ORIGINAL STUDY
Analysis of Macular and Peripapillary Choroidal Thickness in Glaucoma Patients by Enhanced Depth Imaging Optical Coherence Tomography Hae-Young Lopilly Park, MD, PhD,* Na-Young Lee, MD, PhD,w Hae-Young Shin, MD,z and Chan Kee Park, MD, PhD*
Background: To compare the macular and peripapillary choroidal thickness between normal and glaucoma eyes and find out factors related to choroidal thickness using enhanced depth imaging (EDI) of Heidelberg Spectralis SD-OCT. Study Design: Cross-sectional transverse study. Methods: A total of 108 glaucoma patients and 48 healthy controls were included in the analysis. Choroidal thickness was measured from 6 mm length radial B-scans at the macular and the optic nerve head by EDI OCT. Choroidal thickness was compared between normal controls, normal tension glaucoma (NTG) patients, and primary open-angle glaucoma (POAG) patients. Factors related to choroidal thickness were analyzed by regression analysis. Results: There were no differences in average, temporal, nasal, superior, and inferior macular choroidal thickness between normal, NTG, and POAG eyes. The peripapillary thickness did not differ between normal and POAG eyes; however, average, temporal, nasal, superior, and inferior peripapillary choroidal thickness were significantly thinner in NTG eyes. Axial length (b = 11.36, P < 0.001) was the most significant factor associated with peripapillary choroidal thickness, followed by age (b = 5.10, P < 0.001). Glaucoma type (b = 11.28, P < 0.001) were also significantly associated with peripapillary choroidal thickness. Conclusions: Peripapillary choroidal thickness was significantly reduced in NTG eyes based on EDI OCT measurements in vivo. Key Words: choroidal thickness, enhanced depth imaging, glaucoma
(J Glaucoma 2014;23:225–231)
G
laucomatous optic neuropathy is associated with typical morphologic changes in the retina and the optic nerve head (ONH).1–4 However, the mechanism underlying the changes of glaucoma remains to be elucidated. Increased intraocular pressure (IOP) is the main risk factor for both primary open-angle glaucoma (POAG) and Received for publication November 27, 2012; accepted January 10, 2014. From the *Department of Ophthalmology and Visual Science, Seoul St Mary’s Hospital; wDepartment of Ophthalmology and Visual Science, Incheon St Mary’s Hospital; and zDepartment of Ophthalmology and Visual Science, Uijeongbu St Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea. Disclosure: The authors declare no conflict of interest. Reprints: Chan Kee Park, MD, PhD, Department of Ophthalmology and Visual Science, Seoul St Mary’s Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-ku, Seoul 137-701, Korea (e-mail: [email protected]). Copyright r 2014 by Lippincott Williams & Wilkins DOI: 10.1097/IJG.0000000000000045
J Glaucoma
Volume 23, Number 4, April/May 2014
normal tension glaucoma (NTG). But, especially for NTG, non-IOP factors, such as vascular and hemodynamic factors, are considered to be strongly related to the development and progression of glaucoma.5–7 A few histologic studies found a decrease in choroidal thickness in glaucoma patients.8,9 However, histologic studies measuring the choroidal thickness may be greatly affected by preparation and fixation of tissues. By application of an enhanced depth imaging (EDI) technique, it is possible to capture the image of the full-thickness of the choroid in vivo.10–12 Recently, 2 reports were published that studied the choroid in glaucoma with spectral-domain optical coherence tomography (SD-OCT).13,14 Nevertheless, the results found no association between the choroidal thickness and glaucoma. A study by Hirooka et al15 found reduction of choroidal thickness in NTG patients at 3 mm nasal from the fovea, which is close to the peripapillary choroid around the ONH. To find out the role of choroid in glaucoma, peripapillary choroid that is related to the blood supply of the ONH, which is the choroid just adjacent to the ONH, needs to be investigated. In this study, we performed choroidal thickness measurements from cross-sectional images of EDI SD-OCT at the macula and the ONH in normal control and glaucoma subjects. The purpose of this study was to find out the difference of choroidal thickness and related factors between POAG and NTG.
