Trends in Widefield Fundus Photography and Optical Coherence Tomography Examination in South Korea (2015–2024)

Abstract

Purpose

To understand the nationwide utilization trends of widefield fundus photography (WFP) and optical coherence tomography (OCT) in South Korea from 2015 to 2024.

Methods

This retrospective observational study analyzed national insurance claims data from the Health and Medical Big Data Open System. Data for WFP and OCT were retrieved using their procedure code. We examined the annual number of patients and total examinations, stratified by age, sex, and healthcare facility type. Medical expenses were also analyzed.

Results

Between 2015 and 2024, the number of patients undergoing WFP and OCT increased 11.5-fold (from 334,034 to 3,842,168) and 4.8-fold (from 682,893 to 3,256,514), respectively. Examination volumes grew even more sharply, with a 14.1-fold increase (from 907,009 to 12,796,731) for WFP and 5.9-fold (from 1,821,858 to 10,820,336) for OCT. Women consistently had higher utilization rates than men. Patients aged 50 to 79 years accounted for the majority of both WFP (>60%) and OCT (>70%) procedures, with the 70 to 79 age group showing the highest usage. Medical costs rose 17.6-fold for WFP and 7.4-fold for OCT. The proportion of procedures conducted in primary care settings also rose significantly, from 45.2% to 65.9% for WFP and from 43.4% to 57.9% for OCT.

Conclusions

The use of WFP and OCT in South Korea has markedly increased over the past decade, especially among older adults and in primary care settings. This trend reflects aging demographics, improved access, and policy changes, highlighting the need for efficient resource planning.

In the last two to three decades, ophthalmic imaging technologies have undergone remarkable advancements [1–4]. Among these, widefield fundus photography (WFP) and optical coherence tomography (OCT) have emerged as essential diagnostic tools in routine ophthalmic practice. WFP allows for comprehensive visualization of the retina, including peripheral areas, while OCT provides high-resolution, cross-sectional imaging of the retina, facilitating early detection and monitoring of various retinal and optic nerve diseases [5–16].

The growing global burden of ocular diseases, such as age-related macular degeneration (AMD), diabetic retinopathy, retinal vascular diseases, and glaucoma, has further propelled the widespread adoption of these imaging modalities [8–14]. In South Korea, as in many other aging societies, the prevalence and incidence of these conditions have continued to rise, likely leading to an increased utilization of imaging modalities in clinical settings [17,18].

Despite this increased utilization of both WFP and OCT, there is a lack of studies that have systematically examined nationwide usage trends for these specific imaging modalities. Therefore, this study aims to investigate the trends in utilization of WFP and OCT by analyzing national insurance claims data from South Korea spanning the past 10 years (2015–2024). These findings are expected to provide valuable insights to inform future healthcare policies and guide resource allocation in ophthalmic care.

Materials and Methods

Ethics statement

This study was approved by the Institutional Review Board of Seoul National University Bundang Hospital (No. X-2508-991-901). The requirement for informed consent was waived because it was a retrospective analysis using publicly available database. The study was conducted in accordance with the principles of the 2013 Declaration of Helsinki.

Study design and data source

This was a retrospective observational study using data obtained from the Health and Medical Big Data Open System by Health Insurance Review and Assessment Service (HIRA) in South Korea (https://opendata.hira.or.kr/home.do). This dataset is not raw data but had undergone primary processing by HIRA. Freely accessible to the public, the data facilitated comprehensive analysis of medical procedures, categorized by year, sex, age group, type of medical institution, location of medical institution, and inpatient/outpatient status. From this publicly accessible database, we retrieved detailed information on the statistics of WFP and OCT examinations performed in South Korea between 2015 and 2024.

Variables and data extraction

We extracted data based on specific medical procedure codes: E6674 for WFP and EZ796 for OCT. Our analysis focused on the annual number of patients and total examinations for WFP and OCT. We also examined their distributions, stratified by patient age, sex, and type of healthcare facility. Healthcare facilities were categorized into three levels: primary care (local clinics), secondary care (hospitals and general hospitals), and tertiary care (tertiary hospitals). Furthermore, medical expenses incurred by these examinations were extracted and analyzed. To facilitate international comparison, these costs were presented in both Korean won and US dollar, with the latter calculated by converting the annual costs using the purchasing power parity (PPP) conversion factor for South Korea corresponding to each respective year.

