Comparison of techniques for measuring anterior chamber depth: Orbscan imaging, Smith’s technique, and van Herick’s method

Eperjesi, Frank; Holden, Claire

doi:10.1007/s00417-010-1500-0

Cited by 6 publications

(6 citation statements)

References 24 publications

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“…The length of the slit beam with the two images in contact is multiplied by a constant, commonly 1.4 or 1.31, to obtain a value for ACD in millimetres. Both of these techniques are imprecise – one study estimated that Van Herick's method often overestimated grade while Smith's often overestimated ACD (Eperjesi & Holden ) – but they provide a sense of a patient's risk for angle closure without requiring gonioscopy.…”

Section: Diagnosismentioning

confidence: 99%

Primary angle‐closure glaucoma: an update

Wright

Tawfik

Waisbourd

et al. 2015

Acta Ophthalmologica

171

118

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ABSTRACT. Primary angle-closure glaucoma is potentially a devastating disease, responsible for half of glaucoma-related blindness worldwide. Angle closure is characterized by appositional approximation or contact between the iris and trabecular meshwork. It tends to develop in eyes with shallow anterior chambers, anteriorly positioned or pushed lenses, and angle crowding. Risk of primary angle-closure glaucoma is high among women, the elderly and the hyperopic, and it is most prevalent in Asia. Investigation into genetic mechanisms of glaucoma inheritance is underway. Diagnosis relies on gonioscopy and may be aided by anterior segment optical coherence tomography and ultrasound biomicroscopy. Treatment is designed to control intraocular pressure while monitoring changes to the angle and optic nerve head. Treatment typically begins with medical management through pressurereducing topical medications. Peripheral iridotomy is often performed to alleviate pupillary block, while laser iridoplasty has been found effective for mechanisms of closure other than pupillary block, such as plateau iris syndrome. Phacoemulsification, with or without goniosynechialysis, both in eyes with existing cataracts and in those with clear lenses, is thus far a viable treatment alternative. Long-term research currently underway will examine its efficacy in cases of angle closure in early stages of the disease. Endoscopic cyclophotocoagulation is another treatment option, which can be combined with cataract surgery. Trabeculectomy remains effective therapy for more advanced cases.

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Section: Diagnosismentioning

confidence: 99%

Primary angle‐closure glaucoma: an update

Wright

Tawfik

Waisbourd

et al. 2015

Acta Ophthalmologica

171

118

View full text Add to dashboard Cite

show abstract

“…By contrast, Pentacam does not require extensive experience for image acquisition, while AS-OCT always causes an image degradation due to a motion artifact secondary to the patient's microsaccades [12]. Additionally, the Orbscan device requires clear re ections from the epithelial and endothelial corneal surfaces to obtain precise data, which might be di cult after the surgery [13].…”

Section: Discussionmentioning

confidence: 99%

Evaluation of anterior chamber morphology following scleral buckling with Pentacam

Zhu

2022

Preprint

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Background: This study was to evaluate anterior segment parameter changes following scleral buckling (SB) surgery for rhegmatogenous retinal detachment (RRD) using the Pentacam Scheimpflug system.Methods: Twenty-eight phakic eyes of 28 patients who underwent SB surgery for RDD were included. The anterior chamber volume (ACV), central anterior chamber depth (CACD), mean anterior chamber angle (ACA) and ACA in a specific position (buckle quadrant), and central corneal thickness (CCT) were evaluated preoperatively and at 1 day, 1 week, and 1 and 3 months postoperatively by an anterior Pentacam Scheimpflug method. Results: The ACV parameters were significantly decreased compared with preoperative levels at 1 day, 1 week, and 1 and 3 months after SB surgery (P<0.05). The mean intraocular pressure (IOP) at 1 day was significantly higher than the preoperative level, but no subsequent significant difference was noted between the preoperative IOP and that at 1 week and 1 and 3 months postoperatively (P>0.05). The CCT at 1 day after surgery increased significantly and subsequently returned to the normal level postoperatively at 1 week and remained stable until 3 months (P>0.05). The degree of postoperative CACD displayed no significant change in the different quadrants. There was a significant increase in the ACA of the buckle quadrants at 1 day, 1 week, and 1 month after surgery (P<0.05), returning to the normal level at 3 months.Conclusion: The changes of anterior chamber parameters after SB can be demonstrated by Pentacam both objectively and quantitatively. The ACV and CCT changes were mild and resumed their preoperative parameters after 1week, while the increase of the ACA at the buckle quadrant returned to normal after 3 months.

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“…There are several methods for ACD measurement, including ultrasonic devices and optically based instruments. In order to several complications of the conventional method of ultrasonic wave, like patient discomfort, risk of infection and off-axis measurements, the new instruments using optical devices are seems to have an important role in ACD measurement [6].…”

Section: Discussionmentioning

confidence: 99%

“…One of the practical and mostly reliable methods for ACD measurement is Orbscan II [5]. The other methods applied are optical coherence tomography (OCT) like Visante OCT, optical methods as IOL Master, and scheimpflug imaging techniques as Pentacam or Galilei [6,7]. On the other hand, methods applied in the clinic using the slit lamp like grading of limbal chamber depth using van Herick's technique is also used as a surrogate for measuring central ACD [5].…”

Section: Introductionmentioning

confidence: 99%

Normative Values and Contralateral Comparison of Anterior Chamber Depth Measured by Orbscan II in an Iranian Population

Gharaee¹,

Abrishami²,

Shafiee³

et al. 2014

J. Ocul. Dis. Ther.

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Purpose: The objective of study was (i) to determine the normative values of anterior chamber depth (ACD) with Orbscan II Topography System and (ii) to compare right and left eyes data in the normal young population. Methods: A total of 1001 healthy participants aged 18-45 years participated in this observational cross-sectional study. The study population consisted of 616 female and 385 male subjects. The ACD was measured with the Orbscan II. In our study, ACD was defined as the distance between the corneal epithelium and the anterior lens surface. The differences between genders, between right and left eyes and age-related changes were evaluated. Statistical analyses were performed using student t test. Results: The average ACD in our study population was recorded as 3.653 ± 0.306 mm (median: 3.670 mm, mode: 3.70 mm, minimum: 2.35 mm and maximum: 6.60 mm, 95% Confidence interval: 3.640 to 3.666). The ACD was 3.64±0.30 mm in males and 3.67±0.32 mm in females which was statistically different between genders (P < 0.01). There was a much similarity in ACD values in both eyes. ACD was decreased with age (r= -0.250, p<0.001). Conclusion: Detailed description and analysis of ACD with Orbscan demonstrated that the obtained average value of ACD was higher in female than male and decreased slightly with increasing age. There was no difference between the eyes.

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Comparison of techniques for measuring anterior chamber depth: Orbscan imaging, Smith’s technique, and van Herick’s method

Abstract: Smith's technique (constant 1.31) provided an ACD that is closer to that found with Orbscan compared to a constant of 1.40 or LCDvh. Our findings also suggest that Smith's technique would produce values closer to that obtained with Orbscan by using a constant of 1.22.

Cited by 6 publications

References 24 publications

Primary angle‐closure glaucoma: an update

Primary angle‐closure glaucoma: an update

Evaluation of anterior chamber morphology following scleral buckling with Pentacam

Normative Values and Contralateral Comparison of Anterior Chamber Depth Measured by Orbscan II in an Iranian Population

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