|Year : 2018 | Volume
| Issue : 2 | Page : 60-63
Impact of cataract surgery on visual functions and quality of life in Azare, North-Eastern Nigeria
Mohammed Dantani Adamu1, Ahmed Saidu2, Mahmud Alhassan Babanini3, Ahmadu Shehu Mohammed4
1 Department of Ophthalmology, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria
2 Department of Ophthalmology, Nigerian Airforce Hospital, Kano, Nigeria
3 Department of Vitreoretina, National Eye Centre, Kaduna, Nigeria
4 Naval Medical Centre, Victoria Island, Lagos, Nigeria
|Date of Web Publication||7-Mar-2019|
Dr. Mohammed Dantani Adamu
Department of Ophthalmology, Usmanu Danfodiyo University Teaching Hospital, Sokoto
Purpose: The purpose of this study is to assess the impact of cataract surgery on the subjective visual functions (VFs) and quality of life (QoL) of patients who had cataract surgery at the Federal Medical Centre Azare, Bauchi State, Nigeria. Materials and Methods: This was a hospital-based prospective observational study which used the VF and QoL questionnaires. These were administered to the patients preoperatively and also 6 weeks' postoperatively. The visual acuity, VF, and QoL scores of the pre- and post-operative period were compared. A paired t-test was used for comparison. Results: A total of 181 patients were recruited. The mean age of the patients was 60.5 years, and 110 (60.8%) were males. The mean preoperative VF and QoL scores were 55.1 (Standard deviation [SD] ± 19.7) and 39.5 (SD ± 17.8), respectively. The mean postoperative VF and QOL scores were 31.5 (SD ± 9.9, t = 18.79, P = <0.001) and 25.4 (SD ± 2.4, t = 10.87, P ≤ 0.001) respectively. Conclusion: This study shows that both VFs and QoL of cataract patients can be greatly improved with cataract surgery.
Keywords: Cataract, quality of life, visual function
|How to cite this article:|
Adamu MD, Saidu A, Babanini MA, Mohammed AS. Impact of cataract surgery on visual functions and quality of life in Azare, North-Eastern Nigeria. Sudanese J Ophthalmol 2018;10:60-3
|How to cite this URL:|
Adamu MD, Saidu A, Babanini MA, Mohammed AS. Impact of cataract surgery on visual functions and quality of life in Azare, North-Eastern Nigeria. Sudanese J Ophthalmol [serial online] 2018 [cited 2019 Jul 15];10:60-3. Available from: http://www.sjopthal.net/text.asp?2018/10/2/60/253677
| Introduction|| |
Globally, cataract is known to be the leading cause of blindness and low vision accounting for 48% of the causes of blindness. In Africa, it accounts for 50%–55% of blindness while in Nigeria, the National Blindness and Low Vision Survey of 2007 reported that 43% of blindness was due to cataract. Cataract was also reported to be the most common cause of severe visual impairment.,,
Conventionally, the gains from cataract surgery have only been demonstrated clinically by change in Snellen visual acuity (VA) in the operated eye. Most often, the functional outcome of cataract surgery as it relates to everyday life with respect to vision-dependent activities or quality of life (QoL) is not assessed separately. This is due to the assumption that improved VA would automatically translate to improved QoL. However, it is possible that the measurement of other aspects of visual function (VF) after cataract surgery might be a better outcome measure than VA alone. It is against this background that the World Health Organization recommended that assessment of VF and vision-related QoL be given more attention in people with visual impairment.
Most studies assessing VFs and QoL were conducted in developed countries with very few in developing countries like Nigeria and none actually conducted in Azare, North Eastern Nigeria to the best of the author's knowledge. The purpose of this study was to assess the impact of cataract surgery on the VFs and QoL from patients' perspectives.
| Materials and Methods|| |
This study was a hospital-based, prospective observational study conducted at Federal Medical Centre (FMC), Azare. All cataract patients aged 40 years or older who presented to the eye unit of FMC Azare from October 5, 2015–February 26, 2016, with presenting VA of <6/60 to The perception of light in either eye were consecutively recruited for the study. All patients had small incision cataract surgery with posterior chamber intraocular lens implantation performed by two Ophthalmic Surgeons.
