Jae Lim Chung

Bevacizumab application delays epithelial healing in rabbit cornea.

PURPOSE Vascular endothelial growth factor (VEGF) is essential for neovascularization, but the use of anti-VEGF therapies to inhibit neovascularization may influence epithelial wound healing. Here, the effects of bevacizumab on corneal epithelial wound healing time in rabbit models, cell proliferation, and expression of integrins in human corneal epithelial and fibroblast cells were evaluated. METHODS To compare epithelial wound healing times, epithelial defect sizes were measured after application of bevacizumab topical eye drops at 0, 0.5, 1.0, 1.5, 2.5, or 5 mg/mL, twice daily, to mechanically debrided epithelia of rabbit corneas. The cellular covering of wounded areas and expression of Ki67 were assessed after scrape injuries in cultures of human corneal epithelial and fibroblast cells. Expression of cell surface integrins and collagens was measured using plates coated with mouse monoclonal antibodies against human adhesion molecules, and relevant mRNA levels were assessed by reverse-transcription-polymerase chain reaction (RT-PCR). RESULTS The application of bevacizumab topical eye drops at 1.0, 1.5, 2.5, or 5 mg/mL delayed rabbit corneal epithelial healing. Cell cultures growing under high concentrations of bevacizumab showed delay in the proliferation of corneal epithelial and fibroblast cells. Surface expression of mRNA encoding integrins and collagens were decreased by 1.5 mg/mL of bevacizumab. CONCLUSIONS Bevacizumab delayed corneal epithelial wound healing and inhibited integrin expression. When bevacizumab is used to reduce the development of new corneal vessels, slight delays in epithelial wound healing are possible and cellular proliferation is to be expected.

Antibiotic susceptibility of conjunctival bacterial isolates from refractive surgery patients.

PURPOSE To determine the in vitro antibiotic susceptibility patterns of conjunctival bacterial flora isolated before surgery from patients undergoing refractive surgery. DESIGN In vitro laboratory investigation. PARTICIPANTS One hundred five eyes from 105 patients scheduled for refractive surgery at Balgensesang Ophthalmology Clinic between September 2005 and January 2006 were studied. Among 105 patients, 71 (67.6%) underwent LASIK using a femtosecond laser, 24 (22.9%) underwent LASIK using an automated microkeratome, 8 (7.6%) underwent LASEK, and 2 (1.9%) patients underwent phakic intraocular lens implantation. METHODS Preoperative conjunctival swab samples were inoculated directly in culture media at the bedside before topical anesthetic or antibiotic application. Blood agar, chocolate agar, thioglycolate broth, Sabouraud dextrose agar, and Ogawa media were used for bacterial, fungal, and mycobacterial cultures. MAIN OUTCOME MEASURES Minimum inhibitory concentrations (MICs) of ofloxacin (OFX), levofloxacin (LEV), gatifloxacin (GAT), moxifloxacin (MOX), gemifloxacin (GEM), and other commonly used antibiotics were determined using an E test. RESULTS From 105 patients, 73 (85%) coagulase-negative staphylococci (CNS), 2 (2.3%) Staphylococcus aureus, 1 (1.2%) Streptococcus pneumoniae, and 5 (4.8%) gram-negative bacilli were isolated. No fungi or mycobacteria were isolated. The MIC that would inhibit the growth of 90% of the tested bacterial isolates (MIC(90)) of OFX, LEV, GAT, MOX, and GEM for methicillin-susceptible CNS (n = 46) were 0.5 microg/ml, 0.19 microg/ml, 0.094 microg/ml, 0.047 microg/ml, and 0.023 microg/ml, respectively. The MIC(90) values for methicillin-resistant CNS (n = 27) were 32 microg/ml, 4 microg/ml, 1 microg/ml, 0.5 microg/ml, and 0.25 microg/ml, respectively (P<0.001). CONCLUSIONS The most effective against conjunctival bacteria isolated from refractive surgery patients were GEM, MOX, and GAT; however, resistance to earlier-generation fluoroquinolones (OFX and LEV) is increasing among methicillin-resistant CNS. It may be a therapeutic option to use newer fluoroquinolones in patients undergoing refractive eye surgery to reduce such infections as methicillin-resistant CNS. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Univariate and bivariate polar value analysis of corneal astigmatism measurements obtained with 6 instruments.

