Assessing Eye Care Needs Among Patients with Chronic Kidney Disease on Hemodialysis

Abstract

The prevalence of vision impairment and eye disease is higher among patients with chronic kidney disease (CKD), yet there are no standardized guidelines for this vulnerable population. We hypothesized that there are self-reported unmet ophthalmic care needs among patients receiving hemodialysis. We also hypothesized that limited awareness of the connection between eye health and CKD is a significant barrier to receiving eye care. Methods: From June 2022 to July 2022, patients on dialysis were recruited in-person at two Independent Dialysis Foundation sites in Baltimore, Maryland. Participants completed a survey assessing recent eye exam history, barriers to care, and health literacy. Results: Of 82 participants, 43 (52%) had not received a complete eye exam within the past year. The most common reasons were scheduling conflicts (15 [35%]), not wanting an eye exam (12 [28%]), and costs (6 [14%]). Less than half of respondents (40, 41%) were unaware of a relationship between kidney disease and eye health. Conclusions: Results suggest potential unmet eye care needs and low awareness of CKD-related ocular risks among dialysis patients. Interventions to enhance provider recommendations, improve health literacy, and reduce logistical barriers may help prevent avoidable vision loss in this high-risk population.

1. Introduction

The prevalence of vision impairment and eye disease is estimated to be approximately two to seven times higher in individuals with chronic kidney disease (CKD) compared to those without CKD [1,2,3]. As kidney function declines and patients become dependent on dialysis, several factors contribute to their increased risk of ocular complications. An estimated 14% of adults in the United States are affected by CKD, a percentage that is projected to rise in the coming decades due to population aging and the growing incidence of comorbidities such as obesity, diabetes, and hypertension [4,5]. Despite this, there are currently no standardized, evidence-based guidelines for routine eye screenings or referral criteria tailored specifically for this vulnerable population. The lack of guidelines may contribute to underdiagnosis and delayed management, ultimately leading to vision loss and morbidity.

From an anatomical perspective, the eye and kidney share structural and functional similarities. The extensive microvascular networks found in the choroid and glomerulus are structurally similar, and the developmental pathways of the inner retina and glomerular filtration barrier are alike [6]. Due to these parallels, systemic diseases that damage the microvasculature, such as diabetes and hypertension, are leading causes of both eye disease and CKD. At the molecular level, common pathophysiological mechanisms such as atherosclerosis, inflammation, and oxidative stress are implicated in disease progression of both organs [6,7]. One documented association is retinal arteriolar narrowing, which has been linked to CKD in multiple cross-sectional and prospective studies. This vascular remodeling is postulated to occur, in part, from dysfunction of the Renin–Angiotensin–Aldosterone System (RAAS), a critical regulator of both systemic blood pressure and microvasculature tone [6]. Retinal arteriolar narrowing may further predispose patients with CKD to developing clinically significant eye disease, especially in the presence of other systemic risk factors.

In addition to RAAS dysregulation, CKD may adversely impact eye health due to changes in the blood composition. For example, a study examining the effects of uremia on corneal structures found that elevated blood urea levels were associated with increased central corneal thickness and a reduction in corneal endothelial cell density. These findings may indicate a predisposition to future corneal dysfunction and pathology [8]. Hyperphosphatemia, a common electrolyte imbalance in CKD, has been directly linked to the development of calcific band keratopathy, particularly in the setting of elevated calcium-phosphate product. Patients with CKD also commonly have anemia, largely due to impaired erythropoietin production, which can exacerbate retinal hypoxia and may increase the risk of retinal hemorrhage [9].

For patients with CKD who require dialysis, additional ophthalmic complications may arise from the treatment itself due to changes in intraocular pressure and ocular perfusion pressure [10]. A 2021 meta-analysis reviewing changes in intraocular pressure following hemodialysis found no change in intraocular pressures overall, but did find that patients with a history of glaucoma or narrow angles were at increased risk for developing elevated intraocular pressures with dialysis sessions [11]. Rapid fluid shifts during hemodialysis are also of concern with regard to compromising ocular perfusion. Studies involving optical coherence tomography angiography have demonstrated decreased choroidal and choriocapillaris density following hemodialysis correlating with ultrafiltration volumes [12].

