Study design and period

A hospital based cross-sectional study was conducted to determine the pattern of vitreoretinal diseases at University of Gondar tertiary eye care and training center from October 2017-September 2018.

Study area

The study was conducted at University of Gondar Tertiary Eye Care and Training Center, a major eye care and training center in Ethiopia. It is an ophthalmic referral center for an estimated 14 million people living in North-West Ethiopia. The center provides eye care services both at the base hospital and rural outreach sites and annually, over 80,000 patients are seen at both sites. The base hospital has 8 out-patient clinics, facilities for in-patient care with 30 beds and five operation theatres. Currently, the center has 10 ophthalmologists, five of them with subspecialty training. There are also 26 optometrists, 5 ophthalmic officers, and 29 general clinical nurses actively working in the outpatient clinics and operation theatres of the tertiary eye care and training center. The current student population of the center includes 26 Ophthalmology residents, over 200 BSC and MSC optometry students and 38 BSC ophthalmic Nursing students.

Available manpower, facilities and equipment for the management of vitreoretinal diseases at the center include, vitreoretina out-patient clinic, one vitreo-retinal consultant, Laser treatment room with Diod laser and Argon Green Laser equipments, Fundus Camera machine, four indirect ophthalmoscopes, B-scan ultrasound and facilities for intravitreal pharmacotherapy (Steroid and Anti-VEGF). There is no equipment for Scleral buckling and posterior vitrectomy surgeries.

Study population

All patients with vitreoretinal diseases who visited the vitreoretina clinic of UOG tertiary eye care and training center for the first time during the study period were included in the study. Patient who had no vitreoretinal diseases, follow up patients and those with ocular media opacity for fundus evaluation were excluded from the study.

Data collection procedure

Comprehensive Ophthalmic evaluation which included detailed demographic information, presenting complaint, associated ocular and systemic symptoms and past treatment history for ocular or systemic illnesses were taken for each patient. Best corrected visual acuity, intraocular pressure measurement and slit-lamp examination of the anterior and posterior segments were performed. Posterior segment evaluation was performed with +90D funduscopic lens on the slit-lamp for each patient by a vitreoretinal specialist after dilation of the pupil with 1% tropicamide eye drop. Indirect ophthalmoscopy with +20D lens was used to examine patients when indicated. Diagnosis was made based on clinical examination findings by a retina specialist. Pertinent and supportive laboratory investigations were also done for all patients. In some cases, there was more than one retinal diagnosis in one eye. For instance, an eye could have a retino-choroidal scar due to AMD as well as a branch retinal vein occlusion. On the other hand, both eyes could have different retinal diagnosis. For example, the right eye could have AMD and the left eye a central retinal vein occlusion. Alternatively both right and left eyes could have a single diagnosis for example diabetic retinopathy in both eyes. Each of the diagnosis was recorded separately on the data extraction format. Information on co-existing systemic diseases known previously were obtained from patients themselves, or diagnosed after systemic work-up.

Grading of best corrected visual acuity for visual impairment and blindness was done using the WHO/ICD 10 categorization of visual impairment as follows:

Normal-Best corrected visual acuity better or equal to 6/18 in the better eye.

Moderate visual impairment-Best corrected visual acuity between 6/24 and 6/60 in the better eye.

Severe visual impairment-Best corrected visual acuity less than to 6/60 and better than or equal to counting fingers at 3m in the better eye.

Blindness-Best corrected visual acuity less than counting fingers at 3m distance in the better eye.

Discussion

In this study, the mean age was 50.26 ±19.36 years and more than half of study patients, 441 (59.7%), were aged between 21 and 60 years. The mean age is comparable with a retrospective study done at Stanford University (USA) and a similar hospital based retrospective study done in South-eastern Nigeria in the University of Enugu, 52.2± 25.6 and 49.±16.8 year respectively but slightly higher than a prospective cross-sectional study done in Menillik-II tertiary eye care and training center in Ethiopia, 45.2±17.3 years and another Nigerian study 46.3 ± 21.4 years [7,9–11].

