Dry eye, a disease characterized by a loss of homeostasis of the tear film and accompanied by ocular symptoms,1 is frequently encountered in clinical practice. Across the globe, the prevalence of dry eye is estimated at 5 to 50%, with preponderance in women, Asians, and contact lens wearers.2 Other well-defined risk factors for dry eye include smoking, older age, history of arthritis, diabetes mellitus, refractive surgery, and vitamin A deficiency.2–4 Direct and indirect costs associated with dry eye management constitute a significant economic burden. For instance, the average annual cost of managing dry eye has been estimated to be $783 and $11,302 per patient from the patient and societal perspectives, respectively.5 Dry eye is also associated with reduced quality of life and reduced workplace and non–job-related performances.6,7
Accurate diagnosis and effective treatment are crucial for reducing dry eye–associated burden. However, the diagnosis and management of dry eye remain a challenge owing to the complex and multifactorial nature of the condition.1,8 Although guidelines exist, there is largely a lack of consensus on the diagnosis and management of dry eye,9,10 which in part is due to poorly defined diagnostic cutoff values for most routinely used clinical tests and the seemingly poor reliability of these tests.10,11 In a bid to harmonize the modalities of diagnosis and treatment of dry eye, the 2017 Tear Film and Ocular Surface Society International Dry Eye Workshop II, through scientific evidence and consensus, has reported a recommended battery of diagnostic tests and a treatment algorithm for dry eye.12,13
Although a few studies have assessed the diagnosis and treatment patterns of dry eye, there is a dearth of studies investigating the challenges faced by eye care professionals in clinical dry eye practice. Furthermore, studies profiling dry eye practice have been conducted largely in regions with seemingly advanced economies and health care systems. Dry eye is a condition with a global prevalence, and given that the state of an economy impacts health care delivery,14 there is a need to extend such studies to regions with developing economies. This study thus sought to examine the diagnostic perspectives, treatment and management modalities, and challenges in clinical dry eye practice in Ghana, a country where approximately 44% of college students15 and up to 80% of glaucoma patients reportedly experience dry eye (Kobia-Acquah et al. IOVS 2019;60:ARVO E-Abstract 2741). The outcome of the study will potentially lead to strategies to improve dry eye practice and treatment outcomes in Ghana.
Participants and Study Design
The study followed the tenets of the Declaration of Helsinki and was approved by the institutional review board of the University of Alabama at Birmingham. The target population for the study was certified ophthalmologists and optometrists in Ghana. At the time of the study, at least 351 optometrists and 50 ophthalmologists were eligible to participate in the survey, based on data available from the Ghana Optometric Association and the Ophthalmological Society of Ghana. All eligible optometrists obtained their doctor of optometry degrees from the two optometry training institutions in Ghana: the University of Cape Coast and the Kwame Nkrumah University of Science and Technology. The contact information of potential participants was obtained from a database and social media platforms of eye care professionals. The database of the Ghana Optometric Association contains up-to-date information on most optometrists who are in good standing relative to post-qualification certification and continuous professional development. Excluded from the study were certified practitioners who were not in active clinical practice. Most Ghana eye care professionals are in independent and government practices, whereas a few are in academic medical/optometric and corporate practice. A survey regarding dry eye diagnostic and management patterns, developed by Downie et al.,16 was adapted for use in this study (Appendix, available at http://links.lww.com/OPX/A442). The anonymous Internet-based survey was administered using SurveyMonkey (San Mateo, CA) and distributed to potential participants via a web link sent through e-mail or text message. Potential participants who could not be contacted through e-mail or text messaging were sent a paper questionnaire. The number of surveys sent was limited by the lack of contact or address information for some practitioners and the fact that not all certified professionals actively see patients. To boost the response rate, reminders and prompts were sent three times to practitioners who received the survey through e-mail or text message. The survey focused primarily on demographic information of eye care practitioners, frequency of dry eye assessment and diagnosis, diagnostic techniques, dry eye treatment and management modalities, referral pattern, and barriers to practice. The survey was conducted between late 2016 and early 2017.