Ethical approval was obtained from the Ethical Review Committee of the FMC, Azare. The procedure involved and the implications for participating in this study were explained to the participants and informed consent obtained from willing participants. Patients with ocular and systemic comorbidities and those who could not consent for the study were excluded. A total of 168 patients met the inclusion criteria and were recruited into the study.
Visual functions/quality of life questionnaires
A VFs/QoL questionnaire that was developed, validated, and initially used in India for a clinical trial on cataract surgery was used in this study. It is an interviewer-administered questionnaire that has been used in other developing countries including Nigeria. For standardization, the questionnaire was translated into the local Hausa dialect and then back-translated to English language with the help of a trained linguist. The questionnaire was then tested on 18 cataract patients awaiting cataract surgery in Azare General Hospital, which is also situated in the same town as the FMC Azare. Patients recruited for the pilot study were not included in the final analysis of the data collected in this study.
Visual functions questionnaire
The VF questionnaire measures an individual's visual capabilities using five subscales:
- General vision: This is assessed by a single question (question 1)
- Visual perception: This is assessed by four questions (questions 2–5), which measure limitation in everyday activities, near vision, intermediate vision, and distant vision
- Peripheral vision: This is assessed by a single question (question 6)
- Sensory adaptation: This is assessed by six questions (questions 7a and 7b, 8, 9,11a and 11b), measuring light/dark adaptation, visual search, color discrimination, and glare disability
- Depth perception: This is assessed by a single-question subscale.
Quality of life questionnaire
The QoL questionnaire assessed the difficulties individuals face in everyday life because of visual loss under the following subscales:
- Self-care (bathing, eating, dressing, and toileting)
- Mobility (walking to the home of neighbors, walking to shops, and doing household chores)
- Social functions (attending social function and meeting with friends)
- Mental feelings (feeling of being a burden to others, dejection, and loss of confidence).
Scoring of visual function and quality of life questionnaire
In this study, the style of scoring of the questionnaires as used by Monsudi et al. was adopted. The scoring was done on the basis of best judgment, and a simple scoring scheme was used. For each response, the 4-point rating scale was scored from 1 (no problem) to 4 (maximum problem), with 2 and 3 being the intermediate ranking. The total cumulative score was first calculated for each subscale and expressed as a percentage of the maximum possible score. The scores across all the subscales are then added together to obtain the overall VF and QoL scores. The higher the value of the score, the poorer the VF/QoL. Conversely, the lower the value of the score, the better the QoL/VF as the case may be. Decreasing scores from baseline, therefore, meant improvement in VF or QoL.
The principal investigator administered the questionnaires to the patients preoperatively and also 6 weeks' postoperatively during follow-up. All patients had comprehensive ocular examination pre- and post-operatively including refraction at 6 weeks' postoperative visit.
All data were collected and analyzed using SPSS version 22.0 (IBM Corporation, SSPS Inc., Chicago, Illinois, USA) statistical package and expressed as mean and/or Standard Error of Mean. Snellen's VA values were converted to LogMAR VA for ease of calculation. VA of counting fingers, hand motion, and light perception has no precise Snellen's equivalent but has to be assumed and worked out. We, therefore, assigned values of 2.3, 2.6, and 2.9, respectively, to them. This was based on a similar validated scoring in a previous study in southern India. Pre- and post-operative findings were compared using Student's t-test. The correlation coefficient was used to determine the association between the VA, VF, and QoL score preoperatively and 6 weeks' postoperatively.
| Results|| |
A total of 201 patients were enrolled in the study. However, at 6 weeks' follow-up postoperatively, only 181 patients were assessed, giving an attrition rate of 9.9%, with 20 patients lost to follow-up.
