Graefes Arch Clin Exp Ophthalmol (2014) 252:847–848 DOI 10.1007/s00417-014-2596-4
LETTER TO THE EDITOR
Choroidal thickness is affected by many factors which may change the effect of ranibizumab Yakup Aksoy & Kadir Çolakoglu & Abdullah Kaya
Received: 4 January 2014 / Accepted: 4 February 2014 / Published online: 18 March 2014 # Springer-Verlag Berlin Heidelberg 2014
Dear Editor, We read the article “Reduction in choroidal thickness of macular area in polypoidal choroidal vasculopathy patients after intravitreal ranibizumab therapy” by Nishide et al. with great interest [1]. The authors aimed to evaluate changes in retinal and choroidal thickness after three intravitreal ranibizumab (IVR) injections for polypoidal choroidal vasculopathy (PCV) using enhanced depth-imaging-optical coherence tomography (EDI-OCT). They concluded that the subfoveal choroidal thickness might be reduced by introductory-stage IVR in patients with PCV. In particular, choroidal thickness (CT) at the fovea was reduced during the early stage of treatment. We congratulate the authors for their enlightening study about this current subject regarding agerelated macular degeneration and CT. We would like to make some criticisms and contributions about the study. The choroid is the middle vascular layer of the eye, lying between the retina and sclera. It accounts for 85 % of ocular This work, or parts of it, has not been published or presented in a conference/seminar. We have no support in financial or other relationships that might lead to a conflict of interest. The manuscript has been read and approved by all the authors; the requirements for authorship as stated earlier in this document have been met, and each author believes the manuscript represents honest work. Y. Aksoy (*) Department of Ophthalmology, Hakkari Military Hospital, Hakkari, Turkey e-mail: [email protected] K. Çolakoglu Department of Ophthalmology, Kasımpasa Military Hospital, İstanbul, Turkey e-mail: [email protected] A. Kaya Department of Ophthalmology, GATA HaydarpasaTraining Hospital, Istanbul, Turkey e-mail: [email protected]
blood flow and plays a major role in the oxygenation, nourishment, cooling, and viability of retinal pigment epithelium and the outer retinal layers, which have the highest metabolic activity. CT changes have been shown to play a role in the pathogenesis or progression of chorioretinal disease. With recent improvements in technology, investigators are increasingly interested in choroidal imaging using EDI-OCT, which enables the visualization of choroid and measurement of the choroidal thickness. Also, the normative data for CT in healthy individuals were reported as a guide for further investigations [2, 3]. Therefore, OCT is a valuable tool for the diagnosis and management of chorioretinal disease, as well as for helping clinicians understand the underlying pathology. There are many factors affecting CT. The most reported of these factors are age, ethnicity, myopia, axial length, diabetes mellitus, hypertension, central serous chorioretinopathy, and intraocular surgery [4, 5]. We believe that since age, ethnicity, axial length, and myopia are factors which would not change in three or four months during the IVR injection period, they wouldn’t affect the CT measurement results in patients. But diabetes mellitus, hypertension, central serous chorioretinopathy, and intraocular surgery are factors which might affect the CT measurements after IVR injections. Besides this, it has also been reported in some studies that sildenafil citrate and intravenous acetazolamide increase choroidal thickness [6, 7]. The authors didn’t report if the patients had such diseases, intraocular surgery, or used relevant medication before and after the injections or during the three IVRinjection period. We feel that if anypatients do have these factors, it should be noted as a limitation of the study by the authors. Also it has been reported in some studies that CT shows a significant diurnal variation. The studies showed that the choroid thickens the most around midnight and thins the most around noon.This change was between 30 to 60 μm [8, 9]. In this present study of Nishide et al. the measurement time of
848
day is not mentioned. We think that the results would be changed if all of the measurements had been performed at noon or midnight. To ensure consistency and minimize any influence from potential diurnal fluctuation in CT, all measurements should be performed at the same time of day.
Graefes Arch Clin Exp Ophthalmol (2014) 252:847–848
4.
5.
