Prevention, diagnosis, and management of acute postoperative bacterial endophthalmitis

This distillation of the peer-reviewed scientific literature on infection after cataract surgery summarizes background material on epidemiology, etiology, and pathogenesis, describes the roles of surgical technique and antibiotic prophylaxis in prevention, and discusses diagnostic and therapeutic interventions in cases of suspected endophthalmitis.

Nano-scaled Pt/Ag/Ni/Au contacts on p-type GaN for low contact resistance and high reflectivity

We synthesized the vertical-structured LED (VLED) using nano-scaled Pt between p-type GaN and Ag-based reflector. The metallization scheme on p-type GaN for high reflectance and low was the nano-scaled Pt/Ag/Ni/Au. Nano-scaled Pt (5 A) on Ag/Ni/Au exhibited reasonably high reflectance of 86.2% at the wavelength of 460 nm due to high transmittance of light through nano-scaled Pt (5 A) onto Ag layer. Ohmic behavior of contact metal, Pt/Ag/Ni/Au, to p-type GaN was achieved using surface treatments of p-type GaN prior to the deposition of contact metals and the specific contact resistance was observed with decreasing Pt thickness of 5 A, resulting in 1.5 x 10(-4) ohms cm2. Forward voltages of Pt (5 A)/Ag/Ni contact to p-type GaN showed 4.19 V with the current injection of 350 mA. Output voltages with various thickness of Pt showed the highest value at the smallest thickness of Pt due to its high transmittance of light onto Ag, leading to high reflectance. Our results propose that nano-scaled Pt/Ag/Ni could act as a promising contact metal to p-type GaN for improving the performance of VLEDs.

In vivo structural characteristics of the femtosecond LASIK-induced opaque bubble layers with ultrahigh-resolution SD-OCT

The authors report in vivo morphology of opaque bubble layers with ultrahigh-resolution anterior-segment optical coherence tomography (UHR-OCT) in 3 patients. Two patients were operated on with a 30-kHz IntraLase femtosecond laser (Abbott Medical Optics, Abbott Park, IL) and one patient was operated on with a 500-kHz VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). UHR-OCT images from the patient operated on with the 500-kHz femtosecond laser revealed that the opaque bubble layer extended anterior to the flap dissection plane up to Bowman's membrane. The lamellar flap dissection was incomplete in this patient. The opaque bubble layer in the patients operated on with the 30-kHz femtosecond laser extended posterior to the flap dissection plane and these patients experienced complete lamellar dissections with uncomplicated flap lifts. UHR-OCT imaging can be used to demonstrate the structural characteristics of OBL. It has the potential to be used to predict incomplete lamellar flap dissections in patients with opaque bubble layers.

In vivo morphologic characteristics of Salzmann nodular degeneration with ultra-high-resolution optical coherence tomography

PURPOSE

To examine the in vivo morphologic properties of Salzmann nodular degeneration with ultra-high-resolution optical coherence tomography (OCT).

DESIGN

Interventional case series.

METHODS

SETTING

Single-center academic practice.

STUDY POPULATION

Nineteen eyes of 12 patients with Salzmann nodular degeneration were recruited to participate in the study.

OBSERVATIONAL PROCEDURE

Subjects were imaged using novel, custom-built ultra-high-resolution OCT. Images were used to describe in vivo characteristics of subepithelial nodules. Morphometric measurements were made with custom-built software. Ultra-high-resolution OCT findings were compared with histopathologic findings in 3 patients.

MAIN OUTCOME MEASURES

Identifiable in vivo morphologic characteristics of Salzmann nodular degeneration with ultra-high-resolution OCT.

RESULTS

Ultra-high-resolution OCT images demonstrate intraepithelial fibrous nodules with epithelial thinning and corneal surface elevation. The Bowman layer could be differentiated in 9 of 12 patients. The difference between the mean thickness of epithelium above the nodule and the thickness of normal epithelium was statistically significant (P < .0001). The correlation between thickness of the epithelium and thickness of the nodule was statistically significant (r = -0.48; P < .0001). The correlation between thickness of the nodule and total surface thickness (thickness of the epithelium + thickness of the nodule) was statistically significant (r = 0.98; P < .0001). Ultra-high-resolution OCT findings were consistent with histopathologic results.

CONCLUSIONS

Ultra-high-resolution OCT can be used to noninvasively image the cornea in Salzmann nodular degeneration. This new imaging technique helps us to demonstrate different in vivo morphologic characteristics of Salzmann nodular degeneration.

