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Optical Coherence Tomography (Oct) and Fundus Fluorescein Angiography (FFA) in Neuro-Ophthalmology
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Ramandeep Singh, Deeksha Katoch, Mohit Dogra, Basavaraj Tigari, Simar Rajan Singh, Sahil Jain, Bruttendu Moharana, Sabia Handa, Mangat R. Dogra
On examination, her best-corrected visual acuity (BCVA) was 6/6 in the right eye and counting fingers at 1 m in the left eye. Intraocular pressure was 10 and 12 mmHg with Goldmann applanation tonometry in right and left eye, respectively. Extraocular movements were full and free in both eyes with pain on adduction and abduction in the left eye. Left eye pupil showed relative apparent pupillary defect (RAPD). Rest of the anterior segment examination was within normal limits. Right eye fundus examination was within normal limits (Figure 3A.5a). Fundus examination revealed disc edema in the left eye (Figure 3A.5b). A clinical diagnosis of left eye optic neuritis was made. Fundus fluorescein angiography (FFA) findings were consistent with clinical diagnosis. Late phase of FFA showed normal findings in the right eye, whereas left eye late phase of FFA showed disc leakage and staining (Figure 3A.5c and d).
Arterial Pressure Waveform Analysis
Published in Wilmer W Nichols, Michael F O'Rourke, Elazer R Edelman, Charalambos Vlachopoulos, McDonald's Blood Flow in Arteries, 2022
Tonometry is widely used in ophthalmology for measuring intraocular pressure and for the assessment of glaucoma and its response to treatment. Applanation tonometry was first applied to the determination of arterial pressure waves by Pressman and Neugard in 1963. This has proved a major advance over all other methods for noninvasive determination of the arterial pressure pulse (Drzewiecki et al., 1983). The single-element transducers introduced by Huntly Millar in 1989 (Kelly et al., 1989a, 1989b) have been extended into multiunit arrays (Kemmotsu et al., 1991a, 1991b; Sato et al., 1993), as in the instrument developed by Nippon-Colin (Komaki, Japan) and subsequently popularized by Omron (Hoofddorp, The Netherlands). The combination of an array that can straddle an artery, together with a servo-controlled placement system and with the automatic application of pressure from behind, permits automatic operation of the sensor and optimal placement of the operational tonometric element for the recording of radial artery pressure. While this system has definite advantages (Chen et al., 1997), most data have to date been obtained with the single-unit handheld systems (Kelly et al., 1989c; London et al., 1992; Roman et al., 1992, 2007, 2009; Jiang et al., 2002; Lakatta and Levy, 2003a, 2003b; Laurent et al., 2006; Williams et al., 2006; Ding et al., 2011; Davies et al., 2012; Ding et al., 2013; Zhang et al., 2013; Agnoletti et al., 2014; Butlin and Qasem, 2017).
Ocular Irritation Testing
Published in David W. Hobson, Dermal and Ocular Toxicology, 2020
George P. Daston, F. E. Freeberg
Measurement of intraocular pressure, at least by applanation tonometry, may be difficult to carry out. The tonometer must be adjusted for changes in corneal thickness which are likely to occur during corneal injury; there appears to be measurable interoperator variability in reading the tonometer; the cornea must be anesthetized; and a contrasting medium must be introduced on the surface of the eye in order to visualize the applanation rings of the tonometer (Walton and Heywood used evaporated milk).
A Review of Corneal Biomechanics and Scleral Stiffness in Topical Prostaglandin Analog Therapy for Glaucoma
Published in Current Eye Research, 2023
Steven R. Shen, Gloria P. Fleming, Shelly Gupta Jain, Cynthia J. Roberts
It is essential to interpret clinical IOP data gathered transcorneally in the context of the tonometry technique used to measure IOP. This is because different tonometers use different technologies representing the mechanism of force delivery which will influence the measurements gathered.13,14 It is well known that Goldmann Applanation Tonometry (GAT) is affected by central corneal thickness (CCT), resulting in overestimation of IOP in thick corneas and underestimation in thin corneas. However, it has also been theoretically shown to be affected by biomechanical properties, resulting in overestimation in a stiff cornea and underestimation in a compliant cornea.7 As such, it is imperative to be aware of the potential measurement biases associated with each tonometer, especially when comparing studies using differing tonometry technologies.
Inter-optometrist variability of IOP measurement for modern tonometers and their agreement with Goldmann Applanation Tonometry
Published in Clinical and Experimental Optometry, 2021
Peter Campbell, David F Edgar, Rakhee Shah
The CT-1P Non-Contact tonometer showed close agreement with GAT and these results are similar to findings for other non-contact tonometers. The Icare ic100 rebound tonometer and Pulsair IntelliPuff tonometer measured IOP lower than GAT, and this may be clinically significant. Inter-optometrist agreement for four tonometers commonly used in community optometry practice was comparable with an agreement for similar tonometers obtained by non-optometrist clinicians. Intra-optometrist agreement for GAT was good. There was a weak but statistically significant positive association between CCT and both GAT and the CT-1P NCT, but negligible associations for Pulsair and iCare. Further work is needed to investigate the clinical impact of the choice of tonometer used in the detection of patients at risk of glaucoma.
Thyroid eye disease with choroidal folds
Published in Orbit, 2021
Ann Q. Tran, Sandy X. Zhang-Nunes, Kenneth Cahill, Chrisfouad R. Alabiad, Erin M. Shriver, Tiffany Ho, David A. Weinberg, Steven M. Couch, Dianne M. Schlachter, John Nguyen, Sara T. Wester
In regards to the ophthalmologic findings at the time of presentation of CRFs, the majority of patients were mildly hyperopic (53%, 9/17 eyes), with less than +2.50 D of hyperopia. The average intraocular pressure measured by tonometry was 22.6 ± 7.4 (range 14–40). CRF were typically found bilaterally (70%, 7/10 of patients). Compressive optic neuropathy was seen in 47% of eyes (8/17 of eyes). Documented disc edema was seen in 31% of eyes (5/17 of eyes), two of which occurred in unilateral cases. Exophthalmos measurements were on average 23.8 ± 3.2 mm on Hertel exophthalmometry, and average clinical activity score was 3.6 ± 2.1. The most commonly enlarged EOMs were the medial rectus (76%, 13/17 eyes), inferior and superior rectus (64%, 11/17 eyes and 64%, 11/17 eyes) and lateral rectus (35%, 6/17 of eyes).