PURPOSE: To report the occurrence of corneal ectasia (ECT) in patients with history of Stevens-Johnson syndrome (SJS), and to make the case for an association between these 2 diagnoses. We also report the impact of prosthetic replacement of the ocular surface ecosystem (PROSE) treatment on visual acuity (VA) in these patients. DESIGN: Retrospective cohort study. METHODS: A manufacturing database of PROSE patients from 2002 to 2014 at Boston Foundation for Sight (BFS), a single-center clinical practice, was reviewed to identify patients with diagnoses of both SJS and ECT. RESULTS: Nine patients were identified with diagnoses of both SJS and ECT. In each case, review of the medical record revealed that diagnosis of SJS preceded that of ECT. The prevalence of ECT in this population exceeded that in the general population (P < .0001). Videokeratography was available for 13 eyes in 7 patients; using Krumeich's classification of keratoconus, 3 eyes were found to be at stage 1, 3 at stage 2, 1 at stage 3, and 6 at stage 4. Sixteen of 18 eyes underwent PROSE treatment. Of these 16 eyes, initial median VA was 20/200 (range, count fingers to 20/20; logMAR 1.0). Median VA after PROSE customization was 20/30 (range, 20/60-20/15; logMAR 0.1761, P < .0025). CONCLUSIONS: ECT occurs at a higher-than-expected rate in patients with a history of SJS. PROSE treatment improves VA in these patients. The basis of the association between SJS and ECT is considered, as well as the role of plausible contributory factors such as corneal microtrauma and matrix metalloproteinases.
PURPOSE: We discovered that dihydrotestosterone (DHT) decreases the ability of lipopolysaccharide, a bacterial toxin, to stimulate the secretion of leukotriene B4, a potent proinflammatory mediator, by immortalized human meibomian gland epithelial cells (IHMGECs). We hypothesize that this hormone action reflects an androgen suppression of proinflammatory gene activity in these cells. Our goal was to test this hypothesis. For comparison, we also examined whether DHT treatment elicits the same effect in immortalized human corneal (IHC) and conjunctival (IHConj) ECs. METHODS: Differentiated cells were cultured in media containing vehicle or 10 nM DHT. Cells (n = 3 wells/treatment group) were then processed for RNA isolation and the analysis of gene expression by using Illumina BeadChips, background subtraction, cubic spline normalization and Geospiza software. RESULTS: Our results demonstrate that DHT significantly suppressed the expression of numerous immune-related genes in HMGECs, such as those associated with antigen processing and presentation, innate and adaptive immune responses, chemotaxis, and cytokine production. DHT also enhanced the expression of genes for defensin β1, IL-1 receptor antagonist, and the anti-inflammatory serine peptidase inhibitor, Kazal type 5. In contrast, DHT had no effect on proinflammatory gene expression in HCECs, and significantly increased 33 gene ontologies linked to the immune system in HConjECs. CONCLUSIONS: Our findings support our hypothesis that androgens suppress proinflammatory gene expression in IHMGECs. This hormone effect may contribute to the typical absence of inflammation within the human meibomian gland.
PURPOSE OF REVIEW: Obtaining precise postoperative target refraction is of utmost importance in today's modern cataract and refractive surgery. Given the growing number of patients undergoing premium intraocular lens (IOL) implantations, patient expectation continues to rise. In order to meet heightened patient expectations, it is crucial to pay utmost attention to patient selection, accurate keratometry and biometry readings, as well as to the application of correct IOL power formula with optimized lens constants. This article reviews recent advances in the field of clinical biometry and IOL power calculations. RECENT FINDINGS: Recently developed low-coherence reflectometry optical biometry is comparable to older ultrasonic biometric and keratometric techniques. In addition, the new IOLMaster software upgrade has improved reproducibility and enhanced signal acquisition. Further, the modern lens power formulas currently determine the effective lens position and the shape of the intraocular lens power prediction curve more accurately. SUMMARY: In order to reach target refraction, precise biometric measurements are imperative. Understanding the strengths and limitations of the currently available biometry devices allows prevention of high variability and inaccuracy, ultimately determining the refractive outcomes.
