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Feenstra HMA, van Dijk EHC, Cheung CMG, Ohno-Matsui K, Lai TYY, Koizumi H, Larsen M, Querques G, Downes SM, Yzer S, Breazzano MP, Subhi Y, Tadayoni R, Priglinger SG, Pauleikhoff LJB, Lange CAK, Loewenstein A, Diederen RMH, Schlingemann RO, Hoyng CB, Chhablani JK, Holz FG, Sivaprasad S, Lotery AJ, Yannuzzi LA, Freund KB, Boon CJF. Central serous chorioretinopathy: An evidence-based treatment guideline. Prog Retin Eye Res 2024; 101:101236. [PMID: 38301969 DOI: 10.1016/j.preteyeres.2024.101236] [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] [Received: 09/12/2023] [Revised: 12/30/2023] [Accepted: 01/02/2024] [Indexed: 02/03/2024]
Abstract
Central serous chorioretinopathy (CSC) is a relatively common disease that causes vision loss due to macular subretinal fluid leakage and it is often associated with reduced vision-related quality of life. In CSC, the leakage of subretinal fluid through defects in the retinal pigment epithelial layer's outer blood-retina barrier appears to occur secondary to choroidal abnormalities and dysfunction. The treatment of CSC is currently the subject of controversy, although recent data obtained from several large randomized controlled trials provide a wealth of new information that can be used to establish a treatment algorithm. Here, we provide a comprehensive overview of our current understanding regarding the pathogenesis of CSC, current therapeutic strategies, and an evidence-based treatment guideline for CSC. In acute CSC, treatment can often be deferred for up to 3-4 months after diagnosis; however, early treatment with either half-dose or half-fluence photodynamic therapy (PDT) with the photosensitive dye verteporfin may be beneficial in selected cases. In chronic CSC, half-dose or half-fluence PDT, which targets the abnormal choroid, should be considered the preferred treatment. If PDT is unavailable, chronic CSC with focal, non-central leakage on angiography may be treated using conventional laser photocoagulation. CSC with concurrent macular neovascularization should be treated with half-dose/half-fluence PDT and/or intravitreal injections of an anti-vascular endothelial growth factor compound. Given the current shortage of verteporfin and the paucity of evidence supporting the efficacy of other treatment options, future studies-ideally, well-designed randomized controlled trials-are needed in order to evaluate new treatment options for CSC.
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Affiliation(s)
- Helena M A Feenstra
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | - Elon H C van Dijk
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | - Chui Ming Gemmy Cheung
- Singapore Eye Research Institution, Singapore National Eye Centre, Singapore; Duke-NUS Medical School, National University of Singapore, Singapore
| | - Kyoko Ohno-Matsui
- Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University, Tokyo, Japan
| | - Timothy Y Y Lai
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong
| | - Hideki Koizumi
- Department of Ophthalmology, Graduate School of Medicine, University of the Ryukyus, Nishihara, Japan
| | - Michael Larsen
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark; Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Giuseppe Querques
- Department of Ophthalmology, University Vita-Salute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Susan M Downes
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK; Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, UK
| | - Suzanne Yzer
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Mark P Breazzano
- Retina-Vitreous Surgeons of Central New York, Liverpool, NY, USA; Department of Ophthalmology & Visual Sciences, State University of New York Upstate Medical University, Syracuse, NY, USA
| | - Yousif Subhi
- Department of Ophthalmology, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Ramin Tadayoni
- Ophthalmology Department, AP-HP, Hôpital Lariboisière, Université de Paris, Paris, France
| | - Siegfried G Priglinger
- Department of Ophthalmology, Hospital of the Ludwig-Maximilians-University, Munich, Germany
| | - Laurenz J B Pauleikhoff
- Department of Ophthalmology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands; Eye Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Clemens A K Lange
- Department of Ophthalmology, St. Franziskus Hospital, Muenster, Germany
| | - Anat Loewenstein
- Division of Ophthalmology, Tel Aviv Medical Center, Tel Aviv University, Tel Aviv, Israel
| | - Roselie M H Diederen
- Department of Ophthalmology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands
| | - Reinier O Schlingemann
- Department of Ophthalmology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands; Ocular Angiogenesis Group, Amsterdam University Medical Centers, Location AMC, University of Amsterdam, Amsterdam, the Netherlands; Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - Carel B Hoyng
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Jay K Chhablani
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Frank G Holz
- Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Sobha Sivaprasad
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Lawrence A Yannuzzi
- Vitreous Retina Macula Consultants of New York, New York, NY, USA; LuEsther T. Mertz Retinal Research Center, Manhattan Eye, Ear, and Throat Hospital, New York, NY, USA; Department of Ophthalmology, New York University Grossman School of Medicine, New York, USA; Department of Ophthalmology, Manhattan Eye, Ear and Throat Hospital, New York, NY, USA
| | - K Bailey Freund
- Vitreous Retina Macula Consultants of New York, New York, NY, USA; Department of Ophthalmology, New York University School of Medicine, New York, NY, USA
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands; Department of Ophthalmology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands.
