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Sauer L, Vitale AS, Jacoby RS, Hart B, Bernstein PS. FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY IN PATIENTS WITH MACULAR TELANGIECTASIA TYPE 2 WITH AND WITHOUT DIABETES. Retina 2023; 43:1597-1607. [PMID: 37263186 PMCID: PMC10524946 DOI: 10.1097/iae.0000000000003851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
PURPOSE Macular telangiectasia type 2 (MacTel) is a vision-altering retinal disease with a high prevalence of diabetes. Differences between patients with MacTel with and without diabetes were investigated using fluorescence lifetime imaging ophthalmoscopy (FLIO). METHODS Eighty-six patients with MacTel (59 ± 12 years) were included. 40 patients (46%) did not have diabetes, 16 patients (19%) were prediabetic, and 30 patients (35%) were diabetic. Of these, seven had diabetic retinopathy. 18 diabetic patients without MacTel and 42 age-matched healthy controls were included. FLIO lifetimes (FLTs) were obtained in short (SSC, 498-560 nm) and long (LSC, 560-720 nm) spectral channels from different areas of interest using a Heidelberg Engineering FLIO. RESULTS Fundus autofluorescece lifetimes did not show significant differences when comparing diabetic with nondiabetic MacTel eyes (MacTel zone, SSC, diabetic: 243 ± 65 ps; nondiabetic: 232 ± 51 ps; P = 1.0; LSC, diabetic: 327 ± 66 ps; nondiabetic: 309 ± 54 ps; P = 0.582). Longitudinal changes were similarly unrelated to diabetes status. A nonsignificant trend of increased FLT progression with higher body mass index was found. Fundus autofluorescece lifetimes in diabetic patients without MacTel were significantly shorter within the MacTel zone and longer in the periphery compared with diabetic patients with MacTel. CONCLUSION Although MacTel has a high prevalence of diabetes, FLTs from the MacTel zone are unrelated to diabetes. Fluorescence lifetime imaging ophthalmoscopy retains diagnostic abilities in patients with MacTel even in the presence of prediabetes, diabetes, and advanced diabetic retinopathy. The lack of diabetic FLT changes in the periphery of diabetic patients with MacTel is an interesting finding that needs further investigation.
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Affiliation(s)
- Lydia Sauer
- John A. Moran Eye Center, University of Utah, Salt Lake City, Utah
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Sauer L, Bernstein PS. Macular Telangiectasia Type 2 versus Tamoxifen Retinopathy: How to Hit a Diagnostic Bullseye. Ophthalmol Retina 2023; 7:97-100. [PMID: 36496296 DOI: 10.1016/j.oret.2022.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/18/2022] [Accepted: 10/20/2022] [Indexed: 12/14/2022]
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Macular Telangiectasia Type 2: A Classification System Using MultiModal Imaging MacTel Project Report Number 10. OPHTHALMOLOGY SCIENCE 2022; 3:100261. [PMID: 36846105 PMCID: PMC9944556 DOI: 10.1016/j.xops.2022.100261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 12/05/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
Purpose To develop a severity classification for macular telangiectasia type 2 (MacTel) disease using multimodal imaging. Design An algorithm was used on data from a prospective natural history study of MacTel for classification development. Subjects A total of 1733 participants enrolled in an international natural history study of MacTel. Methods The Classification and Regression Trees (CART), a predictive nonparametric algorithm used in machine learning, analyzed the features of the multimodal imaging important for the development of a classification, including reading center gradings of the following digital images: stereoscopic color and red-free fundus photographs, fluorescein angiographic images, fundus autofluorescence images, and spectral-domain (SD)-OCT images. Regression models that used least square method created a decision tree using features of the ocular images into different categories of disease severity. Main Outcome Measures The primary target of interest for the algorithm development by CART was the change in best-corrected visual acuity (BCVA) at baseline for the right and left eyes. These analyses using the algorithm were repeated for the BCVA obtained at the last study visit of the natural history study for the right and left eyes. Results The CART analyses demonstrated 3 important features from the multimodal imaging for the classification: OCT hyper-reflectivity, pigment, and ellipsoid zone loss. By combining these 3 features (as absent, present, noncentral involvement, and central involvement of the macula), a 7-step scale was created, ranging from excellent to poor visual acuity. At grade 0, 3 features are not present. At the most severe grade, pigment and exudative neovascularization are present. To further validate the classification, using the Generalized Estimating Equation regression models, analyses for the annual relative risk of progression over a period of 5 years for vision loss and for progression along the scale were performed. Conclusions This analysis using the data from current imaging modalities in participants followed in the MacTel natural history study informed a classification for MacTel disease severity featuring variables from SD-OCT. This classification is designed to provide better communications to other clinicians, researchers, and patients. Financial Disclosures Proprietary or commercial disclosure may be found after the references.
