Illness perceptions in people newly diagnosed with glaucoma and ocular hypertension.

BACKGROUND/AIMS: To determine whether self-reported illness perceptions in newly diagnosed patients with primary open-angle glaucoma (POAG) and ocular hypertension (OHT) are more negative compared with peers who have lived with their diagnosis for more than 2 years. METHODS: A cross-sectional study of 58 newly diagnosed patients with POAG and OHT recruited at their first clinic visit. Electronic patient records were used to identify similar patients (n=58, related by age and severity of visual field loss) who had their diagnosis for >2 years. All participants completed the Brief Illness Perception Questionnaire (BIPQ), EQ5D general health measure and Type D Personality Scale (DS14). RESULTS: Average BIPQ scores were similar for people newly diagnosed with POAG and POAG diagnosed >2 years and were no different to newly diagnosed OHT and OHT diagnosed >2 years POAG (p=0.46). An analysis correcting for personality type (DS14) and general health (EQ5D) indicated newly diagnosed patients with POAG to have marginally better illness perceptions on individual BIPQ items quantifying impact on life in general, experience of symptoms and 'understanding' of their condition (all p<0.01). In contrast, patients with POAG with a diagnosis >2 years understood better their condition to be long-term (p<0.01). CONCLUSIONS: Some illness perceptions differed between newly diagnosed people and patients living with their diagnosis for >2 years. Illness perception for people with manifest glaucoma and at risk of glaucoma (OHT) were similar; the latter might benefit from an intervention at diagnosis that highlights the better prognosis for OHT compared with POAG.

Interobserver agreement using Goldmann applanation tonometry and dynamic contour tonometry: comparing ophthalmologists, nurses and technicians.

PURPOSE: To compare agreement between ophthalmologists and non-ophthalmologists (nurses and ophthalmic technicians) when measuring the intraocular pressure (IOP) using Goldmann applanation tonometry (GAT) and Pascal dynamic contour tonometry (DCT). METHODS: Patients attending for their routine glaucoma outpatient appointment were invited to participate. IOP was measured in one eye by either two ophthalmologists (observer group 1), two non-ophthalmologists (observer group 2) or one ophthalmologist and one non-ophthalmologist (observer group 3). All were experienced in using GAT and some experienced in using the DCT. The order of tonometer and staff was randomised. Agreement was calculated by Bland-Altman analysis, with the mean difference and 95% limits of agreement (LoA) of measurements calculated for each observer group. RESULTS: One hundred eyes were measured within each observer group. The mean difference (95% LoA) in IOP measurements were GAT: group 1=-0.20 (4.9) mm Hg, group 2=0.6 (5.4) mm Hg and group 3=0.0 (3.7) mm Hg; DCT: group 1=0.8 (7.7) mm Hg, group 2=0.3 (4.2) and group 3=0.0 (5.2) mm Hg. The DCT consistently over-read the GAT for all observer groups. DISCUSSION/CONCLUSIONS: Ophthalmologists show good levels of agreement with each other when using GAT, while technicians/nursing staff show better agreement when using the DCT. The DCT may be a better tonometer to use if permanently delegating IOP measurements to non-ophthalmologists, but measurements cannot be interchanged with the GAT.

Applanation tonometry: interobserver and prism agreement using the reusable Goldmann applanation prism and the Tonosafe disposable prism.

PURPOSE: To evaluate the levels of agreement between the standard reusable prism and a disposable prism, and to examine the agreement between ophthalmologists, nursing and technical staff when measuring intraocular pressure (IOP) using the Goldmann applanation tonometer. METHODS: Three hundred eyes of 300 patients were recruited. IOP measurements were made in a randomised order by three observer groups consisting of ophthalmologists and ophthalmic technicians/nurses taken from a pool of clinicians working within a busy outpatient clinic. Agreement was calculated by Bland-Altman analysis, showing the mean difference and 95% limits of agreement (LoA) of measurements. RESULTS: The mean difference between the reusable and disposable prism IOP measurements was <0.5 mm Hg. The LoA ranged from ±3.1 to ±4.9 mm Hg, depending on the observer group. The interobserver variability was <1 mm Hg across all observer groups; the LoA was slightly higher for observers using the reusable prism (range between ±4.3 and ±5.6 mm Hg) compared with using the disposable prism (range between ±3.7 and ±5.4 mm Hg) across observer groups. CONCLUSIONS: There is an acceptable agreement between IOP measurements made with the reusable Goldmann tonometer prism and the disposable Tonosafe prism. Interobserver variability in IOP measurements within an outpatient setting is larger than that found within a research setting, and may be of a level that impacts on clinical decision-making.

Relationship between visual field sensitivity and retinal nerve fiber layer thickness as measured by optical coherence tomography.

PURPOSE: To evaluate the strength and pattern of the relationship between visual field (VF) sensitivity and retinal nerve fiber layer (RNFL) thickness as measured by StratusOCT (Carl Zeiss Meditec, Inc., Dublin, CA). METHODS: Three hundred eleven subjects--45 normal, 102 with preperimetric glaucoma (PPG), and 164 with primary open-angle glaucoma (POAG)--were enrolled in this cross-sectional study. The relationship between RNFL thickness and VF sensitivity, expressed as mean deviation (MD) and mean sensitivity (MS), were evaluated with linear and nonlinear regression models, and the coefficient of determination (R(2)) was calculated. The association between RNFL/VF was described by bivariate Pearson correlation coefficients. RESULTS: The correlation of RNFL and the VF parameters MS and MD in normal and PPG eyes was not significant. In POAG eyes, RNFL and both MS (r = 0.733) and MD (r = 0.718) correlated significantly. Linear regression plots of MS or MD against RNFL thickness demonstrated a negligible degree of determination in normal (R(2) = 0.0378 and 0.0121, respectively) and PPG groups (R(2) = 0.0215 and 0.0151, respectively), whereas their relationship fit a curvilinear regression model (R(2) = 0.6947 and 0.723) in the POAG group. Receiver operating characteristic (ROC) curves describing the VF parameters and average RNFL thickness (AVG) were evaluated to differentiate PPG from POAG eyes. Repeated analysis with the best-performing test parameter, pattern standard deviation (PSD) (AUROC = 0.937) with a cutoff of 1.9 dB, showed that regression profiles in the POAG group with PSD >1.9 dB maintained a strong curvilinear RNFL/VF relationship, whereas those with PSD <1.9 dB exhibited a relationship almost indistinguishable from the PPG group. CONCLUSIONS: Evaluation of the structure-function relationship in normal subjects and those with PPG or POAG showed strong curvilinear regression in POAG eyes with PSD >1.9 dB and RNFL AVG thickness below 70 microm, whereas no correlation was detectable above these values.