Results

In 2015, the total number of patients who underwent WFP in South Korea was 334,034, corresponding to a rate of 654 per 100,000 population. 3,842,168 patients received WFP in 2024, equivalent to 7,417 per 100,000 population. This indicated an approximate 11.5-fold increase in the number of patients undergoing WFP over the 10-year period (Table 1 and Fig. 1). Meanwhile, a total of 682,893 patients underwent OCT in 2015, yielding a rate of 1,337 per 100,000 population. 3,256,514 patients received OCT in 2024, corresponding to 6,286 per 100,000 population. This signified an approximately 4.8-fold increase in the number of patients undergoing OCT over the decade (Table 2 and Fig. 1).

Table 1.

Number and proportions of patients and examinations for widefield fundus photography from 2015 to 2024 by sex and age group in South Korea

	Year
	2015	2016	2017	2018	2019	2020	2021	2022	2023	2024
No. of patients
Total	334,034 (654)	546,220 (1,065)	840,279 (1,634)	1,168,785 (2,264)	1,655,938 (3,198)	1,935,631 (3,735)	2,494,708 (4,822)	2,924,995 (5,659)	3,428,374 (6,622)	3,842,168 (7,417)
Male	151,347 (591)	247,216 (962)	378,469 (1,469)	523,310 (2,022)	725,094 (2,794)	842,312 (3,250)	1,059,610 (4,099)	1,239,736 (4,799)	1,464,710 (5,654)	1,639,299 (6,322)
Female	182,687 (718)	299,004 (1,169)	461,810 (1,800)	645,475 (2,507)	930,844 (3,604)	1,093,319 (4,219)	1,435,098 (5,544)	1,685,259 (6,518)	1,963,664 (7,590)	2,202,869 (8,514)
No. of examinations
Total	907,009	1,573,951	2,503,759	3,559,669	5,114,004	6,132,298	8,048,902	9,479,697	11,395,090	12,796,731
Male	419,553	732,582	1,164,765	1,645,330	2,321,641	2,776,658	3,560,589	4,178,449	5,087,339	5,716,696
Female	487,457	841,369	1,338,994	1,914,339	2,792,363	3,355,640	4,488,313	5,301,248	6,307,751	7,080,035
Age group, %
0–9	2.2 (161)	1.9 (229)	1.5 (291)	1.5 (405)	1.3 (543)	1.2 (584)	1.4 (956)	1.4 (1,149)	1.5 (1,536)	1.4 (1,780)
10–19	3.2 (192)	2.8 (291)	2.6 (422)	2.5 (596)	2.3 (799)	2.1 (873)	2.3 (1,268)	2.4 (1,573)	2.6 (1,972)	2.7 (2,290)
20–29	5.5 (271)	4.8 (384)	5.0 (617)	5.4 (906)	4.9 (1,176)	5.0 (1,390)	5.1 (1,881)	4.9 (2,189)	5.0 (2,658)	5.1 (3,165)
30–39	7.4 (321)	6.5 (472)	6.4 (722)	6.5 (1,032)	6.1 (1,390)	5.9 (1,625)	5.9 (2,151)	5.7 (2,482)	5.9 (2,980)	6.1 (3,396)
40–49	12.5 (484)	11.9 (758)	11.9 (1,179)	11.8 (1,665)	11.6 (2,335)	11.6 (2,758)	11.8 (3,678)	11.7 (4,316)	11.6 (5,058)	11.5 (5,729)
50–59	22.3 (912)	22.2 (1,469)	22.0 (2,235)	21.8 (3,029)	21.8 (4,245)	21.8 (4,976)	21.4 (6,299)	20.9 (7,210)	19.5 (7,862)	19.1 (8,534)
60–69	24.1 (1,638)	25.8 (2,693)	26.1 (3,984)	25.9 (5,231)	26.7 (7,238)	27.5 (8,148)	27.9 (9,983)	28.3 (11,463)	28.1 (12,848)	27.9 (13,946)
70–79	18.0 (1,935)	18.7 (3,249)	18.9 (4,859)	18.8 (6,500)	19.1 (9,093)	18.8 (10,151)	17.8 (12,272)	18.0 (14,061)	18.5 (16,422)	18.8 (17,774)
≥80	4.9 (1,232)	5.4 (2,076)	5.7 (3,092)	5.9 (4,182)	6.3 (5,817)	6.2 (6,367)	6.3 (7,745)	6.7 (9,013)	7.3 (10,979)	7.5 (12,120)

Values are presented as number only or (%) number. Number of patients undergoing examination per 100,000 persons in each group are indicated within parentheses.

Fig. 1.