METHODS The study was a cross-sectional design that investigated 135 Korean adults with newly diagnosed glaucoma and 54 normal controls (healthy volunteers). Participants were recruited from Seoul St Mary’s Hospital between June and August 2010. In cases in which both eyes of the patient were eligible for the study, only 1 eye was randomly chosen for inclusion. The study was performed with the informed consent of the participants and followed all of the guidelines for experimental investigation in human subjects required by the Institutional Review Board of Seoul St Mary’s Hospital. All investigations were carried out in accordance with the Declaration of Helsinki. Each participant was subjected to comprehensive ophthalmic assessment, including the measurement of best-corrected visual acuity, slit-lamp biomicroscopy, Goldmann applanation tonometry, gonioscopy, dilated stereoscopic, color disc and red-free retinal nerve fiber layer (RNFL) photography (VX-10; Kowa Optimed, Tokyo, Japan), RNFL thickness by Cirrus OCT, achromatic automated perimetry using the 24-2 Swedish Interactive Threshold Algorithm standard program (Humphrey Visual www.glaucomajournal.com |
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Park et al
Field Analyzer; Carl Zeiss-Meditec Inc., Dublin, CA), and measurement of axial length (IOL Master; Carl ZeissMeditec Inc.). To be included, eyes had to have a best-corrected visual acuity of Z20/40, a spherical refraction within ± 6.0 D, cylinder correction within ± 3.0 D, and no history of retinal diseases such as diabetic retinopathy, macular degeneration or retinal detachment, and inflammatory eye diseases. Those who were under 18 years of age, diagnosed as secondary glaucoma, angle-closure glaucoma, or angleclosure suspects, who had ocular trauma, previous laser therapy or intravitreal injection, ocular surgery other than cataract surgery, nonglaucomatous optic neuropathy or visual field loss, and active, chronic, or recurrent uveitis were excluded. Eyes with consistently unreliable visual fields (defined as false negative >25%; false positive >25%; and fixation losses >20%) were also excluded. POAG was defined as the presence of an abnormal glaucomatous optic disc (diffuse or focal thinning of the neuroretinal rim), an abnormal visual field consistent with glaucoma and an IOP > 21 mm Hg (without topical medical treatment), and open-angle by gonioscopy. Patients were defined as NTG if they had an abnormal glaucomatous optic disc, an abnormal glaucomatous visual field, open-angle by gonioscopy, and an IOPr21 mm Hg (without topical medical treatment) during the repeated measurements taken on 3 different days. The normal control group was defined as those having an IOP < 21 mm Hg with no history of increased IOP, an absence of glaucomatous disc appearance, no visible RNFL defect according to red-free photography, and a normal standard automated perimetry result. An absence of the glaucomatous disc appearance was defined as an intact neuroretinal rim without peripapillary hemorrhages, notches, or localized pallor. A glaucomatous visual field change was defined as the consistent presence of a cluster of Z3 nonedge points on the pattern deviation plot with a probability of occurring in
Analysis of Macular and Peripapillary Choroidal Thickness in Glaucoma Patients by Enhanced Depth Imaging Optical Coherence Tomography Hae-Young Lopilly Park, MD, PhD,* Na-Young Lee, MD, PhD,w Hae-Young Shin, MD,z and Chan Kee Park, MD, PhD*
Background: To compare the macular and peripapillary choroidal thickness between normal and glaucoma eyes and find out factors related to choroidal thickness using enhanced depth imaging (EDI) of Heidelberg Spectralis SD-OCT. Study Design: Cross-sectional transverse study. Methods: A total of 108 glaucoma patients and 48 healthy controls were included in the analysis. Choroidal thickness was measured from 6 mm length radial B-scans at the macular and the optic nerve head by EDI OCT. Choroidal thickness was compared between normal controls, normal tension glaucoma (NTG) patients, and primary open-angle glaucoma (POAG) patients. Factors related to choroidal thickness were analyzed by regression analysis. Results: There were no differences in average, temporal, nasal, superior, and inferior macular choroidal thickness between normal, NTG, and POAG eyes. The peripapillary thickness did not differ between normal and POAG eyes; however, average, temporal, nasal, superior, and inferior peripapillary choroidal thickness were significantly thinner in NTG eyes. Axial length (b = 11.36, P < 0.001) was the most significant factor associated with peripapillary choroidal thickness, followed by age (b = 5.10, P < 0.001). Glaucoma type (b = 11.28, P < 0.001) were also significantly associated with peripapillary choroidal thickness. Conclusions: Peripapillary choroidal thickness was significantly reduced in NTG eyes based on EDI OCT measurements in vivo. Key Words: choroidal thickness, enhanced depth imaging, glaucoma
(J Glaucoma 2014;23:225–231)
G
