KERATOCONUS IS A bilateral, asymmetric, progressive thinning of the cornea resulting in irregular astigmatism and poor spectacle acuity. The prevalence in the world population is 1.4 in 1,000 people¹ and in some populations as high as 23 in 1,000 or 2.3%.² There is no accepted sex predilection, and correlations are often contradictory in the literature.¹ Age of onset varies among populations studied, but it is known that the earlier keratoconus presents, the more aggressive the progression.³ While environmental factors play a large part in the development and progression of keratoconus, upwards of 28% of cases are familial.⁴

SOCIAL AND PERSONALITY IMPLICATIONS

First described by Gorskova in 1998, psychological testing among patients who have keratoconus revealed commonalities now referred to as the “keratoconic personality.”^5-7 Keratoconus patients have been described as less conforming to treatment than normal controls,⁶ lacking trust in providers,⁶ more passive-aggressive,^6,8 exhibiting a type A personality,⁸ and experiencing generalized anxiety.⁸

An explanation as to why these personality commonalities exist is that keratoconus patients often receive their diagnosis at an early age or during immature years resulting in a disability that has negative impacts on activities of daily living (ADL).^6,9 Coping mechanisms can be maladaptive and lead the patient to be less respectful, conforming, or cooperative.¹⁰ The negative impact on ADL may not be reflected in clinical measures, and, therefore, a dissonance between patient and physician perceptions of disease burden can result.¹⁰ This can then manifest in a disconnected patient-physician relationship.

As a disease of unknown etiology with an uncertain prognosis, keratoconus can greatly affect a patient’s mental health. From the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) study, the quality of life (QOL) scores of keratoconus patients who had normal visual acuity were equal to that of patients who had advanced potentially blinding disease.⁹ There was also an increase in anxiety-related disorders among keratoconus patients, often related to concerns about worsening vision or future surgery.^9,11 Mental health was also affected by disease progression; as visual acuity decreased, anxiety and depression increased.^12,13

Concerns about one’s future health may provoke anxiety. Unfortunately, mental health is often not discussed with eyecare providers. Combine this with the fact that keratoconus patients often are dissatisfied or do not trust information given by providers,¹⁴ resulting in difficult exams and trouble communicating. However, patient education can alleviate or significantly lessen anxiety experienced by keratoconus patients¹⁵ (Figure 1).

QUALITY OF LIFE

QOL can be measured in many domains. Health-related QOL (HR-QOL) is defined as the extent to which one’s usual or expected physical, emotional, and social well-being are affected by a medical condition or its treatment.⁹ Under the HR-QOL umbrella is vision-related QOL (VR-QOL), which is more specific to the visual abilities of the patient.

Keratoconus greatly impacts QOL.⁹ This disease involves young patients, is progressive, and can cause vision to fluctuate, all of which can negatively affect QOL. QOL is significantly affected before the onset of visual impairment and functional disability.¹² Visual acuity measured at 20/40 or worse is associated with decreased QOL and negatively affects the patient’s ability to complete ADL.⁹ Keratoconus individuals that show difficulty with ADL secondary to visual impairment also show higher rates of anxiety and depression, increased dependency on others, and decreased driving ability.⁹

In the CLEK study, keratoconus patients scored low on all measures of QOL.⁹ Worse visual acuity and steeper corneas were most strongly associated with low QOL scores.¹² Disease progression marked a decline in all subscales measured. Keratoconus also affected patients’ work abilities. Approximately 36% of patients noted that keratoconus greatly affected their ability to work and approximately 12% were dismissed from their jobs.¹⁶

Perceived vision loss is disproportionate to visual acuity, illustrating a discrepancy between visual acuity and visual quality. Visual quality is degraded in a keratoconic eye that has 75 times more vertical coma than a normal cornea.¹⁷ Reduced quality of vision in keratoconus patients can be attributed to irregular astigmatism and higher-order aberrations due to the irregular cornea shape.

It is important for eyecare providers to acknowledge the patients’ awareness of decreased quality of vision and document the patients’ descriptions of their subjective vision quality. This provides confirmation to the patients that the provider is understanding of the nuances of their condition and not focusing solely on the acuity measurement.

