Chul Young Choi

Ginkgo biloba Extract and Bilberry Anthocyanins Improve Visual Function in Patients with Normal Tension Glaucoma

Ginkgo biloba extract (GBE) and anthocyanins are considered beneficial for various vascular diseases. This study was performed to evaluate the effect of GBE and anthocyanins on visual function in patients with normal tension glaucoma (NTG) based on the vascular theory of mechanisms of glaucomatous optic nerve damage. Retrospective analysis was carried out by a chart review of 332 subjects (209 men and 123 women) who were treated with anthocyanins (n=132), GBE (n=103), or no medication (control, n=97). Humphrey Visual Field (HVF) test, logarithm of the minimal angle of resolution best-corrected visual acuity (logMAR BCVA), intraocular pressure, blood pressure, and fasting blood glucose were determined before and after treatment. Complete ocular and systemic examinations were performed. The mean follow-up duration was 23.82±9.84 (range, 12-59) months; the mean anthocyanin treatment duration was 24.32±10.43 (range, 6-53) months, and the mean GBE treatment duration was 23.81±10.36 months (range, 6-59) months. After anthocyanin treatment, the mean BCVA for all eyes improved from 0.16 (±0.34) to 0.11 (±0.18) logMAR units (P=.008), and HVF mean deviation improved from -6.44 (±7.05) to -5.34 (±6.42) (P=.001). After GBE treatment, HVF mean deviation improved from -5.25 (±6.13) to -4.31 (±5.60) (P=.002). A generalized linear model demonstrated that the final BCVA was not affected by demographic differences among the groups. These results suggest that anthocyanins and GBE may be helpful in improving visual function in some individuals with NTG.

Relation between Axial Length and Ocular Parameters

Purpose: To investigate the relation between axial length (AL) and ocular parameters. Methods: Measurements of ocular biometric parameters were performed with an optical biometer, pachymeter, optical coherence tomography, and an automatic refractometer. AL, refractive error (RE), central corneal thickness, anterior chamber depth (ACD), corneal curvature (CC), white-to-white distance (WWD), and retinal nerve fiber layer (RNFL) thickness were measured. AL was evaluated in relation to ocular parameters. The Pearson correlation coefficient (r) was used to statistically evaluate each scattergram. Results: With elongation of the AL, the mean RE (r = –0.790, p < 0.001), CC (r = –0.444, p < 0.001), and RNFL thickness (r = –0.306, p < 0.001) all decreased, while the mean ACD (r = 0.506, p < 0.001) and WWD (r = 0.279, p < 0.001) increased. Conclusions: In shorter eyes, there was a tendency toward hyperopia, a steeper cornea, and a thicker RNFL, and in longer eyes toward myopia, a flatter cornea, and a thinner RNFL.

The effect of cataract surgery on diurnal intraocular pressure fluctuation.

PurposeWe examined prospectively the effects of cataract surgery on diurnal intraocular pressure (IOP) fluctuation in patients without glaucoma. Materials and MethodsWe evaluated 42 eyes from 42 patients without glaucoma that underwent clear corneal phacoemulsification and intraocular lens implantation by the same surgeon without complications. The diurnal IOP was measured using a Goldmann applanation tonometer the day before surgery and at least 4 weeks after surgery. The diurnal IOP was measured from 9 AM to 11 PM every 2 hours by the same clinician. ResultsThe mean age of the 14 men and 28 women was 69.7±7.6 (SD) years. The mean preoperative IOP was 12.2±2.5 mm Hg. Postoperatively, the mean IOP was 10.7±2.1 mm Hg. The maximum IOP was significantly decreased from the mean preoperative level of 13.7±2.7 mm Hg to 12.3±2.7 mm Hg at follow-up. The minimum IOP was also significantly decreased from 10.9±2.7 mm Hg to 9.7±2.1 mm Hg. Cataract surgery reduced IOP significantly at all measurement time points (P<0.05). However, there was no significant difference in the range of IOP before (2.8±1.3 mm Hg) and after (2.7±1.5 mm Hg) surgery (P=0.498). ConclusionsWe found a significant decrease in IOP after cataract surgery in nonglaucoma patients. However, change of diurnal IOP fluctuation after surgery was not statistically different. These results can be used as baseline data for diurnal IOP fluctuation studies in glaucoma patients after cataract surgery.

