Aplication of <i>in Vivo</i>Confocal Microscopy in Ophtalmology—Overview

Confocal microscopy is a method which has been increasingly used over the last decade in the study of the anterior ocular surface. The method allows testing and in vivo high resolution imaging of the structures of the anterior eye segment, at a cellular level, which is close to the histological examination of tissues. The data provided by this method allow for a better understanding of both the functional and pathological processes occurring in the anterior ocular surface not only for scientific purposes but also in clinical practice. The aim of the present work is to summarize the current knowledge and applications of confocal microscopy of the anterior ocular surface.

Anterior Segment Optical Coherence Tomography Indices and Their Value in Diagnosing Corneal Ectasia

Purpose: To determine the diagnostic value of the anterior segment optical coherence tomography (AS-OCT) indices in differentiating normal from ectatic corneas. Material and Methods: Two groups of patients—with corneal ectasia and normal controls were compared. Each group consists of 80 eyes of 43 age and sex-matched patients. All of them underwent corneal topography with OCULUS Keratograph 5M and corneal pachymetry with AS-OCT with RTVue-100. The indices generated by the AS-OCT pachymetric scans were analyzed. Results: There was a statistically significant difference for all the examined indices between the two groups with p values <0.001 and a confidence interval of 95%. The minimal corneal thickness (Min) was the best performing index according to the ROC analysis with an area under the curve of 0.976 and a combination of sensitivity and specificity of 0.925 and 0.911 respectively, and a “cut-off” value of 484 microns, followed by the indices of focal thinning—Min-Med and Min-Max with an area under the curve of 0.973 and 0.971 and sensitivity/specificity of 0.938/0.962 and 0.938/0.937 respectively. The rest of the examined parameters had an area under the curve in the range between 0.950 for the central corneal thickness and 0.814 for the outer superior segment. Conclusion: The anterior segment OCT indices showed excellent capability in differentiating ectatic from normal corneas.

Optical Coherence Tomography Parameters in Preperimetric Open-Angle Glaucoma

Purpose: To evaluate the measurements of the peripapillary retinal neurofiber layers (RNFL) and the ganglion cells complex (GCC) obtained by Optical Coherence Tomography (OCT) in eyes with preperimetric open-angle glaucoma. Methods: One hundred and forty eyes of 75 patients (21 male and 54 female), 80 eyes with preperimetric glaucoma (PPG) (45 patients) and 60 normal eyes (30 subjects) were included in this study. Automated visual field examination was done to all participants using Humphrey field analyzer, program 30-2. The GCC thickness and peripapillary RNFL thickness were measured using RTVue-100 (Optivue, Inc., Fremont, CA). The areas under ROC (receiver operating characteristic)—curves (AUCs) were defined for all examined GCC and RNFL parameters. Results: GCC of the eyes with PPG was significantly thinner than GCC of the normal eyes: (89.58 vs 97.82 microns, P < 0.001). There was no significant difference between upper and lower GCC halves in both study groups. We found a reduction of RNFL thickness in glaucomatous eyes (P < 0.001) compared with normals. AUCs for GCC parameters in eyes with PPG were larger than AUCs for RNFL parameters. Conclusion: Our study showed that the peripapillary RNFL and GCC thickness are lower in preperimetric glaucoma than in normal eyes. Despite the fact that GCC measurements (especially GLV) show better AUC than peripapillary measurements, we suggest that two scans (GCC and ONH) put together are superior in detecting early structural glaucomatous damage. Several diagnostic parameters should be considered in the clinical diagnosis of preperimetric glaucoma.

Hertel Exophthalmometry and Computed Tomography for the Evaluation of Exophthalmos in Patients with Thyroid-Associated Ophthalmopathy

Objective: To compare the values of exophthalmos measured by computed tomography (CT) and Hertel exophthalmometry (HE) in patients with thyroid-associated ophthalmopathy (TAO). Material and Methods: One hundred and seventy eyes were examined in 85 patients with TAO. Each patient underwent a complete ophthalmic examination, Hertel exophthalmometry, and CT of the orbits through a 16-slice CT scanner (Bright Speed, General Electric), measuring the extraocular muscles, the total muscle thickness sum (MTS), and proptosis. The patients were divided into two groups-with activity and without TAO activity, the activity being assessed by means of the Clinical Activity Score (CAS) and the severity-according to the EUGOGO classification. Results: TAO activity was detected in 45 patients (90 eyes, 53%) with MTS of 23.54 ± 5.73 mm, IOP of 19.78 ± 4.49 mm Hg, Hertel exophthalmos of 23.08 ± 4.19 mm and measured by CT-23.32 ± 4.33 mm. Forty patients (80 eyes, 47%) were without TAO activity, with MTS of 19.28 ± 4.03, IOP of 16.6 ± 4.51 mm Hg, Hertel exophthalmos of 20.03 ± 3.84 mm and measured by CT-19.84 ± 4.47 mm. A correlation was detected between exophthalmos and: MTS, IOP, the activity and severity of TАО. High congruence was established between the two methods of measuring exophthalmos-CT and HE (Pearson correlation, r = 0.690, p = 0.000). Conclusion: Our results showed a high degree of consistency between Hertel exophthalmometry and multidetector CT for the evaluation of exophthalmos in patients with TAO. Exophthalmos is an important clinical feature and its measurement and monitoring over time assess the clinical course and outcome of treatment.