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PubMed1984

Leprosy in a trachomatous population.

In an Egyptian leprosy hospital, 17% of 133 patients had a visual acuity of less than 3/60. Corneal opacity, phthisis bulbi, and cataract accounted for 85% of blindness. Leprosy and trachoma together produce blinding corneal opacity by exposure, leprous keratitis, and trichiasis and entropion. Inturned lids, a late result of conjunctival scarring due to childhood trachoma, were less frequent in patients with lepromatous leprosy than in patients with tuberculoid leprosy; because conjunctival scarring from trachoma depends on cell-mediated immunity, patients with lepromatous leprosy may not have had severe trachomatous scarring develop due to their lifelong abnormality in cellular immunity. In patients with leprosy, even when complicated by trachoma, simple measures to prevent or restore vision include medical treatment of leprosy, surgical correction of lid deformities, sector iridectomy for constricted pupils or central corneal opacities, and cataract extraction.

Adult↗
PubMed2001

Temporary graft for closed-system cataract surgery during corneal triple procedures.

Performing phacoemulsification during a triple corneal procedure has many advantages. Operating in a closed chamber makes surgery easier and safer. In some cases, however, a dense corneal opacity may prevent closed-chamber surgery, necessitating the use of an open-sky technique. In these cases, a temporary corneal graft using a corneal button not suitable for penetrating keratoplasty is proposed to allow phacoemulsification and foldable intraocular lens implantation through a corneal tunnel. The temporary corneal graft is replaced with a permanent graft after these steps are completed. This technique was effective in 3 patients with cataract and dense corneal opacity.

Cataract↗
PubMed2006

Factors predicting unsuccessful big bubble deep lamellar anterior keratoplasty.

PURPOSE: To evaluate the role of corneal structural resistance as a surgical failure factor in deep lamellar keratoplasty (DLK). METHOD: A total of 10 eyes of 10 patients underwent DLK at the Ophthalmic Hospital in Rome. The big bubble technique was performed for deep stromal dissection by air injection. Seven patients were affected by advanced keratoconus and corneal thinning ranging from 441 to 235 microm. Two patients were affected by central corneal opacity from herpetic keratitis, and one patient suffered from corneal leucoma caused by bacterial keratitis. Clinical follow-up comprising final astigmatism and visual acuity findings were evaluated with a minimum follow-up of 12 weeks. RESULTS: DLK was successfully performed in eight eyes, five of which were affected by moderate to advanced keratoconus and three by post-infective corneal opacity. In these patients preoperative ultrasonic pachymetry ranged between 441 and 287 microm. In the remaining two patients a perforation of the Descemet's membrane (DM) occurred while attempting to separate it from the overlying stroma by the big bubble technique, requiring a penetrating keratoplasty (PK) to be performed. In both cases preoperative ultrasonic pachymetry was below 250 microm. Both perforations occurred at a different site than the needle site and at the operative time of the big-bubble injection. DISCUSSION: An ultrastructurally weakened DM may suffer a loss of resistance to a stressing force, becoming unable to tolerate the big bubble technique, and thus being perforated. Since the weakening of the DM is related to end-stage keratoconus corneal thinning, the preoperative corneal thickness rather than the surgeon's ability can play a major role in surgical failure of DLK. Our study reveals a very high risk of perforation of the DM when pre-operative total pachymetry is below limit of 250 microm.

Adult↗
PubMedDate not supplied

Phototherapeutic keratectomy in the treatment of corneal scarring from trachoma.

Trachoma is still one of the world's major blinding diseases. Characteristically, trachoma causes deep scarring of the conjunctiva and tarsus that can result in tear deficiency, trichiasis, and entropion. Another common finding is a diffused corneal opacity that is the end stage of peripheral and central corneal infiltrates. The conventional treatment of the corneal opacities is keratoplasty, which has a guarded prognosis because of severe dryness and trichiasis. We report on our experience in treating patients with corneal trachoma with phototherapeutic keratectomy (PTK) with the excimer laser.

Aged↗
PubMed2001

Therapeutic lamellar keratoplasty with an automated microkeratome.

