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Biomedical subjects

Christopher Khng

Publications and source records attributed to Christopher Khng.

7 recordsLinked to original sources
PubMed2006

Intraocular pressure during phacoemulsification.

PURPOSE: To assess changes in intraocular pressure (IOP) during standard coaxial or bimanual microincision phacoemulsification. SETTING: Oregon Eye Center, Eugene, Oregon, USA. METHODS: Bimanual microincision phacoemulsification (microphaco) was performed in 3 cadaver eyes, and standard coaxial phacoemulsification was performed in 1 cadaver eye. A pressure transducer placed in the vitreous cavity recorded IOP at 100 readings per second. The phacoemulsification procedure was broken down into 8 stages, and mean IOP was calculated across each stage. Intraocular pressure was measured during bimanual microphaco through 2 different incision sizes and with and without the Cruise Control (Staar Surgical) connected to the aspiration line. RESULTS: Intraocular pressure exceeded 60 mm Hg (retinal perfusion pressure) during both standard coaxial and bimanual microphaco procedures. The highest IOP occurred during hydrodissection, ophthalmic viscosurgical device injection, and intraocular lens insertion. For the 8 stages of the phacoemulsification procedure delineated in this study, IOP was lower for at least 1 of the bimanual microphaco eyes compared with the standard coaxial phaco eye in 4 of the stages (hydro steps, nuclear disassembly, irritation/aspiration, anterior chamber reformation). CONCLUSION: There was no consistent difference in IOP between the bimanual microphaco eyes and the eye that had standard coaxial phacoemulsification. Bimanual microincision phacoemulsification appears to be as safe as standard small incision phacoemulsification with regard to IOP.

Anterior Chamber↗
PubMed2006

Surgical options in the face of positive pressure.

Positive pressure during cataract surgery can adversely affect the clinical outcome if the surgeon is unprepared. A variety of surgical maneuvers are described, including dry insertion of the phacoemulsification needle, capsule protection with the second instrument, dry cortical aspiration in an ophthalmic viscosurgical device (OVD) environment, intraocular lens restraint with an injection cannula at the end of OVD removal, aspiration or vitrectomy through the pars plana, a technique of OVD clearance to manage extreme cases of positive pressure, and intraoperative ophthalmoscopy using a lens designed to function with the operative microscope. Mastery of these important surgical maneuvers will help the surgeon manage challenging cases of positive pressure.

Humans↗
PubMed2005

Iris reconstruction with a multipiece endocapsular prosthesis in iridocorneal endothelial syndrome.

Iris reconstruction in cases of iridocorneal endothelial (ICE) syndrome is extremely challenging because of the nature of the iris tissue, which is typically friable and poorly suited to suture repair. Reconstruction in such cases often requires artificial iris implantation. This report illustrates cataract extraction and iris reconstruction with a multipiece endocapsular iris prosthesis that can be inserted through a small incision. Maintenance of a small incision size is a distinct advantage when glaucoma is coexistent in patients with ICE syndrome. It also demonstrates the presence of an ICE membrane over the anterior capsule and the importance of recognizing this membrane rather than confusing it with the anterior capsule when performing the capsulorhexis.

Adult↗