Keunheung Park

Dr. Keunheung Park


Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 July 2020 in PLOS ONE
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Journal Article
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KPKeunheung Park
Keunheung Park
JKJinmi Kim
Jinmi Kim
JLJiwoong Lee
Jiwoong Lee
We developed a deep learning architecture based on Inception V3 to predict visual field using optical coherence tomography (OCT) imaging and evaluated its performance. Two OCT images, macular ganglion cell-inner plexiform layer (mGCIPL) and peripapillary retinal nerve fibre layer (pRNFL) thicknesses, were acquired and combined. A convolutional neural network architecture was constructed to predict visual field using this combined OCT image. The root mean square error (RMSE) between the actual and predicted visual fields was calculated to evaluate the performance. Globally (the entire visual field area), the RMSE for all patients was 4.79 ± 2.56 dB, with 3.27 dB and 5.27 dB for the normal and glaucoma groups, respectively. The RMSE of the macular region (4.40 dB) was higher than that of the peripheral region (4.29 dB) for all subjects. In normal subjects, the RMSE of the macular region (2.45 dB) was significantly lower than that of the peripheral region (3.11 dB), whereas in glaucoma subjects, the RMSE was higher (5.62 dB versus 5.03 dB, respectively). The deep learning method effectively predicted the visual field 24–2 using the combined OCT image. This method may help clinicians determine visual fields, particularly for patients who are unable to undergo a physical visual field exam.

15 January 2018 in BMC Ophthalmology
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KPKeunheung Park
Keunheung Park
JSJonghoon Shin
Jonghoon Shin
JLJiwoong Lee
Jiwoong Lee
We evaluated the relationships between corneal biomechanical properties and structural parameters in patients with newly diagnosed, untreated normal-tension glaucoma (NTG). All subjects were evaluated using an Ocular Response Analyzer (ORA) measuring corneal hysteresis (CH) and the corneal resistance factor (CRF). Central corneal thickness (CCT), Goldmann applanation tonometric (GAT) data, axial length, and the spherical equivalent (SE), were also measured. Confocal scanning laser ophthalmoscopy was performed with the aid of a Heidelberg retina tomograph (HRT III). We sought correlations between HRT parameters and different variables including CCT, CH, and the CRF. Multiple linear regression analysis was performed to identify significant associations between corneal biomechanical properties and optic nerve head parameters. We enrolled 95 eyes of 95 NTG patients and 93 eyes of 93 normal subjects. CH and the CRF were significantly lower in more advanced glaucomatous eyes (P = 0.001, P = 0.008, respectively). The rim area, rim volume, linear cup-to-disc ratio (LCDR), and mean retinal nerve fiber layer (RNFL) thickness were significantly worse in more advanced glaucomatous eyes (P < 0.001, P < 0.001, P < 0.001, and P = 0.001). CH was directly associated with rim area, rim volume, and mean RNFL thickness (P = 0.012, P = 0.028, and P = 0.043) and inversely associated with LCDR (P = 0.015), after adjusting for age, axial length, CCT, disc area, GAT data, and SE. However, in normal subjects, there were no significant associations between corneal biomechanical properties and HRT parameters. A lower CH is significantly associated with a smaller rim area and volume, a thinner RNFL, and a larger LCDR, independent of disc size, corneal thickness, intraocular pressure, and age.