Penetrating keratoplasty (PKP) is the predominant form of corneal transplantation because both manual and automated lamellar keratoplasty are technically difficult and lead to complications such as irregularities and scarring. A microkeratome for laser in situ keratomileusis can be used to overcome these disadvantages. We describe a technique of lamellar keratoplasty performed with an automated microkeratome to treat corneal opacities in the anterior third of the cornea. This easy, accurate technique leads to good visual results and represents a good alternative to PKP in treating anterior corneal opacities.

Cornea↗
PubMedDate not supplied

Keratoplasty in infants and children.

The most common causes of acquired corneal scarring before age 6 are herpes simplex keratitis, penetrating injuries, and congenital dystrophies. We performed 18 keratoplasties in 16 eyes of 15 patients under the age of 12 years, achieving clear grafts in 14 eyes (87%). We also performed 11 grafts in nine eyes of eight patients with congenital, central corneal opacities, achieving only one clear graft and four instances of phthisis bulbi or enucleation for buphthalmos. We do not recommend penetrating keratoplasty in patients with unilateral, congenital corneal opacities. However, those with bilateral cloudy corneas should have an attempt at kertoplasty as early in life as possible. The social and psychologic condition of the family often makes the difference between success and failure.

Aftercare↗
PubMed2005

Bilateral retinal dysplasia and secondary glaucoma associated with homozygous protein C deficiency.

PURPOSE: Protein C deficiency is an autosomal recessive disorder, which predisposes the patient to potentially blinding and widespread lethal thromboembolic complications, especially in the homozygous type. We here report the first Korean case of ophthalmic involvement and its surgical treatment in homozygous protein C deficiency. METHODS: A 3.4kg, full term girl was born by normal delivery but showed bilateral leukocoria on day 2. Laboratory results disclosed a very low protein C activity level (10%) in the patient and moderately decreased levels in the other family members. Ophthalmic examination showed bilateral corneal opacity and shallow anterior chamber. B-scan ultrasonography which showed intravitreal mass lesions without microphthalmos and a funnel-shaped retinal detachment suggested bilateral retinal dysplasia. RESULTS: As the eyes were under progression of secondary glaucoma, bilateral lensectomies were performed at 2 months old and corneal opacity was regressed to some degree. However, at 14 months old, the left eye showed moderate corneal opacity with a band keratopathy. CONCLUSIONS: Although visual outcome was very poor after surgery, we could impede or slow down the progression of secondary glaucoma and save the eyeballs in the infant with homozygous protein C deficiency.

Anterior Chamber↗
PubMed1993

An eye irritation test protocol and an evaluation and classification system.

An in vivo test protocol and an evaluation and classification system for the determination of eye irritation potential of chemicals and mixtures (substances) is proposed. The protocol uses two or three rabbits and reduces distress in test animals. The test substances are classified as non-irritant, irritant or severe irritant to meet regulatory needs. They may be classified on the basis of past experience with similar compounds or mixtures. Screens such as structure-activity relationships, pH extremes, validated and accepted in vitro tests, severe dermal irritation (primary dermal irritation index > or = 5) or severe dermal toxicity (lethality at < 200 mg/kg body weight) should be used to classify irritant or severe irritant materials when one or more of the screens can provide convincing evidence. For suspected severe irritant materials, the proposed in vivo test permits the use of one rabbit and instillation of 0.01 ml (0.01 g) of the test material into the cornea. Materials that are not classified irritant or severe irritant by screens or severe irritant by one rabbit test are tested in two or three rabbits; 0.1 ml (0.1 g) is instilled into the conjunctival sac. The responses (corneal opacity, iritis and conjunctival redness) are scored according to the modified Draize scoring system at 24, 48 and 72 hr and 7 days post-instillation. A rabbit is considered positive when corneal opacity of 1 or above, iritis of 1 or above or conjunctival redness of 2 or above is present at 24, 48 or 72 hr post-instillation. The material is classified as a severe irritant when the rabbit in the one-animal test or two or more rabbits in the standard test have responses of corneal opacity of 3 or above and iritis of 2 at 24, 48 or 72 hr, or positive responses on day 7 after instillation. The material is classified as an eye irritant when two or more rabbits are positive but the responses are not severe and they clear 7 days after instillation. The material is classified as a non-irritant when no more than one rabbit is positive. The opinions expressed in this article are those of the authors and do not necessarily reflect the views of US Federal agencies.

