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Chong Fai Chung

Publications and source records attributed to Chong Fai Chung.

5 recordsLinked to original sources
PubMed2005

Safety of trypan blue 1% and indocyanine green 0.5% in assisting visualization of anterior capsule during phacoemulsification in mature cataract.

PURPOSE: To evaluate the safety of trypan blue 1% and indocyanine green (ICG) 0.5% in assisting visualization of anterior capsule during phacoemulsification in mature cataract. SETTING: Department of Ophthalmology, United Christian Hospital, Hong Kong, China. METHODS: This prospective randomized clinical trial comprised 46 eyes with mature cataract receiving phacoemulsification and posterior chamber intraocular lens implantation. They were randomized into 3 groups (trypan blue, ICG, and control without stain). Visual acuity, endothelial cell count, corneal clarity, anterior chamber reaction, and intraocular pressure (IOP) were documented before surgery and 1 week, 1 month, and 3 months postoperatively. The absolute phaco time was also recorded. RESULTS: There was no significant difference in absolute phaco time (P=.17), mean endothelial cell loss (P=.72 at 1 week, P=.43 at 1 month, and P=.60 at 3 months) and no significant correlation between the absolute phaco time and the change in endothelial cell count (P=.50 at 1 week, P=.10 at 1 month, and P=.60 at 3 months) in the 3 groups. None of the patients had postoperative IOP greater than 21 mm Hg. All eyes had clear corneas and a quiet anterior chamber 3 months after surgery. CONCLUSION: Both trypan blue 1% and ICG 0.5% are safe for assisting visualization of the anterior capsule during phacoemulsification of mature cataract.

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PubMed2004

Visual sensation during phacoemulsification and intraocular lens implantation using topical and regional anesthesia.

PURPOSE: To evaluate patients' visual sensations at different stages of phacoemulsification and posterior chamber intraocular lens (PC IOL) implantation under topical and regional anesthesia. SETTING: Department of Ophthalmology, United Christian Hospital and Tseung Kwan O Hospital, Kowloon, Hong Kong, China. METHODS: Seventy-six consecutive patients having phacoemulsification were randomized to a topical anesthesia group (n = 35) or regional anesthesia group (n = 41). The topical anesthesia group received lidocaine hydrochloride 2% gel (Xylocaine) and the regional anesthesia group, a peribulbar or retrobulbar injection of lignocaine 2%. The patients' visual sensations, including light and color sensations, shape of objects, and visual patterns, were evaluated at different stages of surgery. RESULTS: Two patients (4.9%) in the regional anesthesia group and none in the topical anesthesia group experienced total loss of light sensation throughout surgery (P =.50). There was a significant association between color perception and the type of anesthesia at stages 1 and 2 (P<.05) but not at stages 3, 4, and 5 (P>.05). The perception of objects and visual patterns had no association with the type of anesthesia at any stage (P>.05). Of all patients in the study, 56 (73.7%) reported color changes as surgery proceeded. Both groups saw waves, defined as curves with periodic fluctuations in amplitude, at all stages. The perception of some colors and a rectangular moving object was significantly associated with the type of anesthesia at some or all stages (P<.05). CONCLUSIONS: Patients having phacoemulsification and PC IOL implantation under topical or regional anesthesia had a wide spectrum of visual sensations that were similar at most stages of surgery. Patients in the topical anesthesia group perceived more colors at the early stages and more blue throughout surgery than patients in the regional anesthesia group.

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