Accuracy of two devices and three different calculation methods for predicting residual astigmatism after intraocular lens implantation.

This study examined how different methods of biometric measurement, types of intraocular lens calculation, and levels of surgeon experience affected predicted postoperative astigmatism with toric intraocular lens implantation. The error in predicted residual astigmatism was determined using the IOL Master 500 and Lenstar LS 900 devices and was calculated by the Alcon toric calculator, Alcon toric calculator with Baylor nomogram, and Barrett toric calculator. Results were reviewed from 147 eyes of 125 patients. Of the three calculations, the Barrett toric calculator had the lowest mean absolute error in predicted residual astigmatism (P < 0.0001). The mean absolute errors of the IOL Master 500 and the Lenstar LS 900 were not significantly different when compared using three different calculation methods (P = 0.54). The mean absolute error was significantly lower (P = 0.049) for ophthalmology staff than for ophthalmology residents when calculation methods were considered. In conclusion, the calculation method used for IOL selection in cataract surgery significantly affects the accuracy of both staff and residents.

Rescue of human corneal epithelial cells after alkaline insult using renalase derived peptide, RP-220.

AIM: To study the effect of renalase peptide, RP-220, on cell viability of human corneal epithelial cells after alkali insult. METHODS: A dose-response relationship between cell viability and exposure to NaOH solution were characterized using cultured human corneal epithelial cells. Viability of corneal epithelial cells was determined using commercially available MTT and CyQUANT® assays. RESULTS: At a concentration of 6 mmol/L, insult with NaOH leads to reduced corneal epithelial cell viability by approximately 30%. This reduced viability was prevented by treating the cells after initial insult with the 20-amino acid renalase derived peptide (RP-220). CONCLUSION: RP-220 has a pro-survival role for RP-220 following alkaline insult to corneal epithelial cells.

Absence of Therapeutic Benefit of the Anti-Inflammatory Protein TSG-6 for Corneal Alkali Injury in a Rat Model.

Purpose: To investigate the therapeutic efficacy of tumor necrosis factor (TNF)-α stimulated gene/protein 6 (TSG-6) in a rat model of corneal alkali injury. Methods: Corneal alkali injury was produced by placing an NaOH-soaked filter paper disk on the central cornea of the right eye of an anesthetized male Lewis (LEW/Crl) rat. Recombinant human TSG-6, or an equal volume of phosphate-buffered saline (PBS), was administered intravenously (IV), by anterior chamber (AC) injection, or as a topical drop. The affected eyes were photographed daily using a dissecting microscope and documented for clinical time course analysis of corneal opacification. Corneal tissue was excised at pre-determined therapeutic endpoints, with subsequent qRT-PCR or histological analyses. Results: The continuous monitoring of corneal alkali injury progression revealed TSG-6 treatments do not show sufficient effectiveness in vivo regardless of IV injection, AC injection, or topical application. Corneal opacification and neovascularization were not diminished, and gene expression was not impacted by these treatments. However, both IV and AC administration of TSG-6 significantly suppressed pro-inflammatory cytokines compared to PBS-treated eyes. Conclusion: We conclude that the therapeutic potential of TSG-6 is insufficient in a rat corneal alkali injury model.

Comprehensive Modeling of Corneal Alkali Injury in the Rat Eye.

PURPOSE: To characterize the molecular, clinical, and histopathological profiles in the rat cornea after alkali injury over a 21-day period. METHODS: Alkali injury was induced in one eye of male Lewis rats. Corneal opacity and corneal neovascularization were assessed daily. Real-time qRT-PCR analysis and immunohistochemical staining were conducted to examine inflammation, neovascularization, and fibrosis. RESULTS: We found that within 2 hours of chemical exposure, corneal opacification rapidly developed with an acute increase in various cytokine expressions, while several cytokines demonstrated a secondary peak by day 7. Early neutrophil infiltration peaked at day 1 post-injury while macrophage infiltration peaked at day 7. Throughout the time course of the study, corneal opacity persisted and neovascularization, lymphangiogenesis, and fibrosis progressed. CONCLUSIONS: This study highlights the molecular, clinical, and histopathological changes throughout the progression of alkali injury in the rat cornea. These profiles will assist in the development of new strategies and therapies for ocular alkali injury.

