Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CORNEAL OPACITY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources
PubMed1986

Deep corneal stromal opacities with contact lenses.

Two patients with deep corneal stromal opacities occurring after prolonged contact lens wear are described. The opacities were associated with folds or striae in Descemet's membrane which they overlay. Development of the opacities was associated with ocular discomfort, photophobia, reduced vision and a history of prolonged daily wearing times. Although the corneal endothelial cell counts were within the normal range, the count was reduced in the affected eye in the patient with the unilateral deep stromal opacity and there was mild polymegathism of the endothelial cells. It is possible that the long-term effects of subtle endothelial cell changes may cause a keratopathy with later scarring and opacification. Poor oxygen transmissibility, carbon dioxide build-up, or suction effects by the lens may all be aetiological factors. Early recognition and treatment, particularly with a better fitting lens of high oxygen transmissibility is important, as once developed the opacities regress only slowly and may result in permanent visual impairment.

Adult↗
PubMed2001

Natural history of trachomatous scarring in The Gambia: results of a 12-year longitudinal follow-up.

PURPOSE: The sight-threatening complications of trachoma are trichiasis and corneal opacity, and these remain the world's most common cause of preventable blindness. The aim of the study was to investigate the rate of progression of trachomatous conjunctival scarring to trichiasis and corneal opacity and to investigate risk factors for such progression. DESIGN: A 12-year, longitudinal study of the incidence and risk factors for the development of trichiasis and corneal opacity in a cohort of patients initially identified with trachomatous scarring in The Gambia. PARTICIPANTS: Six hundred thirty-nine subjects with some degree of trachomatous scarring were identified from the 1986 survey, and attempts were made to trace all these subjects. METHODS: Successfully traced subjects were interviewed, examined, and graded for trachoma. MAIN OUTCOME MEASURES: (1) Twelve-year rates of progression. (2) Risk factors for progression of disease. RESULTS: Three hundred twenty-six of six hundred thirty-nine (51%) subjects were traced and examined, 108 (17%) had died, and 205 (32%) were lost to follow-up. After 12 years, 6.4% (95% confidence interval [CI], 4.0-9.97) of scarred subjects had trichiasis develop, 5.96% (95% CI, 3.67-9.42) had corneal opacity develop, 16.51% (95% CI, 12.71-21.13) had visual impairment/blindness develop, and 2.5% (95% CI, 1.2-5.0) had corneal visual impairment/blindness develop. Mandinka ethnicity was a risk factor for trichiasis (odds ratio [OR], 4.3; 95% CI, 1.3-14.4), and trichiasis at baseline was a risk factor for corneal opacity (OR, 8.4; 95% CI, 1.8-39.2). History of lid surgery for trichiasis was associated with corneal opacity at follow-up (OR, 4.4; 95%CI, 1.4-14.0). Older age was a significant risk factor for development of trichiasis, corneal opacity, and visual loss (OR, 1.07; 95% CI, 1.01-1.12). Bilateral cataract was present in 40% of traced subjects and was associated with the incidence of visual impairment/blindness (OR, 9.4; 95%CI, 4.5-19.6) CONCLUSIONS: This is the first study to demonstrate the link between trichiasis and future corneal opacity, and it provides the rationale for performing lid rotation surgery on patients with trichiasis who do not yet have corneal opacity. The association between corneal opacity at follow-up and previous surgery among trichiasis patients suggests late presentation as a problem. The planning of surgical services will be aided by the incidence figures generated by this study.

Adolescent↗
PubMed1975

Xerophthalmia and anterior-segment blindness among preschool-age children in El Salvador.

A countrywide prevalence survey of 9,508 children was conducted in El Salvador to determine the prevalence of anterior-segment abnormalities and magnitude of clinical vitamin A deficiency. Thirty-six children had corneal opacities, 56% of them secondary to trauma. Such traumatic corneal opacities were 19 times more frequent among urban than rural children, 57.6 vs. 3.1 per 1,000. Keratomalacia accounted for only 8% of all corneal opacities, and for one (and possibly two) of the five cases of bilateral anterior-segment blindness encountered. The prevalance of Bitot spots and vitamin-A-related corneal opacities was 5.3 and 3.2 per 10,000, respectively. There are an estimated 43 new surviving cases of vitamin-A-related corneal opacities in the country each year, one third of which result in bilateral blindness. Fifteen percent of all children examined had grossly purulent conjunctivitis.

