Bilateral Boston keratoprosthesis type 1 in a case of severe Mooren's ulcer.

INTRODUCTION: Mooren's ulcer is a painful, inflammatory chronic keratitis that affects corneal periphery, progressing centripetally, ultimately ending in perforation. The first line of treatment includes systemic immunomodulators, with surgery being the last option. We present a case of bilateral Boston keratoprosthesis implantation for severe Mooren's ulcer that responded differently in each eye. CLINICAL CASE: A 32-year-old male with corneal opacification, anterior staphylomas, vision of hand movement, was started on systemic immunosuppression with cyclosporine. After two failed penetrating keratoplasties in each eye, high intraocular pressure despite diode cyclophotocoagulation, and cystic macular edema, we performed Boston keratoprosthesis type 1 in both eyes. The right eye responded initially well, with a best-corrected visual acuity of 20/80 and normal intraocular pressure. The left eye presented high intraocular pressure, which required cyclophotocoagulation, ultimately resulting in hypotony. Boston keratoprosthesis was performed but had peripheral corneal necrosis that progressed despite amniotic membrane transplantation and aggressive intensive treatment with medroxyprogesterone, autologous platelet-rich-in-growth-factors eye drops, and oral doxycycline. Thus, replacement of the semi-exposed Boston keratoprosthesis with tectonic penetrating keratoplasty was necessary. However, both eyes developed phthisis bulbi with final visual acuity of perception of light with poor localization. CONCLUSION: Mainstay treatment of Mooren's ulcer is systemic immunomodulation. Surgical treatment must be considered only when risk of perforation, preferably with inflammation under control. Penetrating keratoplasty frequently fails, and Boston keratoprosthesis may be a viable option. However, postoperative complications, especially uncontrolled high intraocular pressure, corneal necrosis, and recurrence of Mooren's ulcer may jeopardize the outcomes and need to be addressed promptly with intensive topical and systemic treatment.

Unilateral spontaneous filtering bleb dissecting into the cornea in a patient with high myopia.

PURPOSE: To report a case of a unilateral spontaneous filtering bleb dissecting into the cornea in a patient with high myopia. CLINICAL CASE: A 33-year-old woman with high myopia (-18 D) presented with discomfort in the left eye. Ocular history included pars plana vitrectomy and cataract extraction and posterior chamber intraocular lens implantation in the left eye. Best-corrected visual acuity was 0.65 and intraocular pressure was 20 mmHg. Slit-lamp examination showed a filtering bleb in the upper-temporal quadrant, which extended and dissected the proximal cornea without affecting the visual axis. The morphology and content of the bleb was studied with anterior segment optical coherence tomography, which ruled out a corneal-scleral fistulization into the subconjunctival space. The spontaneous filtering bleb was resected surgically. Due to her high myopia, two strips of fascia lata were used to strengthen the area. In the postoperative period, a complete resection of the bleb was confirmed, without apparent leaking points and with a well-vascularized conjunctiva. No complications were noted. The patient maintained the same best-corrected visual acuity and intraocular pressure than before surgery. CONCLUSION: The formation of a spontaneous filtering bleb is a rare entity in patients with high myopia, whose risk increases due to their thinned sclerae. The risk is even greater if they have undergone ocular surgeries. Resection of the filtering bleb in our case halted the progression of the corneal dissection, therefore respecting the transparency of the visual axis and preserving visual acuity.

Challenges in using both eyes of the same patient when evaluating the results after implantation of intrastromal corneal ring segments.

PURPOSE: To assess correlation between results from both eyes of the same patient after implantation of intrastromal corneal ring segments (ICRS) and define whether they can be used together in clinical studies. METHODS: A review of medical records of 74 patients with keratoconus implanted with bilateral Ferrara ICRS at Centro de Oftalmología Barraquer from January 2005 until December 2014. Data were collected on uncorrected visual acuity, best-corrected visual acuity and subjective refractive values (sphere, cylinder and axis). RESULTS: A total of 39 patients were male (53%), and 35 were female (47%). Mean age at the time of implantation was 32.5 ± 10 years. No major complications occurred. A significant correlation between the results from right and left eyes was found (p < 0.0043), indicating that both eyes significantly resembled each other. No significant interaction in the magnitude of change between eye and surgery was observed under classic and mixed models. CONCLUSION: Based on our data, whenever application is not possible under mixed-model analyses, we recommend the use of a first eye operated only, either right or left, in order to avoid bias and errors derived from autocorrelation and guarantee the independence of the registered observations.

