uu.seUppsala University Publications
Change search
Link to record
Permanent link

Direct link
BETA
Alternative names
Publications (10 of 78) Show all publications
Sandberg Melin, C., Malmberg, F. & Söderberg, P. G. (2019). A strategy for OCT estimation of the optic nerve head pigment epithelium central limit-inner limit of the retina minimal distance, PIMD-2π. Acta Ophthalmologica, 97(2), 208-213
Open this publication in new window or tab >>A strategy for OCT estimation of the optic nerve head pigment epithelium central limit-inner limit of the retina minimal distance, PIMD-2π
2019 (English)In: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 97, no 2, p. 208-213Article in journal (Refereed) Published
Abstract [en]

Purpose To develop a semi-automatic algorithm for estimation of pigment epithelium central limit-inner limit of the retina minimal distance averaged over 2 pi radians (PIMD-2 pi) and to estimate the precision of the algorithm. Further, the variances in estimates of PIMD-2 pi were to be estimated in a pilot sample of glaucomatous eyes. Methods Three-dimensional cubes of the optic nerve head (ONH) were captured with a commercial SD-OCT device. Raw cube data were exported for semi-automatic segmentation. The inner limit of the retina was automatically detected. Custom software aided the delineation of the ONH pigment epithelium central limit resolved in 500 evenly distributed radii. Sources of variation in PIMD estimates were analysed with an analysis of variance. Results The estimated variance for segmentations and angles was 130 mu m(2) and 1280 mu m(2), respectively. Considering averaging eight segmentations, a 95 % confidence interval for mean PIMD-2 pi was estimated to 212 +/- 10 mu m (df = 7). The coefficient of variation for segmentation was estimated at 0.05. In the glaucomatous eyes, the within-subject variance for captured volumes and for segmentations within volumes was 10 mu m(2) and 50 mu m(2), respectively. Conclusion The developed semi-automatic algorithm enables estimation of PIMD-2 pi in glaucomatous eyes with relevant precision using few segmentations of each captured volume.

National Category
Ophthalmology Medical Image Processing
Research subject
Computerized Image Processing
Identifiers
urn:nbn:se:uu:diva-362723 (URN)10.1111/aos.13908 (DOI)000459637900020 ()30198106 (PubMedID)
Funder
Gun och Bertil Stohnes Stiftelse
Available from: 2018-09-10 Created: 2018-10-09 Last updated: 2020-02-20Bibliographically approved
Söderberg, P., Yu, Z. & Sandberg Melin, C. (2019). Optic nerve head morphometry for glaucoma diagnosis, optimization of clinical measurement strategy. Paper presented at Conference on Ophthalmic Technologies XXIX, SPIE BiOS 2019, San Francisco, California, United States, Feb 2-3, 2019. Proceedings of SPIE, 10858, 45:1-45:8, Article ID 108581C.
Open this publication in new window or tab >>Optic nerve head morphometry for glaucoma diagnosis, optimization of clinical measurement strategy
2019 (English)In: Proceedings of SPIE, ISSN 0277-786X, Vol. 10858, p. 45:1-45:8, article id 108581CArticle in journal (Refereed) Published
Abstract [en]

The present study aimed to develop a strategy for evaluation of instant PIMD-2 pi measurements as a basis for clinical monitoring of glaucoma. PIMD-2 pi is a morphometric measure of the waist of the nerve fiber layer at the optic nerve head (ONH). Clinical measurements of PIMD-2 pi in patients with early to moderate stage glaucoma demonstrated a high variability among subjects. The high variability among subjects renders comparison of instant PIMD-2 pi measurements to tolerance limits for normality derived from a normative database inefficient. It is suggested to instead compare sequential measurements of PIMD-2 pi within a patient. Initially, the difference between an instant measurement and the average of previous measurements can be compared to tolerance limits for difference between measurements within subject. Once, a potential loss of PIMD-2 pi is detected, a sufficient number of measurements within a sufficiently wide time interval can be used to estimate the PIMD-2 pi loss rate with regression and the deviation of the estimated loss rate can be evaluated as a 95 % confidence interval for the loss rate. If the upper confidence limit excludes 0, a significant loss rate has been detected. The currently proposed strategy has the potential to detect glaucoma earlier than the current gold standard, computer perimetry, with less inconvenience for the patient.