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2
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Sonntag SR, Hamann M, Seifert E, Grisanti S, Brinkmann R, Miura Y. Detection sensitivity of fluorescence lifetime imaging ophthalmoscopy for laser-induced selective damage of retinal pigment epithelium. Graefes Arch Clin Exp Ophthalmol 2024:10.1007/s00417-024-06449-2. [PMID: 38587656 DOI: 10.1007/s00417-024-06449-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 03/05/2024] [Accepted: 03/08/2024] [Indexed: 04/09/2024] Open
Abstract
PURPOSE To investigate the sensitivity of fluorescence lifetime imaging ophthalmoscopy (FLIO) to detect retinal laser spots by comparative analysis with other imaging modalities. METHODS A diode laser with a wavelength of 514 nm was applied with pulse durations of 5.2, 12, 20, and 50 µs. The laser pulse energy was increased so that the visibility of the laser spot by slit-lamp fundus examination (SL) under the irradiator's observation covers from the subvisible to visible range immediately after irradiation. The irradiated areas were then examined by fundus color photography (FC), optical coherence tomography (OCT), fundus autofluorescence (AF), FLIO, and fluorescein angiography (FA). The visibility of a total of over 2200 laser spots was evaluated by two independent researchers, and effective dose (ED) 50 laser pulse energy values were calculated for each imaging modality and compared. RESULTS Among examined modalities, FA showed the lowest mean of ED50 energy value and SL the highest, that is, they had the highest and lowest sensitivity to detect retinal pigment epithalium (RPE)-selective laser spots, respectively. FLIO also detected spots significantly more sensitively than SL at most laser pulse durations and was not significantly inferior to FA. AF was also often more sensitive than SL, but the difference was slightly less significant than FLIO. CONCLUSION Considering its high sensitivity in detecting laser spots and previously reported potential of indicating local wound healing and metabolic changes around laser spots, FLIO may be useful as a non-invasive monitoring tool during and after minimally invasive retinal laser treatment.
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Affiliation(s)
- Svenja Rebecca Sonntag
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | - Maximilian Hamann
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
- Department of Ophthalmology, Hannover Medical School, Hannover, Germany
| | | | - Salvatore Grisanti
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | - Ralf Brinkmann
- Medical Laser Center Lübeck, Lübeck, Germany
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
| | - Yoko Miura
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany.
- Medical Laser Center Lübeck, Lübeck, Germany.
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany.
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3
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Burri C, Salzmann S, Wandel J, Hoffmann L, Považay B, Meier C, Frenz M. Real-time OCT feedback-controlled RPE photodisruption in ex vivo porcine eyes using 8 microsecond laser pulses. BIOMEDICAL OPTICS EXPRESS 2023; 14:6328-6349. [PMID: 38420306 PMCID: PMC10898567 DOI: 10.1364/boe.503941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/24/2023] [Accepted: 11/12/2023] [Indexed: 03/02/2024]
Abstract
Selective retinal pigment epithelium (RPE) photodisruption requires reliable real-time feedback dosimetry (RFD) to prevent unwanted overexposure. In this study, optical coherence tomography (OCT) based RFD was investigated in ex vivo porcine eyes exposed to laser pulses of 8 µs duration (wavelength: 532 nm, exposure area: 90 × 90 µm2, radiant exposure: 247 to 1975 mJ/µm2). For RFD, fringe washouts in time-resolved OCT M-scans (central wavelength: 870 nm, scan rate: 85 kHz) were compared to an RPE cell viability assay. Statistical analysis revealed a moderate correlation between RPE lesion size and applied treatment energy, suggesting RFD adaptation to inter- and intraindividual RPE pigmentation and ocular transmission.
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Affiliation(s)
- Christian Burri
- optoLab, Institute for Human Centered Engineering, Bern University of Applied Sciences, Biel, Switzerland
- Biomedical Photonics Group, Institute of Applied Physics, University of Bern, Bern, Switzerland
| | - Simon Salzmann
- optoLab, Institute for Human Centered Engineering, Bern University of Applied Sciences, Biel, Switzerland
| | - Jasmin Wandel
- Institute for Optimisation and Data Analysis, Bern University of Applied Sciences, Burgdorf, Switzerland
| | - Leonie Hoffmann
- optoLab, Institute for Human Centered Engineering, Bern University of Applied Sciences, Biel, Switzerland
| | - Boris Považay
- optoLab, Institute for Human Centered Engineering, Bern University of Applied Sciences, Biel, Switzerland
| | - Christoph Meier
- optoLab, Institute for Human Centered Engineering, Bern University of Applied Sciences, Biel, Switzerland
| | - Martin Frenz
- Biomedical Photonics Group, Institute of Applied Physics, University of Bern, Bern, Switzerland
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4
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Burri C, Salzmann S, Amstutz M, Hoffmann L, Považay B, Meier C, Frenz M. Investigation of the Influence of Pulse Duration and Application Mode on Microsecond Laser Microsurgery of the Retinal Pigment Epithelium. Life (Basel) 2023; 13:1314. [PMID: 37374097 DOI: 10.3390/life13061314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023] Open
Abstract
Optical microsurgery confined to the retinal pigment epithelium (RPE) requires locally optimized laser parameters and reliable real-time feedback dosimetry (RFD) to prevent unwanted neuroretinal overexposure. This study aimed to compare pulses of different durations and application modes (single, ramp, burst). Moreover, optical coherence tomography (OCT)-based RFD was investigated in an ex vivo experiment, utilizing nine porcine eyes that were exposed to laser pulses of 8, 12, 16 and 20 µs duration (wavelength: 532 nm, exposure area: 90 × 90 µm2, radiant exposure: 247 to 1975 mJ/µm2). Simultaneously, time-resolved OCT M-scans were recorded (central wavelength: 870 nm, scan rate: 85 kHz) for RFD. Post irradiation, retinal changes were assessed with color fundus photography (CFP) and cross-sectional OCT B-scans. RPE cell damage was quantified via fluorescence-based cell viability assay and compared to the OCT dosimetry feedback. Our experiments indicate cumulative RPE damage for pulse bursts of 16 µs and 20 µs, whereas no cumulative effects were found for pulse durations of 8 µs and 12 µs applied in ramp mode. According to statistical analysis, OCT-RFD correctly detected RPE cell damage with 96% sensitivity and 97% specificity using pulses of 8 µs duration in ramp mode.
