PURPOSE: To evaluate crosslinking of cornea in vivo using green light activation of Rose Bengal (RGX) and assess potential damaging effects of the green light on retina and iris. METHODS: Corneas of Dutch belted rabbits were de-epithelialized, then stained with Rose Bengal and exposed to green light, or not further treated. Corneal stiffness was measured by uniaxial tensiometry. Re-epithelialization was assessed by fluorescein fluorescence. Keratocytes were counted on hematoxylin and eosin (H&E)-stained sections, and iris cell damage was assessed by lactate dehydrogenase staining. Thermal effects on the blood-retinal barrier (BRB) were assessed by fluorescein angiography and those on photoreceptors, retinal pigment epithelium (RPE), and choriocapillaris by light microscopy and transmission electron microscopy. RESULTS: RGX (10-min irradiation; 150 J/cm) increased corneal stiffness 1.9-fold on day 1 (1.25 ± 0.21 vs. 2.38 ± 0.59 N/mm; P = 0.036) and 2.8-fold compared with controls on day 28 (1.70 ± 0.74 vs. 4.95 ± 1.86 N/mm; P = 0.003). Keratocytes decreased only in the anterior stroma on day 1 (24.0 ± 3.0 vs. 3.67 ± 4.73, P = 0.003) and recovered by day 28 (37.7 ± 8.9 vs. 34.5 ± 2.4, P = 0.51). Iris cells were not thermally damaged. No evidence of BRB breakdown was detected on days 1 or 28. Retina from RGX-treated eyes seemed normal with RPE cells showing intact nuclei shielded apically by melanosomes, morphologically intact photoreceptor outer segments, normal outer nuclear layer thickness, and choriocapillaris containing intact erythrocytes. CONCLUSIONS: The substantial corneal stiffening produced by RGX together with the lack of significant effects on keratocytes and no evidence for retina or iris damage suggest that RGX-initiated corneal crosslinking may be a safe, rapid, and effective treatment.
Publications
2016
PURPOSE: To evaluate the diagnostic performance of a 3-dimensional (3D) neuroretinal rim parameter, the minimum distance band (MDB), using optical coherence tomography (OCT) high-density volume scans for open-angle glaucoma. DESIGN: Reliability analysis. METHODS: setting: Institutional. STUDY POPULATION: Total of 163 patients (105 glaucoma and 58 healthy subjects). OBSERVATION PROCEDURES: One eye of each patient was included. MDB and retinal nerve fiber layer (RNFL) thickness values were determined for 4 quadrants and 4 sectors using a spectral-domain OCT device. MAIN OUTCOME MEASURES: Area under the receiver operating characteristic curve (AUROC) values, sensitivities, specificities, and positive and negative predictive values. RESULTS: The best AUROC values of 3D MDB thickness for glaucoma and early glaucoma were for the overall globe (0.969, 0.952), followed by the inferior quadrant (0.966, 0.949) and inferior-temporal sector (0.966, 0.944), and then followed by the superior-temporal sector (0.964, 0.932) and superior quadrant (0.962, 0.924). All 3D MDB thickness AUROC values were higher than those of 2D RNFL thickness. Pairwise comparisons showed that the diagnostic performance of the 3D MDB parameter was significantly better than 2D RNFL thickness only for the nasal quadrant and inferior-nasal and superior-nasal sectors (P = .023-.049). Combining 3D MDB with 2D RNFL parameters provided significantly better diagnostic performance (AUROC 0.984) than most single MDB parameters and all single RNFL parameters. CONCLUSIONS: Compared with the 2D RNFL thickness parameter, the 3D MDB neuroretinal rim thickness parameter had uniformly equal or better diagnostic performance for glaucoma in all regions and was significantly better in the nasal region.
PURPOSE: To evaluate the effect of deliberate removal of the central Descemet membrane on endothelial function and morphology in patients with Fuchs endothelial dystrophy (FED) and cataract undergoing phacoemulsification. METHODS: In this retrospective case series, patients with FED and visually significant cataract underwent phacoemulsification in an academic cornea practice in Boston, MA. Four millimeters of the central Descemet membrane was stripped and removed after intraocular lens insertion. Vision, corneal pachymetry, and confocal imaging of the endothelial anatomy were performed before surgery and at 1, 3, 6, and 12 months after surgery. Patients were classified as fast responders, responders, slow responders, and nonresponders on the basis of postoperative time to resolution of corneal edema with visible central endothelial mosaic. RESULTS: Eleven patients (13 eyes) aged 51 to 91 years were included in the study. No eyes had countable central endothelial cells by confocal imaging before surgery. Preoperative visual acuity ranged from 20/25 to 20/400. All corneas showed stromal and microcystic edema in the area of Descemet stripping at days 1 and 7 after surgery. Four eyes demonstrated resolution of corneal edema with visible central endothelial cell mosaic (range: 410-864 cells/mm) by postoperative month 1 with visual acuity ranging between 20/25 and 20/40. Four additional eyes demonstrated a similar response by postoperative month 3 and an additional 2 eyes had resolution of corneal edema with an intact central endothelial mosaic at postoperative month 6 or later. Cell counts (range: 428-864 cells/mm) were maintained in all 10 responders at the last follow-up visit (range: postoperative months 6-24). Final vision ranged from 20/15 to 20/20 in these 10 eyes with the exception of 2 eyes with retinal pathology. Three eyes required endothelial keratoplasty. CONCLUSIONS: Repopulation of the central corneal endothelium with corneal deturgescence can occur after deliberate central Descemet stripping in patients with FED who underwent cataract removal. This may offer a novel treatment for patients with FED that could reduce the need for endothelial transplantation. Further studies are needed to delineate the optimal patient population for Descemet stripping because not all patients will respond to this intervention.