1 June 2021 in Translational Vision Science & Technology
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JSJonghoon Shin
Jonghoon Shin
SKSungjoon Kim
Sungjoon Kim
JKJinmi Kim
Jinmi Kim
KPKeunheung Park
Keunheung Park
Purpose: To develop a deep learning model to estimate the visual field (VF) from spectral-domain optical coherence tomography (SD-OCT) and swept-source OCT (SS-OCT) and to compare the performance between them. Methods: Two deep learning models based on Inception-ResNet-v2 were trained to estimate 24-2 VF from SS-OCT and SD-OCT images. The estimation performance of the two models was evaluated by using the root mean square error between the actual and estimated VF. The performance was also compared among different glaucoma severities, Garway-Heath sectorizations, and central/peripheral regions. Results: The training dataset comprised images of 4391 eyes from 2350 subjects, and the test dataset was obtained from another 243 subjects (243 eyes). In all subjects, the global estimation errors were 5.29 ± 2.68 dB (SD-OCT) and 4.51 ± 2.54 dB (SS-OCT), and the estimation error of SS-OCT was significantly lower than that of SD-OCT (P < 0.001). In the analysis of sectors, SS-OCT showed better performance in all sectors except for the inferonasal sector in normal vision and early glaucoma. In advanced glaucoma, the estimation error of the central region was worsened in both OCTs, but SS-OCT was still significantly better in the peripheral region. Conclusions: Our deep learning model estimated the VF 24-2 better with a wide field image of SS-OCT than did with retinal nerve fiber layer and ganglion cell–inner plexiform layer images of SD-OCT. Translational Relevance: This deep learning method can help clinicians to determine the VF from OCT images. OCT manufacturers can equip this system to provide additional VF data.

13 August 2020 in Retina
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Journal Article
Open access
KPKeunheung Park
Keunheung Park
HKHwa Young Kimd
Hwa Young Kimd
JLJae Jung Lee
Jae Jung Lee
HKHan Jo Kwon
Han Jo Kwon
SPSungwho Park
Sungwho Park
JLJi Eun Lee
Ji Eun Lee
Purpose: To investigate the correlation between postoperative metamorphopsia and macular deformation after macular hole surgery. Methods: This study included 28 eyes of 28 patients who underwent vitrectomy and internal limiting membrane removal for an idiopathic macular hole. The retinal vasculatures were compared between preoperative and postoperative photographs, and postoperative deformation of the macula was assessed as deformation of the square grid. The displacement of each node was measured, and deformation of the grid was calculated as differences in the coordinates of the adjacent nodes. These parameters were analyzed to find correlation with metamorphopsia measured using the M-charts after 6 postoperative months. Results: The average deformations in the vertical and horizontal lines of the grid were 94.29 μm and 49.72 μm, respectively. Perifoveal deformation was significantly greater than parafoveal deformation (P = 0.001∼0.019). The multiple regression analysis demonstrated that the vertical M-score correlated with superior perifoveal deformation of the vertical line on the fovea (P = 0.036), and the horizontal M-score correlated with temporal perifoveal deformation of the horizontal line on the fovea (P = 0.032). Conclusion: The parafoveal tissue was displaced with the fovea concurrently after internal limiting membrane removal in macular hole surgery causing perifoveal deformation, which correlated with postoperative metamorphopsia.

19 January 2024 in Journal of Clinical Medicine
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KPKeunheung Park
Keunheung Park
JKJinmi Kim
Jinmi Kim
JLJiwoong Lee
Jiwoong Lee
This study aimed to develop a new index, the average curvature ratio (ACR), to represent the optic nerve head (ONH) tilting and investigate its clinical relevance. Myopic eyes were included and divided into two subgroups: flat ONH (ACR < 1.0) and convex ONH (ACR ≥ 1.0). The occurrences of central and peripheral visual field (VF) defects were compared between the two groups. A total of 375 myopic eyes were recruited, and 231 and 144 eyes were included in the flat and convex ONH groups, respectively. Central scotoma occurred more frequently in the flat ONH group. According to the Patella–Anderson criteria, the number of eyes with central scotoma was 103 (44.6%) in the flat and 44 (30.6%) in the convex ONH groups (p = 0.009). According to Kook’s criteria, the number of eyes with central scotoma was 122 (52.8%) in the flat and 50 (34.7%) in the convex ONH groups (p < 0.001). Peripheral scotoma was not significantly different between the groups. In the correlation analysis, the ACR was positively correlated with spherical equivalence, but not with axial length or central corneal thickness. The ACR reflects the degree of the ONH tilt and is a good index for estimating central VF damage in myopic eyes.