Kyoung Tak Ma

Level of vascular endothelial growth factor in aqueous humor and surgical results of ahmed glaucoma valve implantation in patients with neovascular glaucoma.

PurposeTo determine the associations between the levels of growth factors in aqueous humor and the surgical outcomes of Ahmed glaucoma valve implantation in patients with neovascular glaucoma (NVG). MethodsFrom 19 NVG eyes of 19 patients, a sample of aqueous humor was taken just before Ahmed glaucoma valve implantation. Levels of vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β1, and TGF-β2 in aqueous humor aspirates were measured using a sandwich enzyme-linked immunosorbent assay method. When the postoperative intraocular pressures were ≥21 mm Hg with or without antiglaucoma medications at 2 successive visits or when any other surgical interventions were needed to lower intraocular pressure, that surgery was considered a failure. After patients were classified into success versus failure groups, the levels of the growth factors between the 2 groups was compared. The cumulative probability of success according to Kaplan-Meier analysis was also determined. ResultsMean postoperative follow-up period was 40.9±19.6 months and cumulative probability of success was 43% at 57 months after surgery. Mean VEGF level in the failure group was higher than that of the success group (P=0.014). However, there was no statistical difference in the levels of TGF-β1, TGF-β2, and protein between 2 study groups (all P>0.05). ConclusionsThe level of VEGF in aqueous humor was significantly higher in the failure group after the Ahmed glaucoma implantation compared with the success group. Our results imply that VEGF may play a role in determining surgical success after Ahmed valve implantation in patients with NVG.

Anterior Chamber Measurements by Pentacam and AS-OCT in Eyes With Normal Open Angles

Purpose To assess the reproducibility and agreement of anterior chamber measurements between the Pentacam (PTC) and the Anterior segment optical coherence tomography (AOCT) in normal healthy eyes with open angle. Methods Prospective cross-sectional comparative case series. A total of 162 eyes of 81 healthy volunteers with normal open angle were included in this study. Anterior chamber angle (ACA) and anterior chamber depth (ACD) were measured with PTC and AOCT. Intra-observer variability and inter-methods agreement of both instruments for ACA and ACD were evaluated. Results Values of temporal and nasal ACA measured by two instruments were similar, and the results of ACD were also not significantly different between modalities (p>0.01). ACA and ACD measurements by PTC and AOCT showed good intra-observer and inter-method agreements (all >0.9). Conclusions PTC and AOCT are presumed to be very useful for the anterior chamber angle examination. They may provide good images and quantitative data about the angle structures including ACA and ACD.

Surgical results of Ahmed valve implantation with intraoperative bevacizumab injection in patients with neovascular glaucoma

PurposeTo investigate the surgical results of Ahmed valve implantation with intraoperative bevacizumab injection in patients with neovascular glaucoma (NVG). MethodsA retrospective comparative case series review was conducted on 52 eyes with NVG who underwent Ahmed glaucoma valve implantation with or without intraoperative bevacizumab intravitreal injection. In the intraoperative intravitreous bevacizumab injection group (IVB group, 20 eyes), 1.25 mg of bevacizumab was injected into the vitreous cavity during Ahmed valve implantation. In the control group (32 eyes), only Ahmed valve implantation was performed. Surgical failure was defined when (1) the postoperative intraocular pressure was over 21 mm Hg at consecutive clinic visits, (2) the visual acuity became light perception negative, (3) additional antiglaucomatic surgery was required, or (4) devastating operative or postoperative complications were noted. ResultsAlthough the success rate in the IVB group (70.0%) was higher than that in the control group (62.5%) 1 year after operation, the differences were not statistically significant (P=0.828 by log-rank test). Mean intraocular pressures in the IVB group were significantly lower than those of the control group at 12 and 15 months (P<0.05 by the Mann-Whitney U test). Postoperative complications were similar between the 2 groups. Preoperative history of trabeculectomy was a significant risk factor for surgical failure of Ahmed valve implantation in NVG (relative risk=4.618; P=0.018 by Cox regression model). ConclusionsIntraoperative IVB injection does not seem to be helpful for better surgical outcomes of Ahmed valve implantation in NVG. A history of trabeculectomy is a risk factor for failure after Ahmed valve implantation in patients with NVG.