Shorter axial length observed in patients with primary angle closure glaucoma (PACG) might be due to altered matrix metalloproteinase-9 (MMP9) activity resulting in ECM remodeling during eye growth and development. This study aimed to evaluate common variants in MMP9 for association with PACG. Six tag SNPs of MMP9 were genotyped in a Chinese sample of 1,030 cases, including 572 PACG and 458 primary angle closure (PAC), and 499 controls. None of 6 SNPs were significantly associated with overall PAC/PACG (P > 0.07) or with PAC/PACG subgroups (Pc > 0.18). Meta-analysis of two non-Chinese studies revealed significant association between rs17576 and PACG (ORs = 0.56, P < 0.0001); however, meta-analysis of our dataset with 4 Chinese datasets did not replicate this association (ORs = 1.23, P = 0.29). Prior significant association for rs3918249 in one Caucasian study (OR = 0.63, P = 0.006) was not replicated in meta-analysis of 3 Chinese studies including this study (ORs = 0.91, P = 0.13). Significant heterogeneity between non-Chinese and Chinese datasets precluded overall meta-analysis for rs17576 and rs3918249 (Q = 0.001 and 0.04 respectively). rs17577 was nominally associated with PACG in one Caucasian study (OR = 1.71, P = 0.02), but not in 3 Chinese studies including our study (ORs = 1.20, P = 0.07). Overall meta-analysis revealed nominal association for rs17577 and PAC/PACG (ORs = 1.26, Pc = 0.05). Meta-analysis did not show significant association between the other SNPs and PAC/PACG (P > 0.47). The largest association study to date did not find significant association between MMP9 and PAC/PACG in Chinese; meta-analysis with other Chinese datasets did not produce significant association. In most instances combination with non-Chinese datasets was not possible except for one variant showing nominally significant association. More work is needed to define the role of MMP9 variants in PACG.
PURPOSE: To compare the efficacy of an internet-based versus traditional referral system for retinopathy of prematurity (ROP) screening in Iran. METHODS: Two referral screening systems were compared in this prospective observational study. Group A (internet-based) comprised premature babies who were registered into an online system for screening. Their appointments were scheduled automatically based on standardized criteria. Group B (conventional) comprised premature babies whose referrals were based on oral or written recommendations. Babies were referred based on standard criteria (gestational age, GA, <37 weeks or birth weight < 3000 g). RESULTS: A total of 2115 neonates were screened between October 2011 and October 2012. From these 1896 met the inclusion criteria (group A n = 856, group B n = 1040). Time of first examination for neonates with GA≤27 weeks was 30.07± 2.72 weeks postmenstrual age in group A and 38.52± 7.03 weeks in group B (p = 0.049), and for neonates with GA>27 weeks was 4.86 ±1.77 and 8.16 ±4.93 weeks after birth in groups A and B, respectively (p < 0.001). All registered babies in group A attended their first screening exam. One case (0.1%) of advanced ROP developed in group A (in a patient with poor follow-up compliance), whereas advanced stages of ROP were seen in 26 cases (2.5%) in group B (p < 0.001). CONCLUSION: An internet-based registration system for ROP screening resulted in fewer cases of delayed first examination and resulted in fewer babies with advanced ROP.
Importance: Medulloepithelioma is the second most common primary neuroepithelial tumor of the eye. The full range of its morphologic expressions and appearances in metastases have not been fully explored. Observations: A patient in her 50s with glaucoma for decades had undergone multiple filtering surgical procedures, including the placement of a glaucoma drainage device. A paraspinal mass was discovered, and tumor and bone marrow biopsies disclosed rhabdomyosarcoma. This led to the discovery of a multicystic intraocular tumor. A metastatic rhabdomyosarcoma to the eye was considered unlikely because, to our knowledge, this event had never been reported. An enucleation was performed, and an intraocular tumor composed almost entirely of rhabdomyoblasts (desmin- and myogenin-positive) was discovered along with rare clusters of persistent neuroepithelial cells. Conclusions and Relevance: To our knowledge, this is the first case of a medulloepithelioma in which teratoid rhabdomyoblasts effaced all but trace amounts of neuroepithelium and generated a distant metastasis entirely composed of rhabdomyoblasts. The prolonged history and filtering procedures probably led to these 2 phenomena.