Herpes simplex keratitis (HSK) is a major cause of corneal blindness in the world. Following the primary infection, the virus enters into a latent phase. Recurrent infectious or immune keratitis cause structural damage to the cornea, scarring, and may lead to blindness. Several commercially available topical and oral antiviral drugs for HSK are currently available. However, toxicity and low patient compliance hamper their use in HSK. Further, oral antiviral drugs alone are not always effective in HSK. Thus, there had been a need for safe and effective topical antiviral agents against HSK. Systemic ganciclovir has been in use for the treatment of cytomegalovirus infections. Recently, topical ganciclovir has become available for use in patients with HSK. Ganciclovir 0.15% ophthalmic gel has been shown to be both safe and effective against viruses of the herpes family. Topical ganciclovir ophthalmic gel is well tolerated and does not cause significant toxic effects on the ocular surface. Several multicenter studies have revealed the potential role of ganciclovir ophthalmic gel in the treatment and prophylaxis of epithelial HSK. In this paper, we have reviewed the pharmacology, efficacy, side effects, and the role of ganciclovir ophthalmic gel 0.15% in the treatment of acute herpetic keratitis.
Purpose: The purpose of this study was to investigate the contribution of mast cells to early neutrophil recruitment during ocular inflammation. Methods: In a murine model of corneal injury, the epithelium and anterior stroma were removed using a handheld motor brush. Cromolyn sodium (2% in PBS) eye drops were administered topically for mast cell inhibition. In vitro, bone marrow-derived mast cells were cultured alone or with corneal tissue. The frequencies of CD45+ inflammatory cells, CD11b+Ly6G+ neutrophils, and ckit+FcεR1+ mast cells in the cornea were assessed by flow cytometry. mRNA expression of CXCL2 was evaluated by real-time PCR and protein expression by ELISA. β-Hexosaminidase assays were performed to gauge mast cell activation. Results: Neutrophil infiltration of the cornea was observed within 1 hour of injury, with neutrophil frequencies increasing over subsequent hours. Concurrent expansion of mast cell frequencies at the cornea were observed, with mast cell activation (assessed by β-hexosaminidase levels) peaking at 6 hours after injury. Evaluation of CXCL2 mRNA and protein expression levels demonstrated augmented expression by injured corneal tissue relative to naïve corneal tissue. Mast cells were observed to constitutively express CXCL2, with significantly higher expression of CXCL2 protein compared with naïve corneal tissue. Culture with harvested injured corneas further amplified CXCL2 expression by mast cells. In vivo, mast cell inhibition was observed to decrease CXCL2 expression, limit early neutrophil infiltration, and reduce inflammatory cytokine expression by the cornea. Conclusions: Our data suggest that mast cell activation after corneal injury amplifies their secretion of CXCL2 and promotes the initiation of early neutrophil recruitment.
Since its discovery in the years of the French Revolution, the field of keratoprostheses has evolved significantly. However, the path towards its present state has not always been an easy one. Initially discarded for its devastating complications, the introduction of new materials and the discovery of antibiotics in the last century gave new life to the field. Since then, the use of keratoprostheses for severe ocular surface disorders and corneal opacities has increased significantly, to the point that it has become a standard procedure for corneal specialists worldwide. Although the rate of complications has significantly been reduced, these can impede the long-term success, since some of them can be visually devastating. In an attempt to overcome these complications, researchers in the field have been recently working on improving the design of the currently available devices, by introducing the use of new materials that are more biocompatible with the eye. Here we present an update on the most recent research in the field.
PURPOSE: The aim of this study was to assess the possibility of light damage to the retina by a surgical microscope during implantation of a Boston Keratoprosthesis (B-KPro) in rabbits. METHODS: The retinal irradiance from a Zeiss OPMI Lumera S7 operating microscope was measured at the working distance (16.5 cm). Light transmittance through an isolated B-KPro was measured. A B-KPro was implanted into 1 eye of 12 rabbits with the optic covered during the procedure. The operated eyes were then continuously exposed to a fixed light intensity under the microscope for 1 hour. Fluorescein angiography was carried out on days 2 and 9 postsurgery, after which the animals were euthanized. Further, we compared the potential of these retinal exposures to well-accepted light safety guidelines applicable to humans. RESULTS: Light transmittance of B-KPro revealed a blockage of short wavelengths (<390 nm) and of long wavelengths (1660-1750 nm) of light. In addition, the surgical microscope filtered a part of the blue, ultraviolet, and infrared wavelengths. Neither fluorescein angiography nor a histological examination showed any morphological retinal changes in our rabbits. Moreover, the retinal exposures were well below the safety limits. CONCLUSIONS: Modern surgical microscopes have filters incorporated in them that block the most damaging wavelengths of light. The B-KPro is made of 100% poly(methyl methacrylate), which makes it in itself a blocker of short wavelengths of light. No damage could be demonstrated in the animal study, and the retinal exposures were well below the safety limits. Together, these results suggest that light exposures during B-KPro surgery present a low risk of photochemical damage to the retina.