National Category
Ophthalmology
Identifiers
urn:nbn:se:uu:diva-384735 (URN)10.1117/12.2516319 (DOI)000481649100010 ()
Conference
Conference on Ophthalmic Technologies XXIX, SPIE BiOS 2019, San Francisco, California, United States, Feb 2-3, 2019
Available from: 2019-06-07 Created: 2019-06-07 Last updated: 2019-09-27Bibliographically approved
Söderberg, P. G. & Sandberg Melin, C. (2018). Angular distribution of Pigment epithelium central limit-Inner limit of the retina Minimal Distance (PIMD), in the young not pathological optic nerve head imaged by OCT. In: Manns, F Soderberg, PG Ho, A (Ed.), OPHTHALMIC TECHNOLOGIES XXVIII: . Paper presented at 28th Conference on Ophthalmic Technologies as a part of the SPIE Photonics West BiOS Meeting, JAN 27-28, 2018, San Francisco, CA. SPIE-INT SOC OPTICAL ENGINEERING, Article ID 1047413.
Open this publication in new window or tab >>Angular distribution of Pigment epithelium central limit-Inner limit of the retina Minimal Distance (PIMD), in the young not pathological optic nerve head imaged by OCT
2018 (English)In: OPHTHALMIC TECHNOLOGIES XXVIII / [ed] Manns, F Soderberg, PG Ho, A, SPIE-INT SOC OPTICAL ENGINEERING , 2018, article id 1047413Conference paper, Published paper (Refereed)
Abstract [en]

The present study aimed to elucidate the angular distribution of the Pigment epithelium central limit-Inner limit of the retina Minimal Distance measured over 2 pi radians in the frontal plane (PIMD-2 pi) in young healthy eyes. Both healthy eyes of 16 subjects aged [20; 30[years were included. In each eye, a volume of the optical nerve head (ONH) was captured three times with a TOPCON DRI OCT Triton (Japan). Each volume renders a representation of the ONH 2.8 mm along the sagittal axis resolved in 993 steps, 6 mm long the frontal axis resolved in 512 steps and 6 x mm along the longitudinal axis resolved in 256 steps. The captured volumes were transferred to a custom made software for semiautomatic segmentation of PIMD around the circumference of the ONH. The phases of iterated volumes were calibrated with cross correlation. It was found that PIMD-2 pi expresses a double hump with a small maximum superiorly, a larger maximum inferiorly, and minima in between. The measurements indicated that there is no difference of PIMD-2 pi between genders nor between dominant and not dominant eye within subject. The variation between eyes within subject is of the same order as the variation among subjects. The variation among volumes within eye is substantially lower.

Place, publisher, year, edition, pages
SPIE-INT SOC OPTICAL ENGINEERING, 2018
Series
Proceedings of SPIE, ISSN 0277-786X, E-ISSN 1996-756X ; 10474
Keywords
optic nerve head, morphometry, OCT, PIMD, PIMD-2 pi, variability
National Category
Other Health Sciences
Identifiers
urn:nbn:se:uu:diva-372522 (URN)10.1117/12.2299723 (DOI)000451753300009 ()978-1-5106-1434-5 (ISBN)978-1-5106-1433-8 (ISBN)
Conference
28th Conference on Ophthalmic Technologies as a part of the SPIE Photonics West BiOS Meeting, JAN 27-28, 2018, San Francisco, CA
Available from: 2019-01-08 Created: 2019-01-08 Last updated: 2019-01-08Bibliographically approved
Söderberg, P. & Sandberg Melin, C. (2018). Angular distribution of Pigment epithelium central limit-Inner limit of the retina Minimal Distance (PIMD), in the young not pathological  optic nerve head imaged by OCT. SPIE Proc, 10474, 38:1-38:7
Open this publication in new window or tab >>Angular distribution of Pigment epithelium central limit-Inner limit of the retina Minimal Distance (PIMD), in the young not pathological  optic nerve head imaged by OCT
2018 (English)In: SPIE Proc, Vol. 10474, p. 38:1-38:7Article in journal (Refereed) Published
Abstract [en]

The present study aimed to elucidate the angular distribution of the Pigment epithelium central limit-Inner limit of the retina Minimal Distance measured over 2π radians in the frontal plane (PIMD-2π) in young healthy eyes. Both healthy eyes of 16 subjects aged [20;30[ years were included. In each eye, a volume of the optical nerve head (ONH) was captured three times with a TOPCON DRI OCT Triton (Japan). Each volume renders a representation of the ONH 2.8 mm along the sagittal axis resolved in 993 steps, 6 mm long the frontal axis resolved in 512 steps and 6 x mm along the longitudinal axis resolved in 256 steps. The captured volumes were transferred to a custom made software for semiautomatic segmentation of PIMD around the circumference of the ONH. The phases of iterated volumes were calibrated with cross correlation. It was found that PIMD-2π expresses a double hump with a small maximum superiorly, a larger maximum inferiorly, and minima in between. The measurements indicated that there is no difference of PIMD-2π between genders nor between dominant and not dominant eye within subject. The variation between eyes within subject is of the same order as the variation among subjects. The variation among volumes within eye is substantially lower.