Blindness↗
PubMed2003

Bilateral corneal ring opacity of unknown origin.

PURPOSE: To report one case of a bilateral ring-shaped opacity in the mid-peripheral corneal stroma of unknown origin. METHODS: Case report. RESULTS: The authors describe the clinical history and ocular examination of an asymptomatic 82-year-old woman with a bilateral ring-shaped opacity located in the corneal stroma. This rare corneal anomaly was discovered by chance, and the etiology is unknown. CONCLUSION: An unusual bilateral corneal abnormality is reported.

Aged↗
PubMed2001

Two patterns of opacity in corneal dystrophy caused by the homozygous BIG-H3 R124H mutation.

PURPOSE: To investigate the opacity pattern in corneas with an Arg124His (R124H) homozygous mutation of the BIG-H3 gene. METHODS: Slit-lamp examination was performed on eight patients with corneal dystrophy resulting from a genetically confirmed BIG-H3 R124H homozygous mutation. The birthplace of each patient also was determined. RESULTS: Slit-lamp examination disclosed two types of opacity patterns in corneas with the BIG-H3 R124H homozygous mutation. Type I (n = 4) is a spot-like opacity present in the anterior stroma in which the lesions are confluent. Type I is the same pattern that previous reports have shown to be caused by the BIG-H3 R124H homozygous mutation. The type II corneal opacity pattern (n = 4) is a reticular opacity in the anterior stroma with round translucent spaces. Type II opacity has not been reported previously in association with any corneal dystrophy. The patients with the type I opacity do not share a common birthplace; however, interestingly, the patients with the type II opacity traced their origin to Tottori prefecture in western Japan. CONCLUSION: The BIG-H3 homozygous R124H mutation induces the development of two distinct patterns of corneal opacity, the recognition of which can establish an accurate diagnosis of corneal dystrophy caused by the homozygous BIG-H3 R124H mutation independent of genetic analysis. In addition, genetic factors or circumstantial influences other than the gene responsible for the corneal dystrophy may influence the pattern of corneal opacity.

Adult↗
PubMed2000

Chronic clinical course of two patients with severe corneal dystrophy caused by homozygous R124H mutations in the betaig-h3 gene.

PURPOSE: To report the chronic clinical course of two patients with homozygous R124H mutations in the betaig-h3 gene. METHODS: Case reports. RESULTS: Two patients with homozygous R124H mutations in the betaig-h3 gene developed severe juvenile corneal opacities that required keratoplasty. After surgery, corneal opacities recurred and limited the recovery of visual acuity in the chronic follow-up. CONCLUSION: In patients with homozygous R124H mutations in the betaig-h3 gene, recurrence of corneal opacities after keratoplasty limits the recovery of visual acuity in the chronic follow-up.

Child↗
PubMed2002

Clinical feature of unintended thin corneal flap in LASIK: 1-year follow-up.

To purpose of this study was to evaluate complications of unintended thin corneal flap in laser in situ keratomileusis (LASIK), such as visual acuity and myopic regression, at the one year follow-up. We performed a study on 54 eyes, i.e. 27 patients, having LASIK. The eyes were split into two groups, group one, 27 eyes with unintended thin corneal flap with a thickness of 100 microm or less, and as a control group, 27 eyes with a thickness of 110 microm or more. The average corneal flap thicknesses of the two groups were 88.89 +/- 8.07 microm and 132.70 +/- 19.58 microm, respectively. With regard to postoperative complications, there were no statistical differences between the groups for: foreign bodies in aspects of the interface, mild peripheral infiltration, superficial punctuate keratitis, myopic regression and decreased vision. The only complication showing any statistical difference between the two groups was the central corneal opacity. An unintended thin corneal flap, with an intact Bowman's layer, induced no significant postoperative complications. Central corneal opacity was apparent in 4 of the eyes in group one, so may be related with a thin corneal flap.

Adult↗
PubMed1990

Deep corneal stromal opacities in long-term contact lens wear.

