Hyoung Jun Koh

Intravitreal toxicity of the kenalog vehicle (benzyl alcohol) in rabbits.

Purpose: To test the toxicity of intravitreal injections of benzyl alcohol. Methods: Nine New Zealand rabbits were injected with either a control or a test article at elevating concentrations. The test article was benzyl alcohol calculated to give final injected concentrations of 0.0073%, 0.022%, 0.073%, 0.222%, and 0.733% benzyl alcohol. The 0.022% concentration corresponds to the concentration of benzyl alcohol in human eyes when 0.1 mL of commercial Kenalog (Bristol–Myers Squibb, Princeton, NJ) is used. Baseline examination of the rabbits was performed along with postinjection examinations on days 1, 3, 7, and 14. The eyes were enucleated and examined by light and electron microscopic examinations. Results: Eyes injected with benzyl alcohol concentrations of 0.073%, 0.222%, and 0.733% displayed changes in the outer retina including loss of, and shortening of, outer segments and photoreceptors. Conclusions: Benzyl alcohol at concentrations modestly higher than what is present in commercial Kenalog is toxic to the rabbit eye. This has been shown in other organ systems. If commercial preserved Kenalog is to be used clinically, decanting the supernatant or using other means to remove the benzyl alcohol may be considered, especially if a volume of >0.1 mL of solution is used. We hypothesize that the noninfectious inflammation seen clinically after Kenalog injection is due to the presence of a toxic preservative at unsafe concentrations.

Posterior Vitreomacular Adhesion and Risk of Exudative Age-related Macular Degeneration: Paired Eye Study

PURPOSE To evaluate posterior vitreomacular adhesion as a risk factor for choroidal neovascularization (CNV) in age-related macular degeneration (AMD). DESIGN Retrospective, observational case series. METHODS We retrospectively reviewed optical coherence tomography (OCT) and fluorescein angiography (FA) of 251 consecutive patients with unilateral exudative AMD. Fellow eyes had no sign of exudative AMD. Vitreomacular adhesion was defined when posterior hyaloid line attached to inner retinal surface was seen in OCT. We compared the incidence of posterior vitreomacular adhesion between the 2 eyes and the association between CNV location and vitreomacular adhesion. RESULTS We found posterior vitreomacular adhesion in 56 patients (22.3%), and 3 cases in which it was present in both eyes. CNV was mostly present in eyes with vitreomacular adhesion (44/53, 83%), and rarely found in eyes without vitreomacular adhesion (6/53, 11.3%; P = .0007). The location of vitreomacular adhesion was always observed over the area of the CNV in exudative eyes (50/50). CONCLUSIONS Posterior vitreomacular adhesion is associated with CNV in AMD. Chronic vitreomacular traction may be a risk factor for the development of exudative AMD.

Incidence and clinical patterns of polypoidal choroidal vasculopathy in Korean patients.

PurposeTo determine the incidence, demographic features, and clinical characteristics of polypoidal choroidal vasculopathy (PCV) in Korean patients.MethodsA retrospective review was undertaken of 392 eyes of 321 symptomatic patients suspected of having exudative age-related macular degeneration (AMD) after their first visit to a tertiary hospital between February 2002 and May 2006. All patients underwent a complete ophthalmic examination, including fluorescein and indocyanine green angiography (ICGA).ResultsOf the 321 patients (392 eyes), 79 (98 eyes, 24.6%) were diagnosed with PCV. The mean PCV patient age was 64.6 ± 7.6 years. PCV was more common in men (78.5%), and was usually unilateral (75.9%). In terms of PCV clinical manifestation, 52% of patients showed an exudative pattern, 34.7%, a hemorrhagic pattern, and 13.3%, an extensive hemorrhagic pattern. The mean visual acuity at presentation was 0.231 ± 0.256. Classification was based on ICGA findings; 52% of patients showed relatively large aneurismal dilations, 25.5% showed atypical vessel deformations, and 22.5% showed dense clusters of numerous small hyperfluorescent dots.ConclusionsThe incidence of PCV in Korean exudative AMD patients was relatively high compared with that in other ethnic groups. As in other Asian patient populations, PCV occurred more commonly in men and was predominantly unilateral.

