To date, there has been a lack of evidence-based guidance on the frequency of visual field examinations required to identify clinically meaningful rates of change in glaucoma. The objective of this ...perspective is to provide practical recommendations for this purpose. The primary emphasis is on the period of time and number of examinations required to measure various rates of change in mean deviation (MD) with adequate statistical power. Empirical data were used to obtain variability estimates of MD while statistical modelling techniques derived the required time periods to detect change with various degrees of visual field variability. We provide the frequency of examinations per year required to detect different amounts of change in 2, 3 and 5 years. For instance, three examinations per year are required to identify an overall change in MD of 4 dB over 2 years in a patient with average visual field variability. Recommendations on other issues such as examination type, strategy and quality are also made.
We compared the outcomes of perimetric and visual acuity tests in patients with diabetic retinopathy.
We examined 59 diabetic patients with different degrees of retinopathy using stereo fundus ...photography in accordance with the Early Treatment of Diabetic Retinopathy Study (ETDRS) and fluorescein angiography. Conventional white-on-white perimetry (WWP) and short wavelength automated perimetry (SWAP) were performed and analysed with reference to normal values. Visual acuity was measured with ETDRS charts.
Regression analysis revealed that visual acuity was significantly associated with increasing severity of retinopathy according to the ETDRS scale when visual acuity was estimated by counting logarithm of minimum angle of resolution (LogMar) scores, but not when visual acuity was measured by the conventional reading of the smallest line that could be seen. Visual acuity decreased by 0.02 LogMar per ETDRS step (p=0.03). The degree of visual field loss was significantly associated with increasing severity of retinopathy according to the ETDRS scale, perimetric sensitivity decreasing by 0.44 dB per ETDRS step (p=0.0001) using WWP, and by 0.40 dB per ETDRS step (p=0.04) with SWAP. The size of the area of the foveal avascular zone and adjacent perifoveal intercapillary areas (PIAs) also affected the central visual field as obtained both by WWP (-2.6 dB/mm2, p=0.03), and by SWAP (-7.9 dB/mm2, p=0.002), but did not affect visual acuity. The regression model fit for peripheral retinopathy according to the ETDRS scale was better using WWP than SWAP or visual acuity, while SWAP testing was superior to both WWP and visual acuity when measuring effects caused by enlarged foveal avascular zones and PIAs.
Perimetry can provide more useful information than visual acuity on functional loss in diabetic retinopathy, particularly when the perifoveal capillary network is damaged.
To compare the diagnostic accuracy of the Heidelberg Retina Tomograph's (HRT) Moorfields regression analysis (MRA) and glaucoma probability score (GPS) with that of subjective grading of optic disc ...photographs performed by ophthalmologists with varying experience of glaucoma and by ophthalmology residents.
Digitized disc photographs and HRT images from 97 glaucoma patients with visual field defects and 138 healthy individuals were classified as either within normal limits (WNL), borderline (BL), or outside normal limits (ONL). Sensitivity and specificity were compared for MRA, GPS, and the physicians. Analyses were also made according to disc size and for advanced visual field loss.
Forty-five physicians participated. When BL results were regarded as normal, sensitivity was significantly higher (P<5%) for both MRA and GPS compared with the average physician, 87%, 79%, and 62%, respectively. Specificity ranged from 86% for MRA to 97% for general ophthalmologists, but the differences were not significant. In eyes with small discs, sensitivity was 75% for MRA, 60% for the average doctor, and 25% for GPS; in eyes with large discs, sensitivity was 100% for both GPS and MRA, but only 68% for physicians.
Our results suggest that sensitivity of MRA is superior to that of the average physician, but not that of glaucoma experts. MRA correctly classified all eyes with advanced glaucoma and showed the best sensitivity in eyes with small optic discs.
This review aims to provide guidance in managing glaucoma patients more effectively. It focuses on the importance of detecting progression and measuring its rate within the management of primary ...open-angle glaucoma today. Recent findings strongly indicate that continued monitoring of visual fields (VFs) and reassessment of target intraocular pressures (IOPs) depending on VF progression rates are mandatory in the management of glaucoma.
Data on glaucoma progression from older as well as most recent literature findings are summarized in this article. In addition, the article elaborates on the scientific content from a series of lectures given by experts in the field during several international symposia on 'rate of progression' in 2008.
This review summarizes key findings on the natural history of glaucoma and known factors for disease progression. It highlights the visual function changes observed as glaucoma progresses and discusses disease impact on patients' quality of life. Findings support the need to obtain information on rate of progression and its importance for clinical management. Practical ways to measure rate of progression are given by new software options to help measure major parameters. Finally, on the basis of a patient's individual rate of progression therapeutic options are assessed, such as maximum medical therapy with fixed combinations.
Estimating a patient's individual rate of VF progression by using newly developed analyses will be helpful to forecast the potential future development of the glaucoma. An individualized treatment approach then requires that in patients in whom the risk of becoming visually impaired or blind during their lifetime is higher, a more intensive medical IOP-lowering therapy such as fixed combinations can be considered as treatment option.