Statistical analyses were performed using Statistical Package for the Social Sciences (version 24; SPSS Inc, Cary, NC). Descriptive statistics were used to determine demographic information, treatment modalities, factors influencing treatment patterns, frequency of referral of cases, barriers to dry eye practice, and practitioner's access to diagnostic instruments and tools. There were four categories for “type of practice” variable: independent, government, corporate/group, and academic. However, for analysis considering the limited number of respondents in corporate and academic practice, independent and corporate practices were merged as private practice, whereas government and academic practices were merged as public practice.
A χ2 or Fisher exact test was used to assess possible associations between type of practice and the likelihood of being limited in dry eye practice by reported challenges (perceived inadequate training, unavailability of effective dry eye medication on the market, and patients' inability to afford dry eye treatment). Similarly, χ2 or Fisher exact test was used to assess possible associations between type of practice and the likelihood of referral of cases of dry eye to ophthalmologists by optometrists.
A total of 280 surveys were sent to potential participants between July 2016 and February 2017. One hundred nineteen practitioners responded with interest in the survey, and 113 consented and completed the survey (40.4% response rate). Ninety-six percent of respondents (n = 108) were optometrists, and 4% (n = 5) were ophthalmologists. There were more male respondents (n = 83; 73.5%) than female (n = 30; 27.5%). This reflects the demography of clinicians in Ghana considering that more than 70% of optometrists and medical practitioners in the country are male.17–20 The distribution of respondents' age is as follows: 85% were aged 24 to 34 years, 12.5% were 35 to 49 years old, and 2.5% were older than 49 years. Seventy-two percent practiced in the two most populous regions in Ghana: the Greater Accra and Ashanti regions, which constitute approximately 40% of the country's population of 30.3 million people.21 The remaining 30% was distributed between the remaining regions. Fifty-eight percent of respondents were in independent clinical practice, and 30% were in government practice. The remaining 12% were in corporate practice or academic institutions. The distribution of respondents' years of clinical experience is as follows: 82.5% had 1 to 6 years of practice experience, 14.8% had 7 to 15 years of experience, and 2.7% had more than 15 years of clinical experience.
Frequency of Dry Eye Assessments and Diagnosis
Thirty-four percent of respondents reported performing up to 20 dry eye assessments each month, whereas 13% indicated 21 to 40. Fifty-seven percent also reported making up to 20 dry eye diagnoses per month, whereas 18% reported 21 to 40. Fig. 1 shows the distribution of the frequency of monthly dry eye assessments and diagnoses as reported by respondents. In terms of disease form, evaporative dry eye was the most frequently encountered dry eye, reported by 48.6% of practitioners. It was followed by the mixed-type and aqueous-deficient dry eye, which were reported by 20.5 and 30.5% of respondents, respectively.
Dry Eye Diagnostic and Management Strategies
When asked to identify which dry eye diagnostic procedures they use in clinical practice, 92.5% of participants reported using case history, 87.5% used fluorescein tear breakup time, and 72.5% used corneal fluorescein staining. None of the practitioners surveyed used a dry eye symptoms assessment questionnaire, tear osmolarity technology, meibography, lissamine green stain, or rose bengal staining techniques for the diagnosis of dry eye. When asked to rate the procedures in order of importance for the dry eye diagnosis, 88.8% of respondents ranked case history first. Fluorescein tear breakup time and corneal staining were commonly reported as second (48.6 and 35.5%, respectively) and third (35.5 and 39.4%, respectively) in importance rankings. Fig. 2 shows how respondents ranked the importance of the five topmost reported tests for dry eye diagnosis.
In terms of strategies for grading dry eye severity, 69.3% of respondents reported grading disease severity based on a patient's symptoms and the end points of one to three clinical tests. Approximately 22% also based dry eye severity grading on intuition, whereas 6.9% use symptoms only. Fig. 3 shows the distribution of dry eye severity grading strategies among practitioners.
