|Year : 2019 | Volume
| Issue : 4 | Page : 185-188
Efficacy of Brückner's test for screening of refractive errors by non-ophthalmologist versus ophthalmologist: A comparative study
AR Rajalakshmi, M Rajeshwari
Department of Ophthalmology, Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth (Deemed to be University), Puducherry, India
|Date of Submission||08-May-2019|
|Date of Acceptance||24-Dec-2019|
|Date of Web Publication||29-Jan-2020|
Dr. A R Rajalakshmi
Department of Ophthalmology, Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth (Deemed to be University), Pondy-Cuddalore Main Road, Pillaiyarkuppam, Puducherry - 607 402
Source of Support: None, Conflict of Interest: None
| Abstract|| |
OBJECTIVE: The aim of this study is to assess the efficacy of Brückner's test as a screening tool for identifying refractive errors by a non-ophthalmologist and to assess the inter-observer variation.
SUBJECTS AND METHODS: This was a quasi-experimental study conducted at a tertiary care medical college hospital. Brückner's test was performed by a non-ophthalmologist followed by an ophthalmologist. The results were confirmed by cycloplegic refraction.
RESULTS: The study included 75 children (31 males and 44 females) with a mean age of 13.3 ± 1.2 years. The results of Brückner's test by both non-ophthalmologist and ophthalmologist showed good sensitivity and specificity when compared with cycloplegic refraction. There was a good strength of agreement between the observations of non-ophthalmologist and ophthalmologist.
CONCLUSION: Brückner's test is simple, quick, reliable, and easy to administer on children of all age groups that can provide information about the presence of refractive errors by using a coaxial light source such as direct ophthalmoscope. The application of this test by training primary care providers would be of immense value in the early identification of refractive errors.
Keywords: Brückner's test, efficacy, non-ophthalmologist, refraction, refractive error, screening
|How to cite this article:|
Rajalakshmi A R, Rajeshwari M. Efficacy of Brückner's test for screening of refractive errors by non-ophthalmologist versus ophthalmologist: A comparative study. Middle East Afr J Ophthalmol 2019;26:185-8
|How to cite this URL:|
Rajalakshmi A R, Rajeshwari M. Efficacy of Brückner's test for screening of refractive errors by non-ophthalmologist versus ophthalmologist: A comparative study. Middle East Afr J Ophthalmol [serial online] 2019 [cited 2020 Feb 26];26:185-8. Available from: http://www.meajo.org/text.asp?2019/26/4/185/277259
| Introduction|| |
Visual impairment (VI) is a major public health issue with 80% being due to some preventable cause. Uncorrected refractive errors (UREs) are the leading cause of moderate-to-severe VI and the second-leading cause of blindness in spite of the availability of eye care facilities and are expected to increase by 2020., Early detection would go a long way in avoiding amblyopia and strabismus. Many factors are implicated in underutilization of eye care services, including social, financial and time constraints, lack of family support, lack of understanding of the severity of the problem, and lack of providers.,
Pediatric eye screening protocols vary from country to country depending on the burden of the visually significant problems in children. There are at present no firm recommendations in India due to non-availability of sufficient data on pediatric vision impairment and blindness. Current screening methods such as optotype-based (pediatric vision charts) or instrument-based methods (photo screeners) are cumbersome or expensive or both. Brückner's test, on the other hand, is an easy and simple method requiring only a direct ophthalmoscope carried by all physicians and pediatricians. Screening for refractive errors by applying Brückner's test has been shown to be quick, simple, easily trainable and of high validity., Timely detection of refractive errors or eye problems can be ideally accomplished when screening for refractive error is carried out by the pediatrician/physician who would encounter the child at appropriate ages and in the absence of ocular complaints.
In 1962, Brückner described a simple screening test using the direct ophthalmoscope and compared the red reflex of both eyes simultaneously. The test was found to be extremely useful in young uncooperative children for diagnosing amblyopia and small-angle deviations. Roe and Guyton, in their study on Brückner and the red reflex, described that asymmetrical red reflexes are due to the binocular asymmetry of conjugacy either due to anisometropia or strabismus.