Number of patients and examinations who underwent widefield fundus photography (WFP) and optical coherence tomography (OCT) from 2015 to 2024 in South Korea.

Table 2.

Number and proportions of patients and examinations for optical coherence tomography from 2015 to 2024 by sex and age group in South Korea

	Year
	2015	2016	2017	2018	2019	2020	2021	2022	2023	2024
No. of patients
Total	682,893 (1,337)	955,443 (1,864)	1,242,786 (2,417)	1,501,945 (2,909)	1,866,803 (3,605)	2,007,939 (3,874)	2,410,133 (4,658)	2,743,956 (5,308)	3,008,097 (5,810)	3,256,514 (6,286)
Male	328,842 (1,284)	453,513 (1,765)	584,631 (2,269)	702,654 (2,715)	856,780 (3,301)	917,657 (3,541)	1,078,097 (4,171)	1,217,035 (4,711)	1,347,090 (5,200)	1,455,308 (5,612)
Female	354,051 (1,391)	501,930 (1,963)	658,155 (2,566)	799,291 (3,104)	1,010,023 (3,911)	1,090,282 (4,207)	1,332,036 (5,145)	1,526,921 (5,905)	1,661,007 (6,420)	1,801,206 (6,961)
No. of examinations
Total	1,821,858	2,778,815	3,704,092	4,633,204	5,798,793	6,355,832	7,757,663	8,817,088	10,063,255	10,820,336
Male	891,687	1,346,099	1,785,207	2,225,544	2,742,778	3,008,630	3,603,327	4,057,599	4,696,330	5,045,704
Female	930,171	1,432,717	1,918,885	2,407,660	3,056,015	3,347,203	4,154,336	4,759,489	5,366,925	5,774,632
Age group, %
0–9	0.5 (71)	0.5 (102)	0.5 (136)	0.5 (164)	0.5 (225)	0.5 (269)	0.6 (405)	0.6 (443)	0.6 (530)	0.5 (577)
10–19	1.2 (153)	1.2 (218)	1.2 (283)	1.1 (342)	1.1 (416)	1.0 (441)	1.1 (575)	1.1 (687)	1.2 (770)	1.1 (827)
20–29	2.9 (295)	2.8 (395)	2.8 (513)	2.8 (607)	2.7 (733)	2.8 (825)	2.9 (1,030)	2.8 (1,169)	2.7 (1,278)	2.6 (1,364)
30–39	5.9 (527)	5.6 (711)	5.3 (896)	5.2 (1,071)	5.0 (1,296)	4.9 (1,404)	4.8 (1,689)	4.6 (1,871)	4.6 (2,037)	4.6 (2,174)
40–49	12.1 (957)	11.7 (1,315)	11.6 (1,715)	11.5 (2,081)	11.0 (2,523)	10.9 (2,707)	10.9 (3,292)	10.7 (3,705)	10.4 (3,985)	10.2 (4,318)
50–59	21.2 (1,779)	20.8 (2,419)	20.7 (3,119)	20.6 (3,685)	20.4 (4,504)	20.4 (4,850)	20.4 (5,811)	20.1 (6,541)	19.0 (6,742)	18.7 (7,112)
60–69	26.2 (3,642)	26.9 (4,931)	27.1 (6,143)	27.2 (7,102)	27.8 (8,532)	28.6 (8,803)	29.4 (10,190)	29.9 (11,399)	29.9 (12,033)	29.9 (12,705)
70–79	23.3 (5,131)	23.2 (7,083)	23.1 (8,837)	23.2 (10,355)	23.2 (12,490)	22.6 (12,734)	21.6 (14,423)	21.5 (15,851)	22.2 (17,304)	22.6 (18,126)
≥80	6.7 (3,448)	7.3 (4,866)	7.6 (6,189)	8.0 (7,300)	8.3 (8,692)	8.2 (8,698)	8.2 (9,808)	8.6 (10,894)	9.5 (12,483)	9.8 (13,457)

Values are presented as number only or (%) number. Number of patients undergoing examination per 100,000 persons in each group are indicated within parentheses.

A similar trend was observed when considering the total number of these examinations performed. In 2015, the total WFP examination count was 907,009, and OCT was 1,821,858. By 2024, WFP examinations had increased to 12,796,731, and OCT to 10,820,336. Over the 10 years, the number of WFP examinations increased 14.1-fold, and OCT examinations increased 5.9-fold (Tables 1, 2 and Fig. 1).