Aims/hypothesis We examined to what extent visual acuity and perimetric sensitivity as measures of central and paracentral visual function would be useful for evaluating the presence and severity of ...diabetic macular oedema. Materials and methods We evaluated 59 eyes of 59 diabetic patients by identifying the presence (n=20) or absence (n=39) of macular oedema on stereo fundus photographs. The area of oedema and its distance to the centre of the macula were measured. Ischaemic macular damage was quantified by measuring the foveal avascular zone and adjacent perifoveolar intercapillary areas on fluorescein angiograms. Visual function was assessed by visual acuity charts and by short-wavelength perimetry and standard white-on-white perimetry of the central 10° field. Results Visual acuity did not differ between eyes with and without macular oedema. In eyes with oedema, visual acuity was correlated to the distance of the oedema from the centre of the macula (log of minimum angle of resolution {LogMar} score decreased by 0.15/mm; p=0.006) and to the thickness of the retina when the centre was affected (LogMar score decreased by 0.003/μm of thickness; p=0.0002). Multivariate analyses confirmed the results (R ²=0.46 and 0.77, respectively). Short-wavelength perimetry sensitivity was more depressed in eyes with oedema (p=0.033) but was not significantly associated with the presence of oedema after correction for macular ischaemic damage. There was no correlation between these field defects and the severity of oedema. Conclusions/interpretation Visual acuity was a useful measure of visual function in diabetic macular oedema involving the centre. Visual field defects were more common in eyes with macular oedema but reflected ischaemic damage of the macula rather than macular oedema itself.
To establish whether intraocular pressure (IOP) fluctuations contribute to the risk of developing glaucoma in patients with high-risk ocular hypertension.
Ninety patients included in the Malmö Ocular ...Hypertension Study were examined every 3 months with office-hours diurnal tension curves and computerised perimetry. Patients were followed up prospectively for 10 years or until glaucomatous visual field loss could be demonstrated. Poststudy data were included in the analyses, extending maximum follow-up to 17 years.
After 17 years, 37 patients had developed glaucomatous visual field defects. When applying univariate Cox regression analyses, mean IOP of all measurements during the prospective part of the study was a significant risk factor for developing glaucoma (95% confidence interval CI 1.08-1.39), while IOP fluctuations were almost significant (95% CI 0.98-1.93). When separating effects of mean IOP level and mean IOP fluctuation using Cox multiple regression analysis, only IOP level came out as significant (95% CI 1.09-1.38), and IOP fluctuations did not contribute to the risk (95% CI 0.80-1.60). IOP fluctuation depended linearly on IOP level (p<0.0001), i.e. IOP fluctuation was larger in eyes with higher IOP levels.
IOP fluctuations were not an independent risk factor for the incidence of glaucomatous visual field loss in subjects with ocular hypertension.
Increased intraocular pressure (IOP) has been shown to be one of the most important risk factors for developing glaucoma. Yet it has not been clearly demonstrated that IOP-lowering treatment can ...reduce the incidence of glaucoma damage in patients with ocular hypertension. The aim of the current paper was to report the results of a long-term study addressing this very problem.
We conducted a randomised, double-masked study comparing timolol and placebo treatment in 90 patients with ocular hypertension plus some additional risk factor. Patients were followed at 3-month intervals prospectively for 10 years or until glaucomatous field loss could be demonstrated with computerised perimetry. A post-study analysis was performed including all available data, thus extending maximum follow-up to 17 years.
After 5 years of follow-up eight patients in the placebo group and five patients in the timolol group had developed glaucomatous field loss (NS); the corresponding figures after 10 years were 15 patients in the placebo group and seven patients in the timolol group. Survival analysis showed a tendency but no statistically significant difference between treatment groups (P = 0.07). Study attrition was large. Eighteen patients in each group had developed glaucomatous field loss when also post-study data were included. IOP reduction was greater in eyes passing the 10-year visit without field loss (5.7 mmHg), than in those that reached an end-point (2.3 mmHg; P = 0.0002).
In this long-term study we found a tendency but failed to prove a beneficial effect of topical timolol treatment in patients with elevated IOP, normal visual fields and some additional risk factor. The intent-to-treat analysis showed no difference between treatment groups. The high attrition shows the difficulties associated with very long follow-up.
To report the change over time in intraocular pressure in patients treated with topical timolol or placebo.
Ninety patients with untreated ocular hypertension, defined as elevated intraocular ...pressure and normal visual fields, were randomly assigned to treatment and prospectively observed at 3-month intervals for up to 10 years in a double-masked fashion. The study end point was one eye showing reproducible glaucomatous field defects; patients were also withdrawn if one eye showed intraocular pressure of 35 mm Hg or higher. For each treatment group and visit, the mean and median of all intraocular pressure measurements were calculated. Medians were also calculated for the timolol group, assuming a worst-case scenario in which all patients who reached the end point, or intraocular pressure of 35 mm Hg or more, were assumed to show higher intraocular pressure than those remaining in the study. Distributions of slopes for intraocular pressure over time were compared between treatment groups.
Means and medians of follow-up intraocular pressure over time did not differ between timolol- and placebo-treated patients. This was also true when assuming a worst-case scenario. Slopes of intraocular pressure over time did not differ statistically between treatment groups.
In agreement with other masked and controlled studies and in conflict with uncontrolled ones, the present study did not demonstrate long-term drift of intraocular pressure in patients with ocular hypertension treated with topical timolol.
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