laucomatous optic neuropathy is associated with typical morphologic changes in the retina and the optic nerve head (ONH).1–4 However, the mechanism underlying the changes of glaucoma remains to be elucidated. Increased intraocular pressure (IOP) is the main risk factor for both primary open-angle glaucoma (POAG) and Received for publication November 27, 2012; accepted January 10, 2014. From the *Department of Ophthalmology and Visual Science, Seoul St Mary’s Hospital; wDepartment of Ophthalmology and Visual Science, Incheon St Mary’s Hospital; and zDepartment of Ophthalmology and Visual Science, Uijeongbu St Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea. Disclosure: The authors declare no conflict of interest. Reprints: Chan Kee Park, MD, PhD, Department of Ophthalmology and Visual Science, Seoul St Mary’s Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-ku, Seoul 137-701, Korea (e-mail: [email protected]). Copyright r 2014 by Lippincott Williams & Wilkins DOI: 10.1097/IJG.0000000000000045
J Glaucoma
Volume 23, Number 4, April/May 2014
normal tension glaucoma (NTG). But, especially for NTG, non-IOP factors, such as vascular and hemodynamic factors, are considered to be strongly related to the development and progression of glaucoma.5–7 A few histologic studies found a decrease in choroidal thickness in glaucoma patients.8,9 However, histologic studies measuring the choroidal thickness may be greatly affected by preparation and fixation of tissues. By application of an enhanced depth imaging (EDI) technique, it is possible to capture the image of the full-thickness of the choroid in vivo.10–12 Recently, 2 reports were published that studied the choroid in glaucoma with spectral-domain optical coherence tomography (SD-OCT).13,14 Nevertheless, the results found no association between the choroidal thickness and glaucoma. A study by Hirooka et al15 found reduction of choroidal thickness in NTG patients at 3 mm nasal from the fovea, which is close to the peripapillary choroid around the ONH. To find out the role of choroid in glaucoma, peripapillary choroid that is related to the blood supply of the ONH, which is the choroid just adjacent to the ONH, needs to be investigated. In this study, we performed choroidal thickness measurements from cross-sectional images of EDI SD-OCT at the macula and the ONH in normal control and glaucoma subjects. The purpose of this study was to find out the difference of choroidal thickness and related factors between POAG and NTG.
METHODS The study was a cross-sectional design that investigated 135 Korean adults with newly diagnosed glaucoma and 54 normal controls (healthy volunteers). Participants were recruited from Seoul St Mary’s Hospital between June and August 2010. In cases in which both eyes of the patient were eligible for the study, only 1 eye was randomly chosen for inclusion. The study was performed with the informed consent of the participants and followed all of the guidelines for experimental investigation in human subjects required by the Institutional Review Board of Seoul St Mary’s Hospital. All investigations were carried out in accordance with the Declaration of Helsinki. Each participant was subjected to comprehensive ophthalmic assessment, including the measurement of best-corrected visual acuity, slit-lamp biomicroscopy, Goldmann applanation tonometry, gonioscopy, dilated stereoscopic, color disc and red-free retinal nerve fiber layer (RNFL) photography (VX-10; Kowa Optimed, Tokyo, Japan), RNFL thickness by Cirrus OCT, achromatic automated perimetry using the 24-2 Swedish Interactive Threshold Algorithm standard program (Humphrey Visual www.glaucomajournal.com |
225
Park et al
Field Analyzer; Carl Zeiss-Meditec Inc., Dublin, CA), and measurement of axial length (IOL Master; Carl ZeissMeditec Inc.). To be included, eyes had to have a best-corrected visual acuity of Z20/40, a spherical refraction within ± 6.0 D, cylinder correction within ± 3.0 D, and no history of retinal diseases such as diabetic retinopathy, macular degeneration or retinal detachment, and inflammatory eye diseases. Those who were under 18 years of age, diagnosed as secondary glaucoma, angle-closure glaucoma, or angleclosure suspects, who had ocular trauma, previous laser therapy or intravitreal injection, ocular surgery other than cataract surgery, nonglaucomatous optic neuropathy or visual field loss, and active, chronic, or recurrent uveitis were excluded. Eyes with consistently unreliable visual fields (defined as false negative >25%; false positive >25%; and fixation losses >20%) were also excluded. POAG was defined as the presence of an abnormal glaucomatous optic disc (diffuse or focal thinning of the neuroretinal rim), an abnormal visual field consistent with glaucoma and an IOP > 21 mm Hg (without topical medical treatment), and open-angle by gonioscopy. Patients were defined as NTG if they had an abnormal glaucomatous optic disc, an abnormal glaucomatous visual field, open-angle by gonioscopy, and an IOPr21 mm Hg (without topical medical treatment) during the repeated measurements taken on 3 different days. The normal control group was defined as those having an IOP < 21 mm Hg with no history of increased IOP, an absence of glaucomatous disc appearance, no visible RNFL defect according to red-free photography, and a normal standard automated perimetry result. An absence of the glaucomatous disc appearance was defined as an intact neuroretinal rim without peripapillary hemorrhages, notches, or localized pallor. A glaucomatous visual field change was defined as the consistent presence of a cluster of Z3 nonedge points on the pattern deviation plot with a probability of occurring in
