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At least 19 recordsLinked to original sources

Spontaneous corneal opacities in laboratory mice.

Corneal opacities were observed in numerous strains and stocks of laboratory mice (Mus musculus) from different microbiological environments. The opacities were characterized as acute and chronic inflammatory lesions of the corneal epithelium and anterior corneal stroma, including corneal ulcers and erosions, acute keratitis, stromal neovascularization and mineralization of the basement membrane zone. Some strains and stocks of mice from barrier-reared colonies had a high incidence of corneal opacities [DBA/2 (29.1%), C3H (16.2%), CF1 (16.2%) and BALB/c (10.0%)] while others had a lower incidence [CD-1 (4.3%) and C57BL/6 (4.1%)]. Axenic and gnotobiotic mice had a very low incidence of corneal opacities (1.6%). An experimental study demonstrated that twice weekly cage cleaning would reduce the incidence of corneal opacities to a very low level. A bacterial product, such as ammonia, is proposed as a significant factor in the pathogenesis of spontaneous corneal opacities in laboratory mice.

Animals↗

[Endothelial function in contact lens-induced deep corneal opacities].

Deep stromal and preendothelial corneal opacities have been described to be a problem of growing importance in contact lens wearers, above all in those with a more than ten-year-old history of contact lens wearing. In the present study the corneal endothelial permeability of 21 patients with a more than ten-year-old history of contact lens (HEMA 38%) wearing has been determined and compared with that of an age-matched group of 8 healthy individuals without ocular disease. The corneal endothelial permeability has been measured by a computerized automated fluorophotometer (Coherent Radiation Fluorotron Master) after topical application of a Na-fluorescein solution according to the method described by Jones and Maurice. The corneal endothelial permeability of contact lens wearers with deep corneal opacities has been found to be significantly (p = 0.05) increased when compared with contact lens wearers without corneal opacities. Contact lens wearers without corneal opacities showed no significant increase of their endothelial permeability in comparison to the control group.

Cell Membrane Permeability↗

Bilateral corneal opacities associated with idiopathic multicentric osteolysis.

PURPOSE: To report unusual bilateral corneal opacity and inferior corneal thinning in a patient with idiopathic multicentric osteolysis. METHODS: A 17-year-old girl with a history of idiopathic multicentric osteolysis was evaluated for corneal opacities. RESULTS: She was found to have bilateral, linear, posterior corneal opacity and inferior corneal thinning. Her vision did not appear to be affected. No progression of the corneal findings was noted over a period of 2 years. CONCLUSION: Posterior corneal opacity and inferior corneal thinning may be associated with idiopathic multicentric osteolysis, a rare disorder of unknown etiology characterized by bony abnormalities and nephropathy. Patients with idiopathic multicentric osteolysis should be evaluated by an ophthalmologist for the presence of corneal opacities.

Adolescent↗

Differentiation of posterior polymorphous dystrophy from other posterior corneal opacities by specular microscopy.

Deep corneal opacities due to posterior polymorphous dystrophy, especially if they are mild, are frequently confused with changes due to other corneal conditions. In a series of 64 patients with deep corneal opacities (14 with Descemet's tears, 8 with posterior polymorphous dystrophy, 12 with interstitial keratitis, and 30 with keratoconus), specular microscopy enabled the differentiation of deep corneal changes provided some degree of corneal clarity was retained. The parallel "rail track" borders of old Descemet's tears were characteristic and differed from the "snail tracks" seen in posterior polymorphous dystrophy, which also showed characteristic rounded vesicular or doughnut-like lesions in Descemet's membrane. The appearances in interstitial keratitis were varied with poor detail in most cases because of corneal opacity. However, fine opacities consistent with ghost vessels were seen in interstitial keratitis and a resolving case showed fine, intersecting straight lines different from the bundles of parallel fine vertical lines of deep corneal striae in keratoconus. Specular microscopy also enables an assessment of the corneal endothelium which is important if intraocular surgery is contemplated.

Adolescent↗

Corneal opacity after repeated photorefractive keratectomy.