Keratoconus patients who were able to wear contact lenses experienced a notable change in their QOL.^12,18 Moreira and colleagues described these patients as more optimistic, extroverted, and communicative.⁸ In general, patients wearing contact lenses noted improved QOL levels on all subscales and improved QOL levels over non-contact lens wearers, and displayed the highest QOL scores in all keratoconus patients surveyed.^9,19 Patients who have mild to moderate keratoconus noted a two-fold improvement in visual performance in contact lenses versus spectacles. This doubles for patients who have advanced disease.²⁰

Corneal, rigid GP lens wear in general improved QOL scores.¹² QOL scores were the same between patients wearing GP contact lenses and keratoconic hydrogel lenses.²¹ Scleral lenses can improve visual acuity over corneal GP lenses and, therefore, can significantly improve QOL.^22,23 Scleral lenses offer improved comfort and visual outcomes, especially in those with worsening disease.²⁴ Scleral lenses led to very few complications, apart from difficulty in handling, when compared with corneal GP contact lenses. It is important to note that, even though contact lens wear significantly improved QOL scores, keratoconus QOL scores were still worse than age-matched controls.¹²

Keratoconus patients who had penetrating keratoplasty (PK) in one eye had better vision scores, particularly after a PK was performed in the fellow eye.⁹ Keratoconus patients undergoing PK may still require contact lenses postoperatively for the best visual result.²¹ Contact lens use in an eye with a previous PK showed higher scores in visual and mental functioning.²¹ These results underscore the importance of visual rehabilitation of keratoconus patients who have contact lenses after a PK.

Patients who had a graft age of five years or more scored significantly higher on social functioning and mental health subscales.²¹ Graft age less than five years was strongly associated with lower overall QOL scores. This suggests that transplantation has an adaptation period of five years or longer and it is important to educate patients accordingly.

Patients who have undergone corneal cross-linking (CXL) show improved QOL scores.¹³ The more advanced the keratoconus is, the more significant are the improvements in QOL.²² A therapeutic approach in treating keratoconus may decrease stress and anxiety concerning the progression of disease.²² Patients also experienced better refractive results following CXL, which improved QOL scores.¹⁵

FINANCIAL AND ECONOMIC IMPLICATIONS

The financial and economic impact of keratoconus can be significant to patients (Figure 2). The direct costs of keratoconus care include office visits to eyecare professionals, out-of-pocket expenses, contact lens costs, and additional surgical procedures. The average disease burden of keratoconus is at least 37 years and keratoconus patients have been found to spend up to 30 times more than the general population for eye care.^26,27

Visits to eyecare practitioners are significantly more frequent, noted to be, at minimum, three times per year for 50% or more of keratoconus patients.²⁷ This can be due to complicated contact lens evaluations, prescription changes, complications from contact lens wear, and surgical postoperative visits and follow-up care.

Out-of-pocket costs are any item or service that the patient is directly incurring including contact lens supplies, disinfection solutions, over-the-counter eye drops, etc. Another significant out-of-pocket cost that keratoconus patients incur is due to non-covered services, such as specialty contact lenses and contact lens evaluations. Many insurance plans, particularly medical insurances, may not cover these items and services or the specialty contact lens needed for the patient. Patients also report having difficulty finding eyecare practitioners who understand keratoconus and, when providers are found, they may not be in the patient’s insurance network.^10,27

Indirect costs for keratoconus patients are any costs that are outside of the health care system. These items are usually those to which a specific dollar amount cannot be attributed or exactly quantified. Examples of indirect costs can include loss of productivity at work due to visual impairment, vision accommodations required to complete their work, ability to work, and cost of caregiver support.

Keratoconus has a significant impact on the patient’s ability to work depending on their visual potential with glasses or specialty contact lenses. The amount of time spent on application, removal, and daily care/disinfection of lenses increases with the need for specialty contact lenses.²⁸ If the patient is able to successfully wear specialty contact lenses for improved vision, 50% report at least one adverse incident a year that caused them to miss work due to stopping lens wear, treatment, or follow-up appointments.²⁸

The other component of indirect costs involves patient caregivers. Many times, caregivers (family members and/or parents) are involved in applying or removing contact lenses, driving patients to eyecare appointments, and assisting with ADLs. Time spent to complete these tasks impacts the caregiver from a productivity standpoint in their job as well, increasing the indirect economic cost of keratoconus.