Problems Associated with the 25-Gauge Transconjunctival Sutureless Vitrectomy System during and after Surgery

Objective: To report the initial experiences with the 25-gauge transconjunctival sutureless vitrectomy (TSV) system, including intraoperative and postoperative problems. Methods: We retrospectively reviewed the medical records and surgical videotapes of 50 consecutive patients who underwent vitrectomy performed by one surgeon using the TSV system. Results: Intraoperatively, we encountered such problems as difficulty in inserting the microcannula, which led to deformity, instability of the microcannula, self-disconnection of the infusion tip and resultant lens damage, and conversion to 20-gauge conventional vitrectomy. Postoperatively, there were 8 cases with hypotony (IOP < 6 mm Hg) on day 1, 6 cases with elevated IOP, and 3 cases with retinal detachment during follow-up. Conclusion: Though certain problems exist during and after surgeries using TSV, this system is both convenient and safe for various vitreoretinal procedures.

Concentration of cytokines in the aqueous humor of patients with naive, recurrent and regressed CNV associated with amd after bevacizumab treatment.

Purpose: To evaluate the concentration of various cytokines in the aqueous humor of patients with naive, recurrent, and regressed choroidal neovascularization (CNV) of age-related macular degeneration after bevacizumab treatment. Methods: Aqueous humor samples were collected from 36 eyes with age-related macular degeneration and 10 controls during cataract surgery. Of 36 patients with age-related macular degeneration, 5 eyes were naïve to bevacizumab injection, 14 eyes had recurrent CNV after bevacizumab treatment, and 17 eyes had regressed CNV after bevacizumab treatment. Cytokines were measured by an immunoassay using multianalyte biochip array technology (Evidence investigator cytokine and growth factor biochip array, RANDOX laboratories Ltd., Crumlin, UK). Results: No significant difference in the cytokine levels was noted between the control group and the naïve CNV group (all P > 0.05). Vascular endothelial growth factor in both naive (66.8 ± 35.1 pg/mL) and recurrent CNV groups (55.7 ± 63.0 pg/mL) was significantly higher compared with regressed CNV group (9.8 ± 12.8 pg/mL, P = 0.025 and P = 0.004, respectively) but was not statistically different from the control group (81.8 ± 43.7 pg/mL, P = 0.310 and P = 0.212, respectively). The aqueous humor level of tumor necrosis factor-&agr; and interleukin (IL)-2 was significantly lower in recurrent CNV group (P = 0.036 and P = 0.019) compared with the control group. In the active CNV patients (recurrent and naïve CNV groups), the aqueous humor levels of IL-6 and IL-8 significantly correlated with the size of CNV (&rgr; = 0.692, P = 0.001 and &rgr; = 0.745, P < 0.001, respectively). Conclusion: Levels of Vascular endothelial growth factor measured in the aqueous humor were significantly related to the disease activity of CNV in age-related macular degeneration. Moreover, IL-2, IL-6, IL-8, and tumor necrosis factor-&agr; may be related to the activity of CNV.

Effects of vitreomacular adhesion on anti-vascular endothelial growth factor treatment for exudative age-related macular degeneration.

OBJECTIVE To evaluate the effect of posterior vitreomacular adhesion (VMA), documented by optical coherence tomography (OCT), on the outcome of anti-vascular endothelial growth factor (VEGF) treatment for exudative age-related macular degeneration (AMD). DESIGN Retrospective comparative series. PARTICIPANTS A total of 148 patients (148 eyes) who were newly diagnosed with exudative AMD and were treated by anti-VEGF in 1 eye from 2005 to 2008 with a minimum of 12 months follow-up. METHODS We retrospectively reviewed OCT and medical records of 148 patients with exudative AMD and categorized them according to the presence of posterior VMA into 2 subgroups: VMA (+) group (38 eyes) and VMA (-) group (110 eyes). Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) after anti-VEGF treatment were compared between the 2 groups at baseline; at 1, 3, 6, and 12 months; and at the last visit (mean = 21 months). MAIN OUTCOME MEASURES Mean changes in BCVA, which was converted to logarithm of the minimum angle of resolution (logMAR) values and CRT after anti-VEGF treatment. RESULTS Mean BCVA significantly decreased over time in the VMA (+) group compared with the VMA (-) group (P = 0.039). At the last follow-up, mean BCVA had deteriorated from 0.87 logMAR (20/149 Snellen equivalent; baseline) to 0.98 logMAR (20/189 Snellen equivalent) in the VMA (+) group, but improved from 0.82 logMAR (20/132 Snellen equivalent, baseline) to 0.72 logMAR (20/104, Snellen equivalent) in the VMA (-) group (P = 0.028). In paired comparisons of BCVA between baseline and each follow-up visit, the VMA (-) group showed significant improvement of BCVA at every follow-up visit (P < 0.05); however, the VMA (+) group did not show significant visual improvement at any follow-up visit despite anti-VEGF treatment (P > 0.05). Comparison of mean CRT between baseline and each follow-up visit showed a statistically significant decrease at every follow-up in both groups (P < 0.05). CONCLUSIONS Posterior VMA was associated with an inferior visual outcome after intravitreal anti-VEGF treatment for exudative AMD. Our results suggest that chronic tractional forces may antagonize the effect of anti-VEGF treatment, resulting in poor response to anti-VEGF treatment with patients with VMA.