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Affiliation(s)
- Christian Burri
- Biomedical Photonics Group, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
- Institute for Human Centered Engineering (HuCE)-OptoLab, Bern University of Applied Sciences, Quellgasse 21, 2501 Biel, Switzerland
| | - Simon Salzmann
- Institute for Human Centered Engineering (HuCE)-OptoLab, Bern University of Applied Sciences, Quellgasse 21, 2501 Biel, Switzerland
| | - Mylène Amstutz
- Institute for Human Centered Engineering (HuCE)-OptoLab, Bern University of Applied Sciences, Quellgasse 21, 2501 Biel, Switzerland
| | - Leonie Hoffmann
- Institute for Human Centered Engineering (HuCE)-OptoLab, Bern University of Applied Sciences, Quellgasse 21, 2501 Biel, Switzerland
| | - Boris Považay
- Institute for Human Centered Engineering (HuCE)-OptoLab, Bern University of Applied Sciences, Quellgasse 21, 2501 Biel, Switzerland
| | - Christoph Meier
- Institute for Human Centered Engineering (HuCE)-OptoLab, Bern University of Applied Sciences, Quellgasse 21, 2501 Biel, Switzerland
| | - Martin Frenz
- Biomedical Photonics Group, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
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Yamamoto M, Miura Y, Hirayama K, Kyo A, Kohno T, Theisen-Kunde D, Brinkmann R, Honda S. Comparative Treatment Study on Macular Edema Secondary to Branch Retinal Vein Occlusion by Intravitreal Ranibizumab with and without Selective Retina Therapy. Life (Basel) 2023; 13:life13030769. [PMID: 36983925 PMCID: PMC10058026 DOI: 10.3390/life13030769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/02/2023] [Accepted: 03/07/2023] [Indexed: 03/14/2023] Open
Abstract
The purpose of this study was to compare the safety and efficacy of selective retina therapy (SRT) combined with the intravitreal injection of ranibizumab (IVR) in patients with macular edema (ME) secondary to branch retinal vein occlusion (BRVO). This trial was a 12-month single-center, randomized, single-masked prospective study. Eligible patients were randomized (1:1) to IVR and SRT (IVR + SRT group), or IVR and sham SRT (IVR + sham group). After the initial IVR, all participants received ME resolution criteria-driven pro re nata treatment. SRT or sham SRT was always applied one day after IVR. The primary outcome measure of this study was the mean change in central macular thickness (CMT) from baseline, and the secondary outcome measures were the mean change in visual acuity from baseline and the number of IVR treatments at a 52-week follow-up. Thirteen patients were in the IVR + SRT group, and 11 were in the IVR + sham group. Compared to the baseline, mean CMT and BCVA improved significantly after 52 weeks in both groups, with no significant difference between the two groups. The mean number of IVR was 2.85 ± 1.52 in the IVR + SRT group and 4.73 ± 2.33 in the IVR + sham group at the 52-week follow-up, with a significant difference between the two groups (p < 0.05). IVR combined with SRT may significantly decrease the number of IVR treatments while maintaining the visual and anatomical improvement effect of IVR monotherapy.
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Affiliation(s)
- Manabu Yamamoto
- Department of Ophthalmology and Visual Science, Osaka Metropolitan University Graduate School of Medicine, Osaka 545-8585, Japan
- Correspondence: ; Tel.: +81-6-6645-3867
| | - Yoko Miura
- Institute of Biomedical Optics, University of Lübeck, 23562 Lübeck, Germany
- Department of Ophthalmology, University of Lübeck, 23562 Lübeck, Germany
- Medical Laser Center Lübeck, 23562 Lübeck, Germany
| | - Kumiko Hirayama
- Department of Ophthalmology and Visual Science, Osaka Metropolitan University Graduate School of Medicine, Osaka 545-8585, Japan
| | - Akika Kyo
- Department of Ophthalmology and Visual Science, Osaka Metropolitan University Graduate School of Medicine, Osaka 545-8585, Japan
| | - Takeya Kohno
- Department of Ophthalmology and Visual Science, Osaka Metropolitan University Graduate School of Medicine, Osaka 545-8585, Japan
| | | | - Ralf Brinkmann
- Institute of Biomedical Optics, University of Lübeck, 23562 Lübeck, Germany
- Medical Laser Center Lübeck, 23562 Lübeck, Germany
| | - Shigeru Honda
- Department of Ophthalmology and Visual Science, Osaka Metropolitan University Graduate School of Medicine, Osaka 545-8585, Japan
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Seifert E, Sonntag SR, Kleingarn P, Theisen-Kunde D, Grisanti S, Birngruber R, Miura Y, Brinkmann R. Investigations on Retinal Pigment Epithelial Damage at Laser Irradiation in the Lower Microsecond Time Regime. Invest Ophthalmol Vis Sci 2021; 62:32. [PMID: 33755044 PMCID: PMC7991964 DOI: 10.1167/iovs.62.3.32] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Purpose New lasers with a continuous wave power exceeding 15 W are currently investigated for retinal therapies, promising highly localized effects at and close to the Retinal Pigment Epithelium (RPE). The goal of this work is to evaluate mechanisms and thresholds for RPE cell damage by means of pulse durations up to 50 µs. Methods A diode laser with a wavelength of 514 nm, a power of 15 W, and adjustable pulse durations between 2 µs and 50 µs was used. Porcine RPE-choroidal explants (ex vivo) and chinchilla bastard rabbits (in vivo) were irradiated to determine threshold radiant exposures for RPE damage H¯Cell by calcein vitality staining and fluorescence angiography, respectively. Thresholds for microbubble formation (MBF) H¯MBF were evaluated by time-resolved optoacoustics. Exemplary histologies support the findings. Results H¯MBF
is significantly higher than H¯Cell at pulse durations ≥ 5 µs (P < 0.05) ex vivo, while at 2 µs, no statistically significant difference was found. The ratios between H¯MBF and H¯Cell increase with pulse duration from 1.07 to 1.48 ex vivo and 1.1 to 1.6 in vivo, for 5.2 and 50 µs. Conclusions Cellular damage with and without MBF related disintegration are both present and very likely to play a role for pulse durations ≥ 5 µs. With the lower µs pulses, selective RPE disruption might be possible, while higher values allow achieving spatially limited thermal effects without MBF. However, both modi require a very accurate real-time dosing control in order to avoid extended retinal disintegration in this power range.