Majority of the patients (60.8%) were males with a male: female ratio of 1:0.6; majority (45.3%) were farmers and greater than half of them (58.6%) had no formal education. [Table 1] shows the sociodemographic characteristics of the patients
Visual functions before and after cataract surgery
A total of 362 eyes of 181 patients were studied. The mean overall preoperative VF score was 55.12 ± 19.96 which improved to 31.49 ± 9.88 after cataract surgery. This difference was statistically significant as shown by paired t-test (t = 18.79, df = 180, P < 0.001). This is shown in [Table 2].
|Table 2: Preoperative and 6 weeks' postoperative mean visual functions score|
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Furthermore, a positive correlation (r = 0.745) was found between postoperative VA in the better eye and change in VF scores of patients 6 weeks after cataract surgery. This observed positive correlation was statistically significant at P < 0.001.
Quality of life before and after cataract surgery
The results showed that the mean overall preoperative QoL score was 39.5 ± 17.8 which improved to 25.44 ± 2.39 after cataract surgery. This difference was statistically significant as shown by paired t-test (t = 18.79, df = 180, P < 0.001). The results of other subscales of QoL including self-care, mobility, social activities, and mental feelings are shown in [Table 3].
|Table 3: Preoperative and 6 weeks' postoperative mean quality of life score|
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There was a strong positive correlation (r = 0.812) between postoperative VA in the better eye and change in QoL scores of patients 6 weeks after cataract surgery (P < 0.001).
| Discussion|| |
This hospital-based, prospective, observational study was conducted in the North-Eastern part of Nigeria to assess the impact of cataract surgery on the VFs and QoL from patients' perspectives.
There were more males than females in this study. This could be due to the fact that males are more economically empowered than females in the study area and hence could have more access to healthcare. Furthermore, other cultural and religious norms in the study area often demand that women must obtain permission before attending hospital. This disparity is also similar to findings of other studies in Nigeria.,, The age range of patients in this study (40–86 years) is similar to findings of other studies in Nigeria., Majority of the patients in this study were farmers. This is due to the fact that Bauchi State is mainly an agrarian society.
Preoperatively, there was decreased overall VF with a reduction in all the subscales. This has been reported by Nigeria's National Blindness and Low Vision Survey group. There was improvement in the overall VF following cataract surgery – all the subscales improved. The most affected subscale was “general vision” subscale while the least affected was “depth perception.” This was similar to findings in Nigeria, and Nepal. A possible explanation for the observed improvement in the VF may be the fact that patients with coexisting ocular morbidity were excluded. This possibility was also stated by Mozaffarieh et al.
In general, the findings of this study showed an overall improvement of QoL postoperatively compared to the one preoperatively. This finding compares favorably with the findings of similar studies by Desai et al., Olawoye et al. and Finger et al., all of which reported significant gains in VF and QoL in cataract patients postoperatively. One possible explanation for this improved QoL may be the sociocultural characteristics of the populace to please the interviewer, and not sound offensive by offering negative responses. Another possibility is that being mainly farmers, a slight improvement in their VAs may be adequate for their activities of daily living.
On the individual subscales, “self-care” was reportedly the worst affected by the visual impairment preoperatively, while the least affected was the “mental feelings” subscale. This is possibly so due to the peculiarity of the culture of the people where this research was carried out. The sociocultural and religious norms in that environment which mandate the children to provide care for their parents could have accounted for the less affectation of the patients' mental feelings subscale by visual impairment. This is in contrast to the findings of a similar study in Nepal by Pokharel et al., in which the “mobility” subscale was the worst affected by visual impairment followed by the “mental feelings” subscale. Our study also demonstrated that the “self-care” subscale recorded the most gain postoperatively among all the other subscales. This is very important because it was the subscale that the patients seem to be more concerned about since they would be able to take care of their basic need without any assistance.
| Conclusion|| |
One major limitation of this study is the attrition rate of almost 10%; however, this is usually the norm with prospective studies. The study recommends performance of regular cataract surgical audit and incorporation of the VFs and QoL pro forma in such audits.
This study has shown that cataract surgery can greatly enhance the overall VF and QoL of cataract patients living in a rural community.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]