What are the best artificial lenses for cataract patients in rural Uganda?

Three million people in Africa are blind due to cataract.  Access to and availability of surgery is limited, particularly in rural areas.  In the past, the standard procedure was to remove cataracts and provide patients with spectacles. Since 1995, implanting an artificial lens has become a realistic alternative to spectacles. What kind of artificial lens best suits the needs of patients in rural Uganda?

There are two types of lensesavailable. In developed countries, posterior chamber (PC) lenses are consideredto be superior to anterior chamber (AC) lenses. However, in sub-Saharan Africa,AC lenses may be more appropriate, because:

• it is easier to train surgeons to implant AClenses 
• some eyes are too diseased to support a PC lenses 
• people who have had cataract surgery before andwho were given spectacles could benefit from AC lenses, but not PC lenses
• PC lenses may become opaque, a condition whichmay go untreated in remote areas. 

110 elderly people, withcataracts in both eyes, had surgery in rural Uganda away from a specialist eyehospital.  One eye received an AC lens whilethe other received a PC lens.  Due to theremoteness of their homes and the bad roads, most of the patients were not seenagain until the home follow-up a year later. Therefore, preventing anycomplications could not be dealt with promptly. 

Testing the vision of elderlypeople who are unable to read and write can have its problems.  They can tire easily and it may be difficultto persuade them that they can read small letters at the bottom of achart.  Culturally, they may also believethat it is necessary to appear ill in front of the doctor in order to beprescribed medicine.

Bearing these reservations inmind, the study by Ruharo Eye Hospital, Kampala and the University of Londonand found that:

• The patients could see equally well following thetwo different operations.

• Several complications occurred and some required furthersurgery. Most complications following AC lenses were unavoidable but thecomplications following PC lenses could be avoided with careful surgery.
• PC lenses only rarely became opaque after theoperation.
• Following the operation almost all the patientswere mildly short-sighted.
• Over 80 percent had normal visual acuity (abilityto see fine detail) when wearing spectacles.

Following the operation, fewof the patients wanted spectacles as their vision was adequate for manytasks.  Patients were grateful for thegood close vision that short-sightedness (myopia) gave them for working.  As PC lenses rarely become opaque, the mainobjection to their use in remote areas becomes less valid.  The researchers therefore recommend that:

• Cataract operations should, wherever possible,use the PC procedure because this leads to fewer complications. 
• When the PC method cannot be used immediately dueto lack of training, the AC procedure should be used for the time being.
• In the long term, although surgeons should betrained in both techniques, skills and equipment need to be provided sothat PC surgery can be offered as first choice.