Corneal opacity developed in an eye that had photorefractive keratectomy (PRK) with a 193 nm excimer laser 5 times over 3 years. Six months after the last PRK, a partial penetrating keratoplasty was performed. The cornea was stained and immunohistochemically evaluated for collagen types. Light microscopy showed thickening of epithelial layers, proliferation of subepithelial fibroblasts, and the absence of Bowman's membrane. Transmission electron microscopy showed irregular collagen lamellae and electron-dense deposits adjacent to keratocytes. The staining was positive for Alcian blue, and immunohistochemistry was positive for type IV and VI collagen. This case suggests that corneal opacity after repeated PRK is the result of deposits of type IV and VI collagen and acidic mucoprotein in the extracellular matrix.

Collagen↗

Optical iridectomy for corneal opacities in Peter's anomaly.

Three children were born with partial corneal opacity and anterior segment anomalies but no cataract (Peter's anomaly type 1). In each affected eye, the corneal scar was off center and encroached on the visual axis. Glaucoma (if present) was controlled medically or surgically, after which an optical iridectomy was performed in each eye (in lieu of a penetrating keratoplasty). After surgery, in all patients the pupil extended beyond the corneal opacity and the corneal opacity decreased slightly. All could fixate and follow around the opacity. Optical iridectomy should be considered in selected cases of congenital corneal opacities.

Anterior Eye Segment↗

Endoillumination-assisted cataract surgery in a patient with corneal opacity.

We present a technique to better visualize cataracts through corneal opacity. A 70-year-old Japanese woman with retinal detachment, cataract, and corneal opacity in the left eye was treated with phacoemulsification, 3-port vitrectomy, and intraocular lens implantation. To circumvent the difficulty of performing continuous curvilinear capsulorhexis (CCC) and subsequent cataract surgery through a hazy cornea, we used an endoilluminator as a light source outside the cornea for CCC and inside the anterior chamber for phacoemulsification. As a result, CCC and subsequent cataract surgery were successfully and easily performed despite potentially troublesome corneal opacity. The use of an endoilluminator can be an effective supportive measure for cataract surgery in patients with corneal opacity.

Aged↗

[Corneal Ascher ring. A ring-shaped stromal corneal opacity].

An unusual bilateral ring-shaped corneal opacity has been observed in two patients. Biomicroscopical characteristics are minute greyish dots which are distributed within the outer stromal layers forming an arcus lipoides-like circular band. Besides of a typical arcus senilis no other corneal anomalies can be found. Up to date only 4 patients with similar corneal opacities have been described. Etiology remains unclear and according to the author who has first described this symptom we propose to name this corneal anomaly "Ascher-Ringe".

Aged↗

Ipsilateral rotational autokeratoplasty for the management of corneal opacities.

PURPOSE/BACKGROUND: Penetrating keratoplasty is the logical solution for the management of corneal opacities. In situations such as in Papua New Guinea, where donor corneal tissue is scarce and corneal opacities are plenty, an alternative procedure for the management of corneal opacities in the form of ipsilateral rotational autokeratoplasty was considered. METHODS: In the present prospective study, ipsilateral rotational autokeratoplasty was performed in 17 eyes over a 2 year period in a general hospital. The patient's cornea was trephined eccentrically and the corneal opacity was dialed out of the visual axis and was replaced by clear peripheral cornea. RESULTS: Most opacities were leucomata (76.4%). The average size of the opacity was 5.1 mm and the corneal button size was 7 mm.A final visual acuity of 6/18 or better was obtained in 64.7% of cases (at 12 months). No significant postoperative complications were encountered. No complex formula was needed to calculate the size of the button and, by simply adding 3 mm to the pupillary diameter in standard illumination, one could make an estimation of the graft diameter. CONCLUSIONS: Rotational autokeratoplasty has a definite role in places where donor corneal tissue is scarce, in patients in whom long-term steroids are a risk or in situations where follow up of patients is difficult. Rejection is a theoretical impossibility, but late endothelial failure could occur, requiring regrafting. Rotational autokeratoplasty should be seriously considered as an alternative to conventional penetrating keratoplasty.

Adolescent↗

Corneal opacities in Gaucher disease.

PURPOSE: To describe the corneal findings in a variant of Gaucher disease. METHODS: Case report. In an 18-year-old man, ophthalmic and general clinical evaluation, and enzymatic and molecular genetics studies were performed. RESULTS: Diffuse, well-defined, small, linear, or dotlike corneal opacities were observed through, out the posterior two thirds of the corneal stroma in both eyes. The patient had calcific valvular heart disease. Enzymatic and ultrastructural studies were consistent with Gaucher disease. Analysis of the glucocerebrosidase gene disclosed homozygosity for a D409H mutation. CONCLUSION: Corneal opacities are a distinguishing ocular feature of the variant of Gaucher disease associated with the D409H mutation and with calcific cardiac disease.