Despite the elevated risk of ocular morbidity among individuals with CKD, there remains no formalized, evidence-based guidelines for routine ophthalmologic screening in this population. Establishing standardized guidelines may help improve adherence to preventive eye care, particularly in vulnerable groups.

A relevant precedent can be found for diabetic eye disease. In March 2017, the American Diabetes Association issued formal recommendations for diabetic retinopathy screening, highlighting the importance of early detection to prevent vision impairment [13]. Although early studies assessing the impact of these guidelines did not demonstrate a dramatic increase in screening adherence, subsequent national survey data used by the American Academy of Ophthalmology has suggested a gradual upward trend in screening rates over time [14]. Currently, approximately 60% of individuals with diabetes receive the recommended annual eye exam, indicating room for improvement [14]. Given the potential for preventable vision loss, even modest gains in screening uptake could yield meaningful clinical benefits.

One critical barrier to screening adherence may be limited health literacy. A cross-sectional observational study examining health literacy in patients with type 2 diabetes in one U.S. urban setting found a prevalence of inadequate health literacy of 38%, and a systematic review in CKD populations reported a prevalence of 25% [15,16]. Limited health literacy can impair patients’ understanding of disease risks and the importance of routine eye exams. Other well-documented barriers to diabetic eye screening include low socioeconomic status, housing and food insecurity, lack of insurance, transportation challenges, and a limited perceived need for care—all of which may similarly impact patients with CKD. These challenges further underscore the importance of tailored interventions, such as education and care coordination, to improve access and adherence to preventive eye care.

Given the high burden of eye disease among patients with CKD and the lack of formalized screening guidelines, understanding access to and utilization of eye care in this population is essential [1,2,3]. This study aimed to survey patients undergoing dialysis to assess their eye health and access to ophthalmic care, as well as to identify potential barriers to receiving such care. We hypothesized that there are unmet ophthalmic care needs in this population based on a self-reported survey. By characterizing these gaps, our goal is to provide insight that may guide future efforts to improve eye care delivery and preventive screening for individuals with advanced kidney disease.

2. Materials and Methods

Participants were recruited at two Independent Dialysis Foundation sites in Baltimore City, Maryland. This foundation is affiliated with the University of Maryland Medical Center, and these particular sites were chosen due to their proximity to the academic center and demographics of the patient population. Patients were approached in-person by research personnel while receiving dialysis for recruitment to participate in the survey. Reported data is all self-reported from the surveys. All patients aged 18 to 89 with CKD receiving dialysis were eligible. The study was approved by the University of Maryland, Baltimore Institutional Review Board (Approval code: HP-00099705, Approval date: 4 April 2022). Informed consent was obtained from all participants and access to medical information was obtained in accordance with the Health Insurance Portability and Accountability Act in case medical history would need to be obtained from their electronic health record. Participants were not offered any incentive or compensation to participate. Data was collected over a 6-week period from June 2022 to July 2022.

The 29-question survey was developed and validated to a fifth-grade reading level. This survey collected data including demographic information and past medical history. To better understand participants’ eye health history, we included questions regarding prescription eyewear, diagnosed eye conditions, current eye symptoms, and the timing of their last eye exam. The American Academy of Ophthalmology currently recommends that at-risk individuals over the age of 40 receive annual eye exams [17]. If participants had not received an eye exam in the past one year, they were queried additionally to determine the reasoning. To assess health literacy, participants were asked about their agreement with a statement that stated that having CKD increased risk of eye disease.

Data from the physical surveys was entered into an online REDCap database to aid in analysis. Descriptive statistics, including means with standard deviations (SDs) and counts with percentages, were reported for survey responses. We evaluated which characteristics were related to an increased likelihood of receiving an eye exam within the past one year using bivariate analysis with Chi-Square Test for Independence. Means were compared using nonparametric tests of significance. Variables with a statistically significant relationship were included in final multivariate analyses. Reporting adjusted odds ratios (ORs) and 95% confidence intervals (CIs), with p < 0.05 considered statistically significant.