Oral mucosa for reconstructive surgery in a case of severe inflammatory necrotizing sclero-uveitis.

The purpose of this case is to show the efficacy of buccal mucosa as an alternative to treat a case of severe necrotizing sclero-uveitis (NSU) associated with ocular perforation. We show a severe inflammatory NSU case that did not improve with topical treatment and scleral patch. We performed a buccal mucosa graft taken from the lower lip with excellent functional and anatomical result, with no signs of relapse of the NSU after 2 years of follow-up. Buccal mucosa can be a safe, useful, and effective alternative for the reconstruction of the scleral wall.

Topical sustained drug delivery to the retina with a drug-eluting contact lens.

Intravitreal injections and implants are used to deliver drugs to the retina because therapeutic levels of these medications cannot be provided by topical administration (i.e. eye drops). In order to reach the retina, a topically applied drug encounters tear dilution, reflex blinking, and rapid fluid drainage that collectively reduce the drug's residence time on the ocular surface. Residing under the tears, the cornea is the primary gateway into the eye for many topical ophthalmic drugs. We hypothesized that a drug-eluting contact lens that rests on the cornea would therefore be well-suited for delivering drugs to the eye including the retina. We developed a contact lens based dexamethasone delivery system (Dex-DS) that achieved sustained drug delivery to the retina at therapeutic levels. Dex-DS consists of a dexamethasone-polymer film encapsulated inside a contact lens. Rabbits wearing Dex-DS achieved retinal drug concentrations that were 200 times greater than those from intensive (hourly) dexamethasone drops. Conversely, Dex-DS demonstrated lower systemic (blood serum) dexamethasone concentrations. In an efficacy study in rabbits, Dex-DS successfully inhibited retinal vascular leakage induced by intravitreal injection of vascular endothelial growth factor (VEGF). Dex-DS was found to be safe in a four-week repeated dose biocompatibility study in healthy rabbits.

Epithelial Ingrowth After Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To report the diagnosis, histological findings, and treatment of a patient who developed epithelial ingrowth after Descemet membrane endothelial keratoplasty (DMEK). METHODS: We present the case of a type 2 diabetic 60-year-old man who underwent DMEK for Fuchs dystrophy. Two months after surgery, an epithelial ingrowth in the graft-host interface was suspected. After a 3-month follow-up period in which progressive and centrifugal growth of the epithelial cells in the interface was documented, penetrating keratoplasty (PK) was performed to remove all areas of epithelial ingrowth. No evidence of recurrence was observed 1 year later. RESULTS: Histopathologic evaluation of the corneal button obtained in the PK procedure confirmed the epithelial ingrowth in the interface between the Descemet membrane graft and the host cornea. CONCLUSIONS: Epithelial ingrowth may occur after a corneal endothelium transplant. There have been multiple reports of epithelial ingrowth after Descemet stripping automated endothelial keratoplasty, but this particular case report suggests that epithelial ingrowth may also occur after DMEK. In this case, PK solved the complication.

Acute Chemical Eye Injury and Limbal Stem Cell Deficiency-A Prospective Study in the United Kingdom.