Korean Guidelines for the Diagnosis and Management of Dry Eye: Development and Validation of Clinical Efficacy

Purpose To evaluate the clinical efficacy of newly developed guidelines for the diagnosis and management of dry eye. Methods This retrospective, multi-center, non-randomized, observational study included a total of 1,612 patients with dry eye disease who initially visited the clinics from March 2010 to August 2010. Korean guidelines for the diagnosis and management of dry eye were newly developed from concise, expert-consensus recommendations. Severity levels at initial and final visits were determined using the guidelines in patients with 90 ± 7 days of follow-up visits (n = 526). Groups with different clinical outcomes were compared with respect to clinical parameters, treatment modalities, and guideline compliance. Main outcome measures were ocular and visual symptoms, ocular surface disease index, global assessment by patient and physician, tear film break-up time, Schirmer-1 test score, ocular surface staining score at initial and final visits, clinical outcome after three months of treatment, and guideline compliance. Results Severity level was reduced in 47.37% of patients treated as recommended by the guidelines. Younger age (odd ratio [OR], 0.984; p = 0.044), higher severity level at initial visit, compliance to treatment recommendation (OR, 1.832; p = 0.047), and use of topical cyclosporine (OR, 1.838; p = 0.011) were significantly associated with improved clinical outcomes. Conclusions Korean guidelines for the diagnosis and management of dry eye can be used as a valid and effective tool for the treatment of dry eye disease.

Simple Surgical Approach with High-Frequency Radio-Wave Electrosurgery for Conjunctivochalasis

OBJECTIVE To introduce a new simple surgical approach with high-frequency radio-wave electrosurgery to reduce conjunctivochalasis (CCh). DESIGN Prospective, noncomparative, interventional case series analysis. PARTICIPANTS Twelve patients (20 eyes) with CCh were recruited from the outpatient service of the Department of Ophthalmology, Kangbuk Samsung Hospital, Seoul, Korea. METHODS On the inferior bulbar conjunctiva, subconjunctival coagulation was performed with a fine-needle electrode using a high-frequency radio-wave electrosurgical unit (Ellman Surgitron; Ellman International, Inc., Hewlett, NY) in coagulation mode. MAIN OUTCOME MEASURES Conjunctivochalasis grade; epiphora and dry eye symptoms (the Ocular Surface Disease Index [OSDI]; Allergan Inc., Irvine, CA, holds the copyright); and intraoperative and postoperative complications. RESULTS Eighteen eyes (90%) recovered a smooth, wet, and noninflamed conjunctival surface within 1 month and remained stable for a follow-up period of 3 months. At 3 months postoperatively, 18 eyes (90%) had grade 0 CCh. There was a statistically significant decrease of the OSDI score at 3 months postoperatively (P < 0.001). CONCLUSIONS A surgical approach with high-frequency radio-wave electrosurgery produced a significant reduction in CCh and an improvement in symptoms. Radio-wave surgical techniques represent a favorable alternative to surgical treatment of CCh. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Changes in corneal endothelial cell density in patients with normal-tension glaucoma

PurposeTo study the changes in corneal endothelial cell density in eyes with normal-tension glaucoma compared with those in controls.MethodsA total of 227 subjects in three groups, one each of normal-tension glaucoma and primary open-angle glaucoma patients and one of normal controls, were studied from January 2008 to July 2008 in the Ophthalmology Department of Kangbuk Samsung Hospital. The glaucoma (normal-tension glaucoma and primary open-angle glaucoma) patients included monocular and binocular glaucoma patients. Corneal endothelial cells were examined using a noncontact specular microscope.ResultsThe mean endothelial cell densities in the three groups were as follows: normal-tension glaucoma group, 2696.7 ± 303.9 cell/mm2; primary open-angle glaucoma group, 2370.5 ± 392.3 cell/mm2; and normal group, 2723.6 ± 300.6 cell/mm2. The endothelial cell count was not significantly different between normal-tension glaucoma and normal groups (P = 1.000). Primary open-angle glaucoma patients had significantly lower endothelial cell counts (P < 0.001) than the normal group. The endothelial cell count was also significantly lower in eyes with primary open-angle glaucoma than in normal-tension glaucoma eyes (P < 0.001).ConclusionsThere was a significant decrease in corneal endothelial cell density in eyes with primary open-angle glaucoma, but not in eyes with normal-tension glaucoma. Elevated intraocular pressure likely affected the decrease of corneal endothelial cell density in eyes with glaucoma.

