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Mistry V, An D, Barry CJ, House PH, Morgan WH. Association between focal lamina cribrosa defects and optic disc haemorrhage in glaucoma. Br J Ophthalmol 2019; 104:98-103. [PMID: 31023711 DOI: 10.1136/bjophthalmol-2018-313775] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 02/12/2019] [Accepted: 03/13/2019] [Indexed: 11/04/2022]
Abstract
BACKGROUND/AIMS To explore the relationship between focal lamina defect (LD) size and optic disc haemorrhages (DH) in glaucomatous eyes. METHODS Radial B-scan images at 15° intervals obtained using enhanced depth imaging (EDI) spectral-domain optical coherence tomography (OCT) were performed on a group of subjects previously assessed for DH every 3 months over a period of 5 years. EDI-OCT scans were assessed for the presence of focal lamina cribrosa defects by a single observer. RESULTS 119 eyes from 62 subjects (44 females, 18 males) were analysed. 44 eyes (37%) were noted to have at least 1 LD, and of those, eight eyes had more than one defect. 68 eyes (57%) were observed to have at least one DH occur over the course of monitoring. 48 eyes (40%) had recurrent DH, with a mean of 5.17 haemorrhages over the 5-year period. Type 1 focal LD (p=0.0000, OR 7.17), glaucoma progression (p=0.0024, OR 0.32) and ArtDiff (p=0.0466, OR 1.04) were significantly associated as predictors of DH. No correlation between the size of the LD and DH occurrence (p=0.6449, Spearman rank correlation) was found. CONCLUSION Focal lamina cribrosa hole-type defects were significantly associated with an increase in DH occurrence over the preceding 5 years. The lack of association between defect size and DH suggests that DH and lamina defects may have separate links to the glaucomatous process.
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Affiliation(s)
- Vijay Mistry
- Princess Alexandra Hospital, Woolloongabba, Queensland, Australia .,Center for Ophthalmology and Visual Science, Lions Eye Institute, University of Western Australia, Nedlands, Western Australia, Australia
| | - Dong An
- Center for Ophthalmology and Visual Science, Lions Eye Institute, University of Western Australia, Nedlands, Western Australia, Australia
| | - Christopher J Barry
- Center for Ophthalmology and Visual Science, Lions Eye Institute, University of Western Australia, Nedlands, Western Australia, Australia
| | - Philip H House
- Center for Ophthalmology and Visual Science, Lions Eye Institute, University of Western Australia, Nedlands, Western Australia, Australia
| | - William H Morgan
- Center for Ophthalmology and Visual Science, Lions Eye Institute, University of Western Australia, Nedlands, Western Australia, Australia.,Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia
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Morgan WH, Quill B, Cringle SJ, House PH, Yu DY. Long-Term Results Using Gelatin Microfistulae Implantation without Antimetabolite. Ophthalmology 2018; 125:1828-1829. [PMID: 29921455 DOI: 10.1016/j.ophtha.2018.05.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 05/17/2018] [Accepted: 05/24/2018] [Indexed: 10/28/2022] Open
Affiliation(s)
- William H Morgan
- Lions Eye Institute, University of Western Australia, Nedlands, Australia.
| | | | - Stephen J Cringle
- Lions Eye Institute, University of Western Australia, Nedlands, Australia
| | - Philip H House
- Lions Eye Institute, University of Western Australia, Nedlands, Australia
| | - Dao-Yi Yu
- Lions Eye Institute, University of Western Australia, Nedlands, Australia
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Morgan WH, House PH, Hazelton ML, Betz-Stablein BD, Chauhan BC, Viswanathan A, Yu DY. Intraocular Pressure Reduction Is Associated with Reduced Venous Pulsation Pressure. PLoS One 2016; 11:e0147915. [PMID: 26824849 PMCID: PMC4732770 DOI: 10.1371/journal.pone.0147915] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 01/10/2016] [Indexed: 11/24/2022] Open
Abstract
Purpose To explore whether alterations in intraocular pressure (IOP) affect vein pulsation properties using ophthalmodynamometric measures of vein pulsation pressure. Patients and Methods Glaucoma patients had two retinal vein pulsation pressure (VPP) measurements from upper and lower hemiveins performed by ophthalmodynamometry at least 3 months apart. All subjects had VPP and IOP recorded at two visits, with standard automated perimetry, central corneal thickness (CCT) recorded at the initial visit. Where venous pulsation was spontaneous ophthalmodynamometry could not be performed and VPP was considered equal to IOP. Change in VPP was calculated and binarized with reduction in pressure scored 1 and no change or increase scored as 0. Data analysis used a mixed logistic regression model with change in VPP as response variable and change in IOP, visual field loss (mean deviation), CCT and time interval as explanatory variables. Results 31 subjects (20 females) with mean age 60 years (sd 11) were examined with change in VPP being significantly associated with change in IOP (odds ratio 1.6/mmHg, 95% CI 1.2 to 2.1 in the glaucoma patients but not suspect patients (p = 0.0005). Conclusion Change in VPP is strongly associated with change in IOP such that a reduced intraocular pressure is associated with a subsequent reduction in VPP. This indicates that reduced IOP alters some retinal vein properties however the nature and time course of these changes is not known.