Comparison of the anti-inflammatory effects of induced pluripotent stem cell-derived and bone marrow-derived mesenchymal stromal cells in a murine model of corneal injury.

BACKGROUND AIMS: Mesenchymal stromal cells (MSCs) offer tremendous potential for therapeutic applications for inflammatory diseases. However, tissue-derived MSCs, such as bone marrow-derived MSCs (BM-MSCs), have considerable donor variations and limited expandability. It was recently demonstrated that MSCs derived from induced pluripotent stem cells (iPSC-MSCs) have less pro-tumor potential and greater expandability of homogenous cell population. In this study, we investigated the anti-inflammatory effects and mechanism of iPSC-MSCs in a murine model of chemical and mechanical injury to the cornea and compared the effects with those of BM-MSCs. METHODS: To create an injury, ethanol was applied to the corneal surface in mice, and the corneal epithelium was removed with a blade. Immediately after injury, mice received an intravenous injection of (i) iPSC-MSCs, (ii) BM-MSCs or (iii) vehicle. Clinical, histological and molecular assays were performed in the cornea to evaluate inflammation. RESULTS: We found that corneal opacity was significantly reduced by iPSC-MSCs or BM-MSCs. Histological examination revealed that the swelling and inflammatory infiltration in the cornea were markedly decreased in mice treated with iPSC-MSCs or BM-MSCs. Corneal levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and IL-6 were lower in iPSC-MSC- and BM-MSC-treated mice, compared with vehicle-treated controls. In contrast, iPSC-MSCs with a knockdown of the TNF-α stimulating gene (TSG)-6 did not suppress the levels of inflammatory cytokines and failed to reduce corneal opacity. CONCLUSIONS: Together these data demonstrate that iPSC-MSCs exert therapeutic effects in the cornea by reducing inflammation in part through the expression of TSG-6, and the effects are similar to those seen with BM-MSCs.

Graft Detachment Rate in DSEK/DSAEK After Same-Day Complete Air Removal.

PURPOSE: We retrospectively analyzed the rate of graft detachment from 310 Descemet stripping endothelial keratoplasty (DSEK)/Descemet stripping automated endothelial keratoplasty (DSAEK) cases performed by a single surgeon over a 10-year period using same-day complete air removal. Secondary outcome measures including primary graft failure, late endothelial graft failure, rejection events, and steroid-induced ocular hypertension were also analyzed. METHODS: A retrospective chart review was performed on all patients receiving DSEK/DSAEK for any cause by the same surgeon at 2 separate institutions from January 2005 to December 2014. The air bubble used to promote graft-host apposition was completely removed after 1 hour. Descriptive statistical analysis was used to report the rates of graft detachment, and χ analysis was used to assess for associations with secondary outcomes. RESULTS: Among 310 endothelial keratoplasties analyzed, there were 19 graft detachments (6.1%). The graft detachment rate was higher during the learning curve, but rapidly declined with experience, and was 1.3% for the last 79 cases over a 4-year period. No primary graft failures were reported. The rate of steroid-induced ocular hypertension was 20%. The rate of graft failure was 8%. The rate of graft rejection events was 10.7%. Two of the 6 patients (33%) who underwent trabeculectomy before endothelial keratoplasty suffered a detachment. CONCLUSIONS: A graft detachment rate as low as 1.3% can be achieved in DSEK/DSAEK with same-day complete air removal shortly after surgery. Factors believed to contribute to a low detachment rate include complete interface fluid removal and reconstitution of the normal anterior chamber milieu to assist corneal endothelial function.

TSG-6 protects corneal endothelium from transcorneal cryoinjury in rabbits.