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Key Words
- BCVA, best-corrected visual acuity
- BLR, blue light reflectance
- CART, Classification and Regression Trees
- CF, color fundus
- Classification
- Classification and Regression Trees (CART)
- EZ, ellipsoid zone
- FAF, fundus autoflorescence
- FLIO, fluorescence lifetime imaging ophthalmoscopy
- MacTel, macular telangiectasia type 2
- Machine learning
- Macular telangiectasia type 2
- NHOR, natural history observation registry
- NHOS, natural history observation study
- Neurovascular degeneration
- OCTA, OCT angiography
- SD-OCT, spectral domain-OCT
- VA, visual acuity
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Jaggi D, Solberg Y, Dysli C, Lincke J, Habra O, Wolf S, Zinkernagel M. FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY AS PREDICTOR OF LONG-TERM FUNCTIONAL OUTCOME IN MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENT. Retina 2022; 42:2388-2394. [PMID: 36394892 PMCID: PMC9665949 DOI: 10.1097/iae.0000000000003612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE To assess whether macular fluorescence lifetimes may serve as a predictor for long-term outcomes in macula-off rhegmatogenous retinal detachment. METHODS A single-center observational study was conducted. Patients with pseudophakic macula-off rhegmatogenous retinal detachment were included and evaluated 1 and 6 months after successful reattachment surgery. Fluorescence lifetime imaging ophthalmoscopy lifetimes in the central Early Treatment Diabetic Retinopathy Study grid subfield, in two distinct channels (short spectral channel and long spectral channel) were analyzed. Best-corrected visual acuity optical coherence tomography of the macula and fluorescence lifetimes were measured at month 1 and month 6. RESULTS Nineteen patients were analyzed. Lifetimes of the previously detached retinas were prolonged compared with the healthy fellow eyes. Short lifetimes at month 1 were associated with better best-corrected visual acuity improvement (short spectral channel: r2 = 0.27, P < 0.05, long spectral channel: r2 = 0.23, P < 0.05) and with good final best-corrected visual acuity (short spectral channel: r2 = 0.43, P < 0.01, long spectral channel: r2 = 0.25, P < 0.05). Lifetimes were prolonged in some cases of outer retinal damage in optical coherence tomography scans. CONCLUSION Fluorescence lifetime imaging ophthalmoscopy might serve as a prediction tool for functional recovery in pseudophakic macula-off rhegmatogenous retinal detachment. Retinal fluorescence lifetimes could give insight in molecular processes after rhegmatogenous retinal detachment.
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Affiliation(s)
- Damian Jaggi
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Yasmin Solberg
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Chantal Dysli
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Joel Lincke
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Oussama Habra
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Sebastian Wolf
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Martin Zinkernagel
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
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Schweitzer D, Haueisen J, Klemm M. Suppression of natural lens fluorescence in fundus autofluorescence measurements: review of hardware solutions. BIOMEDICAL OPTICS EXPRESS 2022; 13:5151-5170. [PMID: 36425615 PMCID: PMC9664869 DOI: 10.1364/boe.462559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/25/2022] [Accepted: 07/25/2022] [Indexed: 06/16/2023]
Abstract
Fluorescence lifetime imaging ophthalmoscopy (FLIO), a technique for investigating metabolic changes in the eye ground, can reveal the first signs of diseases related to metabolism. The fluorescence of the natural lens overlies the fundus fluorescence. Although the influence of natural lens fluorescence can be somewhat decreased with mathematical models, excluding this influence during the measurement by using hardware enables more exact estimation of the fundus fluorescence. Here, we analyze four 1-photon excitation hardware solutions to suppress the influence of natural lens fluorescence: aperture stop separation, confocal scanning laser ophthalmoscopy, combined confocal scanning laser ophthalmoscopy and aperture stop separation, and dual point confocal scanning laser ophthalmoscopy. The effect of each principle is demonstrated in examples. The best suppression is provided by the dual point principle, realized with a confocal scanning laser ophthalmoscope. In this case, in addition to the fluorescence of the whole eye, the fluorescence of the anterior part of the eye is detected from a non-excited spot of the fundus. The intensity and time-resolved fluorescence spectral data of the fundus are derived through the subtraction of the simultaneously measured fluorescence of the excited and non-excited spots. Advantages of future 2-photon fluorescence excitation are also discussed. This study provides the first quantitative evaluation of hardware principles to suppress the fluorescence of the natural lens during measurements of fundus autofluorescence.