National Category
Ophthalmology
Identifiers
urn:nbn:se:uu:diva-384738 (URN)10.1117/12.2299723 (DOI)
Available from: 2019-06-07 Created: 2019-06-07 Last updated: 2019-08-21Bibliographically approved
Manns, M., Söderberg, P. & Ho, A. (Eds.). (2018). Ophthalmic Technologies XXVIII. Bellingham, WA, USA: SPIE - International Society for Optical Engineering
Open this publication in new window or tab >>Ophthalmic Technologies XXVIII
2018 (English)Conference proceedings (editor) (Refereed)
Place, publisher, year, edition, pages
Bellingham, WA, USA: SPIE - International Society for Optical Engineering, 2018
National Category
Ophthalmology
Identifiers
urn:nbn:se:uu:diva-384737 (URN)9781510614338 (ISBN)
Available from: 2019-06-07 Created: 2019-06-07 Last updated: 2019-08-29Bibliographically approved
Söderberg, P. G., Malmberg, F. & Sandberg Melin, C. (2017). Further analysis of clinical feasibility of OCT-based glaucoma diagnosis with Pigment epithelium central limit–Inner limit of the retina Minimal Distance (PIMD). In: Ophthalmic Technologies XXVII: . Bellingham, WA: SPIE - International Society for Optical Engineering, Article ID 100450R.
Open this publication in new window or tab >>Further analysis of clinical feasibility of OCT-based glaucoma diagnosis with Pigment epithelium central limit–Inner limit of the retina Minimal Distance (PIMD)
2017 (English)In: Ophthalmic Technologies XXVII, Bellingham, WA: SPIE - International Society for Optical Engineering, 2017, article id 100450RConference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Bellingham, WA: SPIE - International Society for Optical Engineering, 2017
Series
Proc. SPIE ; 10045
National Category
Ophthalmology Medical Image Processing
Research subject
Computerized Image Processing
Identifiers
urn:nbn:se:uu:diva-341869 (URN)10.1117/12.2260139 (DOI)000405820700021 ()978-1-5106-0531-2 (ISBN)
Available from: 2017-02-10 Created: 2018-02-16 Last updated: 2018-03-03Bibliographically approved
Yu, Z., Talebizadeh, N., Kronschläger, M. & Söderberg, P. (2017). Measuring temperature in the lens during experimental heat load indirectly as light scattering increase rate. Journal of Biomedical Optics, 22(1), Article ID 015005.
Open this publication in new window or tab >>Measuring temperature in the lens during experimental heat load indirectly as light scattering increase rate
2017 (English)In: Journal of Biomedical Optics, ISSN 1083-3668, E-ISSN 1560-2281, Vol. 22, no 1, article id 015005Article in journal (Refereed) Published
Abstract [en]

The current study aims to experimentally estimate the temperature in the lens due to heat load indirectly from the measurement of increase rate of temperature-induced light scattering. The lens was extracted from Sprague-Dawley rats and put into a temperature-controlled cuvette filled with balanced salt solution. Altogether, 80 lenses were equally divided on four temperature groups. Each lens was exposed for 5 minutes to temperature depending on group belonging while the intensity of forward light scattering was recorded. The inclination coefficient of light scattering increase at the temperature 37, 40, 43, and 46 ºC was estimated as a CI(0.95), 3.1±0.8, 4.4±0.8, 5.5±0.9 and 7.0±0.8 x10-4 tEDC/s, respectively. The Arrhenius equation implies that the natural logarithm of the inclination coefficient is linearly dependent on the inverse of the temperature. The proportionality constant and the intercept were 9.6±2.4 x103 K and 22.8±7.7. The activation energy was 8.0±2.0 x101 kJ·mol-1. The current experiment implies that if averaging 20 measurements of inclination coefficients in a new experiment at constant heat load, the confidence limits for predicted temperature correspond to ±1.9 °C. With the proportionality constant and the intercept estimated in the current experiment, the in vivo temperature in the lens can be determined retrospectively with sufficient resolution.

