Introduction: Glaucoma is the third leading cause of blindness around the world following cataract and uncorrected refractive errors. Glaucoma is known to cause irreversible blindness, but in developing countries, especially in rural areas, patients still report late with advanced extent of damage. However, little information is known about glaucoma in Uganda.
Methodology: This was a hospital-based, observational cross-sectional study conducted to determine the types, the extent of damage and the risk factors for glaucoma encountered in patients affected by glaucoma. One hundred and nine patients with the condition were consecutively recruited in the study during a period of six months. Participants underwent routine eye examination in their better eye, including vertical cup-to-disc ratio stereoscopical measurement, intraocular pressure (IOP) measurement, central corneal thickness (CCT), gonioscopy, refraction, and perimetry. Patients were asked about their life style (smoking and alcohol consumption), diabetes mellitus, systemic hypertension, education level attainment, occupation, and duration of symptoms at the time of first consultation. Data obtained were entered and analysed using statistical package SPSS version 12.0 and EPI info version 3.4.3 by employing descriptive statistics.
Results: Primary open angle glaucoma (POAG) (64.2%) was the commonest type of glaucoma, followed by Secondary open angle glaucoma (SOAG) (14.6%), Normal tension glaucoma (NTG) (13.8%), Secondary angle closure glaucoma (SACG) (5.5%), and Primary angle closure glaucoma (PACG) (1.8%).
Among the patients included in the study, 67.9% were males and 32.1% females. The mean age of the participants was 63.67 ± 12.97 years. The majority of the participants (51.4%) had normal vision (visual acuity ≥6/18) in their better eye at the time of first presentation, 62.3% of participants had severe visual field defect, and 28.7% had optic disc end-stage cupping. Most of the patients reported 26.36 months after the onset of ocular symptoms for glaucoma. Duration of symptoms was significantly associated with visual acuity deterioration (p=0.031) and visual field defect (p=0.005). Mean vertical cup-to-disc of the study population was 0.807 ± 0.187. Mean intraocular pressure and central corneal thickness of the participants were respectively 32.72 ± 11.55 mm Hg and 516.19 ± 39.95 µm. Vertical cup-to-disc ratio was significantly associated with intraocular pressure (p=0.007). In this study, refraction, occupation of patients, level of education, smoking, alcohol consumption, diabetes mellitus, and systemic hypertension were not established as risk factors for glaucoma.
Conclusion: In South Western Uganda, open angle glaucoma is the commonest type of glaucoma among adult patients. Most of the patients tend to report late to Ruharo Eye Centre with advanced glaucoma damage. Duration of symptoms seems to be related to the severity of damage caused by glaucoma. IOP has a tendency to be higher and CCT to be thinner than those noted in Caucasians and Asians. VCDR tends to worsen with increasing IOP.
There is a need:
To carry out community-based studies in Uganda to determine prevalence and risk factors for glaucoma,
To standardize diagnostic and management strategies for glaucoma,
To provide free glaucoma screening in the community including tonometry and ophthalmolscopy, and targeting the high-risk group of individuals aged 40 years and above,
To establish CCT measurement in routine ocular examination, especially for glaucoma suspects.