Biomedical subjects

Hak Sung Chung

Publications and source records attributed to Hak Sung Chung.

3 recordsLinked to original sources

PubMed2006

Suture reaction masquerading as a conjunctival malignancy.

CASE REPORT: We report a case of conjunctival inflammation secondary to a retained suture masquerading as a neoplastic lesion. Excisional biopsy was performed in the right eye on a superior bulbar conjunctival lesion that appeared to be a conjunctival malignancy. A past history of ptosis surgery was obtained. Careful repeated examination with anesthesia, applying traction to the forniceal conjunctiva, revealed an occult polypropylene suture. Despite clinical features typical of malignancy, histologic examination revealed only chronic inflammatory cells. COMMENTS: Patients with suspicious conjunctival lesions and a history of ptosis surgery should be carefully explored for retained suture fragments. Examination with anesthesia may be needed to find an occult suture.

Biopsy↗

PubMed2005

Pupil response to tropicamide following laser in situ keratomileusis.

PURPOSE: To investigate the effect of corneal thinning after laser in situ keratomileusis (LASIK) on the corneal penetration of topical eye medication. SETTING: Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA. METHODS: Laser in situ keratomileusis surgery was performed in 19 eyes of 10 patients enrolled in this prospective study. Measurements were made before surgery and 3 months postoperatively. After instillation of tropicamide 1%, the change in pupil size over time was measured with a Colvard pupillometer. Central corneal thickness (CCT) was measured with ultrasonic pachymetry before and 3 months after LASIK. The corneal epithelial condition was also examined by fluorescein dye staining. RESULTS: The mean CCT decreased significantly from 564 microm +/- 33 (SD) before LASIK surgery to 514 +/- 48 microm 3 months postoperatively (P<.0001). Pupil diameter 10, 15, and 20 minutes after tropicamide 1% instillation was significantly larger 3 months after surgery than preoperatively (P=.0083, P=.0043, and P=.0144, respectively). The mean time to reach a pupil diameter of 6.0 mm decreased significantly from 14.4 +/- 4.3 minutes in preoperative eyes to 11.5 +/- 2.3 minutes in postoperative eyes (P=.0281). Mild punctate corneal epithelial staining (fewer than 5 spots) were observed in 4 eyes at the 3-month postoperative examination. CONCLUSIONS: Pupil dilation after tropicamide 1% instillation was significantly faster after LASIK surgery. Corneal thinning that resulted from LASIK enhanced corneal penetration of tropicamide 1%.

Adult↗

PubMed2005

Photorefractive keratectomy with intraoperative mitomycin-C application.

PURPOSE: To evaluate the efficacy and safety of photorefractive keratectomy (PRK) with intraoperative application of mitomycin-C (MMC). SETTING: Yonsei Eye Center, Seoul, South Korea. METHODS: This retrospective noncomparative case series included 536 patients (1011 eyes) who had had PRK with intraoperative application of MMC using the Nidek EC-5000 excimer laser. Preoperative and postoperative best spectacle-corrected and uncorrected visual acuities, spherical equivalent (SE) refraction, corneal haze graded by slitlamp biomicroscopy, and endothelial cell density measured by specular microscopy were evaluated. RESULTS: The mean preoperative SE was -7.82 diopters (D) +/- 2.64 (SD); 72% of eyes (732) were more than -6.00 D, and 28% (287) were more than -9.00 D. The mean follow-up was 13 months (range 6 to 27 months). Six months postoperatively, the mean postoperative SE was -0.14 +/- 0.62 D; 86% were within +/-0.50 D and 93% were within +/-1.00 D of desired refraction. Eighty-six percent had 20/20 or better visual acuity, and 98% were 20/40 or better. Regression of more than 1.00 D occurred in 78 eyes (7.6%), and it was more common in eyes with a preoperative SE of -9.00 D or worse (18%). Haze occurred in 32 eyes (3.17%), but in most cases it was limited to grade 1. Grades 2 and 3 haze occurred in 3 eyes and 2 eyes, respectively. The postoperative endothelial cell density measured by specular microscopy did not show a significant difference from preoperative measurements. Delayed epithelial healing was observed in 2 eyes. CONCLUSION: Photorefractive keratectomy with intraoperative application of MMC was a safe procedure that produced excellent visual outcomes with few complications.

Adult↗