Purpose To compare the corneal astigmatism measurements from 6 instruments in preoperative assessment for toric intraocular lens (IOL) implantation. Setting Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea. Design Prospective comparative observational study. Methods This study included patients with cataract and more than 1.00 diopter (D) of corneal astigmatism. For preoperative evaluation of toric IOL implantation, the net astigmatism was evaluated using manual keratometry, autokeratometry, partial coherence interferometry (PCI) (IOLMaster), corneal topography/ray‐tracing aberrometry (iTrace), scanning‐slit topography (Orbscan), and Scheimpflug imaging (Pentacam). All net astigmatisms were converted to polar values. Using the astigmatism measurements from manual keratometry as a standard, Bland‐Altman analysis, linear mixed‐model, and bivariate graphic analysis were performed. Results The study group comprised 257 eyes of 141 patients. Bland‐Altman plots showed good agreement between manual keratometry and each instrument for polar values. There was no significant between‐instrument difference in KP(90) and KP(135) in the linear mixed model analysis or in bivariate polar values in bivariate confidence ellipses. Conclusion The corneal astigmatism measurements from autokeratometry, PCI, corneal topography/ray‐tracing aberrometry, scanning‐slit topography, and Scheimpflug imaging were comparable to those from manual keratometry and can be used interchangeably with manual keratometry to measure corneal astigmatism. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Comparative intraocular penetration of 4 fluoroquinolones after topical instillation.

Purpose: To compare the intraocular penetration of 4 fluoroquinolone eye drops after topical instillation into rabbit eyes. Methods: The tested drugs were levofloxacin 1.5% (LVFX), gatifloxacin 0.3%, moxifloxacin 0.5% (MFLX), and besifloxacin 0.6% (BFLX). Forty-eight New Zealand white rabbits were randomly assigned into 2 groups. For group 1 (40 rabbits, 80 eyes), single instillation was performed, and tissue samples were acquired after 0.5, 1, 2, 4, and 6 hours. For group 2 (8 rabbits, 16 eyes), repeated instillation was performed (4 times, every 15 minutes), and tissues were acquired 1 hour after the fourth instillation. The drug concentrations in ocular tissues (cornea, aqueous, conjunctiva, and trisected vitreous) were analyzed with high-performance liquid chromatography. Results: The AUC0–6 h (area under the curve, in microgram.hour/gram) in group 1 and the mean concentration (in micrograms/gram) in group 2 for LVFX, gatifloxacin 0.3%, MFLX, and BFLX, respectively, were 22.97, 6.44, 13.54, and 3.29 and 22.60, 6.99, 13.69, and 1.91 in cornea; 5.66, 1.43, 3.38, and 0.42 and 5.52, 1.29, 2.47, and 0.19 in aqueous humor; 2.33, 0.91, 2.17, and 9.83 and 4.51, 0.78, 1.48, and 2.09 in bulbar conjunctiva; 0.243, 0.051, 0.134, and 0.018 and 0.182, 0.055, 0.122, and 0.015 in anterior vitreous; none of the drugs achieved enough concentration in equatorial and posterior vitreous. Repeated instillation resulted in approximately 2.1 times greater penetration than single instillation. Conclusions: LVFX and MFLX demonstrated good intraocular penetration particularly in cornea, aqueous humor, and anterior vitreous, and they may be considered the penetrative fluoroquinolones. BFLX showed high concentration in bulbar conjunctiva and may be considered the retentive fluoroquinolone.