PURPOSE: To analyze the incidence, nature, outcomes, and complications of acute chemical eye injuries, including the incidence of limbal stem cell deficiency (LSCD) and to compare the 2 main classifications for ocular chemical injuries: Roper-Hall (RH) and Dua. METHODS: This is a prospective, consecutive, interventional single-center study between April and October 2009 of all new patients with acute chemical eye injury presenting to the Royal Victoria Infirmary eye emergency department (EED). RESULTS: Of 11,683 patients who attended the EED, 98 patients (110 eyes) presented with acute chemical eye injury (60% male). This represents an estimated annual incidence of 5.6 new cases per 100,000 population. Mean age was 36.5 years (1-78; SD 17.1 years), including 7 children (age <10 years). Fifty-one patients (52%) had work-related injuries. The most common chemical agent was alkali (78%). All 4 RH grade IV cases were unilateral, assault with ammonia, and required early amniotic membrane transplantation as per the protocol, but despite full treatment, they developed total LSCD in the affected eye. CONCLUSIONS: Acute chemical eye injuries are rare. Male patients in the working age group are more prone to work-related chemical injuries, whereas young children tend to have domestic injuries. Grade I, II, and III RH and Dua chemical injuries had a very good prognosis with topical treatment only, whereas RH grade IV (Dua grade IV-VI), mainly assaults with ammonia, progressed to total/severe LSCD despite appropriate management including early amniotic membrane transplantation. The Dua classification includes conjunctival involvement, having a greater value in predicting the final clinical outcome when grading chemical eye injuries.

Long-term Results of Corneal Cross-linking for Terrien's Marginal Degeneration.

PURPOSE: To report the long-term clinical outcomes of a patient with Terrien's marginal degeneration who underwent successful peripheral corneal cross-linking (CXL) to arrest progression. METHODS: Clinical assessment included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), corneal topography, anterior segment optical coherence tomography, ultrasonic pachymetry, corneal hysteresis, and corneal resistance factor. Eccentric epithelium-off CXL was performed in both eyes after limbal conjunctival resection. Following the Dresden protocol, fluence irradiation was set at 5.4 J/cm2, using 3 mW/cm2 for a total exposure time of 30 minutes. RESULTS: Nine years of postoperative follow-up showed significant bilateral improvement in visual acuity, refraction, and corneal topography with no signs of progression of Terrien's marginal degeneration. In the right eye, UDVA improved from 0.05 to 0.3 decimal and CDVA from 0.8 to 1.2 decimal, cylinder was reduced from -14.00 to -3.00 diopters (D), simulated keratometry improved from 10.50 to 3.70 D, and the thinnest point on pachymetry remained almost unchanged (from 483 to 469 µm). In the left eye, UDVA improved from 0.1 to 0.2 decimal and CDVA remained unchanged at 1.2 decimal, cylinder was reduced from -6.00 to -2.75 D, simulated keratometry improved from 5.60 to 3.30 D, and the thinnest point on pachymetry remained stable at 486 µm. CONCLUSIONS: Eccentric peripheral CXL can be a safe, noninvasive alternative therapeutic approach for the management of Terrien's marginal degeneration with peripheral thinning. [J Refract Surg. 2018;34(6):424-429.].

Outcomes of Penetrating Keratoplasty Following Autologous Cultivated Limbal Epithelial Stem Cell Transplantation.

The purpose of this study is to investigate the outcomes of penetrating keratoplasty (PKP) following autologous cultivated limbal epithelial stem cell transplantation (CLET). A prospective, single center, interventional cohort study investigating patients with unilateral total limbal stem cell deficiency (LSCD) treated with CLET who underwent PKP. Patients with confirmed corneal re-epithelialization > 6 months post-CLET, and with best-corrected visual acuity (BCVA) <0.3 logMAR were offered PKP. CLET survival assessed by slit lamp, corneal impression cytology (CIC), and in vivo confocal microscopy. Confirmation of corneal re-epithelialization by histological and immunocytochemical (ICC) examination of trephined corneal buttons. Mean change in best-corrected visual acuity (logMAR) following PKP and PKP survival at 12 months were calculated. Twenty patients underwent PKP. Mean time of PKP was 19 months (range 11-41 months, SD 7.26) post-CLET. Median follow-up time post-PKP was 15 months (range 1-32, SD 10.2). CIC and ICC of all corneas confirmed corneal re-epithelialization before PKP. Mean pre-PKP BCVA was 1.46 (range 0.3-2.7, SD 0.94) improving to a mean post-PKP BCVA of 0.74 (range 0-2.7, SD 0.87); mean improvement in BCVA post-PKP of 36 letters (95% CI 15.0-57.1, p = .002). Kaplan-Meier mean graft survival was 90.9% (95% CI 50.8-98.7) at 12 months. We recommend a two-stage approach with CLET followed by PKP >12 months later. Patients experienced a significant improvement in BCVA following PKP. PKP did not have a detrimental effect on CLET survival. PKP survival post-CLET is better than that reported for high risk PKP. Stem Cells 2018;36:925-931.

