Hung-Yin Lai1, Ming-Tse Kuo1, Po-Chiung Fang1, Chi-Chang Lin2, Chun-Chih Chien3, Wan-Hua Cho1, Alexander Chen1, Ing-Chou Lai1. 1. Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan. 2. Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan. 3. Department of Laboratory Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
Abstract
PURPOSE: To implement an emerging noninvasive approach for assessing the dynamic tear film (TF) homeostasis. METHODS: The video records of dynamic TF from 12 healthy orthokeratology lens wearers were obtained by a clinically available TF analyzer and decomposed as image sequences. The trajectories of TF particles were analyzed by two tracking models, the full-span model (FSM) and the fixed-duration model (FDM). FSM tracked a particle for a complete opening blink cycle, while FDM tracked 1 second of the same cycle. A power-law fitting operation [Formula: see text] was used to extract homeostasis markers based on the tracking model for each subject. RESULTS: Comparing two tracking models (N = 6), only one subject had statistical difference in averaged momentary moving speed (MMS; P = 0.0488), while none had significant difference in averaged momentary moving direction (MMD). However, both models showed good correlations in average MMS (ρ = 0.94, P = 0.0048) and MMD (ρ = 1.00, P < 0.0001) and all extracted homeostasis markers [α, β, MMS(0.1), and MMS(2.0)]. Assessing interblink reliability in these markers under FDM tracking (N = 12), only one subject in the MMS (0.1) and another subject in the MMS (2.0) were outside 95% limits of agreement, respectively. CONCLUSIONS: FDM is a good alternative to FSM and has tracking properties of higher efficiency and easier implementation. The homeostasis markers under FDM tracking showed a good interblink consistence; therefore this approach will be a promising method for analyzing dynamic TF homeostasis in future practice. TRANSLATIONAL RELEVANCE: FDM analytical architecture can practice the past experimental platform on a TF analyzer to obtain homeostasis markers of TF.
PURPOSE: To implement an emerging noninvasive approach for assessing the dynamic tear film (TF) homeostasis. METHODS: The video records of dynamic TF from 12 healthy orthokeratology lens wearers were obtained by a clinically available TF analyzer and decomposed as image sequences. The trajectories of TF particles were analyzed by two tracking models, the full-span model (FSM) and the fixed-duration model (FDM). FSM tracked a particle for a complete opening blink cycle, while FDM tracked 1 second of the same cycle. A power-law fitting operation [Formula: see text] was used to extract homeostasis markers based on the tracking model for each subject. RESULTS: Comparing two tracking models (N = 6), only one subject had statistical difference in averaged momentary moving speed (MMS; P = 0.0488), while none had significant difference in averaged momentary moving direction (MMD). However, both models showed good correlations in average MMS (ρ = 0.94, P = 0.0048) and MMD (ρ = 1.00, P < 0.0001) and all extracted homeostasis markers [α, β, MMS(0.1), and MMS(2.0)]. Assessing interblink reliability in these markers under FDM tracking (N = 12), only one subject in the MMS (0.1) and another subject in the MMS (2.0) were outside 95% limits of agreement, respectively. CONCLUSIONS: FDM is a good alternative to FSM and has tracking properties of higher efficiency and easier implementation. The homeostasis markers under FDM tracking showed a good interblink consistence; therefore this approach will be a promising method for analyzing dynamic TF homeostasis in future practice. TRANSLATIONAL RELEVANCE: FDM analytical architecture can practice the past experimental platform on a TF analyzer to obtain homeostasis markers of TF.
Authors: Haixia Liu; Carolyn G Begley; Robin Chalmers; Graeme Wilson; Sangly P Srinivas; Jenni A Wilkinson Journal: Optom Vis Sci Date: 2006-10 Impact factor: 1.973