Analysis of deposit depth and morphology in granular corneal dystrophy type 2 using fourier domain optical coherence tomography

Purpose: Granular corneal dystrophy type 2 (GCD2) causes the formation of corneal deposits having 3 different morphological types. We used Fourier domain optical coherence tomography to assess the depths of each type according to the morphology. Methods: A prospective study was performed in 54 eyes of 54 heterozygous patients with GCD2. Corneal deposits of 54 patients with GCD2 were classified into 3 morphological types: type 1, diffuse haze; type 2, granular shape (2 subgroups: type 2a, round granulated and type 2b, round spiculated); and type 3, linear shape (2 subgroups: type 3a, short side branched and type 3b, long side branched). Using Fourier domain optical coherence tomography, we measured the distances from the Bowman layer to the upper surface of the deposits (USBL), to the lower surface of the deposits (LSBL), and the thickness of the deposits (TD). The deposits formed along the flap interface were also examined among 19 patients who had LASIK. Results: Types 1 and 2 deposits were always adjacent to the Bowman layer; thus the USBLs for each were 0.0 ± 0.0 μm, whereas that of type 3 deposits was 65.4 ± 48.0 μm (P < 0.0001). The LSBL and TD of linear deposits with long side branches (type 3) (313.3 ± 71.4 and 246.2 ± 71.9 μm) were greater than those of type 1 (47.7 ± 10.2 and 47.7 ± 10.2 μm) and type 2 (91.3 ± 39.5 and 91.3 ± 39.5 μm) (P < 0.0001). There were no differences in the measurements between the subgroups type 2a and type 2b or between types 3a and 3b. USBL of the laser in situ keratomileusis group was 54.5 ± 29.8 μm. Conclusions: The depths of corneal deposits in patients with GCD2 were associated with the morphology of the deposits. The linear deposits were located most deeply in the cornea, followed by granular deposits and diffuse haze moving anteriorly. Several deposits have distinct depths according to the morphological types.

Change in Corneal Sensitivity and Corneal Nerve after Cataract Surgery

Purpose: To compare corneal sensitivity and recovery of corneal innervation between temporal and superior clear corneal incisions in cataract surgery. Methods: We compared the change in corneal sensitivity in patients with cataract who had received phacoemulsification using either temporal clear corneal incisions (group 1) or superior clear corneal incisions (group 2). The changes were measured at 1 week, 1 month, and 3 months after surgery using the Cochet-Bonnet esthesiometer. For a different study population, changes of corneal sensitivity in 25 eyes of 20 patients and corneal nerve density with confocal microscopy in 20 eyes of 20 patients who had undergone cataract surgery were also assessed. All parameters were measured preoperatively and at 1 week, 1 month, and 3 months after surgery. Results: There was a significant decrease in sensitivity at the incision site in both groups. At 3 months after surgery, corneal sensitivity mostly recovered to preoperative values. Although postoperative change in corneal sensitivity showed similar patterns in both groups, group 1 showed a larger decrease. At temporal clear corneal incision sites, there was significantly decreased sensitivity at 1 week and 1 month postoperatively. However, corneal sensitivity returned to the preoperative levels by 3 months. Confocal microscopy revealed that at 1 week, 1 month, and 3 months after cataract surgery, subbasal nerve density was significantly reduced to 4113 ± 1421, 3555 ± 1448, and 4198 ± 1239 μm/mm2, respectively. Conclusions: Corneal sensitivity after cataract surgery returned to near preoperative levels by 3 months before complete restoration of normal corneal innervation. Regeneration of subbasal nerve fibers determined by confocal microscopy seems to require more time than the return of corneal sensation after cataract surgery.