Surgical procedures, specifically corneal transplants (PK, deep anterior lamellar keratoplasty [DALK]) and CXL can all significantly impact the cost burden of keratoconus. The rate of corneal transplantation is declining significantly, reported at 64% of keratoconus patients in 2002 and most recently reported at 3.2% of patients.^29,30 This is likely due to the advances in detection of the condition, CXL to slow progression, and the advances in specialty contact lenses to improve vision. Corneal transplantation rates are higher in those of African American race, lower socioeconomic status, and younger age at diagnosis.³¹

When comparing a PK to DALK for cost-effectiveness, multiple factors must be considered. Clinical outcomes in best-corrected vision, postoperative refraction, higher-order aberrations, and contrast sensitivity are comparable.^31,32 DALK is noted to have less endothelial cell loss, less risk of rejection, and fewer intraocular pressure (IOP) complications postoperatively.³¹

Even though most corneal transplants are a covered service for keratoconus patients, it is important to consider the cost burden to the health care system when compared to a specialty contact lens, which is significantly less.^33,34 These procedures are compared in Figure 3.³³ 

Not only has CXL been shown to be a safe procedure for keratoconus, but it can also reduce the need of a future corneal transplant.³⁵ CXL is cost effective, especially compared to having a corneal transplant.³⁶ A $44,000 savings over a patient’s lifetime after having CXL has been reported, but these calculations do not consider the possibility of contact lens re-evaluations.³⁷ It is estimated CXL will provide a $150 million cost savings to the U.S. healthcare system.³⁸ It is important that eyecare professionals educate potential CXL patients on the need for vision correction post-CXL.

PATIENT-CENTRIC RESOURCES

One of the most valuable services that eyecare providers can offer to keratoconus patients is to educate them on their condition and where they can find reliable information about the condition. There are multiple keratoconus-specific resources patients can access online or in printed materials to provide accurate and up-to-date information about keratoconus. Most notable is the National Keratoconus Foundation (NKCF), which has a significant amount of information for patients online, patient-centered webinars, keratoconus provider listings, newsletters, etc. The NKCF is a non-profit organization that also has multiple brochures that eyecare providers can order to dispense in the office.

SOCIAL MEDIA AND RELIABILITY OF ONLINE CONTENT

More patients are turning to social media and other online sources for health-related information, estimated at almost 80% of internet users.³⁸ Social media provides patients who have the ability to connect with others that have the same condition without geographic boundaries, and many patients seek social media outlets for health-related information as the cost to obtain the information is lower than visiting a healthcare provider.³⁹

There are, of course, disadvantages to patients using social media for health-related information. Sumayyia and colleagues reported 73% of patients said information found on social media would influence their health status, and 27% use social media to save time from contacting their provider about their condition. Most patients (75%) do not check the sources of information they find on social media. Patients perceive that information to be the same or better than visiting their health care provider.³⁸

When patients use social media and find inaccurate content, it can lead to unrealistic expectations of their treatment, visual potential, and disease process. This can include how well they can see with certain types of vision correction or how much their vision will be improved after a corneal procedure. These unrealistic expectations can lead to subsequent dissatisfaction with their eyecare provider and a negative impact on the patient/provider relationship.³⁸

There now are multiple scoring systems to assess the reliability and accuracy of social media and online content, specifically for YouTube.³⁸ One specific scoring system, the Keratoconus-Specific Score (KSS), is used to evaluate uploaded videos that are specific to keratoconus.³⁸ Ozdemir Zeydanli and coworkers evaluated all current keratoconus YouTube-related content and overall, most videos scored poorly relating to accuracy and reliability. Notably, 13% of videos were misleading, offering cures for keratoconus, of which 48% were uploaded by health care providers.³⁸

Another study by Çetinkaya and Pota reported lower reliability and accuracy scores on other YouTube content scoring systems, although the scores are higher when the content is uploaded by a health care institution or practitioner.⁴⁰ Bozali and Yalinbas concluded that YouTube content for keratoconus patients includes minimal amounts of useful information and provides no significant benefit to the patient.⁴¹

Eyecare providers should make patients aware of inaccurate and unreliable information on social media and advise them to seek out their practitioner for information and advice first, but the provider must show an effort to be available for this type of information request as well. Eyecare providers should also advise patients to check sources on information obtained online and make them aware that many patients on social media who provide testimonials for a service or item related to their condition are often compensated for providing their story.