Animals↗
PubMedDate not supplied

Prevalence and causes of blindness and low vision in Dambatta local government area, Kano State, Nigeria.

In 1995 a population based cross sectional blindness prevalence survey was conducted in Dambatta local government area (LGA). 3596 people were examined. The prevalence of blindness was 1.14% with 95% confidence limit of (0.8-1.48%). The causes of blindness are cataract 54%, Trachoma 17%, Glaucoma 15%, Corneal opacity 7%, other blinding conditions 7%. The prevalence of low vision was 2.05% with 95% confidence limit (1.60-2.50%). One percent of the population were severely visually impaired (WHO category 2). The causes of low vision are cataract 55%, corneal opacity 14%, uncorrected aphakia 11%, Glaucoma 7%, Refractive error 5%, other conditions 8 percent. Cataract was the leading cause of uniocular blindness with 53%, others were phthisis bulbi 17%, Trauma 14%, corneal opacity 10%, and others 7 percent. Cataract was the single most important cause of blindness, low vision and uniocular blindness accounting for 54%, 55%, and 53%, respectively. Uncorrected aphakia accounted for 11% of the low vision group, 80% of these had couching. This study showed that 93% of the blindness was avoidable in the sense that it could have been primarily prevented or, is treatable. 92% of the causes of low vision are avoidable.

Blindness↗
PubMed2005

Characteristics of trichiasis patients presenting for surgery in rural Ethiopia.

AIMS: To determine the characteristics of trichiasis patients presenting for surgery in Wolayta Zone of Ethiopia. METHODS: Patients referred for trichiasis surgery by community health agents were evaluated by trained integrated eye care workers (IECWs) for the presence of trichiasis, locations of inturned lashes, severity of trichiasis, corneal opacity, and visual acuity. RESULTS: 1635 individuals with trichiasis presented for surgery. 82% had bilateral trichiasis; 91% of patients reported trichiasis duration of >2 years. Epilation was practised by over three fourths of the study subjects. A high proportion of patients tested positive for ocular Chlamydia trachomatis at presentation. 17% had monocular blindness and 8% were binocularly blind. Corneal opacity was highly associated with the trichiasis duration and severity and visual loss was associated with corneal opacity. CONCLUSION: Severe trichiasis reflects the magnitude of the trachoma problem in Ethiopia. Visual impairment due to trichiasis is highly associated with disease severity and duration. Early intervention to correct trichiasis before it become severe is recommended to prevent visual impairment.

Adult↗
PubMed1993

Justification of the enucleated eye test with eyes of slaughterhouse animals as an alternative to the Draize eye irritation test with rabbits.

The enucleated eye test (EET) with the isolated eye of rabbits has been recognized as a valuable alternative to the Draize test, because it represents a test system nearest to the in vivo test, without the need to use live animals. In this ex vivo bioassay, three parameters are measured to detect possible adverse eye effects, namely corneal swelling, corneal opacity and fluorescein retention. The measurement of corneal swelling in this assay guarantees a highly objective and discriminative parameter. In combination with the detailed observation of corneal opacity and fluorescein retention, a reliable evaluation of the eye irritation potential of test materials is achieved. However, laboratory animals are still necessary as eye donors. The use of slaughter animals, such as the cow, the pig and the chicken, as possible as eye donors for the EET was therefore examined. From these candidates, the chicken appeared to be the most practicable. 21 reference compounds, ranging from non-irritant to severe irritant, which had been tested previously in a validation study on alternative test methods for eye irritation testing, sponsored by the Commission of the European Communities, were examined in the Chicken Enucleated Eye Test (CEET). When compared with the in vivo EC classification, the CEET correctly classified each of the compounds that must be labelled in the EC as irritant (R36) or severely irritant (R41). In addition, since the CEET recognizes three levels of irritancy rather than two (as in the case of the EC classification) a small number of the compounds were recognized as slightly irritant, which according to the EC classification need not be labelled. It was concluded that this ex vivo test system is highly accurate in the assessment of eye irritation potential without the use of laboratory animals.