Effects of macular ischemia on the outcome of intravitreal bevacizumab therapy for diabetic macular edema.

Purpose: To evaluate the effects of macular ischemia on visual outcomes in patients with diabetic macular edema (DME), after intravitreal bevacizumab injections. Methods: Data on 59 eyes of 53 consecutive patients treated with intravitreal bevacizumab for DME were retrospectively reviewed. Data from preoperative fluorescein angiography (FA) tests were examined. Patients with an enlarged foveal avascular zone (FAZ), ≥1000 &mgr;m, or a broken perifoveal capillary ring at the border of the FAZ, with a distinct area of capillary nonperfusion within one disk diameter of the foveal center in the transit phase of fluorescein angiography, were defined as having macular ischemia. The patients were thus divided into two groups: with or without macular ischemia. Early Treatment Diabetic Retinopathy Study (ETDRS) scores, and foveal thicknesses measured using third generation ocular coherence tomography (OCT), were evaluated at baseline and at 1 month and 3 months after treatment. Results: At 3 months after treatment, the mean visual acuity (VA) score decreased from a baseline VA of 0.52 ± 0.27 (approximate Snellen equivalent, 20/63) to 0.57 ± 0.21 (20/80) in the ischemic group. In the nonischemic group, by contrast, the VA improved from 0.66 ± 0.34 (20/100) at baseline to 0.59 ± 0.33 (20/80) at 3 months post-treatment. Nine of 18 eyes (50%) in the ischemic group, but only 9 of 41 eyes (21%) in the nonischemic group, experienced visual losses of ≥1 line on the ETDRS chart (P = 0.031, Pearson chi-square test). Four eyes (22%) in the ischemic group, but only 2 eyes (5%) in the nonischemic group, lost ≥3 lines (P = 0.042, Pearson chi-square test). Conclusion: Macular ischemia may have a negative effect on short term visual outcomes after intravitreal bevacizumab injections in patients with DME.

Association between choroidal thickness and ocular perfusion pressure in young, healthy subjects: enhanced depth imaging optical coherence tomography study.

PURPOSE To investigate the correlation of choroidal thickness (CT) with ocular perfusion pressure (OPP) in young, healthy subjects using enhanced depth imaging optical coherence tomography (EDI-OCT). METHODS A single horizontal section and a single vertical section of EDI-OCT scans in each eye of 69 young, healthy subjects were obtained at the macula. CT was measured at the fovea, and up to 3 mm, at intervals of 0.5 mm, away from the fovea in the superior, inferior, nasal, and temporal choroid. Univariable and multivariable analyses were performed to assess the association of CT with OPP while axial length (AL), refractive error (RE), sex, and/or body mass index (BMI), were taken into consideration. RESULTS Mean subfoveal CT was 307.03 ± 91.27 μm (mean age, 22.3 ± 3 years; mean axial length, 25.35 ± 1.14 mm; mean refractive error, -3.89 ± 2.02 diopters; mean OPP, 44.18 ± 5.49 mm Hg). Multivariable regression analysis showed that in eyes with <6 diopters of myopia, subfoveal CT (325.92 ± 88.46 μm) changed most significantly in association with RE and mean OPP (β = 25.941, P < 0.001; β = -3.551, P = 0.042, respectively; adjusted R(2) = 0.249). In subjects with myopia of >6 diopters, subfoveal CT (225.17 ± 49.37 μm) was significantly thinner (P < 0.0001), and a significant correlation with OPP was not observed (P > 0.05). CONCLUSIONS In vivo subfoveal CT as measured by EDI-OCT was significantly associated with OPP in young, healthy subjects when adjusted for RE, suggesting that subfoveal CT may be indirectly indicative of subfoveal ocular perfusion status. This association was not observed in subjects with high myopia.