3. Results

3.1. Patient Characteristics

A total of 82 individuals participated across two dialysis center locations. 54% identified as male, 85% identified as African American, 56% had a high school diploma or GED equivalent or less, 71% were insured by Medicare or Medicaid, and 52% had an annual household income less than USD 25,000. Regarding medical history, 67 patients (82%) had hypertension, 35 (43%) had diabetes, 31 (38%) had high cholesterol, 22 (27%) had cardiovascular disease, 13 (16%) had a prior stroke, and 38 (46%) had been receiving dialysis for more than 5 years. Figure 1 (below) demonstrates the overlap between the three most reported comorbidities. Additional characteristics of the survey participants are reported in

Table 1. Distribution of Selected Characteristics Among Participants.

Demographics
Age, mean (SD), y	62 (11)
Gender, No. (%)
Male	44 (54)
Female	38 (46)
Race, No. (%)
White	4 (5)
Black	71 (87)
Other/Multiracial	7 (9)
Ethnicity, No (%)
Hispanic or Latino	2 (2)
Non-Hispanic or Latino	80 (98)
Education, No. (%)
Less than high school	12 (15)
High School/GED	34 (41)
Some college/associate degree/trade school/Bachelor’s degree or higher	36 (44)
Annual Household Income, No. (%)
USD 0–USD 25,000	43 (58)
USD 25,000–USD 50,000	16 (22)
More than USD 50,000	15 (20)
Household Size, No. (%)
1	30 (37)
2	28 (34)
3 or more	24 (29)
Health Insurance Type, No. (%)
Private Insurance	9 (11)
Medicaid/Medicare	52 (65)
Combined Insurance (Private/VA Benefits +/− Medicare/Medicaid)	19 (24)
Estimated Monthly Out-of-Pocket Healthcare Expenses, No. (%)
Less than USD 100	58 (76)
More than USD 100	18 (24)
Smoking History, No. (%)
Current smoker	15 (18)
Former smoker	23 (28)
Never smoker	44 (54)
Alcohol Use, No. (%)
Never	63 (77)
Monthly or less	12 (15)
2–4 times a month or more	7 (9)
Medical History
Past Medical History, No. (%)
Hypertension	67 (82)
Diabetes	35 (43)
Stroke	13 (16)
Cardiovascular disease	22 (27)
High cholesterol	31 (38)
Length of dialysis, No. (%)
Less than 1 year	16 (20)
1–5 years	28 (34)
More than 5 years	38 (46)
Main causes of CKD, No. (%)
Hypertension	40 (41)
Diabetes	20 (20)
Other	21 (21)
Unsure	17 (17)
Eye Health
Number of previously diagnosed eye conditions, mean (SD)	2 (2)
Wears prescription eyeglasses/contacts, No. (%)	43 (52)
Had a complete eye exam in the past one year, No. (%)	39 (48)
Has been recommended to receive an eye exam by a doctor, No. (%)	36 (44)
Has family history of eye disease, No. (%)	27 (33)
Number of daily eye symptoms, mean (SD)	2 (2)
Experiencing eye symptoms currently, No. (%)	22 (27)
Health Literacy
Statement: “Chronic kidney disease can increase the risk of eye diseases”, No. (%)
Agree/Strongly Agree	42 (51)
Neutral/Unsure	30 (37)
Disagree/Strongly Disagree	10 (12)

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3.2. Eye Exams

Forty-three participants (52%) had not received a complete eye exam within the past one year, and among these participants the three most common reasons for not having a recent eye exam were scheduling conflicts (15 [35%]), not wanting an eye exam (12 [28%]), and cost (6 [14%]). Patients with a past medical history of diabetes were significantly more likely to have received a recent eye exam compared to patients without diabetes (66% vs. 34%; p < 0.005). The associations between various participant characteristics and receiving a recent eye exam are shown in

Table 2. Association between social factors and medical history and eye exam in the last year.

