |
|
absolute glaucoma |
1 |
– |
|
others & multiple complications |
4 |
– |
|
age-related macular degeneration |
– |
2* |
|
Total: blind eyes |
16# |
2 |
* both eyes of one patient
# 6 eyes: no perception of light
Table 3. Intraocular pressure (no. of eyes)
|
Intraocular Pressure |
Couched |
Cataract Extraction |
|---|---|---|
|
< 8mm Hg |
2 |
– |
|
³ 8 – < 25mm Hg |
18 |
22 |
|
³ 25mm Hg |
7 |
– |
|
not measured |
1 |
4 |
Table 4. Reason for presenting
|
Patients |
Couched |
Cataract Extraction |
|---|---|---|
|
poor vision |
12* |
1 |
|
severe pain |
7 |
3 |
|
for surgery in second eye |
3 |
4 |
|
for aphakic spectacles |
– |
6 |
|
others |
2 |
7 |
|
Total |
24 |
21 |
* 7 patients could be improved with aphakic spectacles
Table 5. Costs of treatment (< last 2 years)
|
Costs |
Couched |
Cataract Extraction |
|---|---|---|
|
£ N 1000 (US $12.50) |
10 (6x £ N500) |
1 (free) |
|
£ N 2000 (US $ 25.00) |
6 |
5 |
|
> N 2000 |
2 |
4 |
|
Unknown |
2 |
1 |
|
Total |
20 |
11 |
Discussion
The technique of couching is usually ascribed to Susruta, India, in the period 1000BC to 500 BC. It is presently being practised mainly in remote areas where there is a lack of surgical facilities, particularly in West Africa, the Indian Sub-Continent and in China. In China it is an officially recognised technique used by doctors in hospitals. Elsewhere it is not practised in hospitals and is only performed by traditional healers.
The technique, as practiced by the traditional healers, is secret and even eye nurses, who are close to the community, cannot witness it. The obvious advantages are: low costs, simple technique with locally available materials, performed in the village where the patients live, and it is culturally and religiously acceptable.
In these remote and poor places, a success rate of only 50% may be considered by patients and their guardians as worthwhile, if there is no alternative.
Fifty-seven per cent of the couched eyes were either blind or had severe pain, compared to 8% of the surgically treated eyes. None of the couched patients had aphakic spectacles but the eyesight of 7 couched patients could be improved or restored with aphakic spectacles. Our results are in agreement with a series of couched eyes reported from Mali, which had a success rate of 23% and a failure rate of 47%.1
Eyes said to have had their cataracts couched by the ‘blunt’ method showed better results than eyes said to have been couched by the ‘sharp’ method, but the numbers for ‘blunt’ couching are small. No point of entry could be seen in any of the ‘sharp’ couched eyes.Only one eye (couched 8 years earlier) had absolute glaucoma. Another eye with end stage glaucoma had only been couched one month earlier. Raised IOPs in other eyes were secondary to other complications (Table 3).
This study showed that couching is commonly performed in the catchment area of the clinic.
It is important to note that the selection of couched patients in this study is biased because it was mainly those with severe pain or poor vision who presented. Uncomplicated cases will not usually present at the clinic.
It had been our impression from visiting villages, that the results of couching are better than indicated by this study. It would be very interesting to study the results of couching, through a rapid assessment method, by examining 1000 people > 50 years old at village level, comparing the results of couching and cataract extraction and assessing, at the same time, the prevalence of cataract blindness.
Couching remains a widespread practice. Efforts should continue to observe the technique and to study the various methods, preferably prospectively. Traditional healers could possibly improve their results by using safer practice, such as disinfecting instruments. Potentially the treatment can be ‘successful’ as the 4 eyes with a VA of > 6/18 show. Given the enormous burden of blindness in the remotest areas, the knowledge and experience of traditional healers should be appreciated and possibly adapted, with constructive exchange of views. At the same time every effort should be made to extend affordable surgical facilities into remote rural areas.
Reference
1 Mariotti JM, Amza A. Traitement traditionnel de la cataracte au Niger, 22 cas. J Fr Ophthalmol 1993; 16: (3) 170-7.
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