Regarding sex, both WFP and OCT showed a higher number of patients examined and total examinations performed in women compared to men (Tables 1 and 2). Analyzing by age group, WFP demonstrated a general decreasing trend in the proportion of patients aged 0–59 years over time, while the proportion increased among patients aged 60–69 and ≥80 years. Notably, patients aged 50–79 years consistently accounted for over 60% of all WFP patients (Table 1). Regarding OCT, the proportion of patients aged 30–59 years showed a decreasing trend over time. Consistent with WFP, the proportions within patients aged 60–69 and ≥80 years exhibited an increasing trend. Patients aged 50–79 years consistently constituted over 70% of all OCT patients (Table 2). Furthermore, for both WFP and OCT, the highest patient counts per 100,000 population were observed in 70–79–year age group across all age groups, with average 10-year counts of 9,631 for WFP and 12,233 for OCT (Fig. 2).

Fig. 2.

Average number of patients who underwent examinations from 2015 to 2024 per 100,000 persons by age group. WFP = widefield fundus photography; OCT = optical coherence tomography.

In terms of cost, both WFP and OCT consistently showed an annual increase. In 2015, the costs were 8,922,070 and 63,904,664 PPP dollars for WFP and OCT, respectively. By 2024, these costs rose to 157,364,097 and 470,020,696 PPP dollars. This showed a 17.6-fold increase for WFP and a 7.4-fold increase for OCT (Table 3 and Fig. 3).

Table 3.

Total medical costs for WFP and OCT from 2015 to 2024 in South Korea (in 1,000 KRW and PPP dollars)

	2015	2016	2017	2018	2019	2020	2021	2022	2023	2024
WFP	7,649,515 (8,922,070)	13,586,234 (15,819,837)	22,110,894 (25,338,514)	32,189,966 (37,654,808)	47,247,884 (55,746,427)	58,021,379 (69,959,220)	77,658,821 (93,579,502)	93,739,073 (114,790,503)	114,961,187 (138,776,647)	132,012,741 (157,364,097)
OCT	54,789,942 (63,904,664)	85,119,295 (99,113,069)	116,124,152 (133,075,281)	148,624,890 (173,856,715)	190,042,748 (224,226,002)	212,988,100 (256,810,191)	264,984,124 (319,307,993)	308,213,770 (377,430,805)	358,454,597 (432,712,366)	394,300,362 (470,020,696)

The medical costs in PPP dollars, calculated using the PPP conversion factor for South Korea corresponding to each respective year, are indicated within parentheses.

WFP = widefield fundus photography; OCT = optical coherence tomography; PPP = purchasing power parity.

Fig. 3.

Total medical expenses of examinations performed from 2015 to 2024 in South Korea. Medical cost was calculated based on the purchasing power parity (PPP) conversion factor for South Korea corresponding to each respective year. WFP = widefield fundus photography; OCT = optical coherence tomography.

Regarding healthcare facility type, primary care facilities accounted for less than 50% of total examinations for both WFP (45.2%) and OCT (43.4%) in 2015. However, these proportions increased to 65.9% for WFP and 57.9% for OCT in 2024 (Fig. 4A, 4B).

Fig. 4.

Percentage of examinations from 2015 to 2024 by healthcare facility type. (A) Widefield fundus photography. (B) Optical coherence tomography.

Discussion

This study showed a consistent increase in the number of patients undergoing WFP and OCT over the past decade in South Korea, as well as the total number of examinations and associated costs for both modalities. The primary causes of the rise in patient numbers and examination volumes for these tests are likely the increased prevalence and diagnosis rates of ophthalmic diseases recently [17,18]. Continuous advancements in diagnostic equipment have led to improved diagnostic accuracy, fostering a positive feedback loop where enhanced technology drives greater utilization. Furthermore, there has been a growing emphasis in South Korea on the necessity of regular fundus examinations, leading to an increase in their inclusion in routine health checkups [19]. In South Korea, the designation of ultra-WFP as a new medical technology has resulted in a higher reimbursement fee, approximately 1.64 times the rate for conventional fundus photography. This financial factor may also have driven the greater use of WFP. It is also important to note that 2015 was the first year that OCT equipment became covered by national health insurance in South Korea [20]. This reimbursement policy contributed to reducing financial barriers to the widespread adoption of this imaging modality.