PURPOSE: To investigate the effect of an anti-inflammatory protein, TNF-α stimulated gene/protein (TSG)-6 and an antiapoptotic protein, stanniocalcin (STC)-1 on corneal endothelium in rabbits with transcorneal cryoinjury. METHODS: Transcorneal freezing (-80°C) was applied to rabbit corneas for 30 seconds. Immediately post injury, either TSG-6 (10 µg/100 µL), STC-1 (10 µg/100 µL), or the same volume of balanced salt solution (BSS) was injected into the anterior chamber. Each eye was examined for corneal opacity, corneal thickness, endothelial cell density, and endothelial hexagonality every 2 to 6 hours for 48 hours post injury. The concentrations of myeloperoxidase (MPO) and IL-1ß were measured in the aqueous humor every 6 hours. At 48 hours post injury, each cornea was assayed for TNF-α, IL-1ß, IL-6, and MPO, and histologically evaluated with alizarin red-trypan blue staining, hematoxylin-eosin staining, and immunostaining for neutrophils. RESULTS: Tumor necrosis factor-α stimulated gene/protein-6 significantly decreased the development of corneal opacity and edema after cryoinjury compared with STC-1 or BSS. The corneal endothelial cell density and hexagonality were markedly preserved by TSG-6. The mRNA levels of TNF-α, IL-1ß, and IL-6 in the cornea and the protein levels of MPO and IL-1ß in the aqueous humor and cornea were significantly lower in TSG-6-treated eyes than BSS-treated controls. Similarly, the expression of fibroblast growth factor-2 was reduced by TSG-6 treatment. Histologic evaluation demonstrated that neutrophil infiltration of the cornea was decreased in TSG-6-treated eyes. CONCLUSIONS: Tumor necrosis factor-α stimulated gene/protein-6 protected corneal endothelial cells from transcorneal cryoinjury through suppression of inflammation.

Endoscopic photocoagulation in the management of epithelial downgrowth.

PURPOSE: Epithelial downgrowth, a rare but devastating complication of intraocular surgery and penetrating ocular trauma, remains a therapeutic dilemma in ophthalmology. We present an interventional case report of an instance successfully treated with diode laser photocoagulation by using a purely endoscopic approach. METHODS: Case report and literature review. RESULTS: An 81-year-old woman initially presented with worsening visual acuity, diffuse corneal edema, band keratopathy, peripheral anterior synechiae, and an atypical iris cyst with angle involvement. Histopathologic examination of the iris cyst revealed nonkeratinized stratified squamous epithelium consistent with epithelial downgrowth. After thorough treatment of the epithelial downgrowth by an endoscopic technique, penetrating keratoplasty and cryoablation of the remaining corneal tissue were performed for visual rehabilitation. One year after treatment, no signs of recurrence were present. CONCLUSIONS: Diode photocoagulation by using an endoscopic approach potentially offers an effective, safe, and minimally invasive surgical approach for the management of epithelial downgrowth in patients with corneal opacity.

Diagnostic and therapeutic challenge of Aspergillus flavus scleritis.

PURPOSE: To discuss the diagnostic and therapeutic challenges involved in the management of Aspergillus flavus scleritis and present a review of related literature. METHODS: Case report and literature review. RESULTS: A healthy 54-year-old woman presented with a 1-week history of severe pain and redness in her left eye. She was treated with prednisone for presumed idiopathic autoimmune scleritis after extensive evaluation revealed no apparent etiology. While on immunosuppressant therapy, the patient developed a scleral nodule that proved to be a scleral abscess with normal overlying scleral architecture. Culture of the abscess and extensive infectious disease evaluation did not offer an etiologic explanation. Biopsy of a subsequent scleral nodule revealed fungal hyphae on fixed tissue stains, and A. flavus was identified on fungal culture. The patient later acknowledged intravenous drug use in the 2 months preceding her presentation. Oral voriconazole and intravenous caspofungin along with repeated surgical drainage of emerging scleral abscesses eradicated the active disease after 3 months. CONCLUSIONS: Despite its rare occurrence, Aspergillus sp. should be considered as a potential cause of an unusual progressive scleritis. Specific questioning regarding intravenous drug use may prove relevant. Scleral biopsy was instrumental in establishing the diagnosis. Aggressive multidrug medical therapy combined with repeated surgical debridement resulted in a positive clinical outcome.

