OBJECTIVE: To assess the accuracy of classification of narrow anterior chamber (AC) angles using quantitative imaging by optical coherence tomography (OCT) and ultrasound biomicroscopy (UBM). DESIGN: Observational comparative study. METHODS: A high-speed (4000 axial scans/s) anterior segment OCT prototype was developed using a 1.3-microm light source. Seventeen normal subjects (17 eyes) and 7 subjects (14 eyes) with narrow angle glaucoma were enrolled. All subjects underwent gonioscopy, OCT, and UBM. Quantitative AC angle parameters (angle opening distance, angle recess area, and the trabecular-iris space area [a new parameter we have defined]) were measured from OCT and UBM images using proprietary processing software. MAIN OUTCOME MEASURES: Specificity and sensitivity in identifying narrow angles with image-derived AC angle parameters. RESULTS: Eight of 31 eyes were classified as having narrow angles (Shaffer grade < or =1 in all quadrants). The AC angle parameters measured by both OCT and UBM had similar mean values, reproducibility, and sensitivity-specificity profiles. Both OCT and UBM showed excellent performance in identifying eyes with narrow angles. Areas under the receiver operating characteristic curves for these parameters were all in the range of 0.96 to 0.98. CONCLUSIONS: Optical coherence tomography was similar to UBM in quantitative AC angle measurement and detection of narrow angles. In addition, it was easier to use and did not require contact with the eye. Optical coherence tomography is a promising method for screening individuals at risk for narrow angle glaucoma.

Adult↗

PubMed2005

Glaucoma in patients with ocular inflammatory disease.

Uveitic glaucoma can pose some of the most challenging management problems faced by the ophthalmologist. A better understanding of the pathogenesis of glaucoma associated with ocular inflammatory disease is an important key to making appropriate therapeutic decisions. This article provides an update on recent advances in understanding the epidemiology and pathogenesis of uveitic glaucoma, as well as developments in the diagnosis and management of this condition.

Glaucoma↗

PubMed2005

Optical coherence tomography imaging of the anterior chamber angle.

Primary angle closure glaucoma is a common cause of visual loss worldwide. Gonioscopy and other current methods of assessment of the anatomy of the anterior segment relevant to the diagnosis of this disease, such as ultrasound biomicroscopy, have significant limitations. Anterior segment optical coherence tomography, with its rapid, noncontact, and high-resolution image acquisition, seems to be a promising tool for the evaluation of the anterior chamber angle configuration, including changes induced by illumination and laser peripheral iridotomy. It has the potential for use as a rapid screening tool for detection of occludable angles. Ongoing clinical studies should help to evaluate its efficacy in this regard.

Anterior Chamber↗

PubMed2005

Predictive value of frequency doubling technology perimetry for detecting glaucoma in a developing country.

PURPOSE: To determine the feasibility and diagnostic precision of Frequency Doubling Technology (FDT) perimetry as a method to detect glaucoma in rural villages of a developing country. DESIGN: Cross-sectional study. METHODS: Testing included FDT perimetry (C-20-5 screening protocol), tonometry, anterior segment biomicroscopy, and dilated ophthalmoscopy in 296 rural, non-English speaking residents of Southern India over 35 years old. Participants repeated the FDT if they had a location with reduced sensitivity or an unreliable result. We defined an abnormal FDT as one location of reduced sensitivity present on both the initial and repeat examination. We determined the diagnostic precision of FDT separately for a glaucomatous optic disc, a cup to disc ratio (C/D) > or = 0.7, and a C/D > or = 0.8. RESULTS: Ninety-three percent of subjects were able to complete the test satisfactorily. With repeat FDT testing, 37% of eyes with abnormal FDT results subsequently converted to normal and 67% of eyes with unreliable results subsequently became reliable. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for a glaucomatous optic disc were 7%, 87%, 13%, 76%, and 69%, respectively; for a C/D > or = 0.7, they were 0%, 87%, 0%, 91%, and 81%, respectively; and for a C/D > or = 0.8, they were 0%, 87%, 0%, 99%, and 87%, respectively. CONCLUSION: Clinicians can use FDT perimetry to rapidly screen for glaucoma in rural villages of a developing country. FDT testing had high specificity and negative predictive value, but low sensitivity and positive predictive value. The low sensitivity suggests that FDT has limited applicability as the sole test for glaucoma screening in this population. Repeat testing of FDT results that are unreliable or suspected of being abnormal is beneficial for this screening procedure.

Adult↗

PubMed2005