Hong Kyun Kim

In Vivo Corneal Endothelial Safety of Intracameral Bevacizumab and Effect in Neovascular Glaucoma Combined With Ahmed Valve Implantation

PurposeTo evaluate the corneal toxicity of intracameral bevacizumab in rabbit eyes and also the effects of intracameral bevacizumab in neovascular glaucoma patients combined with Ahmed glaucoma valve implantation. Materials and MethodsIntracameral bevacizumab (1.25 mg/0.05 mL) was injected into 5 eyes of 5 New Zealand white rabbits. A balanced salt solution (0.05 mL) was injected intracamerally in another 5 rabbits as a control. The corneal thickness, endothelial cell counts, and intraocular pressure were measured before and at 1, 2, and 4 weeks after the intracameral injection of bevacizumab and a balanced salt solution. Scanning electron microscopic examinations were performed at 1 and 4 weeks after injection. In the clinical cases, 6 patients who received an intracameral injection of bevacizumab (1.25 mg) and Ahmed glaucoma valve implantation were enrolled. The visual acuity, intraocular pressure, and regression of iris rubeosis by iris fluorescein angiography were recorded before and at 1 week, 1 month, and 2 months after the intracameral bevacizumab injection and Ahmed glaucoma valve implantation. ResultsNo morphologic and functional changes in the corneal endothelial cells were observed in the rabbit eyes after the intracameral bevacizumab and balanced salt solution injections. Iris rubeosis regression was observed in all eyes within 1 week after the injection. The visual acuity remained stable or improved, and the intraocular pressure was controlled in all eyes throughout the follow-up period. There were no ocular and systemic complications associated with the combined procedure. ConclusionsAn intracameral injection of bevacizumab may be a safe alternative treatment for iris rubeosis in neovascular glaucoma when combined with Ahmed glaucoma valve implantation.

Dried Human Amniotic Membrane Does Not Alleviate Inflammation and Fibrosis in Experimental Strabismus Surgery

Purpose. The purpose of this study was to evaluate the efficacy of dried human amniotic membrane (AM) in reducing the postoperative inflammatory response and scarring after strabismus surgery. Methods. The inflammatory response at the extraocular muscle reattachment site was analyzed after superior rectus (SR) resection in 12 rabbits. Dried human AM (Ambiodry2) was applied between the resected SR muscle plane and Tenons capsule of the left eyes of rabbits. As a control, the right eyes of rabbits underwent SR resection only. The surgeon randomly ordered which eye gets operated first during the experiment. Two weeks later, enucleation was performed. Six sagittal sections were made for each eye at the insertion of the SR muscle. The grade of postoperative inflammation and the presence of fibrosis were evaluated in histological examinations. Results. There was no statistically significant difference in the intensity of inflammation and fibrous proliferation between the eyes treated with dried human AM after SR resection and those treated with SR resection only. Conclusions. The use of dried human AM was not effective in controlling the postoperative inflammation and scarring in rabbit eyes after extraocular muscle surgery. However, this may be due to the devitalized dry preparation of human AM (Ambiodry2), which may have lost the expected anti-inflammatory and anti-scarring properties, and further studies on humans may be necessary.

Clinical analysis of risk factors contributing to recurrence of pterygium after excision and graft surgery

AIM To find the risk factors related to the reproliferation of the pterygial tissue after excision and graft surgery. METHODS Charts of 130 eyes of 130 patients who had pterygial excision from March 2006 to April 2011 were reviewed. Preoperative pterygium morphology, surgical methods, and adjunctive treatments were statistically analyzed for their relationship with recurrence. RESULTS During the follow-up period, recurrence was observed in 20 eyes (15.4%). None of the preoperative morphologic features were affected the rate of the recurrence. However, an age < 40y [P =0.085, odds ratio (OR) 3.609, 95% confidence interval (CI) 0.838-15.540] and amniotic membrane graft instead of conjunctival autograft (P =0.002, OR 9.093, 95% CI 2.316-35.698) were statistically significant risk factors for recurrence. Multivariate analysis revealed that intraoperative mitomycin C (MMC) (P=0.072, OR 0.298, 95% CI 0.080-1.115) decreased the rate of recurrence. CONCLUSION Younger age is a risk factor for reproliferation of pterygial tissue after excision and amniotic membrane transplantation (AMT) are less effective in preventing recurrence of pterygium after excision based on the comparison between conjunctival autograft and AMT. Intraoperative MMC application and conjunctival autograft reduce recurrence.

Autologous Platelet-rich Plasma Eye Drops in the Treatment of Recurrent Corneal Erosions

Purpose To evaluate the effect of platelet-rich plasma (PRP) eye drops in the treatment of recurrent corneal erosions (RCE). Methods A total of 47 eyes were included in this retrospective study. Clinical records of 20 consecutive patients with RCE who had been treated with conventional lubricant eye drops (conventional treatment group) from June 2006 to December 2008 and 27 consecutive patients treated with autologous PRP eye drops in addition to lubricant eye drops (PRP eye drops treated group) from January 2009 to September 2014 were reviewed. Major and minor recurrences were recorded and compared between two groups. Results This study included 31 men and 16 women. The mean age was 44.5 ± 14.5 years (range, 19 to 86 years), and the mean follow-up duration was 14.9 ± 14.4 months (range, 6 to 64 months). Of the 27 cases in the PRP eye drops treated group, there were seven major recurrences in six eyes (22.2%) and ten minor recurrences in seven eyes (25.9%). In contrast, 16 eyes (80.0%) from the 20 patients in the conventional lubricant eye drops treated group had major recurrences, and all patients in this group reported minor recurrences. The mean frequency of recurrence was 0.06 ± 0.08 per month in the PRP eye drops treated group and 0.39 ± 0.24 per month in the conventional treatment group (p = 0.003). No side effects were noted in any of the patients over the follow-up period. Conclusions The use of PRP eye drops for the treatment of RCE was shown to be effective in reducing the recurrence rate without any significant complications.