PURPOSE: To describe and further analyze the long-term results in visual acuity (VA), anatomical retention, and rate of complications from patients who underwent Boston keratoprosthesis (B-Kpro) type 1 after ocular chemical burns in the Dominican Republic. METHODS: A retrospective review of 42 eyes (22 OD:20 OS) of 36 patients who underwent B-Kpro type 1 implantation after severe ocular burn at Hospital Elías Santana in Santo Domingo, Dominican Republic, between April 2006 and October 2014, were included. RESULTS: Demographics, VA, anatomical retention, and the rates of postoperative complications and concurrent surgeries were evaluated. CONCLUSIONS: The excellent anatomical retention rates and visual outcomes presented in this study support the remarkable capability of B-Kpro type 1 to restore functional VA in eyes with severe chemical injuries. However, strict control of the postoperative complications is necessary for long-term success. In conclusion, the use of a B-Kpro type 1 after severe chemical burn is a viable option in patients otherwise condemned to the high risk of failure associated with conventional corneal grafts.
Proteoglycan 4 (PRG4, or lubricin) is a lubricating mucin-like glycoprotein recently discovered at the ocular surface, where it functions as a boundary lubricant and appears to play a protective role. Recent technological advances have enabled abundant expression of full-length recombinant human PRG4 (rhPRG4). The objectives of this study were to 1) biochemically characterize the gross structure and glycosylations of full-length rhPRG4, and 2) assess the ocular surface boundary lubricating ability of rhPRG4 at both human cornea-eyelid and human cornea-polydimethylsiloxane (PDMS) biointerfaces. rhPRG4 expressed by a Chinese hamster ovary cell line was characterized and compared to native bovine PRG4 by SDS-PAGE western blotting, and protein identity was assessed by tandem mass spectrometry (MS/MS). Human corneas were articulated against PDMS or human eyelids, at effective sliding velocities of 0.3-30 mm/s under physiological loads of ∼15 kPa, to assess and compare the ocular lubricating ability of rhPRG4 to PRG4. Samples were tested serially in PRG4, rhPRG4 (both 300 μg/ml), then saline. Western blotting indicated that rhPRG4 had immunoreactivity at the appropriate apparent molecular weight, and possessed O-linked glycosylation consistent with that of PRG4. rhPRG4 protein identity was confirmed by MS/MS. Both PRG4 and rhPRG4 significantly, and similarly, reduced friction compared to saline at both human cornea - PDMS and human cornea-eyelid biointerfaces. In conclusion, the rhPRG4 studied here demonstrated appropriate higher order structure, O-linked glycosylations, and ocular surface boundary lubricating. Purified rhPRG4 may have clinical utility as a topical treatment of dry eye disease or contact lens biomaterial coating to promote more comfortable wear.
This review highlights recent findings that describ how purines modulate the physiological and pathophysiological responses of ocular tissues. For example, in lacrimal glands the cross-talk between P2X7 receptors and both M3 muscarinic receptors and α1D-adrenergic receptors can influence tear secretion. In the cornea, purines lead to post-translational modification of EGFR and structural proteins that participate in wound repair in the epithelium and influence the expression of matrix proteins in the stroma. Purines act at receptors on both the trabecular meshwork and ciliary epithelium to modulate intraocular pressure (IOP); ATP-release pathways of inflow and outflow cells differ, possibly permitting differential modulation of adenosine delivery. Modulators of trabecular meshwork cell ATP release include cell volume, stretch, extracellular Ca(2+) concentration, oxidation state, actin remodeling and possibly endogenous cardiotonic steroids. In the lens, osmotic stress leads to ATP release following TRPV4 activation upstream of hemichannel opening. In the anterior eye, diadenosine polyphosphates such as Ap4A act at P2 receptors to modulate the rate and composition of tear secretion, impact corneal wound healing and lower IOP. The Gq11-coupled P2Y1-receptor contributes to volume control in Müller cells and thus the retina. P2X receptors are expressed in neurons in the inner and outer retina and contribute to visual processing as well as the demise of retinal ganglion cells. In RPE cells, the balance between extracellular ATP and adenosine may modulate lysosomal pH and the rate of lipofuscin formation. In optic nerve head astrocytes, mechanosensitive ATP release via pannexin hemichannels, coupled with stretch-dependent upregulation of pannexins, provides a mechanism for ATP signaling in chronic glaucoma. With so many receptors linked to divergent functions throughout the eye, ensuring the transmitters remain local and stimulation is restricted to the intended target may be a key issue in understanding how physiological signaling becomes pathological in ocular disease.