Keywords
forward light scattering; lens; cataract; temperature; Arrhenius equation
National Category
Neurosciences
Research subject
Ophtalmology
Identifiers
urn:nbn:se:uu:diva-308820 (URN)10.1117/1.JBO.22.1.015005 (DOI)000396370600009 ()
Available from: 2016-11-30 Created: 2016-11-30 Last updated: 2018-01-13Bibliographically approved
Talebizadeh, N., Zhou Hagström, N., Yu, Z., Kronschläger, M., Söderberg, P. & Wählby, C. (2017). Objective automated quantification of fluorescence signal in histological sections of rat lens. Cytometry Part A, 91(8), 815-821
Open this publication in new window or tab >>Objective automated quantification of fluorescence signal in histological sections of rat lens
Show others...
2017 (English)In: Cytometry Part A, ISSN 1552-4922, E-ISSN 1552-4930, Vol. 91, no 8, p. 815-821Article in journal (Refereed) Published
Abstract [en]

Visual quantification and classification of fluorescent signals is the gold standard in microscopy. The purpose of this study was to develop an automated method to delineate cells and to quantify expression of fluorescent signal of biomarkers in each nucleus and cytoplasm of lens epithelial cells in a histological section. A region of interest representing the lens epithelium was manually demarcated in each input image. Thereafter, individual cell nuclei within the region of interest were automatically delineated based on watershed segmentation and thresholding with an algorithm developed in Matlab™. Fluorescence signal was quantified within nuclei, cytoplasms and juxtaposed backgrounds. The classification of cells as labelled or not labelled was based on comparison of the fluorescence signal within cells with local background. The classification rule was thereafter optimized as compared with visual classification of a limited dataset. The performance of the automated classification was evaluated by asking 11 independent blinded observers to classify all cells (n = 395) in one lens image. Time consumed by the automatic algorithm and visual classification of cells was recorded. On an average, 77% of the cells were correctly classified as compared with the majority vote of the visual observers. The average agreement among visual observers was 83%. However, variation among visual observers was high, and agreement between two visual observers was as low as 71% in the worst case. Automated classification was on average 10 times faster than visual scoring. The presented method enables objective and fast detection of lens epithelial cells and quantification of expression of fluorescent signal with an accuracy comparable with the variability among visual observers.

National Category
Ophthalmology Medical Image Processing
Research subject
Computerized Image Processing
Identifiers
urn:nbn:se:uu:diva-322627 (URN)10.1002/cyto.a.23131 (DOI)000408333700011 ()28494118 (PubMedID)
Available from: 2017-05-11 Created: 2017-05-28 Last updated: 2018-09-03Bibliographically approved
Manns, M., Ho, A. & Söderberg, P. (Eds.). (2017). Ophthalmic Technologies XXVII. Bellingham, WA, USA: SPIE - International Society for Optical Engineering
Open this publication in new window or tab >>Ophthalmic Technologies XXVII
2017 (English)Conference proceedings (editor) (Refereed)
Place, publisher, year, edition, pages
Bellingham, WA, USA: SPIE - International Society for Optical Engineering, 2017
National Category
Ophthalmology
Identifiers
urn:nbn:se:uu:diva-384741 (URN)9781510605312 (ISBN)
Available from: 2019-06-07 Created: 2019-06-07 Last updated: 2019-08-29Bibliographically approved
Sandberg Melin, C., Malmberg, F. & Söderberg, P. G. (2016). An OCT variable for glaucoma follow-up: Pigment epithelium central limit - Inner limit of the retina, Minimal Distance, PIMD. Paper presented at Annual Meeting of the Association-for-Research-in-Vision-and-Ophthalmology (ARVO), MAY 01-05, 2016, Seattle, WA. Investigative Ophthalmology and Visual Science, 57(12)
Open this publication in new window or tab >>An OCT variable for glaucoma follow-up: Pigment epithelium central limit - Inner limit of the retina, Minimal Distance, PIMD
2016 (English)In: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 57, no 12Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2016
National Category
Ophthalmology
Identifiers
urn:nbn:se:uu:diva-321044 (URN)000394174002292 ()
Conference
Annual Meeting of the Association-for-Research-in-Vision-and-Ophthalmology (ARVO), MAY 01-05, 2016, Seattle, WA
Available from: 2017-04-28 Created: 2017-04-28 Last updated: 2017-04-28Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7157-2802

Search in DiVA

Show all publications