Comparison of OCT and HRT Findings Among Normal, Normal Tension Glaucoma, and High Tension Glaucoma

Purpose To evaluate the relationship between optic disc and retinal nerve fiber layer (RNFL) measurements obtained with the optical coherence tomography (OCT) and the Heidelberg retina topography (HRT) in normal, normal tension glaucoma (NTG), and high tension glaucoma (HTG). Methods Normal, NTG and HTG subjects who met inclusion and exclusion criteria were evaluated retrospectively. One hundred seventy eyes of 170 patients (30 normal, 40 NTG, and 100 HTG) were enrolled. Complete ophthalmologic examination, HRT, OCT, and automated perimetry were evaluated. Results Disc area, cup area and cup/disc area ratio measured with HRT were significantly different between NTG and HTG (all p<0.05). Mean RNFL thickness measured by OCT with ascanning diameter of 3.4 mm was larger in NTG than HTG (84.97±24.20 µm vs. 73.53±27.17 µm, p=0.037). Four quadrant RNFL thickness measurements were not significantly different between NTG and HTG (all p>0.05). Mean deviation and corrected pattern standard deviation measured by automated perimetry was significantly correlated with mean and inferior RNFL thickness in both NTG and HTG (Pearsons r, p<0.05). Mean RNFL thickness/disc area ratio was significantly larger in HTG than NTG (35.21±18.92 vs. 31.30±10.91, p=0.004). Conclusions These findings suggest that optic disc and RNFL damage pattern in NTG may be different from those of HTG.

The Effect of Swimming Goggles on Intraocular Pressure and Blood Flow within the Optic Nerve Head

Purpose Goggles are frequently worn in the sport of swimming and are designed to form a seal around the periorbital tissue orbit. The resultant pressure on the eye may have the potential to affect intraocular pressure and blood flow of the optic nerve head. This study evaluates the influence of wearing swimming goggles on intraocular pressure (IOP) and blood flow of the ocular nerve head (ONH) in normal subjects. Materials and Methods Thirty healthy participants took part in this study. The IOP of each participant was measured using a Goldmann tonometer. Measurements were taken immediately before putting on swimming goggles, at 5, 10, 30, and 60 minutes after putting on swimming goggles, and then immediately after taking off the goggles. Blood flow of the ONH was measured using the Heidelberg retinal flowmeter. Results The average IOP before, during and after wearing the swimming goggles were 11.88 ± 2.82 mmHg, 14.20 ± 2.81mmHg and 11.78 ± 2.89 mmHg, respectively. The IOP increased immediately after putting on the goggles (p < 0.05) and then returned to normal values immediately after removal (p > 0.05). Blood flow of the ONH was 336.60 ± 89.07 Arbitrary Units (AU) before and 319.18 ± 96.02 AU after the goggles were worn (p < 0.05). Conclusion A small but significant IOP elevation was observed immediately after the swimming goggles were put on. This elevated IOP was maintained while the goggles were kept on, and then returned to normal levels as soon as they were taken off. Blood flow of the ONH did not change significantly throughout the experiment. These facts should be considered for safety concerns, especially in advanced glaucoma patients.

Modified Siepser sliding knot technique for scleral fixation of subluxated posterior chamber intraocular lens.

UNLABELLED We describe a new technique of scleral fixation for the management of dislocated intraocular lenses (IOL). A suture is tied inside the eye around the dislocated haptic to prevent slippage of the IOL after surgery. The technique, which is safe and less invasive than previous methods, was used in 3 patients and the results are presented. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.

Potential benefit of intraocular pressure reduction in normal-tension glaucoma in South Korea.

PURPOSE The aim of this study was to evaluate the potential benefit of intraocular pressure (IOP) reduction in normal tension glaucoma (NTG) Asian adult patients in South Korea. METHODS This was a retrospective, multicenter analysis of 166 NTG Asian adult patients in South Korea. The patient population consisted of Korean patients with NTG with at least 5 years of records available for evaluation. Patients all had typical glaucomatous optic-disc and/or visual-field changes but had never had a recorded IOP >21 mmHg. RESULTS Overall, 48 (29%) patients were progressed and 116 (71%) were stable over the follow-up period. Of patients with IOPs <or=14 mmHg (21/93), 23% progressed and >or=15 mmHg (27/73) 37% progressed (P = 0.041). The mean IOP for the stable group was 14.0 +/- 1.8 mmHg, whereas with the progressed group the average mean IOP was 14.4 +/- 1.6 mmHg (P = 0.20). The mean peak IOP was 17.4 +/- 2.2 mmHg in the stable group and 17.8 +/- 2.0 mmHg in the progressed group (P = 0.26). Multivariate linear regression analysis did not any identify independent risk factors for progression, including age, gender, or mean and peak IOP. CONCLUSIONS This study provides initial evidence that Korean patients with normal-tension glaucoma, treated to lower IOPs, may have a decreased incidence of progression over 5 years than those patients with higher IOPs. More research is required to confirm this finding.