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Affiliation(s)
| | | | | | | | | | - Reginald Birngruber
- Medical Laser Center Lübeck, Lübeck, Germany.,Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
| | - Yoko Miura
- Department of Ophthalmology, University of Lübeck, Lübeck, Germany.,Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
| | - Ralf Brinkmann
- Medical Laser Center Lübeck, Lübeck, Germany.,Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
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Burri C, Al-Nawaiseh S, Wakili P, Salzmann S, Krötz C, Považay B, Meier C, Frenz M, Szurman P, Schulz A, Stanzel B. Selective Large-Area Retinal Pigment Epithelial Removal by Microsecond Laser in Preparation for Cell Therapy. Transl Vis Sci Technol 2021; 10:17. [PMID: 34842907 PMCID: PMC8631056 DOI: 10.1167/tvst.10.10.17] [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] [Received: 06/09/2021] [Accepted: 10/16/2021] [Indexed: 11/25/2022] Open
Abstract
Purpose Cell therapy is a promising treatment for retinal pigment epithelium (RPE)-associated eye diseases such as age-related macular degeneration. Herein, selective microsecond laser irradiation targeting RPE cells was used for minimally invasive, large-area RPE removal in preparation for delivery of retinal cell therapeutics. Methods Ten rabbit eyes were exposed to laser pulses 8, 12, 16, and 20 µs in duration (wavelength, 532 nm; top-hat beam profile, 223 × 223 µm²). Post-irradiation retinal changes were assessed with fluorescein angiography (FA), indocyanine green angiography (ICGA), and optical coherence tomography (OCT). RPE viability was evaluated with an angiographic probit model. Following vitrectomy, a subretinal injection of balanced salt solution was performed over a lasered (maximum 13.6 mm2) and untreated control area. Bleb retinal detachment (bRD) morphology was then evaluated by intraoperative OCT. Results Within 1 hour after irradiation, laser lesions showed FA and ICGA leakage. OCT revealed that large-area laser damage was limited to the RPE. The angiographic median effective dose irradiation thresholds (ED50) were 45 µJ (90 mJ/cm2) at 8 µs, 52 µJ (104 mJ/cm2) at 12 µs, 59 µJ (118 mJ/cm2) at 16 µs, and 71 µJ (142 mJ/cm2) at 20 µs. Subretinal injection over the lasered area resulted in a controlled, shallow bRD rise, whereas control blebs were convex in shape, with less predictable spread. Conclusions Large-area, laser-based removal of host RPE without visible photoreceptor damage is possible and facilitates surgical retinal detachment. Translational Relevance Selective microsecond laser-based, large-area RPE removal prior to retinal cell therapy may reduce iatrogenic trauma.
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Affiliation(s)
- Christian Burri
- Institute for Human Centered Engineering (HuCE)–optoLab, Bern University of Applied Sciences, Biel, Switzerland
- Biomedical Photonics Group, Institute of Applied Physics, University of Bern, Bern, Switzerland
| | - Sami Al-Nawaiseh
- Eye Clinic Sulzbach, Knappschaft Hospital Saar, Sulzbach, Saar, Germany
- Department of Ophthalmology, University of Münster, Münster, Germany
| | - Philip Wakili
- Eye Clinic Sulzbach, Knappschaft Hospital Saar, Sulzbach, Saar, Germany
| | - Simon Salzmann
- Institute for Human Centered Engineering (HuCE)–optoLab, Bern University of Applied Sciences, Biel, Switzerland
| | - Christina Krötz
- Fraunhofer Institute for Biomedical Engineering, Sulzbach, Saar, Germany
| | - Boris Považay
- Institute for Human Centered Engineering (HuCE)–optoLab, Bern University of Applied Sciences, Biel, Switzerland
| | - Christoph Meier
- Institute for Human Centered Engineering (HuCE)–optoLab, Bern University of Applied Sciences, Biel, Switzerland
| | - Martin Frenz
- Biomedical Photonics Group, Institute of Applied Physics, University of Bern, Bern, Switzerland
| | - Peter Szurman
- Eye Clinic Sulzbach, Knappschaft Hospital Saar, Sulzbach, Saar, Germany
- Klaus Heimann Eye Research Institute, Sulzbach, Saar, Germany
| | - André Schulz
- Eye Clinic Sulzbach, Knappschaft Hospital Saar, Sulzbach, Saar, Germany
- Klaus Heimann Eye Research Institute, Sulzbach, Saar, Germany
| | - Boris Stanzel
- Eye Clinic Sulzbach, Knappschaft Hospital Saar, Sulzbach, Saar, Germany
- Klaus Heimann Eye Research Institute, Sulzbach, Saar, Germany
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8
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Kim U, Kwon M, Jung G, Kim Y, Lee Y, Im S, Cense B, Lee H, Ohm WS, Joo C. Optical dosimeter for selective retinal therapy based on multi-port fiber-optic interferometry. BIOMEDICAL OPTICS EXPRESS 2021; 12:4920-4933. [PMID: 34513233 PMCID: PMC8407823 DOI: 10.1364/boe.434812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
Selective retinal therapy (SRT) employs a micro-second short-pulse lasers to induce localized destruction of the targeted retinal structures with a pulse duration and power aimed at minimal damage to other healthy retinal cells. SRT has demonstrated a great promise in the treatment of retinal diseases, but pulse energy thresholds for effective SRT procedures should be determined precisely and in real time, as the thresholds could vary with disease status and patients. In this study, we present the use of a multi-port fiber-based interferometer (MFI) for highly sensitive real-time SRT monitoring. We exploit distinct phase differences among the fiber ports in the MFI to quantitatively measure localized fluctuations of complex-valued information during the SRT procedure. We evaluate several metrics that can be computed from the full complex-valued information and demonstrate that the complex contour integration is highly sensitive and most correlative to pulse energies, acoustic outputs, and cell deaths. The validity of our method was demonstrated on excised porcine retinas, with a sensitivity and specificity of 0.92 and 0.88, respectively, as compared with the results from a cell viability assay.