A Case of Weill-Marchesani Syndrome with Inversion of Chromosome 15

Purpose To present a case of Weill-Marchesani syndrome with corneal endothelial dysfunction due to anterior dislocation of a spherophakic lens and corneolenticular contact. Methods A 17-year-old woman presented with high myopia and progressive visual disturbance. She was of short stature and had brachydactyly. Her initial Snellen best corrected visual acuity (BCVA) was 20/50 (-sph 20.50 -cyl 3.00 Ax 180) in her right eye and 20/40 (-sph 16.00 -cyl 6.00 Ax 30) in her left eye. Slit lamp examination revealed a dislocated spherophakic lens touching corenal endothelium. A microspherophakic lens, hypoplastic ciliary body, and elongated zonules were confirmed on rotating Scheimpflug camera (Pentacam®) and on ultrasound biomicroscopy. Specular microscopy showed corneal endothealial dysfunction. Systemic evaluation was performed, and chromosomal study showed 46, XX, inv (15) (q13qter). The patient was diagnosed with Weill-Marchesani syndrome. Results Due to impending corneal decompensation, phacoemulsification and suture fixation of the intraocular lens were performed. The operation and postoperative course were uneventful. Three months postoperatively, the visual acuity was 20/30 (OD) and 20/40 (OS) without correction, and BCVA was 20/20 (+sph 0.50 -cyl 2.00 Ax 160 : OD) and 20/25 (+sph 1.50 -cyl 3.00 Ax 30 : OS). During the follow-up period, increased corneal endothelial counts, hexagonality, and decreased corneal thickness were achieved. Conclusions In Weill-Marchesani syndrome with a chromosomal anomaly, a dislocated spherophakic lens may cause severe corneal endothelial dysfunction due to corneolenticular contact, and prompt lensectomy is important to prevent such complications.

Successful argon laser photocoagulation of diffuse epithelial ingrowth following concomitant persistent pupillary membrane removal and phacoemulsification

UNLABELLED A 57-year-old woman had concomitant surgery of persistent pupillary membrane removal and uneventful phacoemulsification through the same temporal clear corneal incision in her left eye. Short axial lengths (right eye, 21.08 mm; left eye, 20.39 mm) with shallow angles were noted bilaterally, and other findings were not remarkable. The patient experienced angle-closure attacks 3 and 7 months postoperatively. At the second angle-closure attack, diffuse epithelial ingrowth was observed. The epithelial ingrowth covered the intraocular lens surface in the interpupillary area, the iris surface surrounding the pupil, and the temporal anterior chamber angle, but did not reach the corneal endothelial incision. After observation of iris blanching with laser photocoagulation, argon laser photocoagulation was applied to the epithelium covering the iris and angle 7 times during the following month. The epithelial ingrowth was completely removed and did not recur during the 36-month follow-up. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.

Changes in Spherical Aberration after Various Corneal Surface Ablation Techniques

Purpose The corneal change induced by refractive procedures influence both the postoperative refractive status and the ocular spherical aberration (SA). We evaluated changes in corneal SA after three types of surface ablation: phototherapeutic keratectomy (PTK), myopic photorefractive keratectomy (PRK), and myopic wavefront-guided laser epithelial keratomileusis (LASEK). Methods Twenty-six eyes (25 patients) were subjected to PTK 26 eyes (14 patients) to PRK, and 34 eyes (17 patients) to wavefront-guided LASEK. Corneal SA was measured with the iTrace in all patients both preoperatively and 6 months postoperatively. Results Six months after surgery, mean corneal SA was -0.173 ± 0.171 µm in the PTK group, 0.672 ± 0.200 µm in the PRK group, and 0.143 ± 0.136 µm in the wavefront-guided LASEK group. The mean difference between the preoperative and postoperative corneal SA (ΔSA) was -0.475 µm in the PTK group, 0.402 µm in the PRK group, and -0.143 µm in the wavefront-guided LASEK group. Conclusions Surgically induced changes in corneal SA vary with procedure. The prediction of the pattern of SA change induced by various surface ablation procedures may be helpful for developing future surgical procedures.