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Affiliation(s)
- William H. Morgan
- Lions Eye Institute, University of Western Australia, Nedlands, Australia
- * E-mail:
| | - Philip H. House
- Lions Eye Institute, University of Western Australia, Nedlands, Australia
| | - Martin L. Hazelton
- Statistics and Bioinformatics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Brigid D. Betz-Stablein
- Statistics and Bioinformatics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Balwantray C. Chauhan
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | - Dao-Yi Yu
- Lions Eye Institute, University of Western Australia, Nedlands, Australia
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Morgan WH, Balaratnasingam C, Lind CRP, Colley S, Kang MH, House PH, Yu DY. Cerebrospinal fluid pressure and the eye. Br J Ophthalmol 2015; 100:71-7. [DOI: 10.1136/bjophthalmol-2015-306705] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/22/2015] [Indexed: 11/04/2022]
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Morgan WH, Hazelton ML, Betz-Stablein BD, Yu DY, Lind CRP, Ravichandran V, House PH. Photoplethysmographic measurement of various retinal vascular pulsation parameters and measurement of the venous phase delay. Invest Ophthalmol Vis Sci 2014; 55:5998-6006. [PMID: 25183767 DOI: 10.1167/iovs.14-15104] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Retinal vein pulsation properties are altered by glaucoma, intracranial pressure (ICP) changes, and retinal venous occlusion, but measurements are limited to threshold measures or manual observation from video frames. We developed an objective retinal vessel pulsation measurement technique, assessed its repeatability, and used it to determine the phase relations between retinal arteries and veins. METHODS Twenty-three eyes of 20 glaucoma patients had video photograph recordings from their optic nerve and peripapillary retina. A modified photoplethysmographic system using video recordings taken through an ophthalmodynamometer and timed to the cardiac cycle was used. Aligned video frames of vessel segments were analyzed for blood column light absorbance, and waveform analysis was applied. Coefficient of variation (COV) was calculated from data series using recordings taken within ±1 unit ophthalmodynamometric force of each other. The time in cardiac cycles and seconds of the peak (dilation) and trough (constriction) points of the retinal arterial and vein pulse waveforms were measured. RESULTS Mean vein peak time COV was 3.4%, and arterial peak time COV was 4.4%. Lower vein peak occurred at 0.044 cardiac cycles (0.040 seconds) after the arterial peak (P = 0.0001), with upper vein peak an insignificant 0.019 cardiac cycles later. No difference in COV for any parameter was found between upper or lower hemiveins. Mean vein amplitude COV was 12.6%, and mean downslope COV was 17.7%. CONCLUSIONS This technique demonstrates a small retinal venous phase lag behind arterial pulse. It is objective and applicable to any eye with clear ocular media and has moderate to high reproducibility. ( http://www.anzctr.org.au number, ACTRN12608000274370.).