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Affiliation(s)
- D. Schweitzer
- Department of Ophthalmology, University Hospital Jena, Am Klinikum 1, 07747 Jena, Germany
| | - J. Haueisen
- Institute of Biomedical Engineering and Informatics, POB 100565, 98694 Ilmenau, Germany
| | - M. Klemm
- Institute of Biomedical Engineering and Informatics, POB 100565, 98694 Ilmenau, Germany
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Hammer M, Simon R, Meller D, Klemm M. Combining fluorescence lifetime with spectral information in fluorescence lifetime imaging ophthalmoscopy (FLIO). BIOMEDICAL OPTICS EXPRESS 2022; 13:5483-5494. [PMID: 36425633 PMCID: PMC9664887 DOI: 10.1364/boe.457946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 06/01/2023]
Abstract
Fluorescence lifetime imaging ophthalmoscopy (FLIO) provides information on fluorescence lifetimes in two spectral channels as well as the peak emission wavelength (PEW) of the fluorescence. Here, we combine these measures in an integral three-dimensional lifetime-PEW metric vector and determine a normal range for this vector from measurements in young healthy subjects. While for these control subjects 97 (±8) % (median (interquartile range)) of all para-macular pixels were covered by this normal vector range, it was 67 (±55) % for the elderly healthy, 38 (±43) % for age-related macular degeneration (AMD)-suspect subjects, and only 6 (±4) % for AMD patients. The vectors were significantly different for retinal pigment epithelium (RPE) lesions in AMD patients from that of non-affected tissue (p < 0.001). Lifetime- PEW plots allowed to identify possibly pathologic fundus areas by fluorescence parameters outside a 95% quantile per subject. In a patient follow-up, changes in fluorescence parameters could be traced in the lifetime-PEW metric, showing their change over disease progression.
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Affiliation(s)
- Martin Hammer
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
- Center for Medical Optics and Photonics, Univ. of Jena, Jena, Germany
| | - Rowena Simon
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Daniel Meller
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Matthias Klemm
- Institute of Biomedical Engineering and Informatics, Technical Univ. Ilmenau, Ilmenau, Germany
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LONGITUDINAL FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY ANALYSIS IN PATIENTS WITH MACULAR TELANGIECTASIA TYPE 2 (MacTel). Retina 2021; 41:1416-1427. [PMID: 34137386 DOI: 10.1097/iae.0000000000003055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Fluorescence lifetime imaging ophthalmoscopy (FLIO) shows characteristic patterns in macular telangiectasia Type 2 (MacTel). This study investigates FLIO changes over time to better understand disease progression. METHODS Thirty-three patients with MacTel (age 60 ± 15 years) were followed at the Moran Eye Center with a prototype Heidelberg Engineering FLIO. The mean follow-up time was 19 ± 8 months (range 6-34 months). Fundus autofluorescence was excited at 473 nm, and FLIO lifetimes were recorded in in short (498-560 nm) and long (560-720 nm) spectral wavelengths channels. RESULTS Autofluorescence lifetimes imaging ophthalmoscopy lifetimes from the MacTel area prolonged significantly over time (subfield T1, baseline: short spectral channel 210 ± 54 ps, long spectral channel 269 ± 58 ps; follow-up: short spectral channel 225 ± 59 ps, P < 0.001, long spectral channel 282 ± 64 ps, P < 0.01). The average 12-months prolongation of FLIO lifetimes was 9 ps (short spectral channel) and 8 ps (long spectral channel). Autofluorescence lifetimes changes correlated positively with ellipsoid zone loss and negatively with changes in retinal thickness. CONCLUSION Autofluorescence lifetimes in MacTel slowly prolong over time, and temporal patterns progress to full rings. Detailed knowledge about FLIO changes will aid in understanding disease development and progression.