PURPOSE: Keratoconus (KC) is a complex corneal dystrophy with multifactorial etiology. Previous studies have shown evidence of mitochondrial abnormalities in KC; however, the exact cause of these abnormalities remains unknown. The aim of this study was to identify if transforming growth factor-β (TGF-β) isoforms play a role in the regulation of mitochondrial proteins in human KC cells (HKC). MATERIALS AND METHODS: Human corneal fibroblasts (HCF) and HKC were isolated and cultured for 4 weeks in three different conditions: (a) CONTROL: MEM + 10%FBS, (b) MEM + 10%FBS + TGF-β1 and (c) MEM + 10%FBS + TGF-β3. All samples were processed for mitochondrial damage analysis using real-time PCR. RESULTS: We quantified and analyzed 84 mitochondrial and five housekeeping genes in HCFs and HKCs. Our data showed that when TGF-β1 and/or TGF-β3 were compared with control in HCFs, nine genes were significantly different; however, no genes were significantly regulated by the TGF-β isoforms in HKCs. Significant differences were also seen in seven genes when HFCs were compared with HKCs, in all three conditions. CONCLUSIONS: Overall, our data support the growing consensus that mitochondrial dysfunction is a key player in KC disease. These in vitro data show clear links between mitochondrial function and TGF-β isoforms, with TGF-β1 severely disrupting KC-mitochondrial function, while TGF-β3 maintained it, thus suggesting that TGF-β may play a role in KC-disease treatment.
Corneal transplantation is the most prevalent form of tissue transplantation. The success of corneal transplantation mainly relies on the integrity of corneal endothelial cells (CEnCs), which maintain graft transparency. CEnC density decreases significantly after corneal transplantation even in the absence of graft rejection. To date, different strategies have been used to enhance CEnC survival. The neuropeptide vasoactive intestinal peptide (VIP) improves CEnC integrity during donor cornea tissue storage and protects CEnCs against oxidative stress-induced apoptosis. However, little is known about the effect of exogenous administration of VIP on corneal transplant outcomes. We found that VIP significantly accelerates endothelial wound closure and suppresses interferon-γ- and tumor necrosis factor-α-induced CEnC apoptosis in vitro in a dose-dependent manner. In addition, we found that intracameral administration of VIP to mice undergoing syngeneic corneal transplantation with endothelial injury increases CEnC density and decreases graft opacity scores. Finally, using a mouse model of allogeneic corneal transplantation, we found for the first time that treatment with VIP significantly suppresses posttransplantation CEnC loss and improves corneal allograft survival.
PURPOSE: To quantify the severity of ocular pain in patients with dry eye disease (DED) and evaluate factors associated with pain severity. DESIGN: Cross-sectional study. METHODS: Eighty-four patients with DED were asked to score their severity level of ocular pain using a 10-point scale, with 10 indicating the most severe pain. All patients also had a comprehensive ophthalmic assessment including a detailed history, Ocular Surface Disease Index (OSDI) questionnaire, and ocular surface examination. Regression analysis was used to determine the factors associated with ocular pain severity. RESULTS: The mean OSDI score was 45.6 ± 23.1. At least some degree of ocular pain (score >1) was reported by 88.1% of patients, including mild pain (scores 2-4) in 46.4%, moderate pain (scores 5-7) in 34.5%, and severe pain (scores 8-10) in 7.1% of patients. Ocular pain levels significantly correlated with the OSDI score (rs = 0.49, P < .001). Regression analysis showed that the severity of ocular pain had a significant association with use of antidepressant medications (P = .045) but not with tear breakup time, corneal fluorescein staining, or ocular medications used by patients. In patients without pain, a significant correlation was seen between OSDI and corneal fluorescein staining scores (rs = 0.67, P = .01). However, such a correlation was not observed in those with ocular pain. CONCLUSIONS: A majority of patients with DED report some degree of ocular pain, which correlates only moderately with the OSDI score. Severity of ocular pain correlates with nonocular comorbidities such as use of antidepressant medications rather than with clinical signs of DED.
