Corneal Topography Research of Myopia in Chinese

Purpose: To determine corneal topography parameters of myopia in Chinese and help for studies of causes of myopia, distingiush other corneal diseases (such as early keratoconus), further explore the accurateness and safeness of the clinical effects of radii keratotomy(RK) or photorefractive keratectomy (PRK). Methods: Fifty-eight eyes with mild or moderate myopia were examined by computer-assisted photokeratography. (TMS-1 Computed Anatomy Inc. New York. NY)Results: The corneal topography of most (68%) of the examined eyes showed symmetric bowtie pattern; the corneal surface of most (75%) of the examined eyes showed positive aspheric shape (steeper centrally, flatter peripherally); the refractive power of central cornea is at mean 44. 165 ± 1. 429D; the refractive difference between 1 to 25 ring in keratoscpe was at mean 1. 655 ± 0. 785D; the mean SRI was 0. 558 ± 0. 768, the mean SAI was 0. 296 ± 0. 149; the mean Smik was 44. 209±1. 515D. The apex and visual axis were dislocation in all the cornea     

Corneal Topographic Analysis in Patients with Cataract

We studied the corneal curvature of 161 eyes in 101 patients, aged from 50 to 80 years (mean: 63 years), with senile cataract using the Topographic Modeling System (IMS) preoperatively. The results revealed that mean surface asymmetry index (SAD was 0. 36 and mean surface regularity index (SRI) 0. 79. Simulated keratometry reading (Sim K) was 44. 46 D, and 43. 56 D. Minimun K reading was 42. 60 D. The same patterns of corneal topography in both eyes were 50% in 60 patients who had binocular examination. Astigmatism less than 1 D was 23% in 161 corneas. Corneal patterns included round (21. 2%), oval 16. 1%), symmetric and asymmetric bow-tie (22. 2%), and irregular (40. 4%). SRI and SAI of the irregular pattern were statistically higher than those of the round, oval and bow-tie patterns in our patients (P<0. 01 and P<0. 05). The results of our study determined that the cornea of eye with senile cataract preoperatively is not a perfect spherocylin-der. It is asymmetrically aspheric, with less curvature per     

Production of Hypoxia-induced Corneal Edema in Aged Eyes

IntroductionThecorneahasanextremelywellorganizedstromalarchitecturewhichcontributestowardsauniformrefractiveindex[1].Thecorneahasaten鄄dencytoswellunderapassiveimbibitionpres鄄sure[2].Excessivewatermoleculesaredrivenoutbynumerousenergy鄄consumingionicpumpsontheposteriorcornealendothelium[3]soastomai鄄ntainatransparentcornea.Incaseofanydisrup鄄tiontothisfunction,thehydrationlevelwouldincrease鄄cornealedema.Anydisruptiontoanor鄄malswelling鄄deswellingphysiology[2],mightaf鄄fectthecornealtranspa…     

Corneal thickness in glaucoma: an important parameter?

Central corneal thickness was measured by pachometry in 49 patients with primary open-angle glaucoma (POAG), 41 with ocular hypertension (OHT), 14 with normal tension glaucoma (NTG) and 48 normal subjects. The mean corneal thickness of the OHT patients was significantly greater than that of the normal control group. The NTG patients, on the other hand, had a cornea on average thinner than the normals. These differences may cause misclassification of normals with a thick cornea as ocular hypertensive eyes or, contrarywise, cause those normals whose IOP is underestimated because of a thin cornea to be classed as NTG patients.     

Corneal Nerve and Epithelial Cell Alterations in Corneal Allodynia: An In Vivo Confocal Microscopy Case Series

Purpose

To investigate morphological changes of the corneal epithelium and subbasal nerves in patients with corneal allodynia using in vivo confocal microscopy (IVCM).

Corneal innervation and morphology in primary Sjögren's syndrome

PURPOSE: To analyze the in vivo morphology of the different corneal sublayers and corneal nerves in primary Sj?gren's syndrome (SS). METHODS: Ten eyes of 10 patients with primary SS and 10 eyes of 10 sex- and age-matched control subjects were investigated. Diagnosis was based on American-European consensus criteria. In vivo confocal microscopy with through-focusing was used to investigate corneal morphology and to measure corneal sublayer thickness. RESULTS: Epithelial punctate staining with fluorescein was observed in 6 of 10 SS and none of 10 control corneas. In addition, Schirmer I test results were significantly lower in SS. Epithelial thickness did not differ between the SS and control groups. Confocal microscopy revealed patchy alterations or irregularities in surface epithelial cells in 6 of 10 SS corneas, whereas the basal epithelium appeared normal in all corneas. Average corneal thickness was lower in the SS group (515.9 +/- 22.0 micro m) than in the control (547.4 +/- 42.0 micro m; P = 0.050, t-test). Accordingly, the mean intraocular pressure was lower in the SS group (13.9 +/- 2.1 mm Hg) than in the control (16.7 +/- 2.9 mm Hg; P = 0.022). The subbasal nerve plexus and stromal nerve fiber bundles were present in all corneas. No difference was noted in nerve density. However, in 4 of 10 SS eyes, the subbasal nerve plexus showed structures resembling nerve sprouting, suggesting ongoing active neural growth. None of the control corneas exhibited such features. Signs of anterior keratocyte activation were observed in 5 of 10 SS corneas. CONCLUSIONS: In SS, the corneal surface epithelium was irregular and patchy. Anterior keratocytes frequently showed morphologic features of activation. The subbasal nerve fiber bundles revealed abnormal morphology, and the central corneal thickness was reduced by stromal thinning. The findings confirm epithelial, stromal, and neural abnormalities in the corneas of patients with SS.     