This study was conducted to assess the efficacy of Brückner's test for screening of refractive errors among children aged 5–15 years in the hands of a trained non-ophthalmologist. The effectiveness of the test was compared with Brückner's test performed by an ophthalmologist and also against cycloplegic refraction.
| Subjects and Methods|| |
This was a quasi-experimental study conducted between July and August 2014 on children who presented to the Ophthalmology outpatient department of a tertiary care medical college hospital. The study was carried out after obtaining approval from the institute ethics committee and performed in accordance with the Helsinki protocol. All children between 5 and 15 years, with defective vision, asthenopic symptoms, and headache were included in the study. Those with media opacities, previous history of intraocular surgeries, trauma, and nystagmus were excluded.
An undergraduate medical student (non-ophthalmologist) was trained in Brückner's test and the observations were verified before the study. The training session was conducted over a period of 2 h. At the end of the training session, the skill taught to the trainee was verified by direct observation. Following informed consent, Brückner's test was performed on all participants by the trained non-ophthalmologist. The test was repeated using the same instrument by the ophthalmologist, who was blinded to the observations of the non-ophthalmologist.
The test was performed in a dark room in the undilated pupil of all subjects. The examiner sat 1 m away from the subject. Using the large spot beam of the direct ophthalmoscope (Heine, Beta 200, Optotechnik, Germany), both the eyes of the subject were illuminated simultaneously with the patient looking at a distant target to avoid accommodation and the pupillary reflex was sharply focused. The location and color of the pupillary crescent were noted and results were recorded. Those with an inferior crescent or decentered crescent or >2 mm size superior crescent were taken as ametropic.
Subsequently, all the patients underwent cycloplegic refraction using cyclopentolate (1% eye drops), one drop of which was instilled every 10–15 min for three times and the refractive status was assessed after 30–60 min by a trained optometrist who was blinded to the results of the Brückner's tests.
All data were entered into a data collection pro forma sheet and entered into Excel (MS Excel 2011). A 2 × 2 table was constructed separately for both the observations and further analysis was performed. Inter-observer variability was also assessed.
| Results|| |
A total of 75 children (31 males and 44 females) of mean age 13.3 ± 1.2 years were examined.
The non-ophthalmologist identified 50 ametropias and 25 as emmetropic based on the reflex seen by the Brückner's test. Out of the ametropias, 4 turned out to be emmetropes and 4 of the emmetropes were found to have refractive errors after cycloplegic refraction. The ophthalmologist's observations showed 53 ametropes and 22 emmetropes. There were 4 emmetropes out of the 53 and 1 ametrope from 22 emmetropes by cycloplegic refraction.
Three children had high refractive error and they demonstrated a dull/bright glow with the absence of a crescent which was missed by the non-ophthalmologist. Following cycloplegic refraction, ametropia was found in 50 (66.66%) subjects. The refractive errors noted were myopia ranging from −1.00 D to −8.50 D; hypermetropia ranging from +1.00 D to +5.50 D, and astigmatism from 1.00 to 3.5 D.
[Table 1] shows the results of Brückner's test by the two observers. The kappa statistics showed a good strength of agreement between the two observers. [Table 2] shows the comparative results of the Brückner's test by the two observers against cycloplegic refraction.
| Discussion|| |
URE is the leading cause of vision impairment and the second leading cause of blindness in the world. In 2010, 6.8 million people were blind (7.9% increase from 1990) and 101.2 million were vision impaired due to URE (15% increase since 1990), compared to the much greater 30% increase in the global population during this period. Mathers et al. in their review on the effectiveness of children's vision screening suggested that early vision screening and early treatment improved visual outcome and lowered prevalence of amblyopia. However, early school-based screening was more likely to be more accurate in its results, as well as more accessible to children, than screening performed before school entry.