CARE COLLABORATION: SOCIAL WORKERS

Social workers are a great resource that can benefit patients who have chronic health conditions such as keratoconus. Social workers have a comprehensive approach to helping patients who have chronic health conditions, including addressing their physical and mental health, their social functioning, and the need for additional caregivers/family support.⁴²

As with any other referral, eyecare providers can refer a patient to a licensed social worker for assessment of the patient’s needs. Those needs can include travel assistance to appointments, financial counseling for services/costs not covered by insurance, mental health counseling services, and connecting the patient with peer programs related to the patient’s condition.⁴²

PATIENT EDUCATION

When a provider educates a patient, the goal is to increase the patient’s knowledge, which leads to better clinical outcomes, less anxiety to the patient, and increased patient satisfaction.⁴³ If a patient is not directly asked about information regarding their condition, they are reluctant to raise questions as they assume the provider has already told them any relevant information. Patients often assume they appear foolish by asking more questions.

Keratoconus patients specifically have noted their provider’s explanation of keratoconus to be unsatisfactory and overall dissatisfied with the education from their practitioner.⁴⁴ The most important question surrounding a keratoconus patient is their fear of going blind.⁴⁴ Patients that view their provider as emotionally invested and in a partnership style with the patient show higher patient satisfaction and less anxiety and depression.⁴⁰

CONCLUSION

Keratoconus is a multifactorial disease that may have a significant impact on a patient’s mental health, QOL, and finances. It is important for providers to educate themselves on the condition and information available to patients via social media and other outlets, in order to provide patients with the most accurate and pertinent resources available. As more is known about the precise etiology of keratoconus, more can be done to spearhead early detection, visual rehabilitation, and development of patient and provider education resources.CLS