OBJECTIVE: To analyze overlaps between pregnancy and orbital inflammation (OI). DESIGN: Retrospective observational case series. METHODS: Eight new cases from 1997 to 2015 and 2 previously published cases were identified for inclusion in this investigation to provide the fullest clinical picture. Medical records, imaging studies, and the results of biopsies were reviewed. RESULTS: Three categories of association were discovered: (1) OI arising for the first time during pregnancy (5 cases); (2) OI arising within 3 months of delivery (2 cases); and (3) previously diagnosed OI reactivated or exacerbated by pregnancy (3 cases). One patient had a preexistent systemic autoimmune disease and another's was later diagnosed. One patient had attacks during sequential pregnancies. Findings included eyelid swelling and erythema, conjunctival chemosis, pain on eye movement, minimal diplopia, the usual absence of proptosis, and general preservation of visual acuity. Imaging studies disclosed extraocular muscle swelling (8 cases), most frequently of a single lateral rectus muscle. There were 2 cases of dacryoadenitis; 1 of these and an additional case displayed inflammation of the retrobulbar fat. Corticosteroids effected resolution of most symptoms. Singleton births were normal with the exceptions of an intrauterine fetal demise owing to acrania and a molar pregnancy. CONCLUSION: OI usually affects a single rectus muscle (typically the lateral) and, less often, the lacrimal gland and is often mild when it arises during or after pregnancy. Independent systemic autoimmune disease is an uncommon feature. Corticosteroids were efficacious except in 1 case with severe orbital scarring. No definitive causal relationships between pregnancy and OI could be established based on the clinical data.
PURPOSE: To investigate the association between blood 25-hydroxyvitamin D levels and pterygium. METHODS: Korean National Health and Nutrition Examination Survey 2008-2011 were used for the present epidemiologic study. A total of 19,178 participants aged ≥ 30 years were evaluated for blood 25-hydroxyvitamin D levels and performed ophthalmic slit lamp examinations. Pterygium was considered as a growth of fibrovascular tissue over the cornea. RESULTS: The average blood 25-hydroxyvitamin D levels were 18.6 ng/mL, and prevalence of pterygium was 6.5%. The odds of pterygium significantly increased across blood 25-hydroxyvitamin D quintiles after controlling sun exposure time as well as other confounders such as sex, age, smoking, diabetes, hypertension (P < 0.001). The odds ratios (OR) for pterygium was 1.51 (95% Confidence Interval[95%CI]; 1.19-1.92) in the highest blood vitamin D quintile. Stratified analysis by sex showed a positive association between blood 25-hydroxyvitamin D levels and pterygium in both men (quintile 5 versus 1, OR; 1.68, 95%CI; 1.19-2.37) and women (quintile 5 versus 1, OR; 1.37, 95% CI; 1.00-1.88). CONCLUSIONS: Even after controlling sun light exposure time, we found a positive association between blood 25-hydroxyvitamin D levels and pterygium in a representative Korean population. The mechanism underlying this association is unknown.
INTRODUCTION: Congenital fibrosis of the extraocular muscles type 2 (CFEOM2) is a distinct non-syndromic form of congenital incomitant strabismus secondary to orbital dysinnervation from recessive mutations in the gene PHOX2A. The phenotype includes bilateral ptosis, very large angle exotropia, ophthalmoplegia, and poorly-reactive pupils. Other than amblyopia, afferent visual dysfunction has not been considered part of CFEOM2; however, we have repeatedly observed non-amblyopic subnormal vision in affected patients. The purpose of this study was to document this recurrent feature of the phenotype. METHODS: A retrospective case series (2002-2012). RESULTS: Eighteen patients (four families) were identified; all affected individuals had confirmed homozygous recessive PHOX2A mutations except one individual for whom genetic testing was not done because of multiple genetically confirmed family members. Age at assessment ranged from 5-62 years old (median 10 years old). All patients had decreased best-corrected visual acuity not completely explainable by amblyopia in both the preferred and non-preferred eye. In those patients who had further ancillary testing, visual fields (five patients) and electroretinography (10 patients) confirmed abnormalities not ascribable to amblyopia. CONCLUSIONS: In addition to a distinct form of congenital incomitant strabismus, the phenotype of CFEOM2 includes subnormal vision consistent with retinal dysfunction. This could be the direct result of PHOX2A mutations or a secondary effect of orbital dysinnervation.