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Affiliation(s)
- Uihan Kim
- Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
- These authors contributed equally to this work
| | - Minsung Kwon
- Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
- These authors contributed equally to this work
| | - Gyeongyeon Jung
- Department of Research, Lutronic Corporation, 219 Sowon-ro, Goyang, 10534, Republic of Korea
| | - Youngnam Kim
- Department of Research, Lutronic Corporation, 219 Sowon-ro, Goyang, 10534, Republic of Korea
| | - Yunam Lee
- Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Seonghun Im
- Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Barry Cense
- Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
- Optical and Biomedical Engineering Laboratory, Department of Electrical, Electronic & Computer Engineering, The University of Western Australia, Perth, WA 6009, Australia
| | - Hyungsuk Lee
- Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Won-Suk Ohm
- Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Chulmin Joo
- Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
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Kyo A, Yamamoto M, Hirayama K, Kohno T, Theisen-Kunde D, Brinkmann R, Miura Y, Honda S. Factors affecting resolution of subretinal fluid after selective retina therapy for central serous chorioretinopathy. Sci Rep 2021; 11:8973. [PMID: 33903643 PMCID: PMC8076253 DOI: 10.1038/s41598-021-88372-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 04/12/2021] [Indexed: 02/07/2023] Open
Abstract
The purpose of this study was to investigate the factors of clinical outcome of selective retina therapy (SRT) for central serous chorioretinopathy (CSC). This retrospective study included 77 eyes of 77 patients, who were treated with SRT for CSC and observed at least 6 months after the treatment. SRT laser (527 nm, 1.7 µs, 100 Hz) was used for treatment. The mean best-corrected visual acuity (logMAR), central macular thickness (CMT) and central choroidal thickness were changed from baseline to at 6-months follow-up with significant difference. The multivariate analyses found that the rate of change (reduction) in CMT was associated with focal leakage type on fluorescein angiography (FA) (p = 0.03, coefficient 15.26, 95% confidence interval 1.72–28.79) and larger baseline CMT (p < 0.01, coefficient − 0.13, 95% confidence interval − 0.13 to − 0.05). Complete resolution of subretinal fluid was associated with nonsmoking history (p = 0.03, odds ratio 0.276, 95% confidence interval 0.086–0.887) and focal leakage type on FA (p < 0.01, odds ratio 0.136, 95% confidence interval 0.042–0.437). These results may be useful for predicting the therapeutic effectiveness of SRT.
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Affiliation(s)
- Akika Kyo
- Department of Ophthalmology and Visual Science, Osaka City University Graduate School of Medicine, Osaka, 545-8585, Japan
| | - Manabu Yamamoto
- Department of Ophthalmology and Visual Science, Osaka City University Graduate School of Medicine, Osaka, 545-8585, Japan.