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Affiliation(s)
- William H Morgan
- Lions Eye Institute, University of Western Australia, Nedlands, Western Australia, Australia
| | - Martin L Hazelton
- Statistics and Bioinformatics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Brigid D Betz-Stablein
- Statistics and Bioinformatics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Dao-Yi Yu
- Lions Eye Institute, University of Western Australia, Nedlands, Western Australia, Australia
| | - Christopher R P Lind
- Neurofinity, School of Surgery, University of Western Australia, Nedlands, Western Australia, Australia
| | - Vignesh Ravichandran
- Lions Eye Institute, University of Western Australia, Nedlands, Western Australia, Australia Neurofinity, School of Surgery, University of Western Australia, Nedlands, Western Australia, Australia
| | - Philip H House
- Lions Eye Institute, University of Western Australia, Nedlands, Western Australia, Australia
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Betz-Stablein BD, Morgan WH, House PH, Hazelton ML. Spatial Modeling of Visual Field Data for Assessing Glaucoma Progression. ACTA ACUST UNITED AC 2013; 54:1544-53. [DOI: 10.1167/iovs.12-11226] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Brigid D. Betz-Stablein
- From the Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand; and the
| | - William H. Morgan
- Lions Eye Institute, University of Western Australia, Perth, Australia
| | - Philip H. House
- Lions Eye Institute, University of Western Australia, Perth, Australia
| | - Martin L. Hazelton
- From the Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand; and the
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Turner AW, House PH. The rising tide of diabetic retinopathy in indigenous Australians. Clin Exp Ophthalmol 2011; 39:483-4. [DOI: 10.1111/j.1442-9071.2011.02631.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Morgan WH, Hazelton ML, Balaratnasingamm C, Chan H, House PH, Barry CJ, Cringle SJ, Yu DY. The association between retinal vein ophthalmodynamometric force change and optic disc excavation. Br J Ophthalmol 2008; 93:594-6. [PMID: 19098037 DOI: 10.1136/bjo.2008.149963] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM Retinal vein ophthalmodynamometric force (ODF) is predictive of future optic disc excavation in glaucoma, but it is not known if variation in ODF affects prognosis. We aimed to assess whether a change in ODF provides additional prognostic information. METHODS 135 eyes of 75 patients with glaucoma or being glaucoma suspects had intraocular pressure (IOP), visual fields, stereo optic disc photography and ODF measured on an initial visit and a subsequent visit at mean 82 (SD 7.3) months later. Corneal thickness and blood pressure were recorded on the latter visit. When venous pulsation was spontaneous, the ODF was recorded as 0 g. Change in ODF was calculated. Flicker stereochronoscopy was used to determine the occurrence of optic disc excavation, which was modelled against the measured variables using multiple mixed effects logistic regression. RESULTS Change in ODF (p = 0.046) was associated with increased excavation. Average IOP (p = 0.66) and other variables were not associated. Odds ratio for increased optic disc excavation of 1.045 per gram ODF change (95% CI 1.001 to 1.090) was calculated. CONCLUSION Change in retinal vein ODF may provide additional information to assist with glaucoma prognostication and implies a significant relationship between venous change and glaucoma patho-physiology.
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Affiliation(s)
- W H Morgan
- Department of Physiology and Pharmacology, Lions Eye Institute, Nedlands, Western Australia, Australia.
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Abstract
PURPOSE To investigate the properties of the visual field of high-pass resolution perimetry in normal subjects. METHODS Four centers collected normative data for high-pass resolution perimetry. In two of the centers the subjects were stratified by age. One eye was tested per subject using high-pass resolution perimetry (Ophthimus). We tested 640 normal subjects and describe their visual field results by test location. We also analyzed the data by concentric zone, age, and by testing center. RESULTS The individual test location averages confirmed a reduction in resolution with eccentricity. Resolution thresholds increased with age by 0.025 dB per year (P < 0.001). The mean ring size increased by about 1 dB from age 20 to 70. Among centers there were significant differences in the means and the change in threshold with age (P = 0.009). CONCLUSION The normal visual field of high-pass resolution perimetry is characterized by an increase in threshold with eccentricity. We found significant differences among the centers that were likely due to multiple factors including differences in subject selection criteria. Whether such differences occur with other perimetric techniques is unknown.
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Affiliation(s)
- Michael Wall
- Department of Neurology, University of Iowa, Iowa City, Iowa 52242, USA.
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Eikelboom RH, Yogesan K, Barry CJ, Constable IJ, Tay-Kearney ML, Jitskaia L, House PH. Methods and limits of digital image compression of retinal images for telemedicine. Invest Ophthalmol Vis Sci 2000; 41:1916-24. [PMID: 10845617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
PURPOSE To investigate image compression of digital retinal images and the effect of various levels of compression on the quality of the images. METHODS JPEG (Joint Photographic Experts Group) and Wavelet image compression techniques were applied in five different levels to 11 eyes with subtle retinal abnormalities and to 4 normal eyes. Image quality was assessed by four different methods: calculation of the root mean square (RMS) error between the original and compressed image, determining the level of arteriole branching, identification of retinal abnormalities by experienced observers, and a subjective assessment of overall image quality. To verify the techniques used and findings, a second set of retinal images was assessed by calculation of RMS error and overall image quality. RESULTS Plots and tabulations of the data as a function of the final image size showed that when the original image size of 1.5 MB was reduced to 29 KB using JPEG compression, there was no serious degradation in quality. The smallest Wavelet compressed images in this study (15 KB) were generally still of acceptable quality. CONCLUSIONS For situations where digital image transmission time and costs should be minimized, Wavelet image compression to 15 KB is recommended, although there is a slight cost of computational time. Where computational time should be minimized, and to remain compatible with other imaging systems, the use of JPEG compression to 29 KB is an excellent alternative.