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Sonntag SR, Seifert E, Hamann M, Lewke B, Theisen-Kunde D, Grisanti S, Brinkmann R, Miura Y. Fluorescence Lifetime Changes Induced by Laser Irradiation: A Preclinical Study towards the Evaluation of Retinal Metabolic States. Life (Basel) 2021; 11:life11060555. [PMID: 34199212 PMCID: PMC8231852 DOI: 10.3390/life11060555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/31/2021] [Accepted: 06/06/2021] [Indexed: 12/17/2022] Open
Abstract
Fluorescence Lifetime (FLT) of intrinsic fluorophores may alter under the change in metabolic state. In this study, the FLT of rabbit retina was investigated in vivo after laser irradiation using fluorescence lifetime imaging ophthalmoscopy (FLIO). The retina of the Chinchilla bastard rabbits was irradiated with a 514 nm diode laser. FLIO, fundus photography, and optical coherence tomography (OCT) were conducted 30 min and 1 to 3 weeks after treatment. After strong coagulation, the FLT at laser spots was significantly elongated immediately after irradiation, conversely shortened after more than a week. Histological examination showed eosinophilic substance and melanin clumping in subretinal space at the coagulation spots older than one week. The FLT was also elongated right around the coagulation spots, which corresponded to the discontinuous ellipsoid zone (EZ) on OCT. This EZ change was recovered after one week, and the FLT became the same level as the surroundings. In addition, there was a region around the laser spot where the FLT was temporarily shorter than the surrounding area. When weak pulse energy was applied to selectively destroy only the RPE, a shortening of the FLT was observed immediately around the laser spot within one week after irradiation. FLIO could serve as a tool to evaluate the structural and metabolic response of the retina to laser treatments.
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Affiliation(s)
- Svenja Rebecca Sonntag
- Department of Ophthalmology, University of Lübeck, 23538 Lübeck, Germany; (S.R.S.); (S.G.)
| | - Eric Seifert
- Medical Laser Center Lübeck, 23562 Lübeck, Germany; (E.S.); (D.T.-K.); (R.B.)
| | - Maximilian Hamann
- Institute of Biomedical Optics, University of Lübeck, 23562 Lübeck, Germany; (M.H.); (B.L.)
| | - Britta Lewke
- Institute of Biomedical Optics, University of Lübeck, 23562 Lübeck, Germany; (M.H.); (B.L.)
| | - Dirk Theisen-Kunde
- Medical Laser Center Lübeck, 23562 Lübeck, Germany; (E.S.); (D.T.-K.); (R.B.)
| | - Salvatore Grisanti
- Department of Ophthalmology, University of Lübeck, 23538 Lübeck, Germany; (S.R.S.); (S.G.)
| | - Ralf Brinkmann
- Medical Laser Center Lübeck, 23562 Lübeck, Germany; (E.S.); (D.T.-K.); (R.B.)
- Institute of Biomedical Optics, University of Lübeck, 23562 Lübeck, Germany; (M.H.); (B.L.)
| | - Yoko Miura
- Department of Ophthalmology, University of Lübeck, 23538 Lübeck, Germany; (S.R.S.); (S.G.)
- Medical Laser Center Lübeck, 23562 Lübeck, Germany; (E.S.); (D.T.-K.); (R.B.)
- Institute of Biomedical Optics, University of Lübeck, 23562 Lübeck, Germany; (M.H.); (B.L.)
