1.Predicting renal function using fundus photography: role of confounders
Hyun-Woong PARK ; Hae Ri KIM ; Ki Yup NAM ; Bum Jun KIM ; Taeseen KANG
The Korean Journal of Internal Medicine 2025;40(2):310-320
Background/Aims:
The kidneys and retina are highly vascularized organs that frequently exhibit shared pathologies, with nephropathy often associated with retinopathy. Previous studies have successfully predicted estimated glomerular filtration rates (eGFRs) using fundus photographs. We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas in eGFR prediction.
Methods:
We enrolled patients with fundus photographs and corresponding creatinine measurements taken on the same date. One photograph per eye was randomly selected, resulting in a final dataset of 45,108 patients (88,260 photographs). Data including sex, age, and blood creatinine levels were collected for eGFR calculation using the MDRD and CKD-EPI formulas. EfficientNet B3 models were used to predict each parameter.
Results:
Deep neural network models accurately predicted age and sex using fundus photographs. Sex was identified as a confounding variable in creatinine prediction. The MDRD formula was more susceptible to this confounding effect than the CKD-EPI formula. Notably, the CKD-EPI formula demonstrated superior performance compared to the MDRD formula (area under the curve 0.864 vs. 0.802).
Conclusions
Fundus photographs are a valuable tool for screening renal function using deep neural network models, demonstrating the role of noninvasive imaging in medical diagnostics. However, these models are susceptible to the influence of sex, a potential confounding factor. The CKD-EPI formula, less susceptible to sex bias, is recommended to obtain more reliable results.
2.Predicting renal function using fundus photography: role of confounders
Hyun-Woong PARK ; Hae Ri KIM ; Ki Yup NAM ; Bum Jun KIM ; Taeseen KANG
The Korean Journal of Internal Medicine 2025;40(2):310-320
Background/Aims:
The kidneys and retina are highly vascularized organs that frequently exhibit shared pathologies, with nephropathy often associated with retinopathy. Previous studies have successfully predicted estimated glomerular filtration rates (eGFRs) using fundus photographs. We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas in eGFR prediction.
Methods:
We enrolled patients with fundus photographs and corresponding creatinine measurements taken on the same date. One photograph per eye was randomly selected, resulting in a final dataset of 45,108 patients (88,260 photographs). Data including sex, age, and blood creatinine levels were collected for eGFR calculation using the MDRD and CKD-EPI formulas. EfficientNet B3 models were used to predict each parameter.
Results:
Deep neural network models accurately predicted age and sex using fundus photographs. Sex was identified as a confounding variable in creatinine prediction. The MDRD formula was more susceptible to this confounding effect than the CKD-EPI formula. Notably, the CKD-EPI formula demonstrated superior performance compared to the MDRD formula (area under the curve 0.864 vs. 0.802).
Conclusions
Fundus photographs are a valuable tool for screening renal function using deep neural network models, demonstrating the role of noninvasive imaging in medical diagnostics. However, these models are susceptible to the influence of sex, a potential confounding factor. The CKD-EPI formula, less susceptible to sex bias, is recommended to obtain more reliable results.
3.Predicting renal function using fundus photography: role of confounders
Hyun-Woong PARK ; Hae Ri KIM ; Ki Yup NAM ; Bum Jun KIM ; Taeseen KANG
The Korean Journal of Internal Medicine 2025;40(2):310-320
Background/Aims:
The kidneys and retina are highly vascularized organs that frequently exhibit shared pathologies, with nephropathy often associated with retinopathy. Previous studies have successfully predicted estimated glomerular filtration rates (eGFRs) using fundus photographs. We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas in eGFR prediction.
Methods:
We enrolled patients with fundus photographs and corresponding creatinine measurements taken on the same date. One photograph per eye was randomly selected, resulting in a final dataset of 45,108 patients (88,260 photographs). Data including sex, age, and blood creatinine levels were collected for eGFR calculation using the MDRD and CKD-EPI formulas. EfficientNet B3 models were used to predict each parameter.
Results:
Deep neural network models accurately predicted age and sex using fundus photographs. Sex was identified as a confounding variable in creatinine prediction. The MDRD formula was more susceptible to this confounding effect than the CKD-EPI formula. Notably, the CKD-EPI formula demonstrated superior performance compared to the MDRD formula (area under the curve 0.864 vs. 0.802).