High-irradiance CXL combined with myopic LASIK: flap and residual stroma biomechanical properties studied ex-vivo.

BACKGROUND/AIMS: To evaluate ex vivo biomechanical and enzymatic digestion resistance differences between standard myopic laser in-situ keratomileusis (LASIK) compared with LASIK+CXL, in which high-irradiance cross-linking (CXL) is added. METHODS: Eight human donor corneas were subjected to femtosecond-assisted myopic LASIK. Group A (n=4) served as a control group (no CXL). The corneas in LASIK+CXL group B were subjected to concurrent prophylactic high-irradiance CXL (n=4). Saline-diluted (0.10%) riboflavin was instilled on the stroma, subsequently irradiated with UV-A through the repositioned flap. The cornea stroma and flap specimens were separately subjected to transverse biaxial resistance measurements; biomechanical differences were assessed via stress and Young's shear modulus. Subsequently, the specimens were subjected to enzymatic degradation. RESULTS: For the corneal stroma specimen, stress at 10% strain was 128±11 kPa for control group A versus 293±20 kPa for the LASIK+CXL group B (relative difference Δ=+129%, p<0.05). The stress in group B was also increased at 20% strain by +68% (p<0.05). Shear modulus in group B was increased at 10% strain by +79%, and at 20% strain by +48% (both statistically significant, p<0.05). The enzymatic degradation time to dissolution was 157.5±15.0 min in group A versus 186.25±7.5 min in group B (Δ=+18%, p=0.014). For the flaps, both biomechanical, as well as enzymatic degradation tests showed no significant differences. CONCLUSIONS: LASIK+CXL appears to provide significant increase in underlying corneal stromal rigidity, up to +130%. Additionally, there is significant relevant enzymatic digestion resistance confirmatory to the above. LASIK flaps appear unaffected biomechanically by the LASIK+CXL procedure, suggesting effective CXL just under the flap.

Glaucoma progression and role of glaucoma surgery in patients with Boston keratoprosthesis.

PURPOSE: The aim of this study was to evaluate glaucoma onset and progression after implantation of Boston Keratoprostheses (B-KPro) and the role of glaucoma surgery. METHODS: Records of patients with B-KPro implantation during 2004 to 2009 were reviewed. Parameters relevant to B-KPro surgery and glaucoma status were recorded. The data were analyzed in 5 groups based on the preoperative diagnosis. RESULTS: One hundred six eyes of 87 patients were included, and the average age was 54 ± 6.7 years. Forty-six percent were female. Eighteen eyes had a B-KPro with a titanium back plate, and the others had a poly(methyl methacrylate) back plate. Thirty-three eyes were pseudophakic, and the rest were left aphakic. The follow-up time was 3.3 ± 1.0 years. Indications for implantation included past infection, congenital glaucoma, trauma, autoimmune diseases, aniridia, burns, and others. Sixty-six percent of the eyes had glaucoma preoperatively, and 26% developed de novo glaucoma afterward. The mean intraocular pressure (by finger palpation) was 16.5 ± 5.7 mm Hg. Reliable visual field tests were only available in 59% of the eyes; hence, the cup-to-disc ratio of the optic nerve head was used as the main outcome measure. In B-KPro-implanted eyes with glaucoma, 65% had undergone glaucoma surgery at some point, and 30% did not show progression. Thirty-one percent of the total cohort had disc pallor with a cup-to-disc ratio of <0.8. CONCLUSIONS: Glaucoma in B-KPro remains a challenge, despite aggressive attempts to slow down its progression. Patients with glaucoma before B-KPro implantation should be considered for glaucoma surgery before or simultaneously with B-KPro implantation. The high number of eyes with disc pallor suggests that additional mechanisms other than elevated intraocular pressure may play a role in optic neuropathy.

Very low risk of light-induced retinal damage during Boston keratoprosthesis surgery: a rabbit study.

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.