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Affiliation(s)
- R H Eikelboom
- Lions Eye Institute, Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands.
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Chauhan BC, House PH, McCormick TA, LeBlanc RP. Comparison of conventional and high-pass resolution perimetry in a prospective study of patients with glaucoma and healthy controls. Arch Ophthalmol 1999; 117:24-33. [PMID: 9930157 DOI: 10.1001/archopht.117.1.24] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To determine whether high-pass resolution perimetry detected glaucomatous visual field progression earlier than conventional perimetry. METHODS In a prospective longitudinal study, we observed 113 patients with open-angle glaucoma and with early to moderate visual field damage and 119 healthy control subjects. Each subject underwent testing at 6-month intervals using conventional and high-pass resolution perimetry (program 30-2 of the Humphrey Field Analyzer [Humphrey Instruments, Inc, San Leandro, Calif] and the Ring program of the Ophthimus perimeter [Hi-Tech Vision, Göteborg, Sweden], respectively). Our predetermined criterion for progression with conventional perimetry was the presence of at least 4 overlapping nonedge locations outside the fifth percentile for test-retest variability of threshold deviations (defined by the Glaucoma Change Probability Analysis of the Statpac 2 program) in 2 of 3 consecutive visual fields. We employed the identical criterion for progression with high-pass resolution perimetry using our own test-retest variability data. We repeated this procedure in the controls to measure the false-positive rate of progression. RESULTS Patients were observed for a median of 4.5 years and 11 examinations with each technique. Fifty-seven patients (50.4%) did not show progression with either technique. Twenty-four patients (21.2%) showed progression with high-pass resolution perimetry alone, whereas 6 (5.3%) showed progression with conventional perimetry alone. Of the remaining 26 patients (23.0%) who showed progression with both techniques, 14 (54%) showed progression with high-pass resolution perimetry first (median, 12 months earlier); 5 (19%), with conventional perimetry first (median, 6 months earlier); and 7 (27%), with both techniques at the same time. Controls were observed for a median of 5 years and 11 examinations with each technique. One control (0.8%) showed progression with high-pass resolution perimetry. CONCLUSIONS Our results suggest that high-pass resolution perimetry detects glaucomatous visual field progression earlier than conventional perimetry in most patients with progression.
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Affiliation(s)
- B C Chauhan
- Department of Ophthalmology, Dalhousie University, Halifax, Nova Scotia.
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Yogesan K, Barry CJ, Jitskaia L, Eikelboom RH, Morgan WH, House PH, van Saarloos PP. Software for 3-D visualization/analysis of optic-disc images. IEEE Eng Med Biol Mag 1999; 18:43-9. [PMID: 9934599 DOI: 10.1109/51.740963] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- K Yogesan
- Centre for Ophthalmology and Visual Science, Lions Eye Institute, University of Western Australia.