| | - Kumiko Hirayama
- Department of Ophthalmology and Visual Science, Osaka City University Graduate School of Medicine, Osaka, 545-8585, Japan
| | - Takeya Kohno
- Department of Ophthalmology and Visual Science, Osaka City University Graduate School of Medicine, Osaka, 545-8585, Japan
| | | | - Ralf Brinkmann
- Medical Laser Center Lübeck, Lübeck, Germany.,Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
| | - Yoko Miura
- Medical Laser Center Lübeck, Lübeck, Germany.,Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany.,Department of Ophthalmology, University of Lübeck, Lübeck, Germany
| | - Shigeru Honda
- Department of Ophthalmology and Visual Science, Osaka City University Graduate School of Medicine, Osaka, 545-8585, Japan
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Hirayama K, Yamamoto M, Kohno T, Kyo A, Theisen-Kunde D, Brinkmann R, Miura Y, Honda S. Selective retina therapy (SRT) for macular serous retinal detachment associated with tilted disc syndrome. Graefes Arch Clin Exp Ophthalmol 2020; 259:387-393. [PMID: 32960320 DOI: 10.1007/s00417-020-04931-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/07/2020] [Accepted: 09/10/2020] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Tilted disc syndrome (TDS) may be associated with a macular serous retinal detachment (MSRD). However, ideal therapy for this complication is still unestablished yet to date. The purpose of this study is to investigate the effect of selective retina therapy (SRT) for MSRD associated with TDS. METHODS This retrospective study included 11 eyes of 10 patients (1 male and 9 females), who were treated with SRT for MSRD associated with TDS, and observed at least 12 months after treatment. The mean age was 56 years old (range 44-66). An SRT laser (527 nm, 1.7 μs, 100 Hz; Medical Laser Center Lübeck, Germany) was used for treatment. The changes of best-corrected visual acuity (BCVA), central macular thickness (CMT), and central choroidal thickness (CCT) were examined. Subfoveal curve height (SFCH) was calculated at baseline. RESULTS The mean follow-up period was 24.4 months (range 12-48 months). The mean BCVA (logMAR), CMT, and CCT changed from 0.03 ± 0.10, 324 ± 82 μm, and 194 ± 68 μm preoperatively to 0.07 ± 0.17, 274 ± 94 μm, and 188 ± 65 μm at final follow-up, respectively, with significant difference on CMT (BCVA: p = 0.44, CMT: p < 0.05, CCT: p = 0.21). The MSRD disappeared in 6 eyes (55%) and the average number of SRT irradiations until resolution of MSRD was 2.6 times (range 1-5 times). There was no significant association between SFCH and resolution of MSRD (p = 0.19). CONCLUSIONS SRT may promote absorption of MSRD and maintenance of BCVA for TDS. Randomized and prospective clinical studies are needed to evaluate the effectiveness of SRT for MSRD associated with TDS.
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Affiliation(s)
- Kumiko Hirayama
- Department of Ophthalmology and Visual Science, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585, Japan
| | - Manabu Yamamoto
- Department of Ophthalmology and Visual Science, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585, Japan.
| | - Takeya Kohno
- Department of Ophthalmology and Visual Science, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585, Japan
| | - Akika Kyo
- Department of Ophthalmology and Visual Science, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585, Japan
| | | | - Ralf Brinkmann
- Medical Laser Center Lübeck, Lübeck, Germany.,Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
| | - Yoko Miura
- Medical Laser Center Lübeck, Lübeck, Germany.,Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany.,Department of Ophthalmology, University Medical Center Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | - Shigeru Honda
- Department of Ophthalmology and Visual Science, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585, Japan
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Bliedtner K, Seifert E, Brinkmann R. Towards Automatically Controlled Dosing for Selective Laser Trabeculoplasty. Transl Vis Sci Technol 2019; 8:24. [PMID: 31807369 PMCID: PMC6890396 DOI: 10.1167/tvst.8.6.24] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 09/09/2019] [Indexed: 12/15/2022] Open
Abstract
Purpose Selective laser trabeculoplasty (SLT) is a treatment option for open-angle glaucoma; however, it lacks an instant evidence for successful irradiation. So far ophthalmologists use the visible appearance of permanent champagnelike bubbles (macro bubbles) as an indicator for appropriate pulse energy. We hypothesize that micro bubbles, which start energetically far below the appearance of macro bubbles, already trigger the therapeutic benefit. Here we present two methods to capture the onset of these micro bubbles. Methods The trabecular meshwork of freshly enucleated porcine eye globes was irradiated with a series of 15 pulses with a pulse duration of 1.7 μs and with increasing energy at a repetition rate of 100 Hz per each spot of 200 μm in diameter. An optical and an optoacoustic method have been developed and appropriate algorithms investigated towards the real-time detection of the onset of micro bubbles. Results Both observation methods are capable of detecting micro bubble nucleation. Threshold radiant exposures were found at 310 ± 137 mJ/cm2. By combination of both methods a sensitivity and specificity of 0.96 was reached. Conclusions In case that the therapeutically demanded pressure reduction is already achieved with these micro bubbles, which needs to be proven clinically, then the methods presented here can be used in an automatic feedback loop controlling the laser irradiation. This will unburden the clinicians from any dosing during SLT. Translational Relevance Automatic real-time pulse energy dosing based on the formation of micro bubbles in SLT significantly improves and facilitates the treatment for the physician.
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Affiliation(s)
| | | | - Ralf Brinkmann
- Medical Laser Center Lübeck, Lübeck, Germany.,Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
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12
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Chhablani J, Roh YJ, Jobling AI, Fletcher EL, Lek JJ, Bansal P, Guymer R, Luttrull JK. Restorative retinal laser therapy: Present state and future directions. Surv Ophthalmol 2018; 63:307-328. [DOI: 10.1016/j.survophthal.2017.09.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Revised: 09/13/2017] [Accepted: 09/22/2017] [Indexed: 01/30/2023]
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13
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Zbinden S, Kucur ŞS, Steiner P, Wolf S, Sznitman R. Automatic assessment of time-resolved OCT images for selective retina therapy. Int J Comput Assist Radiol Surg 2016; 11:863-71. [PMID: 27067098 PMCID: PMC4893370 DOI: 10.1007/s11548-016-1383-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/09/2016] [Indexed: 11/24/2022]
Abstract
Purpose In recent years, selective retina laser treatment (SRT), a sub-threshold therapy method, avoids widespread damage to all retinal layers by targeting only a few. While these methods facilitate faster healing, their lack of visual feedback during treatment represents a considerable shortcoming as induced lesions remain invisible with conventional imaging and make clinical use challenging. To overcome this, we present a new strategy to provide location-specific and contact-free automatic feedback of SRT laser applications. Methods We leverage time-resolved optical coherence tomography (OCT) to provide informative feedback to clinicians on outcomes of location-specific treatment. By coupling an OCT system to SRT treatment laser, we visualize structural changes in the retinal layers as they occur via time-resolved depth images. We then propose a novel strategy for automatic assessment of such time-resolved OCT images. To achieve this, we introduce novel image features for this task that when combined with standard machine learning classifiers yield excellent treatment outcome classification capabilities. Results Our approach was evaluated on both ex vivo porcine eyes and human patients in a clinical setting, yielding performances above 95 % accuracy for predicting patient treatment outcomes. In addition, we show that accurate outcomes for human patients can be estimated even when our method is trained using only ex vivo porcine data. Conclusion The proposed technique presents a much needed strategy toward noninvasive, safe, reliable, and repeatable SRT applications. These results are encouraging for the broader use of new treatment options for neovascularization-based retinal pathologies.