Ninety-six percent of respondents reported that they would recommend treatment of mild dry eye, whereas all (100%) would provide a form of treatment of moderate and severe dry eye. Across all disease severities, preserved lubricant drops were the most common treatment of dry eye, prescribed by 77.0, 83.2, and 77.0% of respondents, for mild, moderate, and severe forms, respectively. The second most commonly prescribed treatment of mild dry eye was nonpreserved lubricant drops (15.9% of respondents), whereas preserved gel was the second most common treatment of moderate (31.9%) and severe (35.4%) forms of the disease. Across all disease severities, only 2.7 and 5.3% reported prescribing topical cyclosporine ophthalmic emulsion, 0.05% (Restasis, Irvine, CA) and punctal plugs, respectively, and none treated dry eye with autologous serum tears, scleral lens, or thermal pulsation treatment. Fig. 4 illustrates the dry eye treatment pattern among respondents.
Factors Influencing Pattern of Dry Eye Practice
Almost all respondents (98.3%) reported having a clinical interest in dry eye. When asked to identify the top 2 factors that influence their clinical dry eye practice patterns, 82.3% of respondents chose their graduate professional (medical or optometric) training as one of their responses, and 60.2% indicated online resources. Continuing education programs (0.9%) were selected with the lowest frequency.
Referral of Cases of Dry Eye to Ophthalmologists by Optometrists
Approximately 29% of optometrists reported referring to an ophthalmologist at least half of the time if it was determined that a systemic medication is needed to treat dry eye. Although 60.8% of optometrists would refer to an ophthalmologist in cases of severe dry eye, at least half the time, 92.8% considered a referral in cases where dry eye is unresponsive to treatment. Ninety-eight percent of optometrists reported referring a patient to an ophthalmologist at least half the time if he/she needs a punctal plug, and almost all optometrists (99%) would always refer cases in which a surgical intervention is indicated. Fig. 5 shows the pattern of optometrists' referral of dry eye to ophthalmologists in Ghana.
There was a significant association between type of practice and the likelihood of optometrist's referral of dry eye when it is observed in a child (χ2 = 9.32, P = .002). It was found that optometrists in private practice were more likely to refer dry eye cases to ophthalmologists when it is observed in a child (odds ratio, 8.36; 95% confidence interval, 1.83 to 38.11). However, there was no association between type of practice and the likelihood of referral to ophthalmologists when dry eye is unresponsive to treatment (Fisher exact test, P = .10), when prescription of systemic medication is required (χ2 = 0.21, P = .65; odds ratio, 1.25), when a punctal plug is required (Fisher exact test, P = .08), and in cases of severe dry eye (χ2 = 0.82, P = .37).
Barriers to the Practice of Dry Eye
Eighty-eight percent of practitioners indicated they experience a form of challenge in dry eye practice. When asked to pick their two most significant barriers, 77.9% of respondents reported being limited by the lack of diagnostic tools and techniques availability, whereas 50.4% were limited by the unavailability of effective dry eye treatments on the Ghanaian market. Besides, perceived inadequate training and patients' inability to afford dry eye treatment were each reported as barriers by 15.9% of respondents. There was no significant association between the type of practice and any of these reported challenges (Fisher exact test, P > .005).
Access to Diagnostic Instrumentation and Tools
Approximately 88% of respondents had access to a fluorescein dye, 85.5% had access to a slit-lamp biomicroscope, and 75.2% had access to a keratometer. Also, 15.9, 9.8, and 4.4% had access to Schirmer strips, rose bengal dye, and dry eye questionnaire, respectively. However, none of the respondents had access to a phenol red thread, lissamine green dye, tear osmolarity technology, matrix metalloproteinase-9 test, or meibography device.
This study sought to establish the pattern of dry eye practice among eye care practitioners in Ghana. It is worth noting the timing of the design of this study and the administration of the survey. This study ended before the publication of the 2017 Tear Film and Ocular Surface Society International Dry Eye Workshop II report in July 2017; thus, the design of the survey was informed solely on the body of knowledge that existed before Dry Eye Workshop II.
