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Biomedical subjects

Simon D M Chen

Publications and source records attributed to Simon D M Chen.

14 recordsLinked to original sources

Intravitreal triamcinolone for the treatment of ischemic macular edema associated with branch retinal vein occlusion.

PURPOSE: To evaluate the safety and efficacy of intravitreal triamcinolone acetonide (IVTA) for ischemic macular edema associated with branch retinal vein occlusion (BRVO) and foveal ischemia. DESIGN: Prospective interventional case series. METHODS: setting: Clinical practice. study population: Eighteen eyes of 18 patients with macular edema associated with BRVO and foveal ischemia. intervention: Four mg IVTA. main outcome measures: Visual acuity (VA), optical coherence tomography, macular thickness measurements, and treatment-related complications. RESULTS: The mean duration of BRVO before treatment was 14 months. All patients were followed for a minimum of nine months, and 12 patients completed 12 months follow-up. The mean logarithm of the minimum angle of resolution (logMAR) VA improved significantly from 0.81 +/- 0.36 at baseline to 0.65 +/- 0.30 at one month (P = .03) but did not vary significantly from baseline at three, six, nine, and 12 months. Macular thickness improved significantly in all eyes from a mean of 400 +/- 134 mum preinjection, to 228 +/- 58 mum at one month (P < .01) and 256 +/- 121 mum at three months (P < .01) but did not vary significantly from baseline at six, nine, and 12 months. Eight eyes developed posterior subcapsular cataract, intraocular pressure (IOP) exceeded 21 mm Hg in four eyes, and two eyes developed vitreomacular traction during follow-up. CONCLUSIONS: IVTA is effective in reducing ischemic macular edema associated with BRVO and foveal capillary nonperfusion. This reduction is often associated with a temporary improvement in VA. Raised IOP and development of posterior subcapsular cataract are disadvantages of this treatment.

Adult↗

Corneal perforation due to severe peripheral ulcerative keratitis in Crohn disease.

PURPOSE: To describe corneal perforation secondary to severe peripheral ulcerative keratitis (PUK) in a patient with Crohn disease. METHODS: Interventional case report. RESULTS: A 72-year-old male with biopsy-proven Crohn disease presented with reduced vision, PUK, and corneal perforation in the right eye. Despite initial treatment with intravenous methylprednisolone and a conjunctival flap, a tectonic sectorial penetrating keratoplasty was required to preserve the globe and achieve a good visual result. CONCLUSIONS: Crohn disease may be associated with severe PUK leading to corneal perforation. Tectonic corneal grafting combined with treatment of the underlying systemic disease was associated with a favorable outcome.

Aged↗

Videoendoscope-guided fluorescein-assisted vitrectomy for phakic malignant glaucoma.

Malignant glaucoma is a rare secondary glaucoma classically occurring after intraocular surgery in eyes with primary angle closure. Pars plana vitrectomy is reserved for the treatment of malignant glaucoma when medical and laser treatment fail. The primary aim of surgery is the removal of the anterior vitreous to reduce resistance to aqueous flow into the anterior chamber. In phakic eyes, conventional pars plana vitrectomy without lens extraction is frequently unsuccessful because of difficulty visualizing the normally transparent anterior vitreous, combined with the technical challenge of removing the anterior vitreous without damaging the crystalline lens. We describe a technique of intraocular, videoendoscope-guided, fluorescein-assisted pars plana vitrectomy that enables direct visualization and thorough removal of the anterior vitreous without the need for lens extraction in prepresbyopic patients without cataract.

Adult↗

Optical coherence tomography under general anesthesia in a child with nystagmus.

PURPOSE: To describe a method that permits optical coherence tomography scanning to be performed under general anesthesia. DESIGN: Observational case report. METHODS: A 7-year-old child underwent optical coherence tomography scanning under general anesthesia. He was positioned prone, with the neck extended to enable vertical facial alignment on the scanner. An anti-Trendelenburg trend on the operating table minimized the degree of neck extension required. Intravenous fluids, modest ventilator airway pressures, and compression stockings were used to minimize perioperative hemodynamic disturbance and the potential for orthostatic hypotension associated with the anti-Trendelenburg trend. RESULTS: High-quality, diagnostically important optical coherence tomography scans were obtained. CONCLUSION: With appropriate patient positioning and anesthetic management, optical coherence tomography scanning can be performed on uncooperative adults and children under general anesthesia.

Anesthesia, General↗