Automated donor tissue preparation for descemet membrane automated endothelial keratoplasty (DMAEK): an experimental study

BACKGROUND AND OBJECTIVE

Graft harvesting for Descemet membrane endothelial keratoplasty (DMEK) occurs manually and demonstrates surgical difficulties. In the current study, a mechanical automated technique for preparing a donor Descemet membrane (DM) carrying autologous endothelium for DMEK was evaluated.

MATERIALS AND METHODS

Ten rabbit corneas were placed on an artificial anterior chamber and mechanical separation of the DM was conducted using an Epi-keratome (Senturium; Norwood Abbey EyeCare, Victoria, Australia). All DM specimens were properly fixated and optical microscopy was performed.

RESULTS

DM separation was achieved in a controlled fashion in 7 of 10 eyes. As demonstrated by optical microscopy of the specimens, no corneal stroma was attached on the DM, whereas the endothelial layer was preserved in several areas.

CONCLUSION

Automated separation of the DM can be achieved using an Epi-keratome. Additional studies and improvements of the current technique are needed to draw final conclusions.

Phase I study of subconjunctival ranibizumab in patients with primary pterygium undergoing pterygium surgery

PURPOSE

To evaluate the safety and tolerability of ranibizumab given via subconjunctival injection in patients with primary pterygium undergoing pterygium surgery with autograft placement.

DESIGN

Prospective, open-label pilot study.

METHODS

SETTING

Single-center, academic practice.

STUDY POPULATION

Ten patients with primary pterygia.

OBSERVATIONAL PROCEDURE

Subconjunctival ranibizumab (0.5 mg/0.05 mL) administered at the limbus, adjacent to pterygium either 3 days prior to surgery (Group 1, n = 5) or at the time of surgery (Group 2, n = 5). Patients prospectively followed for 6 months after injection.

MAIN OUTCOME MEASURES

Safety and tolerability of subconjunctival ranibizumab as determined by patient reporting, clinical examination, and masked observer interpretation of slit-lamp photographs.

RESULTS

The median age at presentation was 59 years (range 33 to 71 years); 60% of patients were male. Five patients were randomly assigned to be injected with 0.05 mg ranibizumab via subconjunctival injection 3 days prior to surgery; an additional 5 patients were injected with ranibizumab at the time of surgery. All 10 patients tolerated the injection well. The conjunctival autograft remained intact in the 9 patients whose grafts were secured with sutures. There was dehiscence of the autograft in the 1 patient whose graft was secured with fibrin glue. No other safety concerns arose after 6 months of follow-up. Three pterygium recurrences were noted at 6 months (all patients in Group 1). All remaining patients had a normal surgical bed appearance.

CONCLUSIONS

The data from this small pilot study suggest that 1 subconjunctival injection of ranibizumab in conjunction with pterygium surgery is well tolerated.

Immune regulatory effects of simvastatin on regulatory T cell-mediated tumour immune tolerance

Statins are potent inhibitors of hydroxyl-3-methylglutaryl co-enzyme A (HMG-CoA) reductase, and have emerged as potential anti-cancer agents based on preclinical evidence. In particular, compelling evidence suggests that statins have a wide range of immunomodulatory properties. However, little is known about the role of statins in tumour immune tolerance. Tumour immune tolerance involves the production of immunosuppressive molecules, such as interleukin (IL)-10, transforming growth factor (TGF)-beta and indoleamine-2,3-dioxygenase (IDO) by tumours, which induce a regulatory T cell (T(reg)) response. In this study, we investigated the effect of simvastatin on the production of IL-10, TGF-beta and IDO production and the proliferation of T(regs) using several cancer cell lines, and Lewis lung cancer (3LL) cells-inoculated mouse tumour model. Simvastatin treatment resulted in a decrease in the number of cancer cells (3LL, A549 and NCI-H292). The production of the immune regulatory markers IL-10, TGF-beta in 3LL and NCI-H292 cells increased after treatment with simvastatin. The expression of IDO and forkhead box P3 (FoxP3) transcription factor was also increased in the presence of simvastatin. In a murine 3LL model, there were no significant differences in tumour growth rate between untreated and simvastatin-treated mice groups. Therefore, while simvastatin had an anti-proliferative effect, it also exhibited immune tolerance-promoting properties during tumour development. Thus, due to these opposing actions, simvastatin had no net effect on tumour growth.

