Search

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., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Retinal vein pulsation is often absent in glaucoma, but can be induced by applying a graded ophthalmodynamometric force (ODF) to the eye, which is elevated in glaucoma., Aim: To assess whether ODF has a predictive value in determining glaucoma progression., Methods: 75 patients with glaucoma and suspected glaucoma were examined prospectively in 1996, and then re-examined at a mean of 82 months later. All subjects had intraocular pressure, visual fields, stereo optic disc photography and ODF measured on their initial visit. When venous pulsation was spontaneous, the ODF was said to be 0 g. At re-examination, central corneal thickness and blood pressure were also measured. Initial and subsequent optic disc photographs were compared and graded into those that had increased excavation and those that had remained stable. The relationship between increased excavation (recorded as a binary response) and the measured variables was modelled using a multiple mixed effects logistic regression., Results: ODF at the initial visit was strongly predictive of increased excavation (p = 0.004, odds ratio 1.16/g, range 0-60 g), with greater predictive value in women than in men (p = 0.004). Visual field mean deviation was predictive of increased excavation (p = 0.044), as was optic nerve haemorrhage in association with older age (p = 0.038). Central corneal thickness was not significantly predictive of increased excavation (p = 0.074) after having adjusted for other variables., Conclusion: ODF measurement seems to be strongly predictive of the patient's risk for increased optic disc excavation. This suggests that ODF measurement may have predictive value in assessing the likelihood of glaucoma progression.

Photographs of the optic nerve head (optic disc) in the eye are used for the clinical assessment of the disease glaucoma. These images are usually subjectively assessed by a clinician. A case of Sturge-Weber Syndrome which includes glaucoma as a symptom, is presented here. Narrowing of the rim of the optic disc was measured using custom-made measurement software confirming glaucomatous progression. To maximize the information obtained from optic disc images, low cost software can assist with quantifying disc parameters aiding clinical interpretation.

The neuroretinal rims of a set of glaucoma patients were measured using digitized stereo photographs, to determine the reproducibility of computerized stereo measurements of the neuroretinal rim. Each rim was measured five times at 18 locations, with measurement error (ME) defined as the mean of standard deviations of each set of measurements. The following ME were determined: (i) inter-sessional variability (n = 27 right and 24 left eyes, at t1 and t2); (ii) inter-assessor variability (n = 9, 2 assessors); and (iii) variability after colour adjustment algorithms were applied (n = 15). The results were as follows: (i) inter-sessional variability was 3.41+/-1.08 for t1 and 3.22+/-0.84 for t2; (ii) there was a significant difference between the two assessors, although the ME was still low; and (iii) there was no significant differences between the ME of unadjusted and adjusted images. With a measurement error of up to 11% of rim width, these results show that lowcost rim measurements can be made using PC-based software.

Aim: To assess serial, simultaneous stereo optic disc images by four methods for glaucomatous progression., Methods: Using varying techniques, two ophthalmologists assessed serial optic disc images of 52 eyes from 27 patients with a mean duration between images of 18 months. The neuroretinal rim width was qualitatively assessed by four assessment methods and compared with quantitative rim measurements made using PC based software., Results: The highest sensitivity of 83% was achieved using computerised stereo chronoscopy., Conclusion: Stereo chronoscopy improved the detection of subtle optic disc changes when compared with simpler assessment techniques.

Purpose: The digital images of the optic disk from a portable fundus camera were evaluated for suitability in teleophthalmologic screening for glaucoma., Methods: Fifty-one eyes of 27 consecutive patients from our glaucoma clinic were dilated and photographed with a Zeiss FF retinal camera (Carl Zeiss, Oberkochen, Germany) and a portable Nidek NM-100 (Nidek, Tokyo, Japan) fundus camera. Digital images from the portable fundus camera were digitized, compressed and stored in a Fujix DF-10M (Fuji, Tokyo, Japan) digitizer. Lossy compressed digital images and photographs from the Zeiss camera were presented separately in random order to three ophthalmologists for estimation of vertical cup:disk ratios (VCDR) and to evaluate image quality as good, acceptable, or unacceptable for screening glaucoma. Gold standard VCDRs were measured from monoscopic photographic slides obtained using the Zeiss camera by a fourth ophthalmologist., Results: Measurement of agreement (Kappa values) between estimated VCDR of digital images and photographs by the three ophthalmologists were 0.52, 0.38, and 0.50 respectively. Agreement between gold standard and estimated VCDR from photographs were 0.87, 0.45, and 0.84 respectively (specificity between 79% and 97%, sensitivity between 70% and 95%). Kappa values obtained between gold standard and estimated VCDR from digital images were 0.52, 0.49, and 0.49, respectively (specificity between 68% and 79%, sensitivity between 67% and 87%., Conclusion: Moderate to good agreement indicates that the digital images from the portable fundus camera may be suitable for optic disk assessment in the current configuration. This easy to use Nidek hand-held camera could be a viable instrument for teleophthalmology if a better digitizing system is incorporated to improve the quality of the images.