References

1. Hashemi H, Heydarian S, Hooshmand E, et al. The Prevalence and Risk Factors for Keratoconus: A Systematic Review and Meta-Analysis. Cornea. 2020 Feb;39:263-270.
2. Millodot M, Shneor E, Albou S, Atlani E, Gordon-Shaag A. Prevalence and associated factors of keratoconus in Jerusalem: a cross-sectional study. Ophthalmic Epidemiol. 2011 Apr;18:91-97.
3. Buzzonetti L, Bohringer D, Liskova P, Lang S, Valente P. Keratoconus in Children: A Literature Review. Cornea. 2020 Dec;39:1592-1598.
4. Gordon-Shaag A, Millodot M, Shneor E, Liu Y. The genetic and environmental factors for keratoconus. Biomed Res Int. 2015;2015:795738.
5. Gorskova EN, Sevost’ianov EN, Baturin NA. Rezul’taty psikhologicheskogo testirovaniia bol’nykh keratokonusom [Results of psychological testing of patients with keratoconus]. Vestn Oftalmol. 1998 Nov-Dec;114:44-45.
6. Mannis MJ, Morrison TL, Zadnik K, et al. Personality trends in keratoconus: an analysis. Arch Ophthalmol. 1987;105:798–800.
7. Farge EJ, Baer PE, Adams GL, Paton D. Personality Correlates of Keratoconus. In: Fann WE,Karacan E, Pokorny AD, Williams RL, eds. Phenomenology and Treatment of Psychophysiological Disorders. Bridgeport, CT: Spectrum Publications; 1982:243-250.
8. Moreira LB, Alchieri JC, Belfort R Jr, Moreira H. Aspectos psicossociais do paciente com ceratocone [Psychological and social aspects of patients with keratoconus]. Arq Bras Oftalmol. 2007 Mar-Apr;70:317-22.
9. Kymes SM, Walline JJ, Zadnik K, Sterling J Gordon MO; Collaborative Longitudinal Evaluation of Keratoconus Study Group. Changes in the quality-of-life of people with keratoconus. Am J Ophthalmol. 2008 Apr;145:611-617.
10. Mannis MJ, Ling JJ, Kyrillos R, Barnett M. Keratoconus and Personality—A Review. Cornea. 2018 Mar;37:400-404.
11. Tan JC, Nguyen V, Fenwick E, Ferdi A, Dinh A, Watson SL. Vision-Related Quality of Life in Keratoconus: A Save Sight Keratoconus Registry Study. Cornea. 2019 May;38:600-604.
12. Kymes SM, Walline JJ, Zadnik K, Gordon MO; Collaborative Longitudnal Evaluation of Keratonus Study Group. Quality of life in keratoconus. Am J Ophthalmol. 2004 Oct;138:527-535.
13. Tan J, Nguyen V, Fenwick E, Ferdi A, Dinh A, Watson S. Vision-Related Quality of Life in Keratoconus: A Save Sight Keratoconus Registry Study. Cornea. 2009;38:600-604.
14. Alves VL, Alves MR, Lane ST. [The diagnostic communication of keratoconus and its influence on the social representation that the patient has of his/her illness]. Arq Bras Oftalmol. 2007 Sep-Oct;70:790-796.
15. Cingu AK, Bez Y, Cinar Y, et al. Impact of Collagen Cross-linking on Psychological Distress and Vision and Health-Related Quality of Life in Patients With Keratoconus. Eye Contact Lens. 2015 Nov;41:349-353.
16. Zadnik K, Barr JT, Edrington TB, et al. Baseline findings in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study. Invest Ophthalmol Vis Sci. 1998 Dec;39:2537-2546.
17. Gordon-Shaag A, Millodot M, Ifrah R, Shneor E. Aberrations and topography in normal, keratoconus-suspect, and keratoconic eyes. Optom Vis Sci. 2012 Apr;89:411-418.
18. Moreira LB, Alchieri JC, Belfort R Jr., Moreira H. Aspectos psicossociais do paciente com ceratocone [Psychological and social aspects of patients with keratoconus]. Arq Bras Oftalmol. 2007 Mar-Apr;70:317-322.
19. Şengör T, Aydın Kurna S. Update on Contact Lens Treatment of Keratoconus. Turk J Ophthalmol. 2020 Aug 26;50:234-244.
20. Kumar P, Bandela PK, Bharadwaj SR. Do visual performance and optical quality vary across different contact lens correction modalities in keratoconus? Cont Lens Anterior Eye. 2020 Dec;43:568-576.
21. Yildiz EH, Erdurmus M, Elibol ES, Acar B, Vural ET. Contact lens impact on quality of life in keratoconus patients: rigid gas permeable versus soft silicone-hydrogel keratoconus lenses. Int J Ophthalmol. 2015 Oct 18;8:1074-1077.
22. Baali M, Belghmaidi S, Ahammou H, Belgadi H, Hajii I, Moutaouakil A. Évaluation de la qualité de vie des patients équipés en verres scléraux à l’aide d’une version marocaine du NEI-VFQ 25 [Evaluation of the quality of life of patients fitted with scleral lenses using a Moroccan version of NEI-VFQ 25]. J Fr Ophtalmol. 2018 Mar;41:201-205.
23. Formisano M, Franzone F, Alisi L, et al. Effects of Scleral Contact Lenses for Keratoconus Management on Visual Quality and Intraocular Pressure. Ther Clin Risk Manag. 2021 Jan 25;17:79-85.