Recombinant human tumor necrosis factor receptor Fc fusion protein (Etanercept): experience as a therapy for sight-threatening scleritis and sterile corneal ulceration.

PURPOSE: To review the efficacy of Etanercept as an alternate therapy for treatment of necrotizing anterior scleritis and sterile corneal ulceration unresponsive to traditional therapies. METHODS: A retrospective review of 10 patients treated with Etanercept for vision-threatening scleritis and sterile corneal ulceration. RESULTS: Etanercept alone or in combination with other immunosuppressive therapies controlled inflammation, arrested tissue ulceration, and in many cases permitted tapering or cessation of toxic immunosuppressive therapies. No complications or systemic toxicity were observed with Etanercept use. CONCLUSION: Etanercept is an effective treatment for scleritis and sterile corneal ulceration and has a favorable benefit-to-risk ratio. It may be considered for therapy of progressive disease or cases that are unresponsive to traditional therapies.

Delayed-onset mycobacterial keratitis after LASIK.

PURPOSE: To describe the time course, diagnosis, clinical features, and treatment of seven patients with Mycobacterium szulgai keratitis that developed from 7 to 24 weeks after laser in situ keratomileusis (LASIK). METHODS: Seven of 30 eyes of 18 patients were identified with keratitis after LASIK. The first two patients presented 12 to 14 weeks after LASIK; nontuberculous mycobacteria were identified 1 month after the flaps were cultured. Patient recall identified three additional cases by culture and two cases by clinical features alone. Pulsed-field gel electrophoresis (PFGE) was used to type the isolates, and treatment was modified based on susceptibilities. RESULTS: M. szulgai was identified in five patients for whom cultures were performed, but response to empiric therapy based on cultures proved unsatisfactory. The keratitis resolved in all patients with treatment including clarithromycin based on susceptibilities. Medical therapy was sufficient, although one patient required flap amputation. Six of seven patients recovered best-corrected visual acuity (BCVA), while one patient lost one line of BCVA. Two patients lost one line of postoperative uncorrected visual acuity (UCVA), two patients gained one line of UCVA, and three patients recovered postoperative UCVA. PFGE analysis revealed that the M. szulgai strains were identical, and the infection source was contaminated ice used to chill syringes for saline lavage. CONCLUSIONS: Nontuberculous mycobacterial keratitis after LASIK is a diagnostic and management challenge, but outcomes can be preserved with treatment based on susceptibilities. This cluster underscores the importance of adherence to sterile protocol during LASIK.

A Cluster of cases of Mycobacterium szulgai keratitis that occurred after laser-assisted in situ keratomileusis.

Laser-assisted in situ keratomileusis (LASIK) is a recently developed ophthalmic procedure. When 2 patients developed keratitis caused by Mycobacterium szulgai after they underwent LASIK surgery, we conducted a retrospective cohort study of all LASIK procedures performed at Scott & White Clinic (Temple, Texas) during a 4.5-month period. Seven patients had compatible symptoms and signs, 5 of whom had confirmed M. szulgai keratitis. Five cases occurred among 30 procedures performed by doctor A, and there were no cases among 62 procedures performed by doctor B (approximate relative risk, 12.0; 95% confidence interval, 1.6-679.0; P=.0029). Doctor A had chilled syringes of saline solution in ice for intraoperative lavage-the only factor that differentiated the procedures of the 2 surgeons. Cultures of samples from the source ice machine's drain identified M. szulgai; the strain was identical to isolates recovered from all confirmed cases and differed from 4 standard M. szulgai strains, as determined by pulsed-field gel electrophoresis. Intraoperative contamination from ice water apparently led to M. szulgai keratitis in these patients.