School vision-screening programs carried out by teachers in India have been shown to be a highly cost-effective method for identifying VI due to refractive errors in school-age children., However, not all children are examined through school screening, besides a poor response to referral from the school screening program. Comprehensive eye care clinics, on the other hand, may help in the identification and correction of refractive errors but at a higher cost. Therefore, there is a need to revamp the school eye screening program.
The application of Brückner's test has shown considerable promise for screening and identifying refractive errors. It is a simple and easy-to-administer test which can be performed by people with little or no prior experience. The test requires only a direct ophthalmoscope which is much less expensive than a photo screener and less cumbersome than vision charts which are subjective as well. A large population can be screened in a short duration as the test takes very little time to complete.
Our results showed good sensitivity and specificity which can improve further with the experience of the non-ophthalmologist. These results were comparable with that of a previous study by Kothari MT who demonstrated the suitability of this test for screening refractive errors. However he also mentioned that it was difficult to quantify the results and that it was prone to inter-observer and intra-observer variations.
Considering the possibility of inter-observer variation, the reliability of the Brückner's test was compared when performed by an experienced ophthalmologist versus a not-so-experienced non-ophthalmologist in our study. The inter-observer rating as shown by the kappa statistics showed a value of 0.76 (standard error 0.08; 95% Confidence interval: 0.60–0.92), which shows a good strength of agreement between the two observers. This was in accordance with the observations made between a pediatric ophthalmologist and a pediatrician. The clinical agreement (kappa) between the ophthalmologist and the pediatrician was found to be excellent (0.9).
This goes to show that the Brückner test can surely serve as an effective test in the opportunistic screening of refractive errors among children by non-ophthalmologists, especially by pediatricians. This is much more feasible than a population-based school screening program, which demands the availability of infrastructure and trained personnel, and the use of more expensive instruments (photoscreeners). In fact, training pediatricians in the Brückner's test as part of their residency program can go a long way in helping detect refractive errors at an early stage itself.
This study was done in children who visited the hospital with complaints, and hence, a higher percentage of the children examined were found to have refractive errors. The same may not be true for community-based screening/school eye screening. There is a need to develop an effective screening program for identifying this preventable cause of blindness because, if intervened at the right time and corrected, this may prevent the development of amblyopia and strabismus. Screening and treating children with URE can help children overcome reading problems, and possibly improve their scholastic performance.
The National program for control of blindness has incorporated school screening at the middle and high school levels. This is not only for administrative ease but also because the children at this age are more likely to respond to the screening. Earlier detection of refractive errors (18 months to five years) has a better visual outcome due to the treatment of amblyopia. Brückner's test requires little response from the children being examined. This makes the test a better tool for screening pre-school and primary school children. This age group has contact with the country's health-care system during the implementation of the universal immunization program. They are also more likely to visit pediatricians/primary healthcare providers for non-ophthalmic complaints. The rate of ophthalmic reference and follow-up for compliance may be significantly improved if pediatricians/primary health care providers are trained for the detection of refractive errors. Wherever possible, all children have to be subjected to cycloplegic refraction, especially in case the associated asthenopic symptoms demand so.
In our study, the non-ophthalmologist missed three children with high refractive errors which were identified by the experienced ophthalmologist. Although there is limited information that increasing the test distance might help in identifying ametropia, this could not be performed by the authors in this study. This is a limitation of this study.
| Conclusion|| |
Brückner's test is a reliable, simple, and quick method to identify refractive errors. It is now evident that it is an easy-to-train clinical method and an effective tool for screening children. It is more economic than photo screeners. The application of this test on a large scale needs further evaluation. Training of primary health-care providers for identifying amblyopigenic risk factors by using Brückner's test can prove to be a cost-effective method, especially in the pre-school and primary school level children. If found effective in population-based studies, this would be of immense value in resource-starved areas of developing nations.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]