Social Determinants of Health	N (%) Receiving Eye Examination in Last 1 Year	p-Value
Age		0.14
<65 years	21 (41)
≥65 years	18 (58)
Gender		0.63
Male	22 (50)
Female	17 (45)
Race		0.26
White	3 (75)
Non-White	46 (59)
Ethnicity		0.16
Hispanic or Latino	2 (100)
Non-Hispanic or Latino	40 (50)
Education		0.66
High school diploma or beyond	34 (49)
Less than high school	5 (42)
Income		0.13
<USD 25,000	16 (37)
≥USD 25,000	17 (55)
Insurance		0.76
Any private insurance	13 (46)
Public insurance	26 (50)
Monthly health expenses		0.50
<USD 100	27 (47)
≥USD 100	10 (56)
Smoking		0.68
Never	20 (45)
Ever	19 (50)
Alcohol		0.11
None	33 (52)
Any	6 (32)
HTN		0.62
No	8 (53)
Yes	31 (46)
Diabetes		<0.01
No	16 (34)
Yes	23 (66)
Stroke		0.09
No	30 (43)
Yes	9 (69)
Cardiovascular disease		0.44
No	27 (45)
Yes	12 (55)
High cholesterol		0.30
No	22 (43)
Yes	17 (55)

Boldface indicates statistical significance (p < 0.05).

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The odds of receiving an eye exam in the past one year were 50% higher among patients with at least one diagnosed eye condition that the participant could name (adjusted OR = 1.50, 95% CI = 1.06 to 2.12). Twenty-two participants (27%) reported experiencing eye symptoms daily. The reported eye symptoms included eye redness, pain, dryness, and blurred vision. The odds of receiving an eye exam in the past one year were 73% lower in patients currently experiencing eye symptoms (adjusted OR = 0.27, 95% CI = 0.08 to 0.92).

3.3. Health Literacy

Just over half of respondents (42, 51%) agreed or strongly agreed with the statement “chronic kidney disease can increase the risk of eye diseases.” The distribution of these responses is plotted as a function of age in the histogram in Figure 2 (above). Thirty respondents (37%) were neutral or unsure and 10 (12%) disagreed or strongly disagreed. Seventeen participants (21%) were unsure of the main cause of their CKD. No factors were found to have a statistically significant relationship with a greater likelihood of agreeing with this statement in our multivariate analysis.

4. Discussion

We hypothesized that there would be self-reported unmet ophthalmic care needs among patients with chronic kidney disease (CKD) receiving hemodialysis in Baltimore City. This was developed based on the known overlap in risk factors and pathophysiology between CKD and eye disease, as well as multiple factors limiting this patient population’s access to medical services. Among the study participants, the most commonly reported causes of CKD were hypertension and diabetes. These are two chronic conditions known to adversely affect the microvasculature of the eye. These comorbidities increase the risk of developing a wide range of eye conditions, including diabetic retinopathy, hypertensive retinopathy, cataracts, and glaucoma. These risks underscore the importance of routine ophthalmic evaluations in this population for early detection and intervention. Despite this, our findings show that there is a suboptimal rate of eye screening in this patient population, with 52% of participants reporting they have not received a comprehensive eye exam in the past year. This rate of screening falls short of the American Academy of Ophthalmology’s current recommendation, which advises that at-risk individuals over the age of 40 receive annual eye exams [17]. This gap in preventative eye care in this vulnerable group highlights a critical area for intervention to reduce preventable ocular morbidity.

Patients with diabetes were significantly more likely to have received a recent eye exam compared to those without diabetes (66% vs. 34%; p < 0.005). This disparity is likely influenced by formalized screening guidelines published by the American Diabetes Association and the American Academy of Ophthalmology, which specifically recommend regular dilated eye exams for patients with diabetes [13,14]. These guidelines have provided a clear standard of care which may improve provider adherence and patient awareness. Interestingly, other demographic and clinical factors—including age, gender, ethnicity, education, income level, type of insurance, and the presence of additional medical comorbidities—were not found to have a statistically significant association with the likelihood of receiving an eye exam within the previous year.

The survey results revealed notable gaps in health literacy regarding the connection between kidney disease and eye health. Only 51% of participants agreed or strongly agreed that CKD impacts eye health, while the remaining 49% were either unaware or unsure about this relationship. The lack of awareness is clinically meaningful, as patient knowledge and beliefs about disease can play a pivotal role in motivating individuals to seek preventative care. When patients do not understand the relationship between their systemic condition and ocular risks, they may be less inclined to seek preventative eye care, particularly if they are not experiencing symptoms. This highlights an important educational need, that if addressed, could empower patients to obtain eye care.