Adolescent↗

Excimer laser phototherapeutic keratectomy for corneal opacities and recurrent erosion.

BACKGROUND: Phototherapeutic keratectomy (PTK) has been used to treat superficial corneal opacities, as well as the recurrent corneal erosion syndrome. METHODS: We performed PTK 6 eyes of 6 patients to treat corneal opacities, and in one eye of another patient to treat recurrent corneal erosion syndrome. Opacities were caused by a healed corneal ulcer, herpetic keratitis, band keratopathy, corneal burn, corneal dystrophy, and an excised pterygium. The follow-up period ranged from 2 to 6 months. RESULTS: Corneal clarity improved to variable degrees in all eyes with corneal opacities. There was no recurrence in the Recurrent Corneal Erosion Syndrome. A hyperopic shift was observed in 2 eyes. CONCLUSIONS: PTK appears to be an effective alternative to penetrating keratoplasty in patients with selected anterior stromal opacities can treat the Recurrent Corneal Erosion Syndrome.

Adult↗

Visual outcome of cataract surgery with pupillary sphincterotomy in eyes with coexisting corneal opacity.

BACKGROUND: To evaluate the visual outcome following cataract surgery with pupillary sphincterotomy in eyes with coexisting corneal opacity. METHODS: Patients with leucomatous corneal opacity with significant cataract were enrolled for the study. The uncorrected visual acuity and best-corrected visual acuity (BCVA) were recorded and the anterior segment was thoroughly evaluated by a slit lamp biomicroscope before the surgery. Only those patients who had some amount of clear peripheral cornea were selected. Posterior segment pathology was ruled out by indirect ophthalmoscopy after pupillary dilatation, if possible, or by B-scan ultrasonography. Conventional extracapsular cataract extraction with pupillary sphincterotomy was performed and an intraocular lens was implanted. Postoperatively, the eyes were evaluated on day 1, and 1 week and 6 weeks following surgery for similar parameters. RESULTS: Fourteen eyes of 14 patients were included in the study, of which 13 (92.85%) patients were male. The mean age of the patients was 47.85 +/- 7.37 years. All the eyes had a dense central leucomatous corneal opacity. Twelve (85.71%) eyes had two or more quadrants of deep vascularisation. Sphincterotomy was performed mostly (71.42%) in the nasal or inferonasal quadrant. The intraocular lens was implanted in 13 (92.85%) eyes, and one (7.1%) eye was left aphakic due to the occurrence of a large posterior capsular tear. Preoperatively, all eyes had BCVA < 6/60. At 6 weeks after surgery, all eyes had BCVA >or= 6/60 and four (28.57%) eyes had BCVA >or= 6/18. The mean BCVA preoperatively in these eyes was 0.015 +/- 0.009, which changed to 0.249 +/- 0.102 at 6 weeks following surgery. CONCLUSIONS: Extracapsular cataract extraction and intraocular lens implantation with pupillary sphincterotomy provides ambulatory and useful vision to patients of cataract with coexisting central leucomatous corneal opacity.

Cataract Extraction↗

Clinical pathologic correlation of superficial corneal opacities in X-linked ichthyosis.

X-linked ichthyosis is a relatively common oculodermal disorder. Characteristic corneal opacities are small punctate or filiform lesions and are located in the deep corneal stroma. In an unusual case, a 73-year-old man with X-linked ichthyosis and steroid sulfatase deficiency had superficial corneal opacities. The corneal opacities were granular in nature, involving the subepithelial and anterior stromal layers. The opacities resulted in irregular overlying corneal epithelium and were white-gray in color in direct illumination. Histopathologic and electron microscopic studies demonstrated abnormalities of the corneal epithelial basement membrane. The epithelial basement membrane was thickened with irregular extensions into Bowman's layers. Abnormal depositions of basement membrane protein were seen in the anterior stroma. These abnormalities may have resulted from increased production of basement membrane proteins by the corneal epithelium, resulting from hyperactive turnover of the basal layer.

Aged↗

Clinical follow-up of phototherapeutic keratectomy for treatment of corneal opacities.