For both examinations, more women than men underwent examination, with the 70–79–year age group showing the highest number of examinations. Patients aged 50–79 years accounted for 60% of all WFP examinations and 70% of all OCT examinations. The Population and Housing Census data by Statistics Korea indicate that although the overall sex ratio of the South Korean population stabilized in the last decade, an increasingly female predominance is observed among those aged 60 years and older. Given that WFP and OCT are most frequently performed in this elderly patient population, this demographic trend likely explains why these examinations were conducted more often in women than in men. The high examination rate in the elderly aligns with the epidemiology of major ocular diseases, such as AMD, whose prevalence has significantly increased recently and for which advanced age is the most prominent risk factor [17]. Starting from mid-2000s, intravitreal anti–vascular endothelial growth factor injections have been actively administered to these AMD patients [21,22]. Consequently, periodic examinations to assess treatment response have become standard practice, which also likely explains the higher examination rates observed in older patient populations. Similarly, the aging demographic may also contribute to the increased examination rates in older individuals for conditions requiring regular follow-ups, such as diabetic retinopathy and glaucoma [23–25].

Regarding examination costs, the total annual examination costs for OCT procedures were higher than those for WFP, because the individual cost of OCT was greater. According to 2019 data from HIRA, an OCT exam was roughly 3.5 times more expensive than a WFP exam.

Regarding healthcare facility types, the proportion of both WFP and OCT performed in primary care settings, which was less than 50% in 2015, increased to approximately 60% by 2024. Ophthalmic diagnostic equipment has progressively become more compact and affordably priced over time, making it increasingly accessible for primary care facilities [3,26,27]. This trend has likely contributed to the increase in the proportion of examinations performed in primary care settings, as their growth rate has been significantly higher compared to the overall increase in patient and examination numbers across all healthcare institutions.

We previously reported the recent trends of fluorescein angiography (FA) examination in South Korea [28]. The number of patients receiving widefield FA steadily increased, demonstrating a growing preference for this modality. Similar to our study, this research indicated that patients in their 60s accounted for the highest number of examinations. Several other studies based on HIRA’s database have investigated the usage trends of OCT, although they have generally focused on specific diseases rather than broader ophthalmology trends. For example, one study on ethambutol-related optic neuropathy revealed a significant increase in OCT usage for ophthalmic examinations, rising from 23.9% in 2015 to 85.5% in 2021 [29]. Another study on tamoxifen-related retinopathy found that fundus photography was predominantly used for both baseline screening (99.0%) and subsequent monitoring (98.6%), whereas OCT was utilized much less frequently (21.9% and 29.6%, respectively) [30]. However, studies analyzing nationwide trends for specific ophthalmic examination modalities using large-scale insurance databases are uncommon, not only in South Korea but also in other countries.

This study, being based on preprocessed data, inherently possesses several limitations. Notably, it was impossible to analyze trends in WFP and OCT examinations by specific disease. For OCT, further research differentiating between macular and optic disc imaging would allow for more detailed subgroup analysis. Also, the limitation of this study stems from the use of national insurance claims data, which relies on procedure codes. For instance, a montage of multiple standard fundus photographs, which also effectively creates a widefield image, can be billed using the code designated for WFP. While these cases are unlikely to constitute a large proportion of the total, our current study methodology could not differentiate them from true ultra-widefield captures.

Nevertheless, this study holds significant clinical relevance as the first domestic research to analyze the utilization trends of WFP and OCT, two of the most commonly used ophthalmic imaging modalities, leveraging reliable big data provided by the government. Moving forward, as the evaluation of chorioretinal microvasculature gains importance in conditions like diabetic macular edema, AMD, and glaucoma, further research incorporating advanced imaging modalities such as OCT Angiography is warranted.

In conclusion, this study revealed a consistent rise in both the number of patients undergoing these examinations and their total volume over the past decade in South Korea. Patients in their 70s consistently underwent the most WFP and OCT procedures, and there was a steady annual increase in healthcare costs. Significantly, a clear trend of more WFP and OCT examinations being performed in primary healthcare facilities was observed. The findings from this study offer crucial insights for optimizing the future allocation of medical resources.

While the substantial increases in medical costs clearly increase the short-term financial burden, the long-term view must consider that novel technologies provide higher diagnostic accuracy and treatment efficiency. This clinical advantage allows us to treat patients significantly better than in the past, potentially reducing the net social cost associated with long-term vision loss and disability. Nevertheless, institutional and regulatory mechanisms are essential to prevent the unnecessary or excessive examinations, thereby ensuring resources are used judiciously. Therefore, this complex issue of technology adoption and reimbursement cannot be resolved by any single group, including those responsible for national finances, public health, or medical experts. Ultimately, this matter requires social consensus reached through collaborative discussions among these relevant groups.