PURPOSE: The purpose of this study was to assess the influence of axial length on spectral-domain optical coherence tomography (SD-OCT) thickness measurements in patients with subretinal visual implants. METHODS: Data from eight emmetropic pseudophakic eyes of eight patients with subretinal visual implants were analyzed retrospectively. These patients participated in the monocentric part of a multicenter trial. The axial length was measured in three short (<22.5 mm), three medium (22.51-25.50 mm), and two long (>25.52 mm) eyes. Using Heidelberg Spectralis, the known thickness of a subretinal implant microchip (70 μm) was measured on 15 images per eye with SD-OCT, using the software calipers. RESULTS: The mean axial length was 20.8 ± 0.8 mm in short eyes, 23.3 ± 0.4 mm in medium eyes, and 26.3 ± 0.5 mm in long eyes. We found in short eyes, in medium eyes, and in long eyes a mean value of microchip thickness measurements from SD-OCT of 82.9 ± 1.4 μm, 70.5 ± 1.3 μm, and 64.2 ± 1.3 μm, respectively. The thickness measurements decreased in SD-OCT measurements with longer axial lengths significantly (P < 0.0001). CONCLUSIONS:Axial length influences SD-OCT thickness measurements. Our findings demonstrate accuracy of the scaling in SD-OCT thickness measurements in emmetropic medium eyes. Caution is recommended when comparing the measured values of short and long eyes with the normative database of the instrument. There is a need for larger sample-size studies to confirm our results. (ClinicalTrials.gov number, NCT01024803.). Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
RCT Entities:
PURPOSE: The purpose of this study was to assess the influence of axial length on spectral-domain optical coherence tomography (SD-OCT) thickness measurements in patients with subretinal visual implants. METHODS: Data from eight emmetropic pseudophakic eyes of eight patients with subretinal visual implants were analyzed retrospectively. These patients participated in the monocentric part of a multicenter trial. The axial length was measured in three short (<22.5 mm), three medium (22.51-25.50 mm), and two long (>25.52 mm) eyes. Using Heidelberg Spectralis, the known thickness of a subretinal implant microchip (70 μm) was measured on 15 images per eye with SD-OCT, using the software calipers. RESULTS: The mean axial length was 20.8 ± 0.8 mm in short eyes, 23.3 ± 0.4 mm in medium eyes, and 26.3 ± 0.5 mm in long eyes. We found in short eyes, in medium eyes, and in long eyes a mean value of microchip thickness measurements from SD-OCT of 82.9 ± 1.4 μm, 70.5 ± 1.3 μm, and 64.2 ± 1.3 μm, respectively. The thickness measurements decreased in SD-OCT measurements with longer axial lengths significantly (P < 0.0001). CONCLUSIONS: Axial length influences SD-OCT thickness measurements. Our findings demonstrate accuracy of the scaling in SD-OCT thickness measurements in emmetropic medium eyes. Caution is recommended when comparing the measured values of short and long eyes with the normative database of the instrument. There is a need for larger sample-size studies to confirm our results. (ClinicalTrials.gov number, NCT01024803.). Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
Entities:
Keywords:
Heidelberg Spectralis; axial length; in vivo measurement; spectral-domain optical coherence tomography (SD-OCT); subretinal visual implant
Authors: Janelle Tong; Jack Phu; David Alonso-Caneiro; Sieu K Khuu; Michael Kalloniatis Journal: Transl Vis Sci Technol Date: 2022-10-03 Impact factor: 3.048
Authors: Tyler Etheridge; Zhe Liu; Marine Nalbandyan; Spencer Cleland; Barbara A Blodi; Julie A Mares; Steven Bailey; Robert Wallace; Karen Gehrs; Lesley F Tinker; Ronald Gangnon; Amitha Domalpally Journal: Transl Vis Sci Technol Date: 2021-02-05 Impact factor: 3.283