In 32 patients with long-term contact lens wear (up to 19 years), deep whitish opacities directly adjacent to Descemet's membrane were seen in the central part of the cornea. These opacities were seen in soft hydroxyethylmethacrylate (HEMA) as well as in hard (polymethylmethacrylate, PMMA) contact lens wear. These conditions could reduce visual acuity. When contact lens wear was discontinued or when the HEMA or PMMA lenses were replaced by gas-permeable rigid lenses, the lesions gradually diminished and resolved completely in most patients. One possible cause of these opacities is an allergic reaction to thimerosal. Another possible cause is chronic anoxia of the corneal stroma and endothelium. Endothelial cell density was not abnormal, but there was a marked polymegethism of the endothelium as a sign of endothelial stress.

Adult↗
PubMed2003

Visual and ocular changes associated with exposure to two tertiary amines.

AIMS: To determine if exposure to dimethylisopropanolamine (DMIPA) and dimethylaminoethanol (DMAE) in a label printing plant was associated with visual disturbances and/or ocular changes. METHODS: Questionnaires, eye examinations (visual acuity, contrast sensitivity at 2.5% and 1.25% contrast, slit lamp biomicroscopy, and pachymetry), and industrial hygiene monitoring for DMIPA and DMAE were performed over a two week period. RESULTS: Eighty nine per cent of line workers reported having experienced blurry vision while at work in the past 12 months, compared to 12.5% of prime workers. A total of 108 full shift personal breathing zone (PBZ) air samples for the amines were collected. The mean time weighted average (TWA) concentration of DMIPA was significantly higher in the line division than in the prime division, as was the mean TWA concentration for total amines. The mean TWA concentration of DMAE was higher in the prime division than the line division. Higher levels of total amines were associated with increased risk of reporting blurry vision, halo vision, and blue-grey vision. The risk of corneal opacity rose with increasing exposure to total amines. The prevalence of corneal opacity also increased with increasing concentration of total amines. Median corneal thickness increased with increasing grades of corneal opacity. There was a statistically significant relation between total amine concentration and increased risk of reduced bilateral visual acuity and 2.5% contrast sensitivity. CONCLUSIONS: Exposure to tertiary amines was associated with blurry, halo, and blue-grey vision, corneal opacity, and decrements in visual acuity and contrast sensitivity at 2.5% contrast.

Amines↗
PubMed2005

Central corneal mosaic opacities in Schnyder's crystalline dystrophy.

PURPOSE: To report an unusual presentation of Schnyder's corneal crystalline dystrophy (SCCD), sharing the feature of central corneal mosaic opacities. DESIGN: Observational case report. METHODS: A 51-year-old man and his family members were examined. Investigations included slit-lamp biomicroscopy, radiography of knee joint, plasma lipid level, and genotyping of the SCCD candidate region in chromosome 1p34.1-1p36. RESULTS: A symmetric, central, disciform, full-thickness opacity was seen in both corneas of the patient. The opacities appeared in a mosaic pattern, instead of collections of crystals or a diffuse haze as typically detected in SCCD. Small clumps of crystalline deposits and arcus lipoides were also observed. Systemically, hyperlipidemia and bilateral genu valgus were identified. He had 2 daughters, and both of them had bilateral corneal crystalline deposits and genu valgus. No other family members had findings suggesting SCCD. The genetic study demonstrated that all of the affected individuals shared a common haplotype within the region of previously reported SCCD locus. However, 1 unaffected sibling of the proband also had the same haplotype. CONCLUSIONS: Central corneal mosaic opacities may be another variant of SCCD.

Adolescent↗
PubMed1995

Opaque eyes developed in transgenic mice with T-cell receptor delta gene.

PURPOSE: During the generation of transgenic mice (TGs) introduced with mouse T-cell receptor delta (TCR delta) gene, the authors found a TG line with corneal opacity that coincided with the presence of the transgene. The authors investigated the pathogenesis and molecular mechanisms of this corneal opacity in this line. METHODS: The pathologic features and pathogenesis of the corneal opacity in TGs were examined histologically using transmission and scanning electron microscopy, as well as light microscopy. DNA and RNA blot analyses were performed to examine the copy number and the expression of the transgenes, respectively. RESULTS: Histologically, edema of the corneal epithelium and adhesion of the iris to the cornea were observed in adult TGs. In the developmental analysis, the authors first observed relative hypoplasia of the ciliary body on day 18 of gestation and dysgenesis of the anterior chamber angle from postnatal day 2. Corneal opacity was observed from postnatal day 8, coinciding with the histologic vesicular change of the epithelium. No inflammation was observed through its life. In the sublines that have different copy numbers of the transgene, the occurrence of the opacity depended on the copy number of the transgene. Expression of the transgene in the thymus was consistent with the number of the introduced transgene. CONCLUSION: In a TCR delta TG line, the overexpression of transgenes coincided with abnormal development of the ocular anterior segment and the corneal opacity. Pathogenesis is described, and possible molecular mechanisms are discussed.

