Malik Y. Kahook

Accuracy and performance of a commercially available Dosing Aid

Aim: To evaluate the recently introduced Travatan Dosing Aid (TDA) for its accuracy in recording and dispensing eyedrops. Methods: The number of eyedrops dispensed with each lever depression and agreement of total number of drops dispensed with that recorded by the device was evaluated in a controlled setting. Results: The TDA correctly recorded a drop being dispensed 100% of the time with full TDA lever depression for <3 s. Under these conditions, agreement between numbers of drops dispensed and recorded was 99%. However, failure to fully depress the lever or prolonged lever depression for >4 s resulted in unreliable TDA recording. Conclusion: Eyedrops were reliably recorded by the TDA after each full lever depression. However, patients need to be instructed about optimal technique so that evaluation of compliance is not confounded by mechanical factors.

Comparison of acute structural and histopathological changes of the porcine ciliary processes after endoscopic cyclophotocoagulation and transscleral cyclophotocoagulation

Background:u2003 The objective of this study is to investigate the acute histological effects of transscleral cyclophotocoagulation and endoscopic cyclophotocoagulation on the ciliary body and other structures of porcine eyes compared with untreated controls.

Location of glaucoma drainage devices relative to the optic nerve

Background: Limited data are available to guide optimal positioning of glaucoma drainage devices (GDD) in relation to the limbus and optic nerve. The authors aim to provide guidelines for appropriate and safe GDD implantation. Method: The optimal positioning of five different GDD were evaluated using necropsy eyes of varying axial lengths. The dependent variable that was measured was the maximum distance that a GDD could be placed posterior to the limbus while remaining 2 mm away from the optic nerve. Results: The average maximum distance posterior to the limbus of the anterior plate edge ranged between 9.0–15.0 mm in the superotemporal quadrant for the GDD tested. The distances for superonasal, inferonasal, and inferotemporal quadrants ranged between 8.0–14.0 mm, 9.0–14.0 mm, and 11.0–17.0 mm, respectively. The Molteno device could be placed most posteriorly while remaining 2 mm away from the nerve. The Ahmed FP7 and S2 were the least amenable to posterior placement before encroaching on the 2 mm limit. Conclusion: The maximum distance that a GDD can be placed posterior to the limbus, before encroachment around the optic nerve, varies between different devices and quadrants of placement. Taking a measurement of the exact distance of the plate from the limbus during GDD surgery is recommended.