There was a male predominance in this study where nearly two-third (63.1%) of patients were male. This is in agreement with a study done in south eastern Nigeria (59.3%) and in Pakistan (62.8%) but against a study done in south western Nigeria, where 55.6% were females [11–13]. Factors contributing to male predominance in reports from developing countries are undoubtedly complex and it was suggested that men tend to seek medical attention more often than women in agricultural societies and this may certainly have contributed to the trend in our clinic [11,12].

In this study most of the patients, 434 (58.7%), came from urban area and this is similar to the mentioned hospital based cross-sectional study done Pakistan, 66.5% [7].

This study showed 220 (29.7%), 112 (16.2%) and 181(24.5%) patients had bilateral blindness, severe visual impairment and moderate visual impairment at presentation respectively. The rate of bilateral blindness in our study is higher than the previous similar study in Ethiopia 16.1%, a study done in South Eastern Nigeria 6.1% and a Nepalese study 12.26% [6,12,13]. This may be partly due to the fact that one third of our patients (33.5%) had cataract as an ocular comorbidity.

Ocular comorbidities were found in 633 (85.7%) of our patients with cataract 246(33.5%) blepharitis 173(24%) and glaucoma 52 (7%) being the most commonly diagnosed comorbidities. This finding is different from a hospital based retrospective study done in South-eastern Nigeria at the University of Enugu, where refractive error (19.8%) was the commonest but similar with a population based cross-sectional Tehran eye study where cataract (12.47%) was the most commonly diagnosed ocular comorbidity [9,13].

Systemic comorbidities were found in 325 (44%) of our patients with diabetes mellitus 196(26.5%) and hypertension 47(6.3%), being the most common. This is in agreement with a hospital based retrospective study done in South-eastern Nigeria and the Tehran eye study results where diabetes mellitus and hypertension were the two most common systemic comorbidities [9,13].

Our study showed Diabetic retinopathy, Age related Macular Degeneration (AMD) and Rhegmatoginous Retinal Detachment (RRD) were the top three retinal diseases diagnosed in 196 (22.44%), 128(14%) and 77 (8.4%) of our patients respectively. This result is similar with a hospital based study done in Pakistan which showed Diabetic related retinal conditions and Retinal detachment, were the commonest retinal pathologies seen in 39.8% and 20.6% of cases respectively. It is also in agreement with a hospital based study in south eastern Nigeria where diabetic retinopathy 24.9% was the commonest diagnosis. However, our finding was different from two other Nigerian Studies and a population based study in Nepal where Age Related Macular degeneration was the commonest diagnosis [7–9,11,14].

The pattern of retinal diseases seen in our study was comparable with the descriptive cross-sectional study done in Menillik-II tertiary eye care center in Ethiopia, where Retinal vascular diseases accounted for the largest group of patients (38.1%) of which diabetic retinopathy accounted for 75.1% but it differs in that Retinal detachment was the second largest group of diseases, accounting for 24.5% of the total. This is possibly due to the high referral burden rate of retinal detachment cases in Menillik-II Tertiary eye care center as it was a national referral center for surgical treatment of retinal detachment at the time of the study. The prevalence of AMD was 2.7% in this study and this is much lower than our study (14%) and this is possibly due to the fact that our study population was slightly older [7,10,11,15].

Conclusion

Most of the vitreoretinal pathologies in our study were bilateral and males were affected more than females. The age group between 21–60 years accounted nearly two-third of study patients and this is the working age population suffering from vision loss from vitreoretinal diseases. Diabetic retinopathy, Age related macular degeneration and Rhegmatoginous Retinal detachment were the commonest retinal pathologies accounting for nearly half of the vitreoretinal diseases diagnosed and these conditions are treatable either medically or surgically. However, available facilities at the center are inadequate for the management of the most common vitreoretinal diseases. The vision losses at presentation of the study patients were much worse than other similar studies. Systemic and ocular comorbidities were also common findings among study patients. Strengthening the vitreoretina services of the University of Gondar tertiary eye care and training center with relevant equipment and other facilities is recommended.