24. Levit A, Benwell M, Evans BJW. Randomised controlled trial of corneal vs. scleral rigid gas permeable contact lenses for keratoconus and other ectatic corneal disorders. Cont Lens Anterior Eye. 2020 Dec;43:543-552.
25. Panthier C, Moran S, Bourges JL. Evaluation of vision-related quality of life in keratoconus patients, and associated impact of keratoconus severity indicators. Graefes Arch Clin Exp Ophthalmol. 2020 Jul;258:1459-1468.
26. Rebenitsch RL, Kymes SM, Walline JJ, et al. The lifetime economic burden of keratoconus: a decision analysis using a markov model. Am J Ophthalmol. 2011 May;151:768-773.
27. Chan E, Baird PN, Vogrin S, Sundarajan V, Daniell MD, Sahebjada S. Economic impact of keratoconus using a health expenditure questionnaire: A patient perspective. Clin Exp Ophthalmol. 2020 Apr;48:287-300.
28. Shorter E, Schornack M, Harthan J, et al. Keratoconus Patient Satisfaction and Care Burden with Corneal Gas-permeable and Scleral Lenses. Optom Vis Sci. 2020 Sep;97:790-796.
29. Sray WA, Cohen EJ, Rapuano CJ, Laibson PR. Factors associated with the need for penetrating keratoplasty in keratoconus. Cornea. 2002 Nov;21:784-786.
30. Ling JJ, Mian SI, Stein JD, Rahman M, Poliskey J, Woodward MA. Impact of Scleral Contact Lens Use on the Rate of Corneal Transplantation for Keratoconus. Cornea. 2021 Jan;40:39-42.
31. Janiszewska-Bil D, Czarnota-Nowakowska B, Krysik K, et al. Comparison of Long-Term Outcomes of the Lamellar and Penetrating Keratoplasty Approaches in Patients with Keratoconus. J Clin Med. 2021 May 29;10:2421.
32. Sögütlü Sari E, Kubaloglu A, Ünal M, et al. Penetrating keratoplasty versus deep anterior lamellar keratoplasty: comparison of optical and visual quality outcomes. Br J Ophthalmol. 2012 Aug;96:1063-1067.
33. Koo TS, Finkelstein E, Tan D, Mehta JS. Incremental cost-utility analysis of deep anterior lamellar keratoplasty compared with penetrating keratoplasty for the treatment of keratoconus. Am J Ophthalmol. 2011 Jul;152:40-47.
34. Bose S, Ang M, Mehta JS, Tan DT, Finklestein E. Cost-effectiveness of Descemet’s stripping endothelial keratoplasty versus penetrating keratoplasty. Ophthalmology. 2013 Mar;120:464-470.
35. Godefrooij DA, Mangen MJ, Chan E, et al. Cost-Effectiveness Analysis of Corneal Collagen Crosslinking for Progressive Keratoconus. Ophthalmology. 2017 Oct;124:1485-1495.
36. Salmon HA, Chalk D, Stein K, Frost NA. Cost effectiveness of collagen crosslinking for progressive keratoconus in the UK NHS. Eye (Lond). 2015 Nov;29:1504-1511.
37. Lindstrom RL, Berdahl JP, Donnenfeld ED, et al. Corneal cross-linking versus conventional management for keratoconus: a lifetime economic model. J Med Econ. 2021 Jan-Dec;24:410-420.
38. Ozdemir Zeydanli E, Alkan AA. Era of “Dr. YouTube”: Evaluation of YouTube Videos as a Valid Source for Patient Education on Keratoconus. Eye Contact Lens. 2021 Sep 1;47:526-532.
39. Sumayyia MD, Al-Madaney MM, Almousawi FH. Health information on social media. Perceptions, attitudes, and practices of patients and their companions. Saudi Med J. 2019 Dec;40:1294-1298.
40. Çetinkaya AC, Pota CE. Assessment of the quality of information on treatment of keratoconus on YouTube. Int Ophthalmol. 2022 May;42:1499-1505.
41. Bozali E, Yalinbas D. Assessment of YouTube videos as an information resource for keratoconus patients. J Fr Ophtalmol. 2021 Dec;44:1545-1552.
42. Christ G., Diwan S. Chronic Illness and Aging, Section 2: Role of Social Work in Managing Chronic Illness. National Center for Gerontological Social Work Education. Available at cswe.org/getattachment/b537ca55-77eb-4746-80f0-57b113d72cf8/ci-sec2-role-sw.pdf . Accessed Jan. 6, 2023.
43. Friedman AJ, Cosby R, Boyko S, Hatton-Bauer J, Trunbull G. Effective teaching strategies and methods of delivery for patient education: a systematic review and practice guideline recommendations. J Cancer Educ. 2011 Mar;26:12-21.
44. Alves VL, Alves MR, Lane ST. A comunicação diagnóstica de ceratocone e sua influência na representação social que o paciente constrói da sua doença [The diagnostic communication of keratoconus and its influence on the social representation that the patient has of his/her illness]. Arq Bras Oftalmol. 2007 Sep-Oct;70:790-796.