References 6. 1. Nishide T, Hayakawa N, Nakanishi M, Ishii M, Okazaki S, Kimura I, Shibuya E, Mizuki N (2013) Reduction in choroidal thickness of macular area in polypoidal choroidal vasculopathy patients after intravitreal ranibizumab therapy. Graefes Arch Clin Exp Ophthalmol 251: 2415–2420 2. Agawa T, Miura M, Ikuno Y, Makita S, Fabritius T, Iwasaki T, Goto H, Nishida K, Yasuno Y (2011) Choroidal thickness measurement in healthy Japanese subjects by three-dimensional high-penetration optical coherence tomography. Graefes Arch Clin Exp Ophthalmol 249: 1485–1492 3. Yeoh J, RahmanW CF, Hooper C, Patel P, Tufail A, Webster AR, Moore AT, Dacruz L (2010) Choroidal imaging in inherited retinal
7. 8.
9.
disease using the technique of enhanced depth imaging optical coherence tomography. Graefes Arch Clin Exp Ophthalmol 248:1719–1728 Alwassia AA, Adhi M, Zhang JY, Regatieri CV, Al-Quthami A, Salem D, Fujimoto JG, Duker JS (2013) Exercise-induced acute changes in systolic blood pressure do not alter choroidal thickness as measured by a portable spectral-domain optical coherence tomography device. Retina 33:160–165 Koizumi H, Yamagishi T, Yamazaki T, Kawasaki R, Kinoshita S (2011) Subfoveal choroidal thickness in typical age-related macular degeneration and polypoidal choroidal vasculopathy. Graefes Arch Clin Exp Ophthalmol 249:1123–1128 Vance SK, Imamura Y, Freund KB (2011) The effects of sildenafil citrate on choroidal thickness as determined by enhanced depth imaging optical coherence tomography. Retina 31:332–335 Dallinger S, Bobr B, Findl O et al (1998) Effects of acetazolamide on choroidal blood flow. Stroke 29:997–1001 Tan CS, Ouyang Y, Ruiz H, Sadda SR (2012) Diurnal variation of choroidal thickness in normal, healthy subjects measured by spectral domain optical coherence tomography. Invest Ophthalmol Vis Sci 53: 261–266 Brown JS, Flitcroft DI, Ying GS, Francis EL, Schmid GF, Quinn GE, Stone RA (2009) In vivo human choroidal thickness measurements: evidence for diurnal fluctuations. Invest Ophthalmol Vis Sci 50:5–12
LETTER TO THE EDITOR
Choroidal thickness is affected by many factors which may change the effect of ranibizumab Yakup Aksoy & Kadir Çolakoglu & Abdullah Kaya
Received: 4 January 2014 / Accepted: 4 February 2014 / Published online: 18 March 2014 # Springer-Verlag Berlin Heidelberg 2014
Dear Editor, We read the article “Reduction in choroidal thickness of macular area in polypoidal choroidal vasculopathy patients after intravitreal ranibizumab therapy” by Nishide et al. with great interest [1]. The authors aimed to evaluate changes in retinal and choroidal thickness after three intravitreal ranibizumab (IVR) injections for polypoidal choroidal vasculopathy (PCV) using enhanced depth-imaging-optical coherence tomography (EDI-OCT). They concluded that the subfoveal choroidal thickness might be reduced by introductory-stage IVR in patients with PCV. In particular, choroidal thickness (CT) at the fovea was reduced during the early stage of treatment. We congratulate the authors for their enlightening study about this current subject regarding agerelated macular degeneration and CT. We would like to make some criticisms and contributions about the study. The choroid is the middle vascular layer of the eye, lying between the retina and sclera. It accounts for 85 % of ocular This work, or parts of it, has not been published or presented in a conference/seminar. We have no support in financial or other relationships that might lead to a conflict of interest. The manuscript has been read and approved by all the authors; the requirements for authorship as stated earlier in this document have been met, and each author believes the manuscript represents honest work. Y. Aksoy (*) Department of Ophthalmology, Hakkari Military Hospital, Hakkari, Turkey e-mail: [email protected] K. Çolakoglu Department of Ophthalmology, Kasımpasa Military Hospital, İstanbul, Turkey e-mail: [email protected] A. Kaya Department of Ophthalmology, GATA HaydarpasaTraining Hospital, Istanbul, Turkey e-mail: [email protected]