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Morgan WH, Yu DY, Alder VA, Cringle SJ, Cooper RL, House PH, Constable IJ. The correlation between cerebrospinal fluid pressure and retrolaminar tissue pressure. Invest Ophthalmol Vis Sci 1998; 39:1419-28. [PMID: 9660490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
PURPOSE To measure the effects of cerebrospinal fluid pressure (CSFp) on retrolaminar tissue pressure (RLTp) and the translaminar pressure gradient (TLPG), particularly at low CSFp, which is the normal situation in erect posture. METHODS Micropipettes coupled to a servonull pressure system were passed into eyes of anesthetized dogs to the optic disc and advanced in steps through the lamina cribrosa to the optic nerve subarachnoid space (ONSAS), while pressure measurements were taken. Cerebrospinal fluid pressure and intraocular pressure (IOP) were monitored and controlled. The TLPG was measured at varying IOPs and CSFps. The RLTp and ONSAS pressure (ONSASp) were measured at varying CSFps. In separate experiments, the optic nerve dura was incised, and pressure measurements were taken across the pia mater. RESULTS The TLPG was strongly correlated to the difference between IOP and CSFp (r=0.93; n=18) when CSFp was more than zero. Mean RLTp was 3.7+/-0.2 mm Hg (SEM; n=15) when CSFp was 0 mm Hg. The ONSASp and RLTp were largely dependent on the presence of CSFp higher than break point pressures of -0.5 mm Hg and 1.33 mm Hg, respectively. However, below these break points, RLTp (slope 0.07) and ONSASp (slope 0.18) were little influenced by CSFp. Separate measurements across the pia mater revealed that 95% of the pressure drop occurred within 100 microm of the pial surface. CONCLUSIONS The TLPG and RLTp are dependent on CSFp when CSFp is more than -0.5 mm Hg. Below this level, there is no hydrostatic continuity between the intracranial and optic nerve subarachnoid space. In this range, RLTp is stable and is little influenced by CSFp changes.
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Affiliation(s)
- W H Morgan
- The Lions Eye Institute, Centre for Ophthalmology and Visual Science, University of Western Australia, Nedlands, Australia
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Barry CJ, Yogesan K, Jitskaia L, Morgan WH, House PH, Eikelboom RH. A personal computer-based method of stereo chronometry for measuring neuroretinal rim width: a pilot study. Aust N Z J Ophthalmol 1998; 26 Suppl 1:S22-5. [PMID: 9685014 DOI: 10.1111/j.1442-9071.1998.tb01363.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE Quantifying neuroretinal rim width from optic disc photographs to study glaucomatous progression requires precise, reproducible measurements. We explored the use of a personal computer with three-dimensional capabilities to enhance measurement accuracy and repeatability. METHODS A simultaneous stereo retinal camera was used to serially photograph the optic discs often glaucomatous eyes with a mean interval of 18 months. The neuroretinal rims were qualitatively assessed as either stable (five) or narrowing (five). The images were measured using software written for an IBM compatible personal computer The measurements were compared from the earliest to the most recent image and the five narrowed rims were correctly identified. RESULTS This simple, low-cost method allowed both three-dimensional viewing and measurement of the optic disc rim from simultaneous stereo images. CONCLUSIONS This method is, potentially, more sensitive in identifying glaucomatous rim changes than conventional, subjective image comparison techniques.
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Affiliation(s)
- C J Barry
- Centre for Ophthalmology and Visual Science, Lions Eye Institute, Perth, Western Australia, Australia.
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Chauhan BC, House PH. Estimating thresholds in conventional and high-pass resolution perimetry using computer simulation. J Glaucoma 1994; 3:132-139. [PMID: 19920566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
High-pass resolution perimetry is a new technique that uses a vanishing optotype as the test stimulus. This type of stimulus is thought to produce steeper frequency-of-seeing curves than the stimulus used in conventional automated perimetry, resulting in a lower variability in threshold estimates. The purpose of this study was to compare the stimulus properties in both conventional and high-pass resolution perimetry in computer simulation experiments. The computer model contained stimulus-response data sets obtained from frequency-of-seeing experiments in 11 normal subjects tested with each perimetric technique at four retinal locations [(0 degrees , 30 degrees ), (0 degrees , 15 degrees ), (0 degrees , - 15 degrees ), and (0 degrees , - 30 degrees )]. We programmed eight staircase procedures varying from a coarse one with one reversal to an elaborate procedure with four reversals to look at the relationship between accuracy (the difference between the estimated and actual threshold) and efficiency (number of presentations required for estimate) with each technique. Threshold estimates were made 100 times for each location, strategy, perimetric technique, and subject. Our results showed that an increase in accuracy was always coupled with a decrease in efficiency and that the relationship between these two parameters was similar between the two techniques. Some evidence, however, is presented to show that compared to conventional perimetry relatively simple staircase procedures may be used with high-pass resolution perimetry to attain threshold estimates of similar accuracy.