A Comparison of Clinical Outcomes of Dislocated Intraocular Lens Fixation between In Situ Refixation and Conventional Exchange Technique Combined with Vitrectomy.

Purpose. To evaluate surgical efficacy of in situ refixation technique for dislocated posterior chamber intraocular lens (PCIOL). Methods. This was a single-center retrospective case series. 34 patients (34 eyes) who underwent sclera fixation for dislocated IOLs combined with vitrectomy were studied. Of 34 eyes, 17 eyes underwent IOL exchange and the other 17 eyes underwent in situ refixation. Results. Mean follow-up period was 6 months. Mean logMAR best corrected visual acuity (BCVA) was not significantly different between the groups 6 months after surgery (0.10 ± 0.03 in the IOL exchange group and 0.10 ± 0.05 in the refixation group; p = 0.065). Surgically induced astigmatism (SIA) was significantly lower in the refixation group (0.79 ± 0.41) than in the IOL exchange group (1.29 ± 0.46) (p = 0.004) at 3 months, which persisted to 6 months (1.13 ± 0.18 in the IOL exchange group and 0.74 ± 0.11 in the refixation group; p = 0.006). Postoperative complications occurred in 3 eyes in the IOL exchange group (17.6%) and 2 eyes in the refixation group (11.8%). However, all of the patients were well managed without additional surgery. Conclusion. The in situ refixation technique should be preferentially considered if surgery is indicated since it seemed to produce a sustained less SIA compared to IOL exchange.

Generation of Femtosecond Laser-Cut Decellularized Corneal Lenticule Using Hypotonic Trypsin-EDTA Solution for Corneal Tissue Engineering

Purpose To establish an optimized and standardized protocol for the development of optimal scaffold for bioengineering corneal substitutes, we used femtosecond laser to process human corneal tissue into stromal lenticules and studied to find the most efficient decellularization method among various reagents with different tonicities. Methods The decellularization efficacy of several agents (0.1%, 0.25%, and 0.5% of Triton X-100, SDS, and trypsin-EDTA (TE), resp.) with different tonicities was evaluated. Of all protocols, the decellularization methods, which efficiently removed nuclear materials examined as detected by immunofluorescent staining, were quantitatively tested for sample DNA and glycosaminoglycan (GAG) contents, recellularization efficacy, and biocompatibilities. Results 0.5% SDS in hypertonic and isotonic buffer, 0.25% TE in hypotonic buffer, and 0.5% TE in all tonicities completely decellularized the corneal lenticules. Of the protocols, decellularization with hypotonic 0.25 and 0.5% TE showed the lowest DNA contents, while the GAG content was the highest. Furthermore, the recellularization efficacy of the hypotonic TE method was better than that of the SDS-based method. Hypotonic TE-treated decellularized corneal lenticules (DCLs) were sufficiently transparent and biocompatible. Conclusion We generated an ideal protocol for DCLs using a novel method. Furthermore, it is possible to create a scaffold using a bioengineered corneal substitute.

Clinical Analysis of Ocular Parameters Contributing to Intraoperative Pain during Standard Phacoemulsification

Purpose. To study the correlation between ocular parameters and subjective pain that patients perceived during phacoemulsification. Methods. Medical records of 142 patients who underwent standard phacoemulsification under topical anesthesia between March and August 2016 were retrospectively reviewed. The pain during phacoemulsification and 1 h after surgery was assessed and compared using a visual analog scale. In addition, demographic data, preoperative biometric parameters, and intraoperative surgical parameters were recorded. Results. Mean age of patients was 67.49 ± 12.50 years. The mean pain score was 2.26 ± 0.85 during phacoemulsification and 0.40 ± 0.69 postoperatively. Intraoperative pain was significantly associated with higher preoperative intraocular pressure (β = 0.220, P = 0.016), greater anterior chamber depth (β = 0.210, P = 0.028), and greater axial length (β = 0.181, P = 0.043). Conclusions. To reduce the subjective pain when patients have high preoperative intraocular pressure, large anterior chamber depth, or great axial length, supplementary procedures may be required.

Rhus javanica Gall Extract Inhibits the Differentiation of Bone Marrow-Derived Osteoclasts and Ovariectomy-Induced Bone Loss

Inhibition of osteoclast differentiation and bone resorption is a therapeutic strategy for the management of postmenopausal bone loss. This study investigated the effects of Rhus javanica (R. javanica) extracts on bone marrow cultures to develop agents from natural sources that may prevent osteoclastogenesis. Extracts of R. javanica (eGr) cocoons spun by Rhus javanica (Bell.) Baker inhibited the osteoclast differentiation and bone resorption. The effects of aqueous extract (aeGr) or 100% ethanolic extract (eeGr) on ovariectomy- (OVX-) induced bone loss were investigated by various biochemical assays. Furthermore, microcomputed tomography (µCT) was performed to study bone remodeling. Oral administration of eGr (30 mg or 100 mg/kg/day for 6 weeks) augmented the inhibition of femoral bone mineral density (BMD), bone mineral content (BMC), and other factors involved in bone remodeling when compared to OVX controls. Additionally, eGr slightly decreased bone turnover markers that were increased by OVX. Therefore, it may be suggested that the protective effects of eGr could have originated from the suppression of OVX-induced increase in bone turnover. Collectively, the findings of this study indicate that eGr has potential to activate bone remodeling by inhibiting osteoclast differentiation and bone loss.