In addition to health literacy, the survey also provided insight into several specific barriers to eye care within this population. Many participants attributed their lack of recent eye exams to either not wanting one (12 [28%]) or not being advised to obtain one by their healthcare providers (6 [14%]). These responses underscore the importance of both provider recommendations and patient perceptions in shaping health behaviors. Provider recommendation plays a vital role in motivating patients to engage in preventative care. Without these recommendations, patients may not understand the importance of receiving eye exams, especially if they are asymptomatic.

Furthermore, the demanding nature of hemodialysis itself likely contributes to these challenges. Most patients receiving hemodialysis typically attend treatment sessions three times a week, with each visit lasting approximately three to four hours. The physical toll of these sessions, combined with the burden of frequent travel to the treatment center and fatigue afterwards, can leave patients with limited time and energy to have additional medical appointments. This was reflected in our survey results. Among participants who had not received an eye exam in the past year, the most frequently cited reason was scheduling conflicts (15 [35%]). This demonstrates a significant barrier to accessing preventative care.

These challenges may help explain why patients who reported current eye symptoms were less likely to have received an eye exam within the past year. If individuals face significant barriers to care, including difficulty making appointments or limited energy, they may not schedule eye exams. Without timely assessment and treatment, their symptoms can persist and potentially worsen. In contrast, the patients who have received a recent eye exam may have been treated for any eye symptoms they were experiencing, thereby decreasing the likelihood of persistent symptoms reported at the time of the survey. Furthermore, it is important to note that many serious eye conditions common in the population, including glaucoma, diabetic retinopathy, or hypertensive retinopathy, often progress silently and without symptoms early in the disease course. This highlights the importance of routine eye screenings even in the absence of symptoms.

Participants in this study were recruited from two urban dialysis centers in Baltimore, which suggests that the results are likely generalizable to other large urban areas with comparable demographics and socioeconomic characteristics. Within our study population, 85% identified as African American, 56% had a high school diploma or GED equivalent or less, 71% were insured through Medicare or Medicaid, and 52% reported an annual household income of less than USD 25,000. These characteristics reflect a population that may face barriers to healthcare access, further demonstrating the need for targeted research and interventions in similarly underserved urban communities.

These findings highlight the need for further research to better understand the eye care needs of patients undergoing dialysis. Gathering data from a more diverse patient population across different regions could strengthen the evidence for developing eye screening guidelines and refining recommendations. Additionally, conducting studies that include comprehensive eye examinations in this population could help identify undiagnosed conditions and further support the case for targeted screening.

One of the main findings of this paper was the many challenges involved in coordinating care in this population. One method of increasing access to eye care may be with the utilization of telemedicine. A portable fundus imaging device could be used by trained personnel at the dialysis clinics to obtain images, which could then be analyzed by an ophthalmologist remotely. Bringing this screening tool to the dialysis sites would be convenient for patients and help prevent disease progression earlier in its course. Additionally, developing educational materials that focus on the relationship between CKD and eye health could also improve health literacy and increase the likelihood that patients will seek eye care.

These findings support the pressing need for the development and implementation of standardized, evidence-based guidelines for ophthalmologic screening and referral recommendations among patients with CKD receiving dialysis. Our results showing self-reported unmet eye care needs and low rates of routine eye examinations demonstrate a gap in preventative care within this high-risk population. The current absence of formalized recommendations may contribute to inconsistent screening practices, resulting in missed opportunities for the early detection and management of potentially sight-threatening conditions. Given that patients are receiving hemodialysis multiple times a week and interacting with their nephrology team, there is a valuable opportunity to incorporate eye health education and referral into this care. Establishing protocols could help standardize care across providers and healthcare settings. Educating all stakeholders, including patients, nephrologists, and primary care providers, could increase the likelihood of patients being reminded and self-motivated to seek preventative eye care. Implementing these changes has the potential to reduce ocular morbidity, promote early intervention, and improve the overall quality of life for this patient population.