PURPOSE: To explore the feasibility and compare the outcomes of three wide-angle fundus cameras for imaging the peripheral retina through the Type 1 Boston keratoprosthesis. METHODS: The noncontact Optos and the contact RetCam and Panoret wide-angle imaging systems were used to image the retina of eyes implanted with a keratoprosthesis. The failure-to-image rate, ease of acquisition, and quality of the images were noted, and the field of view was compared. Limitations and complications were recorded. Optos was then performed on patients referred for ultrasound B-scan evaluation, and the imaging findings were correlated. RESULTS: Retinal images with all three cameras were obtained on four eyes. Optos could be performed on all four eyes, RetCam on three, and Panoret on two. The field of view was comparable between the three different cameras. The best quality images were obtained with Optos. The external illumination of the Panoret made it impossible to image the only darkly pigmented individual in the series. Both contact devices failed to image another patient who was too agitated. Two patients had some ocular irritation from the coupling agent that resolved with replacement of the contact lens. Optos images were obtained on an additional six eyes, and findings correlated well with those on B-scan. Optos was superior to B-scan in an eye with silicone oil filling. CONCLUSION: Wide-angle fundus imaging through the keratoprosthesis is possible, and all three cameras performed similarly. The good quality of pictures obtained with the noncontact Optos, as well as its ease of use, comfort, and safety make it a preferred choice. Optos complements B-scan in the examination of the peripheral retina through the keratoprosthesis, and it may even be superior in certain settings.
Anterior segment optical coherence tomography (AS-OCT) has recently emerged as an important modality for imaging of the cornea. Since its introduction less than a decade ago, it has been clinically used for the diagnosis and management of an expanding number of corneal conditions. In this review, we will discuss the applications of anterior segment optical coherence tomography after corneal surgery, focusing on penetrating and lamellar keratoplasty, keratoprosthesis, intracorneal ring segments, collagen cross-linking and refractive surgery. Anterior segment optical coherence tomography is useful in evaluating outcomes, detecting adverse events, determining prognosis, guiding management decisions, and surgical planning.
PURPOSE: Loss of corneal strength is a central feature of keratoconus progression. However, it is currently difficult to measure corneal mechanical changes noninvasively. The objective of this study is to evaluate if Brillouin optical microscopy can differentiate the mechanical properties of keratoconic corneas versus healthy corneas ex vivo. METHODS: We obtained eight tissue samples from healthy donor corneas used in Descemet's stripping endothelial keratoplasty (DSEK) and 10 advanced keratoconic corneas from patients undergoing deep anterior lamellar keratoplasty (DALK). Within 2 hours after surgery, a confocal Brillouin microscope using a monochromatic laser at 532 nm was used to map the Brillouin frequency shifts of the corneas. RESULTS: The mean Brillouin shift in the anterior 200 μm of the keratoconic corneas at the cone was measured to be 7.99 ± 0.10 GHz, significantly lower than 8.17 ± 0.06 GHz of the healthy corneas (P < 0.001). The Brillouin shift in the keratoconic corneas decreased with depth from the anterior toward posterior regions with a steeper slope than in the healthy corneas (P < 0.001). Within keratoconic corneas, the Brillouin shift in regions away from the apex of the cone was significantly higher than within the cone region (P < 0.001). CONCLUSIONS: Brillouin measurements revealed notable differences between healthy and keratoconic corneas. Importantly, Brillouin imaging showed that the mechanical loss is primarily concentrated within the area of the keratoconic cone. Outside the cone, the Brillouin shift was comparable with that of healthy corneas. The results demonstrate the potential of Brillouin microscopy for diagnosis and treatment monitoring of keratoconus.
PURPOSE: Dry eye disease affects women twice as often as men, but there is little information on whether dry eye treatments, treatment satisfaction, or the impact of dry eye disease on patients' lives and vision might differ by sex. DESIGN: Questionnaire survey of 4000 participants in the Women's Health Study and the Physicians' Health Studies I and II with a prior report of a diagnosis of DED. METHODS: Among participants who re-confirmed a diagnosis of dry eye disease, we assessed symptoms, treatments, patient satisfaction and impact of dry eye disease, and analyzed differences between men and women using regression models. RESULTS: The final study population consisted of 1,518 women (mean age 70.7 years) and 581 men (mean age 76.7 years), with a mean reported duration of dry eye disease of 10.5 years and 10.1 years, respectively. The frequency and severity of dry eye disease symptoms were higher among women (each P<0.0001), and women reported a greater impact on everyday activities (P<0.0001). Women were more likely to use artificial tears (P<0.0001) use them more often (P<0.0001), and to use Restasis® (P<0.0001), omega-3 fatty acids (P=0.0006), and have punctal occlusion (P=0.005). Women spent more money per month on dry eye treatments (P<0.0001), but reported greater dissatisfaction with treatment side effects (P=0.001), and the amount of time before treatments started working (P=0.03). CONCLUSIONS: These data show that dry eye disease is generally experienced as being more severe among women, having a greater impact on their self-assessed well-being.