Animals↗
PubMed2000

Corneal subepithelial opacities associated with inappropriate contact lens care.

PURPOSE: To report two cases of corneal subepithelial opacities, which may be related to improper lens care by the patients. METHODS: Slit-lamp examination and monitoring of contact lens care procedures. RESULTS: Two female patients experienced similar symptoms of soreness, blurring, and red eyes after wearing soft contact lenses. Slit-lamp examinations demonstrated numerous subepithelial opacities in the central cornea. Both patients used the same kind of cleaner (MiraFlow) inappropriately, which resulted in the possibility of residual cleaner remaining in the lenses. The symptoms and signs gradually subsided after discontinued use of soft contact lens and application of topical steroid. CONCLUSIONS: Residual MiraFlow in soft contact lenses may result in corneal subepithelial opacities.

Adult↗
PubMed2003

[Preliminary clinical results of optical lamellar keratoplasty assisted by homemade-microkeratome].

OBJECTIVE: To evaluate the efficacy and safety of optical lamellar keratoplasty assisted by homemade-microkeratome in treating corneal opacification for optical indications. METHODS: In 12 eyes of 11 patients with corneal opacities and healthy endothelium, the homemade-microkeratome was used for the resection of corneal opacities whose depth measured by optical pachymeter preoperatively, and the donor disc was excised by the same technique. After the resection of corneal opacities, the residual bed thickness was measured by ultrasonopachymeter. The disparities in thickness and diameter between the bed and the donor disc were reduced as least as possible by the use of different suction rings and microkeratome heads. The donor disc was secured with four or eight interrupted sutures. The period of follow-up ranged from 7 to 14 months. The transparency of cornea, donor-host interface and the refractive changes after surgery were examined by slit-lamp microscopy and Keratron videokeratoscope. RESULTS: The slit-lamp microscopic examination showed no severe complications after surgery, all grafts appeared to be transparent without recognizable opacity in the interface except 1 eye with epithelial ingrowth and local graft melting subsequently. Visual acuities were improved in all eyes, 7 eyes had best corrected visual acuity better than 0.5 and 2 eyes reached 0.8. During the follow-up 3 to 6 months, the mean corneal refractive power significantly increased (2.36 +/- 1.25) D (P = 0.016), and the corneal astigmatism significantly decreased (0.97 +/- 0.95) D (P = 0.023) Compared with that before surgery, the increase of the corneal refractive power had negative correlation with the thickness of residual bed (r = -0.830, P = 0.004). CONCLUSIONS: This easy, safe new technique leads to good visual results and represents a good alternative to penetrating keratoplasty in treating corneal opacities.

Adult↗
PubMed1997

Incidence estimates of late stages of trachoma among women in a hyperendemic area of central Tanzania.

The purpose of this study is to estimate 5-year incidences of conjunctival scarring and trichiasis, and 10-year incidence of corneal opacities due to trachoma, using prevalence data from a population sample of 6038 women living in a trachoma-hyperendemic area of central Tanzania. Previous surveys have documented the age-specific prevalence of scarring, trichiasis, and corneal opacities in women in hyperendemic areas. Using the age-stratified prevalences of these different clinical signs, corresponding incidence rates were estimated. Transition rates from one sign to the next were also obtained by restricting the risk group to only women with a specific trachoma sign. Thus, the 5-year incidence of trichiasis among women with conjunctival scarring, and the 10-year incidence of corneal opacities among women with trichiasis were estimated. Incidences of all the signs markedly increased with age. For scarring, 5-year incidence rates increased from 3.1% in the 15-19 age category to 14.3% for women between 55 and 59 years. The 5-year incidence of trichiasis ranged from 0.3% in the 15-19 age category to 7.5% in the age group 55-59. Corneal opacities due to trachoma were highest in the age group 45-54; the 10-year incidence increased to 2.8%. The 5-year incidence of trichiasis among only women with scars increased from 3.2% in the 15-19 age group to 15.1% in women in the 55-59 age group. Once trichiasis is present, almost one-third of the women below 35 and more than 40% of the women older than 45 will develop corneal opacities in a 10-year interval. These estimates are important in understanding the dynamics of progression of trachoma from conjunctival scarring to the potentially blinding signs of trichiasis and corneal opacities. They provide important information for planning adequate services in areas where trachoma is endemic and surgery for trichiasis is a key factor to avoid blindness from trachoma. They also provide clues to the pathogenesis that may be useful in the development of new methods of control.