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Affiliation(s)
- Sarah Zbinden
- ARTORG Research Center Biomedical Engineering Research, University of Bern, Murtenstrasse 50, 3008, Bern, Switzerland
| | - Şerife Seda Kucur
- ARTORG Research Center Biomedical Engineering Research, University of Bern, Murtenstrasse 50, 3008, Bern, Switzerland.
| | - Patrick Steiner
- ARTORG Research Center Biomedical Engineering Research, University of Bern, Murtenstrasse 50, 3008, Bern, Switzerland
| | - Sebastian Wolf
- Department of Ophthalmology, Inselspital Bern, Freiburgstrasse 12, 3010, Bern, Switzerland
| | - Raphael Sznitman
- ARTORG Research Center Biomedical Engineering Research, University of Bern, Murtenstrasse 50, 3008, Bern, Switzerland
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14
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Park YG, Kim JR, Kang S, Seifert E, Theisen-Kunde D, Brinkmann R, Roh YJ. Safety and efficacy of selective retina therapy (SRT) for the treatment of diabetic macular edema in Korean patients. Graefes Arch Clin Exp Ophthalmol 2016; 254:1703-13. [DOI: 10.1007/s00417-015-3262-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 12/21/2015] [Accepted: 12/30/2015] [Indexed: 10/22/2022] Open
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15
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Laser-based strategies to treat diabetic macular edema: history and new promising therapies. J Ophthalmol 2014; 2014:769213. [PMID: 25332833 PMCID: PMC4190043 DOI: 10.1155/2014/769213] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 07/30/2014] [Accepted: 09/04/2014] [Indexed: 02/08/2023] Open
Abstract
Diabetic macular edema (DME) is the main cause of visual impairment in diabetic patients. The management of DME is complex and often various treatment approaches are needed. At the present time, despite the enthusiasm for evaluating several new treatments for DME, including the intravitreal pharmacologic therapies (e.g., corticosteroids and anti-VEGF drugs), laser photocoagulation still remains the current standard in DME. The purpose of this review is to update our knowledge on laser photocoagulation for DME and describe the developments in laser systems. And we will also discuss the new laser techniques and review the latest results including benefits of combined therapy. In this paper, we briefly summarize the major laser therapeutics for the treatment of diabetic macular edema and allude to some future promising laser therapies.
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16
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Park YG, Seifert E, Roh YJ, Theisen-Kunde D, Kang S, Brinkmann R. Tissue response of selective retina therapy by means of a feedback-controlled energy ramping mode. Clin Exp Ophthalmol 2014; 42:846-55. [PMID: 24698550 DOI: 10.1111/ceo.12342] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 03/27/2014] [Indexed: 11/27/2022]
Abstract
BACKGROUND The purpose of the study was to evaluate the safety and selectivity of the retinal pigment epithelium lesions by using automatic energy ramping and dosimetry technique for selective retina therapy and to investigate the healing response. METHODS Ten eyes of Chinchilla Bastard rabbits were treated with an automatic dosage controlled selective retina therapy laser (frequency doubled Q-switched Nd:YLF, wavelength: 527 nm, pulse duration: 1.7 μs, repetition rate: 100 Hz, pulse energy: linear increasing from pulse to pulse up to shut down - maximal 110 μJ, max. number of pulses in a burst: 30, retinal spot diameter: 133 μm). After treatment, fundus photography, optical coherence tomography and fluorescein angiography were performed at three time points from 1 h to 3 weeks. Histological analysis was performed. RESULTS A total of 381 selective retina therapy laser spots were tested (range 13-104 μJ).Typical fundus photographs obtained at 1 h after irradiation showed that 379 out of 381 lesions produced by selective retina therapy were not visible ophthalmoscopically and the lesions could be detected by angiography only. Optical coherence tomography images revealed that the structure of photoreceptors was preserved, but a disrupted retinal pigment epithelium layer was observed as was expected. By 3 weeks, histology showed selective retinal pigment epithelium damage without any effect on the inner retina and focal proliferation of the retinal pigment epithelium layer. CONCLUSIONS Automatically controlled selective retina therapy is a significant improvement in this innovative treatment. It could be demonstrated that the non-contact, reflectometric technique with a controlled pulse energy ramp is safe and selective.