We performed phototherapeutic keratectomy with a 193-nm excimer laser on 18 sighted patients (18 eyes) to treat corneal opacities. The corneal opacities were caused by corneal dystrophies in five patients; corneal scars secondary to corneal ulcers in six patients; corneal scar secondary to trauma in four patients; and band keratopathy, atopy, or corneal calcification in three patients. Mean follow-up was eight months (range, two to 18 months). Corneal clarity improved in 14 of the 18 eyes (77.7%). Four patients, three with band keratopathy or calcification and one with postinfectious corneal scar, did not improve. Uncorrected visual acuity improved in 11 patients, did not improve in five patients (including the four patients in whom treatment failed), and decreased in another two patients, apparently because of an increase in irregular astigmatism. A hyperopic shift was observed in ten patients. None of the successfully treated eyes developed surface problems or recurrence of the disease during the follow-up. Phototherapeutic keratectomy thus appears to be a safe and effective alternative to penetrating keratoplasty in some patients with selected anterior stromal opacities.

Adult↗

[Penetrating keratoplasty in congenital corneal opacities].

The clinical course and histopathological findings in 17 cases of congenital corneal opacity treated by penetrating keratoplasty are described. On the basis of the histopathological findings 9 of the cases of corneal opacity were diagnosed as Peter's anomaly, 5 cases as sclerocornea or mesenchymal dysgenesis, 2 as choristoma, and 1 case as leukoma. Only 2 of the corneal grafts performed in these infants remained clear. The underlying disease in the 2 cases where surgery was successful was Peter's anomaly, with a clear corneal periphery. From the analysis of the corneal buttons the authors deduce that graft failure in most such cases is due to severe structural changes of the host cornea. Three findings represented consistently unfavorable signs: (1) absence of Bowman's layer; (2) absence of Descemet's membrane and (3) corneal vascularization at the cut edge of the button. Immunoreaction or infection of the graft are rare causes of graft failure. Despite the extremely poor prognosis of bilateral congenital corneal opacities, penetrating keratoplasty should be attempted. The histopathological findings may be used as prognostic criteria for graft survival or the extent of anterior segment dysgenesis.

Cornea↗

Recurrent subepithelial corneal opacities after excimer laser phototherapeutic keratectomy.

PURPOSE: To report the recurrence of presumed post-viral conjunctivitis subepithelial corneal opacities after excimer laser phototherapeutic keratectomy (PTK). METHOD: Case report. RESULTS: A 33-year-old ophthalmic technician developed recurrence of opacities after treatment of presumed post-viral keratitis subepithelial corneal opacities with the excimer laser. CONCLUSIONS: Post-viral keratitis subepithelial corneal opacities may recur after removal by excimer laser PTK. Recurrence of these opacities in anterior corneal stroma previously unaffected by opacities before laser treatment suggests the presence of viral antigen in deeper corneal tissue than that occupied by the original subepithelial opacities. The recurrence also suggests likely routes of corneal antibody penetration in the formation of these opacities. Intensive topical steroid treatment may play a role by increasing the depth of viral particle penetration into corneal stroma.

Adult↗

[Clinical application of keratoprosthesis for corneal opacity unsuitable for keratoplasty].

OBJECTIVE: To evaluate the results of keratoprosthesis for complicated corneal opacities unsuitable for keratoplasty. METHODS: Fifteen keratoprosthesis were implanted in 15 patients with bilateral blindness. Preoperative visual acuity (VA) was light perception in all operated eyes. The corneal opacities were caused by severe alkali burn (6 eyes), sulfate acid injury (3 eyes), melting aluminum injury (2 eyes), explosive injury (1 eye), severe dry eye (1 eye) and multi-keratoplasty failure (2 eyes). The keratoprosthesis (MICOF) were made by Moscow eye microsurgery complex in Russia. Surgical techniques consisted of two stages; first, inserting a supporting titanium frame into the lamellar pocket and then, implanting an optical part 3 months later. RESULTS: Follow-up time ranged from 4 to 26 months (9.5 months on average). In 14 of 15 eyes (93%), postoperative VA ranged from 0.12 to 1.0 without correction. Corrected postoperative VA was: 7 eyes (47%) with VA from 0.6 to 1.2; 5 eyes (33%) from 0.3 to 0.5 and 2 eyes (13%) from 0.15 to 0.2. The reason of the only eye without VA improvement was a pre-existing retinal detachment. CONCLUSION: Keratoprosthesis improves vision for corneal opacity patients with complicated conditions such as dense neovascularization and severe ocular surface disorders.

Adolescent↗