Adolescent↗
PubMed2006

[New trends in corneal surgery. Grafting stem cells and performing lameliar graft].

Epithelial, stromal or endothelial diseases can generate corneal opacity. A lake of corneal epithelial cells leads to corneal opacity and low visual acuity. In these cases, corneal epithelial stem cells from the limbus of the healthy eye or from relatives or other people must be grafted to regenerate corneal epithelium. It is also possible to cultivate corneal stem cells harvested from the sick eye, the healthy eye (autologous culture) or from relatives (allotypic culture). Renewing epithelial cells is not always sufficient to restore corneal transparency. It can also be necessary to replace a part or the entire corneal stroma. We can use today surgical lamellar graft technics to replace only stromal corneal layers involved in the disease we cure.

Corneal Diseases↗
PubMed1996

Deep corneal stromal opacities associated with long term contact lens wear.

BACKGROUND: One male and three female long term contact lens wearers (mean age 30.3 years; range 26-33) demonstrated unusual deep corneal stromal opacities which were predominantly just anterior to Descemet's membrane. None had any history of corneal dystrophy. These opacities were more common centrally, but were also identified in the corneal periphery. METHODS: All patients underwent routine ophthalmic examinations and, where appropriate, slit-lamp photography and specular microscopy. RESULTS: Mean lens wear in years and hours per day was 14.3 (range 10-17) and 14.3 (range 12-16) respectively. Specular microscopy disclosed cell densities within normal limits (mean 3041.5 cells per mm2) and coefficient of variation of mean cell area; COV = 0.31. Refractive errors ranged from -12.25 D to +6.25 best vision sphere and all four subjects attained at least 6/9 Snellen visual acuity. The subjects' contact lens wearing history included low water content hydroxymethylmethacrylate (HEMA) contact lenses and high water content HEMA contact lenses. Stromal opacity density was observed to diminish over a period of months on cessation of contact lens wear in two cases. CONCLUSION: The possible causes of these rarely reported opacities are discussed.

Adult↗
PubMed1995

Corneal stromal abscesses in the horse: a review of 24 cases.

The medical records of 24 horses with corneal stromal abscesses were reviewed. Twenty of the horses initially presented with a corneal ulcer, corneal opacity, or evidence of ocular pain. All of the horses were treated with topical antibiotics prior to referral. Most had also been treated with topical atropine sulphate and systemic flunixin meglumine. Ophthalmic examinations revealed focal, yellow-white corneal opacities, corneal vascularisation and evidence of iridocyclitis. Nine of the horses were treated primarily medically as the initial response to topical and systemic medication was rapid. Fifteen horses were treated both medically and surgically. Surgical treatment was undertaken when corneal rupture was imminent, the iridocyclitis was intractable or when there was minimal response to intensive medical therapy. The surgical procedure performed in most cases was a deep keratectomy with a conjunctival pedicle flap. Intraoperative specimens for cytology, culture, and/or histopathology contributed to the aetiological diagnosis in 5 of 8 cases in which preoperative cytology and cultures were nondiagnostic. All horses, excluding one that was enucleated at presentation for iris prolapse, had vision at discharge.

Abscess↗
PubMed2006

Exacerbation of Avellino corneal dystrophy after LASIK in North America.

PURPOSE: To report the first case of Avellino corneal dystrophy exacerbation after LASIK in a white or North American patient. METHODS: Case report and literature review. RESULTS: A 25-year-old white female developed progressive corneal opacities after LASIK. Preoperative examination had revealed only subtle white corneal opacities in each eye. The patient's mother had similar corneal opacities. DNA analysis of the patient revealed a heterozygous mutation at the R124H location in the BIGH3 gene. CONCLUSIONS: LASIK can exacerbate Avellino corneal dystrophy and should be avoided in patients with this condition. A careful history and genetic analysis can identify affected patients and those at risk.

Adult↗