The techniques and tools used by Ghanaian practitioners in the diagnosis of dry eye were assessed considering that diagnosis is crucial for dry eye treatment and management. Case history (92.5%), fluorescein breakup time (87.5%), and corneal fluorescein staining (72.5%) were reported as the most commonly used diagnostic parameters for dry eye diagnosis in Ghana. This compares with findings in the United States, where a retrospective review of 467 patient charts showed that symptoms assessment, corneal fluorescein staining, and tear breakup time are the most frequently used dry eye diagnostic tests.22 Interestingly, symptoms questionnaires were not used by eye care practitioners in Ghana, although more than 75% of the practitioners surveyed considered patient symptoms important in grading dry eye severity. Dry eye questionnaire is an inexpensive, easily accessible instrument for the assessment of dry eye symptoms.23 It is useful for monitoring the progression and patients' response to treatment. Results from our study, however, show limited use of dry eye questionnaires among eye care practitioners in Ghana, with none of the practitioners surveyed reporting it as being a useful technique for dry eye diagnosis. This contrasts findings from the United Kingdom and Australia, where 31 and 10% of optometric practitioners reported routine use of questionnaires in routine dry eye practice, respectively.16,24 The seeming underutilization of questionnaires in routine dry eye practice in Ghana could be attributed to the reliance of practitioners on patients' case history in dry eye assessment. Practitioners may feel that a comprehensive case history with triaging questions can extract most of the information obtained with a dry eye questionnaire, eliminating the questionnaire's need. The underutilization could also be due to practitioners' limited exposure to the questionnaires' use.
This study also investigated access to and utilization of seemingly advanced dry eye diagnostic techniques. Tear osmolarity technology, matrix metalloproteinase-9 test, lactoferrin test, and meibography are recent advancements in dry eye diagnosis. Tear osmolarity, matrix metalloproteinase-9, and lactoferrin tests have higher sensitivity and specificity and have been recommended for use in dry eye practice.13 From the study, however, none of the practitioners surveyed reported having access to any of these tools. Thus, it seems that the approach to dry eye diagnosis in Ghana is access-driven. The lack of access to these diagnostic techniques, however, may not certainly impact dry eye diagnosis considering that there is not necessarily a need for advanced diagnostics when making a dry eye diagnosis,13 although additional testing can improve dry eye classification.
Aside from diagnostic parameters, the study investigated the treatment and management modalities of dry eye in Ghana. Treatment of dry eye is a concern for both patients and practitioners in view of the complex and multifactorial nature of the disease. In an attempt to harmonize dry eye disease treatment, the 2017 Tear Film and Ocular Surface Society International Dry Eye Workshop II proposed a hierarchy of treatment modalities where the level of treatment correlates with disease severity.12 Step 1 management recommendations for dry eye include dietary modifications, ocular lubricants, lid hygiene, and warm compress. Step 2 recommendations include punctal occlusion (punctal plugs), ointment, in-office physical heating and expression of meibum, topical antibiotics, topical steroid, oral macrolide, and topical nonglucocorticoid immunomodulatory drugs, such as cyclosporine. If step 2 fails, step 3 recommendations—oral secretagogues, autologous/allogeneic serum drops, and scleral contact lenses—are explored. If step 3 options are inadequate, the following options are considered at step 4: topical corticosteroid for a longer duration, amniotic membrane grafts, surgical punctal occlusion (cauterization), and other surgical interventions such as tarsorrhaphy and salivary gland transplantation.12 Treatment and management options for the mild and moderate forms of dry eye generally fall within steps 1 and 2, whereas those for severe dry eye are within levels 3 and 4.