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Affiliation(s)
- Young-Gun Park
- Department of Ophthalmology, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
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17
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Pérez-Gutiérrez FG, Camacho-López S, Evans R, Guillén G, Goldschmidt BS, Viator JA, Aguilar G. Plasma membrane integrity and survival of melanoma cells after nanosecond laser pulses. Ann Biomed Eng 2010; 38:3521-31. [PMID: 20589533 PMCID: PMC2949564 DOI: 10.1007/s10439-010-0101-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Accepted: 06/11/2010] [Indexed: 12/05/2022]
Abstract
Circulating tumor cells (CTCs) photoacoustic detection systems can aid clinical decision-making in the treatment of cancer. Interaction of melanin within melanoma cells with nanosecond laser pulses generates photoacoustic waves that make its detection possible. This study aims at: (1) determining melanoma cell survival after laser pulses of 6 ns at λ = 355 and 532 nm; (2) comparing the potential enhancement in the photoacoustic signal using λ = 355 nm in contrast with λ = 532 nm; (3) determining the critical laser fluence at which melanin begins to leak out from melanoma cells; and (4) developing a time-resolved imaging (TRI) system to study the intracellular interactions and their effect on the plasma membrane integrity. Monolayers of melanoma cells were grown on tissue culture-treated clusters and irradiated with up to 1.0 J/cm2. Surviving cells were stained with trypan blue and counted using a hemacytometer. The phosphate buffered saline absorbance was measured with a nanodrop spectrophotometer to detect melanin leakage from the melanoma cells post-laser irradiation. Photoacoustic signal magnitude was studied at both wavelengths using piezoelectric sensors. TRI with 6 ns resolution was used to image plasma membrane damage. Cell survival decreased proportionally with increasing laser fluence for both wavelengths, although the decrease is more pronounced for 355 nm radiation than for 532 nm. It was found that melanin leaks from cells equally for both wavelengths. No significant difference in photoacoustic signal was found between wavelengths. TRI showed clear damage to plasma membrane due to laser-induced bubble formation.
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Affiliation(s)
- Francisco G Pérez-Gutiérrez
- Department of Mechanical Engineering, University of California at Riverside, 900 University Ave., Riverside, CA 92521, USA
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Lee H, Alt C, Pitsillides CM, Lin CP. Optical detection of intracellular cavitation during selective laser targeting of the retinal pigment epithelium: dependence of cell death mechanism on pulse duration. JOURNAL OF BIOMEDICAL OPTICS 2007; 12:064034. [PMID: 18163850 DOI: 10.1117/1.2804078] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Selective laser targeting of the retinal pigment epithelium (RPE) is an attractive method for treating RPE-associated disorders. We are developing a method for optically detecting intracellular microcavitation that can potentially serve as an immediate feedback of the treatment outcome. Thermal denaturation or intracellular cavitation can kill RPE cells during selective targeting. We examined the cell damage mechanism for laser pulse durations from 1 to 40 micros ex vivo. Intracellular cavitation was detected as a transient increase in the backscattered treatment beam. Cavitation and cell death were correlated for individual cells after single-pulse irradiation. The threshold radiant exposures for cell death (ED(50,d)) and cavitation (ED(50,c)) increased with pulse duration and were approximately equal for pulses of up to 10 micros. For 20 micros, the ED(50,d) was about 10% lower than the ED(50,c); the difference increased with 40-micros pulses. Cells were killed predominantly by cavitation (up to 10-micros pulses); probability of thermally induced cell death without cavitation gradually increases with pulse duration. Threshold measurements are discussed by modeling the temperature distribution around laser-heated melanosomes and the scattering function from the resulting cavitation. Detection of intracellular cavitation is a highly sensitive method that can potentially provide real-time assessment of RPE damage during selective laser targeting.
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Affiliation(s)
- Ho Lee
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
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Abstract
Selective Retina Therapy (SRT) is a new and very gentle laser method developed at the Medical Laser Center Lübeck. It is currently investigated clinically in order to treat retinal disorders associated with a decreased function of the retinal pigment epithelium (RPE). SRT is designed to selectively effect the RPE while sparing the neural retina and the photoreceptors as well as the chorioidea. Aim of the therapy is the rejuvenation of the RPE in the treated areas, which should ideally lead to a long term metabolic increase at the chorio-retinal junction. In contrast to conventional laser photocoagulation, which is associated with a complete thermal necrosis of the treated site, SRT completely retains full vision. This paper reviews the methods and mechanisms behind selective RPE effects and reports the first clinical results. An online dosimetry technique to visualize the ophthalmoscopically invisible effects is introduced.
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Affiliation(s)
- Ralf Brinkmann
- Institut für Biomedizinische Optik der Universität zu Lübeck und Medizinisches Laserzentrum LObeck GmbH, Peter-Monnik-Weg 4, D-23562 Lübeck.
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Brinkmann R, Schüle G, Neumann J, Framme C, Pörksen E, Elsner H, Theisen-Kunde D, Roider J, Birngruber R. Selektive Retinatherapie. Ophthalmologe 2006; 103:839-49. [PMID: 17003949 DOI: 10.1007/s00347-006-1416-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Selective retina therapy (SRT) is currently under evaluation, as a new and very subtle laser method, for the treatment of retinal disorders associated with a degradation of the retinal pigmentary epithelium (RPE). SRT makes it possible to selectively effect the RPE, sparing the adjacent neural retina with the photoreceptors and also the choroid below the RPE. In the best case, the therapy leads to regeneration of the RPE and a long-term metabolic increase at the chorio-retinal junction. In contrast to conventional laser photocoagulation, which is associated with complete thermal necrosis of and around the treated site, absolutely no scotoma occurs in SRT. This paper reviews the methods and mechanisms behind the selective effects of the RPE. In vitro and preclinical results are used to describe the bandwidth of selective effects with respect to different irradiation settings. An optoacoustic technique is introduced to visualize effects that cannot be seen by ophthalmoscopy and to facilitate dosimetry control without recourse to angiography completes the report.
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Affiliation(s)
- R Brinkmann
- Medizinisches Laserzentrum Lübeck GmbH, Peter-Monnik-Weg 4, 23562 Lübeck, Germany.
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