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.

Purpose: To retrospectively examine the optic disc photographs of a glaucoma population for optic disc haemorrhages, vascular occlusions and vascular abnormalities., Methods: The optic disc photographs of 906 eyes of glaucoma and suspect glaucoma patients were examined. Optic disc photographs were taken annually, where possible, with the follow-up period varying between 1 and 14 years duration (mean, 2.89). Glaucoma patients are regularly reviewed every 4-6 months and glaucoma suspects every 1-2 years, depending on the ophthalmologist. Low-tension glaucoma patients were reviewed more frequently (mean, every 2.6 months). The results of the findings were compared to a control group of 39 subjects with a mean follow-up period of 7 years, using Fisher's exact test., Results: It was found that during the period under review, 7.4% (n = 67) of eyes had optic disc haemorrhages. The highest frequency of optic disc haemorrhages (37.5%) was found in the low tension glaucoma group (P = 0.0001) followed by 11% of primary open-angle glaucoma eyes (P = 0.03). In the normal group there were three eyes with optic disc haemorrhages and one with a disc collateral, which constitutes 5.1% vascular changes in this sub-group. Of the study eyes 2.8% had central retinal vein occlusions, 1.3% branch vein occlusion, 1.2% disc vessel abnormalities (loops) and 1.1% disc collaterals. Discrete nerve fibre layer haemorrhages and microaneurysms were found in 0.8% and 1.8% of eyes, respectively., Conclusions: A total of 16.8% of the eyes observed in this study had either disc haemorrhages or vascular changes. The underlying trend of vascular and haemorrhagic changes in glaucoma are demonstrated in this sample, which is in general agreement with previous studies. The high percentage of optic disc haemorrhages in low tension glaucoma is highlighted. The presence of microaneurysms and nerve fibre layer haemorrhages is interesting but of unknown significance.

The red-free negatives of 53 right eyes (30 normal eyes and 23 glaucomatous eyes) and 51 left eyes (32 normal eyes and 19 glaucomatous eyes) were analysed using two different image densitometry techniques. The first technique measured the density from rectangular sample areas, while the second measured density from sector-shaped sample areas which more closely follow the course of the nerve fibres in the retina. Indices which measured the deviation of the data from a clinically determined normal 'gold standard' were calculated, and were used to determine the optimum sensitivity and specificity in separating normal from glaucomatous eyes. There is a significant difference between the data from the normal and glaucomatous groups of eyes, when measured from the sector sample areas. The relative efficacy of this technique is also shown by the improved values of sensitivity (from 42%-70% to 70%-91%), although specificity remained fairly constant (from 66%-83% to 62%-88%).

Objective: To compare image measurements of the retina produced by scanning laser ophthalmoscopy with those from red-free photographs (RFP) of the nerve fibre layer., Subjects: The left eyes of 23 subjects (10 normal, 7 glaucoma suspect and 6 glaucomatous) were included in this study., Method: All the eyes were photographed using standard red-free photography, and images of the retina were digitised directly from the SLO., Results: The correlation coefficient for all except three subjects was > 0.45, and the probability (p) that R = 0 was < 0.05 in all but 5 eyes., Conclusions: The data indicate that variations in retinal surface reflectivity as measured by the SLO are similar to those recorded on negative film during RFP. This further suggests that the SLO can be useful for making objective measurements of the RNFL, without the intermediate and variable steps of photography.

Retinal nerve fibre layer (RNFL) photography is an established and integral tool in the management of ocular hypertensives and glaucoma suspects, and in assessing the management of glaucoma in an ophthalmic practice. When RNFL negatives are viewed for analysis, high-contrast negatives yield the most information. When positive prints are subsequently requested, the RNFL negatives are difficult to print. The use of an unsharp mask facilitates the transfer of all the high-contrast negative density range to the print. The use of an unsharp mask has been simplified so that it is quick and efficient and can be adapted for high-contrast negatives other than RNFL images.