From our study, it seems that eye care practitioners in Ghana largely use steps 1 and 2 treatment recommendations and rarely use steps 3 and 4 management modalities. For instance, although between 16 and 83% of practitioners surveyed considered prescribing ocular lubricants, topical steroid, doxycycline/tetracycline, and omega-3 supplements, only a few considered prescribing or using punctal plugs (5.3%) and topical cyclosporine (2.7%). None considered management with autologous serum tears or scleral lens. Thus, severe dry eye seems to be undermanaged in Ghana. The limited treatment with cyclosporine and scleral contact lenses is seen as an access issue considering that these management options are not readily available on the Ghanaian market. The prescription pattern of ocular lubricant observed in the study is similar to that in the United States, where approximately 80% of eye care practitioners consider ocular lubricant prescription for dry eye.25 There seems to be a trend in the recommendation of omega-3 fatty acid supplementation and topical corticosteroid for dry eye in Ghana. The number of practitioners who would consider recommending or prescribing omega-3 fatty acid supplements and topical corticosteroids increased with increasing dry eye severity. Perhaps, this trend is due to the limited availability of other treatment choices for severe forms of dry eye in the country. A similar trend was observed in studies in Australia and the United Kingdom for omega-3 fatty acid supplements.16,24 Corticosteroids are anti-inflammatory, and considering that inflammation increases with dry eye severity, the pattern of corticosteroid prescription seems justified. The trend of omega-3 fatty acid supplement prescription, however, is counterintuitive, given that evidence supporting the beneficial effect of omega-3 fatty acid in dry eye treatment is limited.26,27
To the best of our knowledge, this study is the first to profile the challenges in dry eye practice. Overall, 88% of practitioners surveyed reported being challenged in dry eye practice. Close to 80% of respondents reported being limited by the lack of diagnostic test and dye availability. This is expected considering that fewer than 20% of practitioners surveyed had access to Schirmer strips or rose bengal and none had access to phenol red thread, lissamine green, osmolarity technology, matrix metalloproteinase-9 test, or meibography device, which are of value in dry eye diagnosis.13 The limited access could be due to the unavailability of these diagnostic tools on the Ghanaian market. Despite the aforementioned challenges, practitioners in Ghana should not be limited significantly in the diagnosis of dry eye disease, per the diagnostic algorithm established by the 2017 Tear Film and Ocular Surface Society International Dry Eye Workshop II.13
The 2017 Tear Film and Ocular Surface Society International Dry Eye Workshop II proposes a diagnostic test battery for dry eye consisting of (i) triaging questions, (ii) risk factor analysis, (iii) diagnostic tests, and (iv) disease subtype classification tests.13 Triaging questions help to rule out conditions that may mimic the signs and symptoms of dry eye. Risk factor analysis investigates factors that predispose one to dry eye. The diagnostic test battery consists of assessments of symptoms (using dry eye symptoms questionnaires) and homeostasis biomarkers (tear breakup time, osmolarity, and ocular surface staining). In the presence of symptoms, dry eye is diagnosed when at least one homeostasis test result is positive.13 It is worth noting, however, that without the use of a questionnaire, symptom information could be obtained from triaging questions. Thus, per this diagnostic algorithm, with the necessary clinical competency, a practitioner can diagnose dry eye with access to a slit lamp and diagnostic dye (fluorescein, rose bengal, or lissamine green) only. Thus, given that almost all the practitioners surveyed had access to a slit lamp and fluorescein dye, the lack of advanced diagnostic tools and techniques should not pose a significant limitation to dry eye diagnosis.
Another challenge with dry eye practice, reported by more than half of respondents, is the unavailability of perceived effective dry eye treatments on the Ghanaian market. To the best of our knowledge, the profile of dry eye medication and other treatment options available in Ghana is largely unknown. However, taking into account that availability of treatment options can influence practitioners' prescription patterns, it seems that the limited prescription rates for cyclosporine and underutilization of punctal plugs, scleral lenses, and thermal pulsation treatment could be attributed to the limited availability of these treatment options on the market. Compounding this challenge is the limited health insurance coverage for eye medication and other management options. According to the 2013 Eye Health Systems Assessment Report, just a little more than 50% of ophthalmic therapeutic drugs listed in the Ghana National Essential Medicine List are covered by the National Health Insurance Scheme.28,29 More important, coverage for dry eye treatment is limited to generic methylcellulose, which is less effective for the severe dry eye disease spectrum. Thus, the treatment outcomes for dry eye in persons may be poorer for those who rely heavily on the National Health Insurance Program for their health care needs, especially low-income families.
Patients' inability to afford dry eye treatment is also a challenge reported by approximately 16% of respondents. Given that 21.4% of Ghanaians live below the poverty line,30 affordability of treatment is a crucial health care issue in the country. Similar to the treatment availability issue, the inability of patients to afford medication and other management modalities hurts the quality of care provided by the eye care professional.