The Study of Corneal Topography in Myopic and Hyperopic Children

Purpose: To compare the differences of corneal topographies in myopic and hyperopic children and study the effect of Atropin on their changes. Methods : The refractive components of 136 eyes with different refractive conditions were measured with A-Scan and their corneal topographies with and without cycloplegia were obtained respectively. Results: The mean corneal power of zones 3mm (MD3, P=0.031) and minor keratometer K2 (P=0.003) of myopia are greater than those of hyperopia without cycloplegia. MD3 (.P=0.009) and Keratometer K1 (P = 0.025) increased in hyperopic eyes, while MD3 (P=0.033), K1 (P= 0.035) and K2 (P= 0.002) decreased in myopic eyes significantly after cycloplegia. Similarly, the mean corneal power of zones 5mm (MD5) and 7mm (MD7) in myopic eyes decreased dramatically (P≤0.001). Conclusions: The corneal power was found to be greater in myopia than that in hyperopia. The effect of Atropin on corneal shape of myopia and hyperopia was in the opposite direction. Eye Science 2005;21:15-19.     

Corneal perforation due to limbal involvement in Sézary syndrome

Background  

The majority of lymphomas involving the eye and ocular adnexa are B-cell lymphomas. Ocular involvement by T-cell lymphoma is rare. We report a case of corneal perforation due to direct involvement of the corneal limbus by lymphoma in a patient with Sézary syndrome.     

Cytotoxicity of Contact Lens Care Solution to Human Corneal Epithelium in Vitro

Purpose: To investigate the cytotoxicity of soft contact lens multi-purpose care solutions which are now in common use in China.Methods: The cell culture method was used. Cytotoxicity was indicated by significant increases in the number of dead cells relative to controls.Results: Cells were exposed to soft contact lens care solutions for 15 min. They were irregular in shape and variable in size. The intercellular space increased and variable in size.The in-tercelluar space increased and the cells became scrunken. With the time of exposure elongated , damage of cells became more severe.Conclusions: Four kinds of soft contact lens multi-purpose care solutions may have harmful effects on the culture of human corneal epithelial cells. Soaked lenses should be rinsed with saline before being placed in the eyes in order to reduce the potential toxicity of contact lens care solutions. Eye science 1998; 14 :45 - 47.     

In Vivo Confocal Microscopy of Corneal Nerves in Health and Disease

In vivo confocal microscopy (IVCM) is becoming an indispensable tool for studying corneal physiology and disease. Enabling the dissection of corneal architecture at a cellular level, this technique offers fast and noninvasive in vivo imaging of the cornea with images comparable to those of ex vivo histochemical techniques. Corneal nerves bear substantial relevance to clinicians and scientists alike, given their pivotal roles in regulation of corneal sensation, maintenance of epithelial integrity, as well as proliferation and promotion of wound healing. Thus, IVCM offers a unique method to study corneal nerve alterations in a myriad of conditions, such as ocular and systemic diseases and following corneal surgery, without altering the tissue microenvironment. Of particular interest has been the correlation of corneal subbasal nerves to their function, which has been studied in normal eyes, contact lens wearers, and patients with keratoconus, infectious keratitis, corneal dystrophies, and neurotrophic keratopathy. Longitudinal studies have applied IVCM to investigate the effects of corneal surgery on nerves, demonstrating their regenerative capacity. IVCM is increasingly important in the diagnosis and management of systemic conditions such as peripheral diabetic neuropathy and, more recently, in ocular diseases. In this review, we outline the principles and applications of IVCM in the study of corneal nerves in various ocular and systemic diseases.     

First Identification of a Triple Corneal Dystrophy Association: Keratoconus,Epithelial Basement Membrane Corneal Dystrophy and Fuchs’ Endothelial Corneal Dystrophy

Purpose

To report the observation of a triple corneal dystrophy association consisting of keratoconus (KC), epithelial basement membrane corneal dystrophy (EBMCD) and Fuchs’ endothelial corneal dystrophy (FECD).