Conclusions
Fundus photographs are a valuable tool for screening renal function using deep neural network models, demonstrating the role of noninvasive imaging in medical diagnostics. However, these models are susceptible to the influence of sex, a potential confounding factor. The CKD-EPI formula, less susceptible to sex bias, is recommended to obtain more reliable results.
4.Predicting renal function using fundus photography: role of confounders
Hyun-Woong PARK ; Hae Ri KIM ; Ki Yup NAM ; Bum Jun KIM ; Taeseen KANG
The Korean Journal of Internal Medicine 2025;40(2):310-320
Background/Aims:
The kidneys and retina are highly vascularized organs that frequently exhibit shared pathologies, with nephropathy often associated with retinopathy. Previous studies have successfully predicted estimated glomerular filtration rates (eGFRs) using fundus photographs. We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas in eGFR prediction.
Methods:
We enrolled patients with fundus photographs and corresponding creatinine measurements taken on the same date. One photograph per eye was randomly selected, resulting in a final dataset of 45,108 patients (88,260 photographs). Data including sex, age, and blood creatinine levels were collected for eGFR calculation using the MDRD and CKD-EPI formulas. EfficientNet B3 models were used to predict each parameter.
Results:
Deep neural network models accurately predicted age and sex using fundus photographs. Sex was identified as a confounding variable in creatinine prediction. The MDRD formula was more susceptible to this confounding effect than the CKD-EPI formula. Notably, the CKD-EPI formula demonstrated superior performance compared to the MDRD formula (area under the curve 0.864 vs. 0.802).
Conclusions
Fundus photographs are a valuable tool for screening renal function using deep neural network models, demonstrating the role of noninvasive imaging in medical diagnostics. However, these models are susceptible to the influence of sex, a potential confounding factor. The CKD-EPI formula, less susceptible to sex bias, is recommended to obtain more reliable results.
5.Predicting renal function using fundus photography: role of confounders
Hyun-Woong PARK ; Hae Ri KIM ; Ki Yup NAM ; Bum Jun KIM ; Taeseen KANG
The Korean Journal of Internal Medicine 2025;40(2):310-320
Background/Aims:
The kidneys and retina are highly vascularized organs that frequently exhibit shared pathologies, with nephropathy often associated with retinopathy. Previous studies have successfully predicted estimated glomerular filtration rates (eGFRs) using fundus photographs. We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas in eGFR prediction.
Methods:
We enrolled patients with fundus photographs and corresponding creatinine measurements taken on the same date. One photograph per eye was randomly selected, resulting in a final dataset of 45,108 patients (88,260 photographs). Data including sex, age, and blood creatinine levels were collected for eGFR calculation using the MDRD and CKD-EPI formulas. EfficientNet B3 models were used to predict each parameter.
Results:
Deep neural network models accurately predicted age and sex using fundus photographs. Sex was identified as a confounding variable in creatinine prediction. The MDRD formula was more susceptible to this confounding effect than the CKD-EPI formula. Notably, the CKD-EPI formula demonstrated superior performance compared to the MDRD formula (area under the curve 0.864 vs. 0.802).
Conclusions
Fundus photographs are a valuable tool for screening renal function using deep neural network models, demonstrating the role of noninvasive imaging in medical diagnostics. However, these models are susceptible to the influence of sex, a potential confounding factor. The CKD-EPI formula, less susceptible to sex bias, is recommended to obtain more reliable results.
6.Clinical Practice Guideline for Percutaneous Endoscopic Gastrostomy
Chung Hyun TAE ; Ju Yup LEE ; Moon Kyung JOO ; Chan Hyuk PARK ; Eun Jeong GONG ; Cheol Min SHIN ; Hyun LIM ; Hyuk Soon CHOI ; Miyoung CHOI ; Sang Hoon KIM ; Chul-Hyun LIM ; Jeong-Sik BYEON ; Ki-Nam SHIM ; Geun Am SONG ; Moon Sung LEE ; Jong-Jae PARK ; Oh Young LEE ;
Gut and Liver 2024;18(1):10-26
With an aging population, the number of patients with difficulty swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. Long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach, aided endoscopically, which may be an alternative to a nasogastric tube when enteral nutritional is required for 4 weeks or more. This paper is the first Korean clinical guideline for PEG. It was developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.