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Affiliation(s)
- B C Chauhan
- Department of Ophthalmology, Dalhouste University, Halifax, N.S. Canada, and *Department of Ophthalmology, Royal Perth Hospital, Perth. W.A., Australia
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Abstract
The sensitivity of the visual field declines with age. The density of the crystalline lens increases with age and may be partly responsible for the decline in sensitivity. To determine whether lens opacity influences the mean threshold of the visual field, 82 normal subjects were enrolled. All had their lens opacity measured with the Interzeag Lens Opacity Meter 701 and the visual field assessed with the Ring Resolution Perimeter. Lens opacity was highly correlated with age, while mean visual field threshold was also correlated with age but showed much greater variation. Multiple regression failed to show any influence of lens opacity measurements on the mean field threshold after age had been accounted for.
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Affiliation(s)
- P H House
- Department of Ophthalmology, University of British Colombia, Vancouver, Canada
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Wall M, Conway MD, House PH, Allely R. Evaluation of sensitivity and specificity of spatial resolution and Humphrey automated perimetry in pseudotumor cerebri patients and normal subjects. Invest Ophthalmol Vis Sci 1991; 32:3306-12. [PMID: 1748561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
To determine the sensitivity and specificity of high-pass resolution perimetry ("ring test"), 18 patients with pseudotumor cerebri (PTC) and 18 age-matched controls were examined with the Humphrey program 24-2 and the ring test. Goldmann perimetry also was done to determine if defects found with the ring test were present with another method. Testing with Humphrey perimetry revealed defects in 15 PTC patients and four control subjects; with the ring test, 13 PTC patients and two control subjects had abnormalities. The disturbed areas in the control subjects with both automated tests were not reproducible. Humphrey perimetry had a sensitivity of 83% and the ring test, 72%. The specificities were Humphrey perimetry, 78% and the ring test, 89%. These differences were not statistically significant. Qualitative assessment of the presence and extent of damage using the pointwise probability plots and graphically displayed raw data showed good correlation of the tests in 11 of the 18 patients. The lack of correlation in four of the patients was caused by the presence of a generalized depression or a peripheral contraction on the Humphrey test; this defect, not present on retesting, may have been related to fatigue or poor motivation. The ring test is a sensitive and specific perimetric technique in patients with PTC.
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Affiliation(s)
- M Wall
- Department of Ophthalmology, Tulane University School of Medicine, New Orleans, Louisiana 70112
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Lachenmayr BJ, Drance SM, Chauhan BC, House PH, Lalani S. Diffuse and localized glaucomatous field loss in light-sense, flicker and resolution perimetry. Graefes Arch Clin Exp Ophthalmol 1991; 229:267-73. [PMID: 1869065 DOI: 10.1007/bf00167882] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A total of 75 eyes in 75 patients with different types of glaucoma (21 eyes with low-tension glaucoma, 49 with primary open-angle glaucoma and 5 with pigmentary glaucoma) were examined by automated light-sense, flicker and resolution perimetry. All fields were classified in a masked fashion as being "normal" (N) or as having "diffuse loss" (D), "localized loss" (L) or "diffuse plus localized loss" (DL). The frequency distributions for the various field loss categories were plotted against the highest intraocular pressure ever reported in the patients' records. The frequency distribution for the purely localized defects showed a peak at 20 mmHg and were markedly skewed to low pressure values, whereas those for both diffuse plus localized damage and purely diffuse loss peaked at about 30 mmHg. The data suggest that diffuse field loss may be an indicator of pressure-induced damage.
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Affiliation(s)
- B J Lachenmayr
- Department of Ophthalmology, University of British Columbia, Vancouver, Canada
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Abstract
The authors studied the effects of threshold, age, and visual field location on intratest variability in 11 normal subjects between the ages of 15 and 50 years (mean, 35.37 years). The subjects were tested with a conventional manual (Tübinger) perimeter and a high-pass resolution (Ring) perimeter at the following locations: (0 degrees, 30 degrees), (0 degrees, 15 degrees), (0 degrees, -15 degrees), and (0 degrees, -30 degrees). Frequency-of-seeing curves were constructed to obtain accurate estimates of threshold and intratest variability. Although location did not have a significant effect on intratest variability in conventional perimetry, intratest variability increased with threshold (P = 0.031) and age (P = 0.012). The results with resolution perimetry contrasted sharply and showed that neither threshold, age, nor location had a significant effect on intratest variability (P greater than 0.225). Although the thresholds with the two types of perimetry were correlated, intratest variability was not. These results show that resolution perimetry may be able to bypass some of the limitations encountered in obtaining thresholds with conventional perimetry, thereby providing more reliable information.