Methods

A 55-year-old male patient was referred to our cornea service for blurred vision and recurrent foreign body sensation. He reported bilateral recurrent corneal erosions with diurnal visual fluctuations. He underwent corneal biomicroscopy, Scheimpflug tomography, in vivo HRT confocal laser scanning microscopy and genetic testing for TGFBI and ZEB1 mutations using direct DNA sequencing.

Results

Biomicroscopic examination revealed the presence of subepithelial central and paracentral corneal opacities. The endothelium showed a bilateral flecked appearance, and the posterior corneal curvature suggested a possible concomitant ectatic disorder. Corneal tomography confirmed the presence of a stage II KC in both eyes. In vivo confocal laser scanning microscopy revealed a concomitant bilateral EBMCD with hyperreflective deposits in basal epithelial cells, subbasal Bowman''s layer microfolds and ridges with truncated subbasal nerves as pseudodendritic elements. Stromal analysis revealed honeycomb edematous areas, and the endothelium showed a strawberry surface configuration typical of FECD. The genetic analysis resulted negative for TGFBI mutations and positive for a heterozygous mutation in exon 7 of the gene ZEB1.

Conclusion

This is the first case reported in the literature in which KC, EBMCD and FECD are present in the same patient and associated with ZEB1 gene mutation. The triple association was previously established by means of morphological analysis of the cornea using corneal Scheimpflug tomography and in vivo HRT II confocal laser scanning microscopy.Key words: Keratoconus, Fuchs’ endothelial corneal dystrophy, Epithelial basement membrane dystrophy, Cogan dystrophy, Confocal microscopy, ZEB1     

Trends and Associations in Hospitalizations Due to Corneal Ulcers in the United States, 2002–2012

Purpose: To estimate incidence, temporal trends, and factors associated with inpatient hospitalization due to corneal ulcers in the United States.

Methods: Data on inpatient hospitalizations due to corneal ulcers between 2002 and 2012 were reviewed using the National Inpatient Sample. A literature review was conducted to identify the most common causes of corneal ulcers, and use of contact lenses.

Results: An estimated 19,878 patients were seen in US emergency departments for evaluation of corneal ulcers in 2012. Rates of inpatient hospitalization due to corneal ulcers remained comparable over the decade (2003: 4.9, 95% confidence interval, CI, 3.0–6.7; 2012: 2.7, 95% CI 2.2–3.3 patients per million US population). Among those hospitalized for ophthalmic disease, patients holding public or no insurance (odds ratio, OR, 1.8 and 2.5, respectively, p<0.001), from low-income neighborhoods (OR 1.6, p < 0.001), and of older age (OR 3.4, p < 0.001) were more likely to be hospitalized for corneal ulceration. Medical conditions associated with hospitalization for corneal ulcer included history of keratitis (7.7%, p < 0.001), HIV infection (2.6%, p = 0.003), history of contact lens-related complications (2.5%, p < 0.001), and history of eye injury (2.5%, p = 0.001). Patients with a history of keratitis (p = 0.006) or rheumatoid arthritis (p = 0.001) were each twice as likely to receive a corneal transplant.

Conclusions: Factors associated with hospitalization for corneal ulcer include insurance status in addition to history of contact lens-related disease and keratitis. Efforts should be made to address these factors prior to development of severe ulcers.     

An Analysis of 1 001 Blinding Patients with Corneal Disease in 1960—1989

Purpose:To investigate the condition and change of corneal blindness (CB) in the past 30 years.Methods: 1 001 blinding patients of corneal disease were clinically analysed from 1960 to 1989,including etiology, sex, age, occupation, difference between the urban and rural areas etc.Results: The male predominated. Infection stood the first cause of blinding corneal diseases, followed by trauma,malnutrition and the others.HSV-1 keratitis was the most frequent infection in 1980s. The highest incidence of CB was 20-40 year -old. The number of CB caused by occupational truauma was more than that by ordinary trauma in 1960s,but from 1970s, the latter was more than the former. The number of CB in rural area was more than that in the urban in 1960s,but from 1970s,there was no significant difference between the two areas. The percentage of bilateral CB was gradually decreased.Conclusion: We should try to find more effective strategies to prevent and treat CB caused by HSV-1 keratitis, pay special attention to pres     

Corneal Topographical Changes Following Strabismus Surgery

Purpose: To study corneal topographical changes after strabismus surgery. Methods: Computer-aided corneal topography was used in 43 strabismus patients (45 eyes) one or two days prior to and six or seven days after strabismus surgery. The spherical and cylindrical equivalents were calculated based on the simulated keratome-try.Results: After the surgery, only the changes at 3mm in the inferior quadrant were statistically significant. The changes at 3mm in the rest quadrants and the changes at 7mm were not significant. Significant changes in spherical equivalent were found post-operatively. Neither the horizontal nor the vertical meridional equivalent showed significant changes after surgery.Conclusions: The results of corneal topographical changes following strabismus surgery in our preliminary study indicated the little effect of strabismus surgery on corneal curvature and corneal astigmatism. Eye Science 1999; 15: 174 - 178.