Brevundimonas vesicularis keratitis after laser in situ keratomileusis

A 45-year-old woman developed a corneal infiltrate 14 months after laser in situ keratomileusis (LASIK) enhancement in the left eye. The LASIK flap was lifted, scraped, and irrigated with fortified vancomycin and ceftazidime. Scraped samples were cultured and grew Brevundimonas vesicularis. The patient remained on topical ceftazidime until improvement was noted and was then switched to topical levofloxacin. The keratitis resolved on antibiotic agents with strong gram-negative coverage and a steroid. To our knowledge, this is the first report of a B vesicularis ocular infection.

Corneal Melt While Using Topical Bevacizumab Eye Drops

A 75-year-old man presented with an idiopathic central corneal perforation and was treated with cyanoacrylate glue and a bandage contact lens. The stromal bed healed but the patient was left with 360 degrees of corneal neovascularization. Bevacizumab eye drops (25 mg/mL) were prescribed for 1 month which caused marked regression of the blood vessels. A penetrating keratoplasty was performed and the patient continued to use the bevacizumab eye drops for 6 weeks after surgery. The patient noted decreased visual acuity 5 weeks after surgery and was found to have a melt in the stroma of the donor graft necessitating repeating therapeutic penetrating keratoplasty and Gunderson flap. This case highlights that whereas topical bevacizumab may aid in regression of acute corneal neovascularization, caution should be employed with its use in patients with a history of corneal melt.

Diagnosis of Donor Graft Partial Dislocation Behind the Iris After DSAEK with Anterior Segment OCT

A 65-year-old woman was referred with postoperative persistent corneal edema and interface fluid superiorly without dislocation of the donor button after Descemet's stripping automated endothelial keratoplasty (DSAEK). Slit lamp examination revealed the presence of fluid in the interface between donor and recipient button at the superior part of the cornea but the diagnosis was uncertain clinically due to significant corneal clouding. Anterior segment optical coherence tomography (AS-OCT) examination revealed donor graft dislocation behind the iris at the superior part of the lenticule. This case report demonstrates that donor graft partial dislocation behind the iris after DSAEK could be a potential cause of DSAEK failure. AS-OCT is a useful and noninvasive instrument for detecting the post-DSAEK complication especially in patients in which diagnosis is difficult due to significant corneal clouding.

Interface Haze Formation After Ultra Thin Flap Laser in Situ Keratomileusis

In this case series, five patients (10 eyes) underwent laser in siter keratomileusis (LASIK) for the correction of moderate myopia and astigmatism with the Schwind Carriazo Pendular microkeratome 90 mum head. Flap (superior hinged) thickness measured intraoperatively was assessed less than 70 mum in all eyes. On first month's postoperative examination, subepithelial mild corneal haze with consequent myopic regression was found in all patients. A significant improvement of haze formation and residual refractive error were observed during the following postoperative months. In conclusion, post-LASIK subepithelial corneal haze after thin flap creation is a temporarily potential complication that could affect patient's refractive error during the first postoperative month.

Customized pachymetric guided epithelial debridement for corneal collagen cross linking

Backround

We describe a modified method for deepitheliazation prior to corneal cross linking (CXL). The technique may overcome the current corneal pachymetric limitation parameter (over 400 microns) that is necessary for the safety of the procedure without affecting the overall benefits.

Methods

In a series of two patients, with inferior topographic steepening and regional thinning (less than 400 microns corresponding to the area of corneal steepening), CXL after customized epithelial removal was performed.

Results

There were no intra- or postoperative adverse events seen by the nine month follow up examination. Stabilization of the corneal ectasia was observed up to nine months post-costumized pachymetric-guided epithelial removal.

Conclusion

The technique of customized pachymetric-guided epithelial removal is easy to perform and may overcome the limitations of the preoperative corneal pachymetry expanding the application of the procedure in patients with regional corneal thinning.

Photorefractive Keratectomy in a Patient with Epithelial Basement Membrane Dystrophy

PURPOSE

To report a case of excimer laser photorefractive keratectomy (PRK) in a patient with epithelial basement membrane dystrophy (EBMD).

METHODS

Interventional case report.

RESULTS

A 36-year-old male with clinical manifestations of EBMD underwent bilateral, simultaneous PRK for low myopia correction. A delay (up to 17 days) in the epithelial healing process with unstable epithelium was observed. During the first three postoperative months a visually significant subepithelial haze was developed in both eyes. One year postoperative, an improvement in haze formation and visual acuity in both eyes was found.

CONCLUSIONS

PRK in patients with EBMD could result in favorable refractive and clinical outcome.