Intravitreal anti-VEGF versus photodynamic therapy with verteporfin for treatment of myopic choroidal neovascularization.

Purpose: The purpose of this study was to compare visual outcomes after treatment with intravitreal antivascular endothelial growth factor (anti-VEGF) injection or photodynamic therapy (PDT) in patients with myopic choroidal neovascularization (CNV). Methods: One hundred and forty-two eyes of 128 consecutive patients treated with anti-VEGF (ranibizumab or bevacizumab) and/or PDT for myopic choroidal neovascularization were retrospectively reviewed. Patients were categorized into 3 groups: PDT (51 eyes), anti-VEGF (63 eyes), and a combination group (PDT with anti-VEGF) (28 eyes). Corrected visual acuity values at baseline and 3, 6, 9, and 12 months after treatment were compared. Results: The anti-VEGF group showed significant postoperative improvement in visual acuity compared with the PDT and combination groups (P = 0.01 and 0.04, respectively). The anti-VEGF group demonstrated visual improvement from baseline at every follow-up visit after treatment (P = 0.04, 0.02, 0.01, and 0.002, respectively). The anti-VEGF group showed visual improvement (Snellen equivalent) from 0.57 logarithm of the minimum angle of resolution (0.27) to 0.33 logarithm of the minimum angle of resolution (0.47) (P = 0.01). Furthermore, 98.4% of patients in the anti-VEGF group and 92.8% of those in the combination group lost <15 letters from baseline visual acuity compared with 72.6% in the PDT group (P = 0.001 and 0.02, respectively). In the anti-VEGF group, 39.7% of patients improved from baseline by 15 or more letters compared with 17.7% in the PDT group (P = 0.02) and 21.4% in the combination group (P = 0.07). Conclusion: Intravitreal anti-VEGF injection is superior to PDT alone or a combination of PDT with anti-VEGF for treating myopic choroidal neovascularization.

Choroidal thickness in Behcet's uveitis: an enhanced depth imaging-optical coherence tomography and its association with angiographic changes.

PURPOSE To evaluate the change in subfoveal choroidal thickness between active and quiescent phases of Behcets posterior uveitis and compare this with the healthy population using enhanced depth imaging optical coherence tomography (EDI-OCT). METHODS Thirty eyes from 30 patients with Behcets posterior uveitis (mean age, 47.03 ± 11.01 years) were retrospectively enrolled in the study. Their subfoveal choroidal thickness was measured using EDI-OCT in the active and quiescent phases of Behcets uveitis, and compared with the age, sex, and spherical equivalent-matched healthy population. Changes in retinal vascular leakage on fluorescein angiography (FA) were correlated with the changes in subfoveal choroidal thickness. RESULTS Mean subfoveal choroidal thickness in the acute phase of Behcets uveitis was significantly greater than that in the quiescent phase (398.77 ± 155.59 μm versus 356.72 ± 141.09 μm; P = 0.004). Subfoveal choroidal thickness in the quiescent phase was also significantly greater than that of the healthy population (259.96 ± 65.16 μm; P < 0.0001). There was a statistically significant association between the change in subfoveal choroidal thickness and the change in vascular leakage revealed by FA (ρ = 0.381, P = 0.046). Subfoveal choroidal thickness in the uninvolved fellow eyes of patients with unilateral Behcets uveitis was also evaluated and it was significantly greater than that of the healthy population (n = 13 eyes; P = 0.001) CONCLUSIONS: This study found choroidal thickening during the active phase of Behcets posterior uveitis. Subfoveal choroidal thickness during the quiescent phase was also significantly greater than in normal eyes. The degree of reduction in choroidal thickening was significantly correlated with improvement in retinal vascular leakage as revealed by FA.