The Effect of Soft Contact Lenses During the Measurement of Retinal Nerve Fiber Layer Thickness Using Optical Coherence Tomography

Purpose: To investigate if the measurement of retinal nerve fiber layer (RNFL) thickness using optical coherence tomography (OCT) is affected by soft contact lens wear. Methods: This prospective, observational, cross-sectional clinical study looked at 66 eyes in 66 patients who usually wear soft contact lenses everyday and 36 eyes in 36 patients who did not wear contact lenses during the 6 months prior to the study. No patients had pre-existing retinal or optic nerve pathology or other media opacities that might influence the RNFL thickness. All eyes were scanned using the fast RNFL program of the Stratus OCT with and without soft contact lenses on. Results: The mean RNFL thickness in eyes with and without soft contact lenses was 99.4 ± 9.7 (SD) μ m and 100.8 ± 10.3 μ m, respectively, in contact lens wearers. The mean RNFL thickness in eyes with and without soft contact lenses was 102.8 ± 10.8 μ m and 105.3 ± 9.9 μ m, respectively, in non-contact lens wearers. The mean RNFL thickness in eyes with and without soft contact lenses was significantly different in both groups of patients (p = 0.006, p = 0.001, respectively). The average RNFL thickness without soft contact lenses was statistically significantly increased in non-contact wearers compared with soft contact lens wearers (p = 0.035). Conclusions: Soft contact lenses may affect the measurement of RNFL thickness using OCT. It is recommended that clinicians be careful in measuring RNFL thickness using OCT with myopic patients using soft contact lenses.

Age-related changes of ocular parameters in Korean subjects

Aims: To evaluate the age-related variations of ocular parameters in Korean subjects. Methods: We recruited 314 normal subjects who visited the department of Ophthalmology between January 2007 and October 2007. Refraction, axial length, corneal curvature, white-to-white distance, anterior chamber depth, corneal endothelial cell density, and retinal nerve fiber layer (RNFL) thickness were measured using auto-refractive keratometer, intraocular lens master, noncontact specular microscope, and optical coherence tomography. Result: In correlation analysis, from 19 to 82 years, hyperopic shift showed a strong positive statistical correlation with age (r = 0.553, P < 0.001). Corneal curvatures increased (r = 0.221, P < 0.001), while axial length (r = −0.506, P < 0.001), anterior chamber depth (r = −0.491, P < 0.001) and white-to-white distance (r = −0.205, P < 0.001) decreased with age. Also, corneal endothelial cell density was lower in older patients than in younger patients (r = −0.409, P < 0.001). Compared to younger patients, RNFL thickness was lower in the older patients as well, in all quadrants (superior, r = −0.283, P < 0.001; inferior, r = −0.230, P < 0.001; nasal, r = 0.025, P = 0.676; and temporal, r = −0.393, P < 0.001). According to multiple regression analysis, out of the six parameters measured, only hyperopic shift, anterior chamber depth and corneal endothelial cell density (P < 0.05) had statistically significant correlation with age. Conclusion: Some of the ocular parameters changed with aging. Hyperopic shift, shallowing anterior chamber depth, and reduction of corneal endothelial cell density were only definitely related to age.

Asymmetry of diurnal intraocular pressure fluctuation between right and left eyes.

Purpose:  To evaluate diurnal curves of intraocular pressure (IOP) in the right and left eyes of non‐glaucomatous patients.

Changes in central corneal thickness of preserved corneas over time measured using anterior segment optical coherence tomography.

Purpose: To measure central corneal thickness (CCT) and investigate serial changes in CCT, using anterior segment optical coherence tomography (AS-OCT) on corneas in storage medium. Methods: Between July and August 2006, 10 human corneoscleral discs from 5 donors between 19 and 57 years of age were obtained. Corneoscleral rims were excised and were transferred to Optisol-GS (Bausch & Lomb, Irvine, CA). After preservation, AS-OCT (Visante OCT; Carl Zeiss Meditec) was performed on all corneoscleral discs to detect serial changes in CCT. The corneas were measured with AS-OCT at 0.5, 1, 2, 3, 4, 6, and 12 hours and then at 1, 2, 3, and 4 days after preservation. Results: The mean of the baseline CCT measurements obtained with the ultrasound pachymeter was 632.7 μm. The average CCT on AS-OCT decreased to 534 μm in the first day of preservation. As time proceeded, the CCT of each cornea generally decreased. CCT decreased significantly between 30 minutes and 1 hour after preservation (P = 0.004). Also, CCT changes in the interval from preservation to 30 minutes showed a greater decline than during other intervals. Therefore, the most significant change in CCT occurred in the first hour after preservation. Conclusion: AS-OCT offers a fast easy method for evaluating human donor corneas for corneal thickness and structural changes without the risk of bacterial contamination or mechanical damage.