Perceived inadequate training also seems to limit a significant proportion of respondents (18.1%) in dry eye practice. Clinical training exposes practitioners to diagnostic tools/techniques and treatment modalities. Thus, the underutilization of certain procedures and treatment/management options could, in part, be attributed to the seemingly limited exposure of practitioners to these techniques and treatment modalities during training.
By assessing the diagnostic and treatment modalities for dry eye, the study sought to elucidate the quality of care of the dry eye patient in Ghana. Although most of the eye care facilities are found in and around cities in Ghana, there may be rural settings where eye care is performed. We did not assess the availability of basic amenities such as running water and sink in the clinic space, and it would be interesting to evaluate the quality of the physical space for eye clinics in the future.
The outcome of this study may be affected by some limitations. First, only health care practitioners with a primary interest in eye care were included in the study. Considering the limited number of eye care professionals serving the entire population, the role of general practitioners in diagnosing or managing eye diseases, including dry eye, cannot be underestimated. In fact, in underserved areas and health care facilities where there are no ophthalmologists or optometrists, patients with eye problems always see general practitioners (if they are available) or nurses. Despite this, we delimited the study to only health care professionals whose primary interest is eye care. The inclusion of only ophthalmologists and optometrists thus limits the generalizability of the results to other non–eye care professionals who diagnose or manage eye diseases. Also, given the lower response rate among ophthalmologists, the survey might be more reflective of optometric management of dry eye in Ghana.
Besides, the number of surveys sent out was limited. Although approximately 400 professionals were identified, only 280 surveys could be sent out because not all potential participants could be reached because of the challenge of missing address/contact information for some practitioners. Some certified professionals were also excluded from the study because they were not in active practice. These included professionals currently enrolled in full-time graduate degree and other post-qualification certificate programs and those pursuing nonclinical careers.
In conclusion, this study brings to the fore the challenges faced by eye care professionals in clinical dry eye practice in Ghana and has implications for dry eye practice in the country. There is the need to incorporate exposure of eye care professional trainees to dry eye diagnostic tools and strategies, given the fact that almost all the practitioners surveyed indicated professional training as the major influence on their clinical practice pattern. Additional sponsored continuing education activities on dry eye would also be beneficial to Ghanaian eye care providers. The results of this study also underscore the need for profiling dry eye medication and other treatment options in the country, as this could influence pharmaceutical companies to consider making available dry eye medication and other management tools with limited availabilities on the Ghanaian market. All these would go a long way to enhance dry eye practice and improve treatment outcomes and patient satisfaction in the country.
1. Craig JP, Nichols KK, Akpek EK, et al. TFOS DEWS II Definition and Classification Report. Ocul Surf 2017;15:276–83.
2. Stapleton F, Alves M, Bunya VY, et al. TFOS DEWS II Epidemiology Report. Ocul Surf 2017;15:334–65.
3. Moss SE, Klein R, Klein BE. Prevalence of and Risk Factors for Dry Eye Syndrome. Arch Ophthalmol 2000;118:1264–8.
4. Yang WJ, Yang YN, Cao J, et al. Risk Factors for Dry Eye Syndrome: A Retrospective Case-control Study. Optom Vis Sci 2015;92:e199–205.
5. Yu J, Asche CV, Fairchild CJ. The Economic Burden of Dry Eye Disease in the United States: A Decision Tree Analysis. Cornea 2011;30:379–87.
6. Nichols KK, Bacharach J, Holland E, et al. Impact of Dry Eye Disease on Work Productivity, and Patients' Satisfaction with Over-the-counter Dry Eye Treatments. Invest Ophthalmol Vis Sci 2016;57:2975–82.
7. van Tilborg MM, Murphy PJ, Evans KS. Impact of Dry Eye Symptoms and Daily Activities in a Modern Office. Optom Vis Sci 2017;94:688–93.