7.Bilateral Extensive Serous Retinal Detachment in a Patient with Multiple Myeloma
Jeong Hwa SHIN ; Ik-Chan SONG ; Deog Yeon JO ; Ki Yup NAM
Journal of the Korean Ophthalmological Society 2024;65(4):290-296
Purpose:
To describe a case of bilateral serous retinal detachment in a patient with multiple myeloma.Case summary: A 75-year-old woman presented with sudden-onset of reduced visual acuity in both eyes which had begun 2 days prior. Initial ophthalmological assessment revealed that visual acuities were 0.03 in the right eye and 0.05 in the left eye. Optical coherence tomography indicated pronounced macular elevation and extensive subretinal fluid accumulation in the posterior pole of both eyes. Fluorescein angiography did not detect any significant vascular leakage. Blood tests showed an albumin level of 2.1 g/dL, and plasma protein electrophoresis revealed an M protein level of 0.19 g/dL. Multiple myeloma-related hypoalbuminemia and paraprotein were suspected. The patient's retinal statuses were closely monitored and compared with blood test outcomes. Over 2 months, there was significant improvement, characterized by decreasing macular elevation and reduction of subretinal fluid. This progress was sustained thereafter. Plasma protein electrophoresis showed a gradual decline in paraproteins which coincided with the amelioration of serous retinal detachment.
Conclusions
We encountered a case of acute and extensive serous retinal detachment in both eyes of a patient with multiple myeloma. When fluorescein angiography does not definitively show vascular leakage, light chain deposition disease-related serous retinal detachment should be considered. In such instances, it is important to address and monitor the underlying multiple myeloma.
8.Revascularization of immature retinas with retinopathy of prematurity using combination therapy of deferred laser treatment after a single intravitreal bevacizumab injection
Ju Seouk LEE ; Ki Yup NAM ; Ji Eun LEE ; Joo Eun LEE ; Sang Joon LEE
Kosin Medical Journal 2023;38(1):28-35
Background:
This study aimed to observe the extent of retinal vascularization in patients with retinopathy of prematurity (ROP) who underwent deferred laser treatment (LT) after a single intravitreal bevacizumab injection (IVB).
Methods:
This study retrospectively evaluated 40 consecutive eyes in 21 infants who received a single IVB or LT. Deferred LT was performed in cases of ROP recurrence after a single IVB. To assess the amount of retinal vascularization between the initial IVB and deferred LT, the cases were divided into three groups based on treatment: single IVB, deferred LT after a single IVB, and prompt LT. The growth and associated complications were compared between groups.
Results:
There were 12, 16, and 12 eyes in the single IVB, deferred LT, and prompt LT groups, respectively. Deferred LT was performed at an average of 7.9 weeks after a single IVB. In the single IVB group, retinal vascularization proceeded to zone III, whereas the prompt LT group did not show any growth of vascularization beyond the laser scars. In the deferred LT group, during the window period before LT, retinal vascularization progressed from zone I to zone II posterior and from zone II posterior to zone II anterior, respectively, without further ROP recurrence.
Conclusions
Retinal vascularization progressed during the deferred window period, thereby reducing the area of the retina ablated by LT. A single IVB followed by deferred LT can be an alternative treatment option to prevent ablation of zone I or multiple IVBs.
9.Clinical practice guidelines for percutaneous endoscopic gastrostomy
Chung Hyun TAE ; Ju Yup LEE ; Moon Kyung JOO ; Chan Hyuk PARK ; Eun Jeong GONG ; Cheol Min SHIN ; Hyun LIM ; Hyuk Soon CHOI ; Miyoung CHOI ; Sang Hoon KIM ; Chul-Hyun LIM ; Jeong-Sik BYEON ; Ki-Nam SHIM ; Geun Am SONG ; Moon Sung LEE ; Jong-Jae PARK ; Oh Young LEE ;
Clinical Endoscopy 2023;56(4):391-408
With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tube removal for PEG based on the currently available clinical evidence.
10.Clinical Practice Guideline for Percutaneous Endoscopic Gastrostomy
Chung Hyun TAE ; Ju Yup LEE ; Moon Kyung JOO ; Chan Hyuk PARK ; Eun Jeong GONG ; Cheol Min SHIN ; Hyun LIM ; Hyuk Soon CHOI ; Miyoung CHOI ; Sang Hoon KIM ; Chul-Hyun LIM ; Jeong-Sik BYEON ; Ki-Nam SHIM ; Geun Am SONG ; Moon Sung LEE ; Jong-Jae PARK ; Oh Young LEE ;
The Korean Journal of Gastroenterology 2023;82(3):107-121
With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.

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