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Affiliation(s)
- B C Chauhan
- Department of Ophthalmology, University of British Columbia, Vancouver, Canada
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20
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Abstract
To determine the effectiveness of various combinations of lidocaine, epinephrine, and hyaluronidase with bupivacaine, a prospective, randomized, masked study on 117 patients having cataract extraction under local anesthesia was undertaken. All patients were given a 9 ml peribulbar block by one surgeon, and a graded assessment of analgesia and akinesia was made in a masked fashion one hour later. A mixture using all these agents gave significantly better results than any of the combinations (P = .001). No single agent was shown to be the major determinant of effectiveness. The result suggests a synergistic effect found only when all the agents are combined.
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Affiliation(s)
- P H House
- Department of Ophthalmology, University of British Columbia, Vancouver, Canada
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21
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Hollands RH, Drance SM, House PH, Schulzer M. Control of intraocular pressure after cataract extraction. Can J Ophthalmol 1990; 25:128-32. [PMID: 2361193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We carried out a prospective randomized study in 172 patients undergoing cataract extraction and lens implantation to compare the effects of pilocarpine gel, 1% acetylcholine chloride and 0.01% carbachol on early postoperative intraocular pressure (IOP), to determine the effect of sodium hyaluronate on IOP and to compare the effects of 0.01% carbachol (full-strength) and 0.005% carbachol (half-strength) on IOP, pupil size and brow ache. IOP was measured 3, 6, 9 and 24 hours after surgery, and in the full- and half-strength carbachol groups pupil size and subjective complaints of brow ache were recorded. The mean IOP 3 and 6 hours after surgery was significantly lower in all the treatment groups than in the control groups. At 9 and 24 hours it was significantly lower only in the carbachol groups. The use of sodium hyaluronate was not found to affect the postoperative IOP. There was no difference in postoperative IOP or miosis between the full- and half-strength carbachol groups, but fewer patients in the half-strength group than in the full-strength group reported brow ache at 9 and 24 hours. The results suggest that carbachol is the most effective agent currently available for the management of IOP after cataract extraction.
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Affiliation(s)
- R H Hollands
- Department of Ophthalmology, University of British Columbia, Vancouver
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22
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Abstract
To determine the effect of optically induced blur on the visual field measured with high pass spatially filtered targets, 10 normal subjects had field examinations with 0 diopter + 1.00 diopter or + 2.00 diopter of overcorrection in the cyclopleged state. All subjects showed a significant loss of sensitivity when defocussed, but not with pupil dilation. Mean thresholds for the central field rose from 4.79 +/- 0.68 dB (Mean +/- SD) with the image focussed and pupil dilated, to 7.16 +/- 0.72 dB with two diopters of image blur (P less than 0.001). The effects of defocussing did not differ significantly between the central and peripheral parts of the field. The great influence of defocussing the image on sensitivity should be considered during clinical perimetry as the 2.37 dB decline shown would place the group's mean sensitivity below the fifth percentile for age corrected normals.
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Affiliation(s)
- P H House
- Department of Ophthalmology, University of British Columbia, Vancouver, Canada
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23
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Affiliation(s)
- P H House
- Department of Ophthalmology, University of British Columbia, Vancouver, Canada
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24
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25
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26
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House PH. Postoperative astigmatism using the McIntyre needle. Ophthalmic Surg 1987; 18:654-7. [PMID: 3684182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We performed 30 consecutive cataract extractions using two different needle types to assess postoperative astigmatism. In each case, we used a standard corneal incision followed by an extracapsular cataract extraction and the insertion of a posterior chamber intraocular lens. The incisions in group A were closed with the McIntyre needle and in group B with a standard curve needle. We compared the postoperative astigmatism in each group with sutures in at 3 weeks, and when removed selectively by 12 weeks, and found no significant difference.
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Affiliation(s)
- P H House
- Department of Ophthalmology, Fremantle Hospital, Australia
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27
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House PH. Ocular leprosy: a case report and discussion of the pathology. Aust N Z J Ophthalmol 1986; 14:59-63. [PMID: 3964481 DOI: 10.1111/j.1442-9071.1986.tb00009.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Although leprosy is considered rare in Australia outside the Northern Aboriginal population, its presence within Indian and Southeast Asian migrant groups must be considered. A case of ocular leprosy is presented in which the definitive diagnosis was delayed because lid changes had been diagnosed as senile ectropion. The pathology of ocular leprosy is discussed, together with relevant therapeutic considerations.
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