8. Shtein RM. Post-LASIK Dry Eye. Expert Rev Ophthalmol 2011;6:575–82.
9. Brewitt H, Sistani F. Dry Eye Disease: The Scale of the Problem. Surv Ophthalmol 2001;45(Suppl. 2):S199–202.
10. Savini G, Prabhawasat P, Kojima T, et al. The Challenge of Dry Eye Diagnosis. Clin Ophthalmol 2008;2:31–55.
11. Nichols KK, Mitchell GL, Zadnik K. The Repeatability of Clinical Measurements of Dry Eye. Cornea 2004;23:272–85.
12. Jones L, Downie LE, Korb D, et al. TFOS DEWS II Management and Therapy Report. Ocul Surf 2017;15:575–628.
13. Wolffsohn JS, Arita R, Chalmers R, et al. TFOS DEWS II Diagnostic Methodology Report. Ocul Surf 2017;15:539–74.
14. Frenk J. Health and the Economy: A Vital Relationship. OECD Observer 2004;9–10. Available at: http://oecdobserver.org/news/archivestory.php/aid/1241/Health_and_the_economy:_A_vital_relationship_.html
. Accessed October 10, 2019.
15. Asiedu K, Kyei S, Boampong F, et al. Symptomatic Dry Eye and Its Associated Factors: A Study of University Undergraduate Students in Ghana. Eye Contact Lens 2017;43:262–6.
16. Downie LE, Keller PR, Vingrys AJ. An Evidence-based Analysis of Australian Optometrists' Dry Eye Practices. Optom Vis Sci 2013;90:1385–95.
17. Abdulai T, Abobi-Kanbigs D, Joseph S, et al. Bridging the Inequitable Distribution of Physicians in Ghana: Factors Medical Students and House Officers at UDS and TTH Will Consider in Accepting Postings to Northern Ghana. J Healthc Commun 2017;2:2.
18. Boadi-Kusi SB, Kyei S, Mashige KP, et al. Demographic Characteristics of Ghanaian Optometry Students and Factors Influencing Their Career Choice and Institution of Learning. Adv Health Sci Educ Theory Pract 2015;20:33–44.
19. Boadi-Kusi SB, Ntodie M, Mashige KP, et al. A Cross-sectional Survey of Optometrists and Optometric Practices in Ghana. Clin Exp Optom 2015;98:473–7.
20. Essuman A, Anthony-Krueger C, Ndanu TA. Perceptions of Medical Students about Family Medicine in Ghana. Ghana Med J 2013;47:178–84.
22. Nichols KK, Nichols JJ, Zadnik K. Frequency of Dry Eye Diagnostic Test Procedures Used in Various Modes of Ophthalmic Practice. Cornea 2000;19:477–82.
23. Kawashima M, Yamatsuji M, Yokoi N, et al. Screening of Dry Eye Disease in Visual Display Terminal Workers during Occupational Health Examinations: The Moriguchi Study. J Occup Health 2015;57:253–8.
24. Downie LE, Rumney N, Gad A, et al. Comparing Self-reported Optometric Dry Eye Clinical Practices in Australia and the United Kingdom: Is There Scope for Practice Improvement? Ophthalmic Physiol Opt 2016;36:140–51.
25. Williamson JF, Huynh K, Weaver MA, et al. Perceptions of Dry Eye Disease Management in Current Clinical Practice. Eye Contact Lens 2014;40:111–5.
26. Omega-3 Fatty Acid Supplements Do Not Improve Symptoms of Dry Eye Disease. Drug Ther Bull 2018;56:144.
27. Ton J, Korownyk C. Omega-3 Supplements for Dry Eye. Can Fam Physician 2018;64:826.
28. Alhassan RK, Nketiah-Amponsah E, Arhinful DK. A Review of the National Health Insurance Scheme in Ghana: What Are the Sustainability Threats and Prospects? PLoS One 2016;11:e0165151.
29. Potter A, Debrah O, Ashun J, et al. Eye Health Systems Assessment (EHSA): Ghana Country Report; 2013. Available at: https://www.iapb.org/wp-content/uploads/Ghana-Eye-Health-System-Assessment-Report.pdf
. Accessed March 10, 2019.
30. Bank TW. Poverty Reduction in Ghana: Progress and Challenges; 2015. Available at: http://www.worldbank.org/en/country/ghana/publication/poverty-reduction-ghana-progress-challenges
. Accessed February 15, 2019.