- Correspondence:
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Sauer L, Vitale AS, Modersitzki NK, Bernstein PS. Fluorescence lifetime imaging ophthalmoscopy: autofluorescence imaging and beyond. Eye (Lond) 2021; 35:93-109. [PMID: 33268846 PMCID: PMC7852552 DOI: 10.1038/s41433-020-01287-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 10/20/2020] [Accepted: 11/04/2020] [Indexed: 12/14/2022] Open
Abstract
Fluorescence lifetime imaging ophthalmoscopy, FLIO, has gained large interest in the scientific community in the recent years. It is a noninvasive imaging modality that has been shown to provide additional information to conventional imaging modalities. The FLIO device is based on a Heidelberg Engineering Spectralis system. Autofluorescence lifetimes are excited at 473 nm and recorded in two spectral wavelength channels, a short spectral channel (SSC, 498-560 nm) and a long spectral channel (LSC, 560-720 nm). Typically, mean autofluorescence lifetimes in a 30° retinal field are investigated. FLIO shows a clear benefit for imaging different retinal diseases. For example, in age-related macular degeneration (AMD), ring patterns of prolonged FLIO lifetimes 1.5-3.0 mm from the fovea can be appreciated. Macular telangiectasia type 2 (MacTel) shows a different pattern, with prolonged FLIO lifetimes within the typical MacTel zone. In Stargardt disease, retinal flecks can be appreciated even before they are visible with other imaging modalities. Early hydroxychloroquine toxicity appears to be detectable with FLIO. This technique has more potential that has yet to be discovered. This review article focuses on current knowledge as well as pitfalls of this technology. It highlights clinical benefits of FLIO imaging in different ophthalmic and systemic diseases, and provides an outlook with perspectives from the authors.
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Affiliation(s)
- Lydia Sauer
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah School of Medicine, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
| | - Alexandra S Vitale
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah School of Medicine, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
| | - Natalie K Modersitzki
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah School of Medicine, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
| | - Paul S Bernstein
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah School of Medicine, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA.
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Schweitzer D, Haueisen J, Brauer JL, Hammer M, Klemm M. Comparison of algorithms to suppress artifacts from the natural lens in fluorescence lifetime imaging ophthalmoscopy (FLIO). BIOMEDICAL OPTICS EXPRESS 2020; 11:5586-5602. [PMID: 33149973 PMCID: PMC7587265 DOI: 10.1364/boe.400059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/08/2020] [Accepted: 08/08/2020] [Indexed: 06/11/2023]
Abstract
Fluorescence lifetime imaging ophthalmoscopy (FLIO) has developed as a new diagnostic tool in ophthalmology. FLIO measurements are taken from 30° retinal fields in two spectral channels (short spectral channel (SSC): 498-560 nm, long spectral channel (LSC): 560-720 nm). Because of the layered structure of the eye, the detected signal is an interaction of the fluorescence decay of the anterior part and of the fundus. By comparing FLIO measurements before and after cataract surgery, the impact of the natural lens was proven, despite the application of a confocal laser scanning (cSLO) technique. The goal of this work was to determine the best algorithmic solution to isolate the sole fundus fluorescence lifetime from the measured signal, suppressing artifacts from the natural lens. Three principles based on a tri-exponential model were investigated: a tailfit, a layer-based approach with a temporally shifted component, and the inclusion of a separately measured fluorescence decay of the natural lens. The mean fluorescence lifetime τm,12 is calculated using only the shortest and the intermediate exponential component. τm,all is calculated using all three exponential components. The results of tri-exponential tailfit after cataract surgery were considered as a reference, because the implanted artificial lens can be assumed as non-fluorescent. In SSC, the best accordance of τm,all of the reference was determined with τm,12 of the tailfit before surgery. If high-quality natural lens measurements are available, the correspondence of τm,12 is best with τm,all of the reference. In LSC, there is a good accordance for all models between τm,12 before and after surgery. To study the pure fundus fluorescence decay in eyes with natural lenses, we advise to utilize fluorescence lifetime τm,12 of a triple-exponential tailfit, as it corresponds well with the mean fluorescence lifetime τm,all of eyes with fluorescence-less artificial intraocular lenses.
