Morphometric analyses in patients treated with subthreshold laser photocoagulation for central serous chorioretinopathy.

BACKGROUND AND OBJECTIVE: To analyze changes in selected parameters in optical coherence tomography (OCT) after subthreshold laser coagulation (ST-LP) in patients with central serous chorioretinopathy (CSCR). MATERIALS AND METHODS: Fifty-four eyes of 49 patients with CSCR were included in the study. Each patient underwent therapy with ST-LP with a frequency-doubled Neodym-YAG Laser and OCT imaging. In OCT the thickness of the central subfield, cube volume, average cube thickness, volume under the ETDRS grid, and average thickness under the ETDRS grid were collected. RESULTS: Decreases in total OCT volume and central retinal subfield thickness were statistically significant (p < 0.05). Possible correlations were observed between visual acuity at V3 (3 months after ST-LP) and Baseline and between central retinal subfield thickness at V1 (4 weeks after ST-LP) and visual acuity at BL. CONCLUSION: A decrease in retinal thickness and retinal volume could be shown after ST-LP. Central retinal subfield thickness measured by OCT could be a more sensitive measure than mean retinal thickness or macular volume for early detection of disease recurrence occurring in some patients 3 months after ST-LP.

[New Possibilities in Retinal Diagnostics Using OCT Angiography]. / Neue Möglichkeiten in der retinalen Diagnostik mittels OCT-Angiografie.

BACKGROUND: Instruments for using OCT angiography (OCTA) in daily clinical practice have recently become available. The aim of this paper is to report the possibilities, advantages and limitations of OCTA in the clinical diagnosis of diseases of the posterior segment of the eye. PATIENTS/METHODS: Patients with diabetic retinopathy, retinal vascular occlusions, and age-related macular degeneration who had been assigned to fluorescein angiography (FA) additionally underwent an AngioPlex™-OCTA examination, which captures a 6 × 6 mm scanning area centred on the fovea. If deemed necessary, 3 × 3 mm volume scans were created in regions of interest. The findings of FA and OCTA were correlated and compared. RESULTS: The OCTA procedure took only a few seconds, was easily integrated into the standard OCT diagnostic imaging procedure, and delivered highly detailed, three dimensional images of the entire microvasculature of the retina and choroid. Microvascular changes, such as microaneurysms, intraretinal microvascular abnormalities, non-perfused areas, alterations in the foveal avascular zone (FAZ) and neovascularization were reliably detected. Overall, OCTA results were in good agreement with the results of the FA. Additionally, OCTA provided more detailed and three dimensional information and thus permitted a better assessment of the spatial extension of microvascular abnormalities. Due to OCTA's limited scanning area, vascular alterations in the mid-periphery were detected only if their location had already been determined by FA. Although OCTA does not show leakage, macular oedema can be diagnosed from OCTA, together with OCT thickness measurements. CONCLUSION: OCTA provides important three dimensional information on vascular alterations and is already an indispensable diagnostic method. As the procedure takes just a few seconds and can be performed non-invasively, OCTA is well suited as a monitoring method and may allow early diagnosis. In this sense, prospective studies are required to determine precise OCTA analytical strategies for specific diseases. It is very likely that OCTA will revolutionise the diagnosis of retinal and choroidal diseases; however, it is not yet clear estimated to what extent it will replace FA.

[Chamber Angle Assessment in Clinical Practice - A Comparison between Optical Coherence Tomography and Gonioscopy]. / Kammerwinkelbeurteilung im klinischen Alltag - ein Vergleich zwischen der optischen Kohärenztomografie und der Gonioskopie.

BACKGROUND: In glaucoma the structures of the anterior chamber are important for classification, therapy, progression and prognosis. In this context anterior segment optical coherence tomography (AS-OCT) gains more relevance. This study compares AS-OCT with gonioscopy in diagnostic performance of chamber angle (CA) assessment. PATIENTS AND METHODS: 104 consecutive subjects with glaucoma underwent AS-OCT imaging using the Visante OCT. RESULTS were compared to gonioscopic grading from patient history using the Shaffer system. In addition, anterior chamber depth (ACD) assessment using slitlamp examination was evaluated as a prognostic factor for chamber angle width (CAW) and verified by AS-OCT measurement. RESULTS: Average CAW was 29° (AS-OCT). 17 % of the CAs that were "wide" in gonioscopy (variance 5-55°), showed a "narrow" CA in AS-OCT. 35 % of the CAs that were "narrow" in gonioscopy (variance 0-39°) showed a "wide" CA in AS-OCT. ACD assessment using slitlamp examination is a good predictor for CAW. In this context the technique provides equal informative value as gonioscopy. In cases of "wide" ACDs it is even superior. The critical ACD for an increased risk of angle closure is 2.4 mm. Concerning the critical ACD (< 2.4 mm) the technique gave the possibility to estimate, whether the patients were in the crucial range or not. Average ACD was 2.7 mm (AS-OCT). A strong correlation (correlation coefficient 0.83) between ACD and CAW was observed. Variation of 1 mm in the ACD leads to a change of 18.9° in the CAW. All patients with angle closure glaucoma were below this threshold and 74 % of patients with critical ACD had "narrow" (AS-OCT) CAs. CONCLUSION: In the case of routine clinical practice with inexperienced residents or circumstances that make gonioscopy difficult or impossible, optical coherence tomography is an effective alternative to the gold standard and is to some extent even superior.