blood flow and plays a major role in the oxygenation, nourishment, cooling, and viability of retinal pigment epithelium and the outer retinal layers, which have the highest metabolic activity. CT changes have been shown to play a role in the pathogenesis or progression of chorioretinal disease. With recent improvements in technology, investigators are increasingly interested in choroidal imaging using EDI-OCT, which enables the visualization of choroid and measurement of the choroidal thickness. Also, the normative data for CT in healthy individuals were reported as a guide for further investigations [2, 3]. Therefore, OCT is a valuable tool for the diagnosis and management of chorioretinal disease, as well as for helping clinicians understand the underlying pathology. There are many factors affecting CT. The most reported of these factors are age, ethnicity, myopia, axial length, diabetes mellitus, hypertension, central serous chorioretinopathy, and intraocular surgery [4, 5]. We believe that since age, ethnicity, axial length, and myopia are factors which would not change in three or four months during the IVR injection period, they wouldn’t affect the CT measurement results in patients. But diabetes mellitus, hypertension, central serous chorioretinopathy, and intraocular surgery are factors which might affect the CT measurements after IVR injections. Besides this, it has also been reported in some studies that sildenafil citrate and intravenous acetazolamide increase choroidal thickness [6, 7]. The authors didn’t report if the patients had such diseases, intraocular surgery, or used relevant medication before and after the injections or during the three IVRinjection period. We feel that if anypatients do have these factors, it should be noted as a limitation of the study by the authors. Also it has been reported in some studies that CT shows a significant diurnal variation. The studies showed that the choroid thickens the most around midnight and thins the most around noon.This change was between 30 to 60 μm [8, 9]. In this present study of Nishide et al. the measurement time of
848
day is not mentioned. We think that the results would be changed if all of the measurements had been performed at noon or midnight. To ensure consistency and minimize any influence from potential diurnal fluctuation in CT, all measurements should be performed at the same time of day.
Graefes Arch Clin Exp Ophthalmol (2014) 252:847–848
4.
5.
References 6. 1. Nishide T, Hayakawa N, Nakanishi M, Ishii M, Okazaki S, Kimura I, Shibuya E, Mizuki N (2013) Reduction in choroidal thickness of macular area in polypoidal choroidal vasculopathy patients after intravitreal ranibizumab therapy. Graefes Arch Clin Exp Ophthalmol 251: 2415–2420 2. Agawa T, Miura M, Ikuno Y, Makita S, Fabritius T, Iwasaki T, Goto H, Nishida K, Yasuno Y (2011) Choroidal thickness measurement in healthy Japanese subjects by three-dimensional high-penetration optical coherence tomography. Graefes Arch Clin Exp Ophthalmol 249: 1485–1492 3. Yeoh J, RahmanW CF, Hooper C, Patel P, Tufail A, Webster AR, Moore AT, Dacruz L (2010) Choroidal imaging in inherited retinal
7. 8.
9.
disease using the technique of enhanced depth imaging optical coherence tomography. Graefes Arch Clin Exp Ophthalmol 248:1719–1728 Alwassia AA, Adhi M, Zhang JY, Regatieri CV, Al-Quthami A, Salem D, Fujimoto JG, Duker JS (2013) Exercise-induced acute changes in systolic blood pressure do not alter choroidal thickness as measured by a portable spectral-domain optical coherence tomography device. Retina 33:160–165 Koizumi H, Yamagishi T, Yamazaki T, Kawasaki R, Kinoshita S (2011) Subfoveal choroidal thickness in typical age-related macular degeneration and polypoidal choroidal vasculopathy. Graefes Arch Clin Exp Ophthalmol 249:1123–1128 Vance SK, Imamura Y, Freund KB (2011) The effects of sildenafil citrate on choroidal thickness as determined by enhanced depth imaging optical coherence tomography. Retina 31:332–335 Dallinger S, Bobr B, Findl O et al (1998) Effects of acetazolamide on choroidal blood flow. Stroke 29:997–1001 Tan CS, Ouyang Y, Ruiz H, Sadda SR (2012) Diurnal variation of choroidal thickness in normal, healthy subjects measured by spectral domain optical coherence tomography. Invest Ophthalmol Vis Sci 53: 261–266 Brown JS, Flitcroft DI, Ying GS, Francis EL, Schmid GF, Quinn GE, Stone RA (2009) In vivo human choroidal thickness measurements: evidence for diurnal fluctuations. Invest Ophthalmol Vis Sci 50:5–12