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Affiliation(s)
- D. Schweitzer
- Department of Ophthalmology, University Hospital Jena, Am Klinikum 1, 07747 Jena, Germany
| | - J. Haueisen
- Institute of Biomedical Engineering and Informatics, POB 100565, 98694 Ilmenau, Germany
| | - J. L. Brauer
- Department of Ophthalmology, University Hospital Jena, Am Klinikum 1, 07747 Jena, Germany
| | - M. Hammer
- Department of Ophthalmology, University Hospital Jena, Am Klinikum 1, 07747 Jena, Germany
| | - M. Klemm
- Institute of Biomedical Engineering and Informatics, POB 100565, 98694 Ilmenau, Germany
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Vitale AS, Sauer L, Modersitzki NK, Bernstein PS. Fluorescence Lifetime Imaging Ophthalmoscopy (FLIO) in Patients with Choroideremia. Transl Vis Sci Technol 2020; 9:33. [PMID: 33062396 PMCID: PMC7533737 DOI: 10.1167/tvst.9.10.33] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/24/2020] [Indexed: 12/22/2022] Open
Abstract
Purpose To provide a detailed characterization of choroideremia (CHM) using fluorescence lifetime imaging ophthalmoscopy (FLIO) and to provide a deeper understanding of disease-related changes and progression. Methods Twenty-eight eyes of 14 patients with genetically confirmed CHM (mean age, 28 ± 14 years) and 14 age-matched healthy subjects were investigated in this study. FLIO images of a 30° retinal field were collected at the Moran Eye Center using a Heidelberg Engineering FLIO device. FLIO lifetimes were recorded in short spectral channels (SSC; 498-560 nm) and long spectral channels (LSC; 560-720 nm), and mean autofluorescence lifetimes (τm) were calculated. Optical coherence tomography (OCT) scans were recorded for each patient. Three patients were re-imaged after a year. Results Patients with CHM exhibit specific FLIO lifetime patterns. Prolonged FLIO lifetimes (around 600-700 ps) were found in the peripheral macula corresponding to atrophy in OCT imaging. In the central macula, τm was unrelated to autofluorescence intensity. Some areas of persistent retinal pigment epithelial islands had prolonged FLIO lifetimes, whereas other areas of hypofluorescence had short FLIO lifetimes. At 1-year follow-up, FLIO lifetimes were significantly prolonged within atrophic areas (P < 0.05). Conclusions FLIO shows distinct patterns in patients with CHM, indicating lesions of atrophy and areas of preserved function in the presence or absence of findings in fundus autofluorescence intensity images. FLIO may provide differentiated knowledge about pathophysiology and atrophy progression in CHM compared to conventional imaging modalities. Translational Relevance FLIO shows distinctive lifetime patterns that potentially identify areas of function, atrophy, and disease progression in patients with CHM.
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Affiliation(s)
- Alexandra S. Vitale
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Lydia Sauer
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Natalie K. Modersitzki
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Paul S. Bernstein
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
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Sauer L, Vitale AS, Milliken CM, Modersitzki NK, Blount JD, Bernstein PS. Autofluorescence Lifetimes Measured with Fluorescence Lifetime Imaging Ophthalmoscopy (FLIO) Are Affected by Age, but Not by Pigmentation or Gender. Transl Vis Sci Technol 2020; 9:2. [PMID: 32879759 PMCID: PMC7442880 DOI: 10.1167/tvst.9.9.2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/07/2020] [Indexed: 12/25/2022] Open
Abstract
Purpose Fluorescence lifetime imaging ophthalmoscopy (FLIO) is a novel modality to investigate the human retina. This study aims to characterize the effects of age, pigmentation, and gender in FLIO. Methods A total of 97 eyes from 97 healthy subjects (mean age 37 ± 18 years, range 9-85 years) were investigated in this study. This study included 47 (49%) females and 50 males. The pigmentation analysis was a substudy including 64 subjects aged 18 to 40 years (mean age 29 ± 6 years). These were categorized in groups A (darkly pigmented, 8), B (medium pigmented, 20), and C (lightly pigmented, 36). Subjects received Heidelberg Engineering FLIO and optical coherence tomography imaging. Retinal autofluorescence lifetimes were detected in two spectral channels (short spectral channel [SSC]: 498-560 nm; long spectral channel [LSC]: 560-720 nm), and amplitude-weighted mean fluorescence lifetimes (τm) were calculated. Additionally, autofluorescence lifetimes of melanin were measured in a cuvette. Results Age significantly affected FLIO lifetimes, and age-related FLIO changes in the SSC start at approximately age 35 years, whereas the LSC shows a consistent prolongation with age from childhood. There were no gender- or pigmentation-specific significant differences of autofluorescence lifetimes. Conclusions This study confirms age-effects in FLIO but shows that the two channels are affected differently. The LSC appears to show the lifelong accumulation of lipofuscin. Furthermore, it is important to know that neither gender nor pigmentation significantly affect FLIO lifetimes. Translational Relevance This study helps to understand the FLIO technology better, which will aid in conducting future clinical studies.
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Affiliation(s)
- Lydia Sauer
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | | | - Cole M Milliken
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA.,Storm Eye Institute, Medical University of South Carolina, Charleston, SC, USA
| | | | - J David Blount
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Paul S Bernstein
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
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