Relationship between the Retinal Thickness Analyzer and the GDx VCC Scanning Laser Polarimeter, Stratus OCT Optical Coherence Tomograph, and Heidelberg Retina Tomograph II Confocal Scanning Laser Ophthalmoscopy

Purpose To assess the relationship between the retinal thickness analyzer (RTA) parameters, and those of the GDx VCC scanning laser polarimeter (GDx VCC), Stratus OCT optical coherence tomography (Stratus OCT), and Heidelberg retinal tomograph II confocal scanning laser ophthalmoscopy (HRT II). Methods Twenty-nine primary open-angle glaucoma patients were retrospectively included in this study. Measurements were obtained using the RTA, GDx VCC, Stratus OCT, and HRT II. We calculated the correlation coefficients between the parameters of RTA and those of the other studies. Results Among the optic disc parameters of RTA, the cup volume was best correlated with Stratus OCT (R=0.780, p<0.001) and HRT II (R=0.896, p<0.001). Among the posterior pole retinal thickness parameters, the posterior pole abnormally thin area (PPAT) of the RTA and the inferior average of the GDx VCC were best correlated (R=-0.596, p=0.001). The PPAT of the RTA and the inferior maximum of the Stratus OCT were best correlated (R=-0.489, p=0.006). The perifoveal minimum thickness (PFMT) of the RTA and the cup shape measurement of the HRT II were best correlated (R=-0.565, p=0.004). Conclusions Many RTA optic disc parameters were significantly correlated with those of the Stratus OCT and HRT II. The RTA posterior pole retinal thickness parameters were significantly correlated with those of the GDx VCC, Stratus OCT and HRT II. The RTA optic disc and posterior pole retinal thickness parameters may be valuable in the diagnosis of glaucoma.

Split-thickness hinged scleral flap in the management of exposed tubing of a glaucoma drainage device.

A split-thickness hinged scleral flap technique was devised to aid in tube exposure after glaucoma drainage device implantation. This technique resulted in the successful recovery of the tube without reexposure or serious complications in all 3 observed cases. Split-thickness hinged scleral flaps may be an effective surgical technique for the management of repeated tube exposure after glaucoma drainage device implantation.

Bleb Analysis and Short-Term Results of Biodegradable Collagen Matrix-Augmented Ahmed Glaucoma Valve Implantation: 6-Month Follow-up

PURPOSE To evaluate the short-term efficacy of a biodegradable collagen matrix (BCM) as an adjuvant for Ahmed valve implantation surgery to prevent the hypertensive phase. METHODS This prospective study included 43 refractory glaucoma eyes, all followed for 6 months. Refractory glaucoma was defined as an IOP higher than 20 mm Hg with antiglaucoma eye drops without previous glaucoma surgery. Conventional method was performed in 21 eyes and BCM-augmented Ahmed valve implantation (BAAVI) in 22 eyes. In the BAAVI group, a 10 × 10 × 2-mm BCM was sutured on an Ahmed glaucoma valve FP7 model. Complete success was defined as an IOP of 21 mm Hg or lower (target IOP 1) or 17 mm Hg or lower (target IOP 2) without antiglaucoma medications and qualified success as an IOP of 21 mm Hg or lower with or without medications. Maximal bleb thickness was measured using anterior segment optical coherence tomography images. RESULTS The preoperative IOPs and numbers of preoperative antiglaucoma medications were similar for both groups. Complete target IOP 1 success rates were 38.1% and 86.4%, complete target IOP 2 success rates were 19.0% and 59.1%, and qualified success rates were 52.4% and 90.9% in the conventional and BAAVI groups, respectively (P < 0.05). The hypertensive phase rate was lower in the BAAVI group (4.5% vs. 47.6%, P = 0.002). Maximal bleb thickness was increased in the BAAVI group on postoperative days 30 and 180 (P < 0.05). CONCLUSIONS Success rates were higher in the BAAVI group than in the conventional group with the change of bleb morphology. Furthermore, use of BCM significantly decreased the need for antiglaucoma medications for at least 6 months postoperatively.