Animal Testing Alternatives↗
PubMed1998

Absence of macrophage inflammatory protein-1alpha prevents the development of blinding herpes stromal keratitis.

Prior studies in our laboratory have suggested that the CC chemokine macrophage inflammatory protein-1alpha (MIP-1alpha) may be an important mediator in the blinding ocular inflammation which develops following herpes simplex virus type 1 (HSV-1) infection of the murine cornea. To directly test this hypothesis, MIP-1alpha-deficient (-/-) mice and their wild-type (+/+) counterparts were infected topically on the scarified cornea with 2.5 x 10(5) PFU of HSV-1 strain RE and subsequently graded for corneal opacity. Four weeks postinfection (p.i.), the mean corneal opacity score of -/- mice was 1.1 +/- 0.3 while that of the +/+ mice was 3.7 +/- 0.5. No detectable infiltrating CD4+ T cells were seen histologically at 14 or 21 days p.i. in -/- animals, whereas the mean CD4+ T-cell count per field (36 fields counted) in +/+ hosts was 26 +/- 2 (P < 0.001). In addition, neutrophil counts in the -/- mouse corneas were reduced by >80% in comparison to the wild-type controls. At 2 weeks p.i., no interleukin-2 or gamma interferon could be detected in six of seven -/- mice, whereas both T-cell cytokines were readily demonstrable in +/+ mouse corneas. Also, MIP-2 and monocyte chemoattractant protein-1 protein levels were significantly lower in MIP-1alpha -/- mouse corneas than in +/+ host corneas, suggesting that MIP-1alpha directly, or more likely indirectly, influences the expression of other chemokines. Interestingly, despite the paucity of infiltrating cells, HSV-1 clearance from the eyes of -/- mice was not significantly different from that observed in +/+ hosts. We conclude that MIP-1alpha is not needed to control virus growth in the cornea but is essential for the development of severe stromal keratitis.

Animals↗
PubMed1992

Q-switched Nd:YAG laser treatment for corneal neovascularization.

Q-switched Nd:YAG laser treatment to occlude newly formed corneal vessels was performed in patients with herpetic keratitis to reduce corneal opacity and the risk of graft rejection. Nine neovascularized corneas of 9 patients were treated. In 8 of the 9 patients, corneal neovascularization was markedly reduced with a resulting decrease in corneal opacity. Penetrating keratoplasty was performed in 3 patients after the treatment. Two patients in whom YAG laser treatment was effective had uneventful postoperative courses for 13 and 17 months, respectively. In one patient with ineffective YAG laser treatment, rejection occurred 3 months after keratoplasty, and systemic steroid and ciclosporin therapy was needed. Ultrastructural examination of the corneal button removed during keratoplasty from a patient with successful laser treatment showed destruction of vascular endothelial cells and occlusion of the vascular lumen.

Adolescent↗
PubMed2006

Ocular findings in four children with mucopolysaccharidosis I-Hurler (MPS I-H) treated early with haematopoietic stem cell transplantation.

PURPOSE: To present visual functions and ocular findings in four children with mucopolysaccharidosis I-Hurler (MPS I-H) treated early with stem cell transplantation (SCT). METHODS: Clinical ophthalmological evaluations including visual evoked potentials (VEPs) were carried out. RESULTS: Stem cell transplantation was performed before 20 months of age. Ocular follow-up lasted 1.3-5.6 years (median 4.1 years). Reductions in corneal opacities were observed in all four children post-SCT, but a slight cloudiness persisted. Decreased visual acuity and high hyperopia (median + 6.25 dioptres, range + 4.0 D to + 7.5 D spherical equivalents) were noted in all children. Hyperopia was initially undetected due to dull retinal reflexes and photophobia. Two children developed esotropia, one with amblyopia. Keratometry, performed in two children, demonstrated subnormal values with a mean of 39.33 D (range 37.62-41.00 D). Visual evoked potentials and intraocular pressures were normal. Neither cataract nor dry eye were detected during follow-up. CONCLUSIONS: Early SCT appears to be beneficial in reducing, but not eliminating, corneal opacities in children with MPS I-H. Subjects are at risk of developing high hyperopia and esotropia. Hyperopia might be caused by the storage of glucosaminoglucans that increase corneal rigidity, thereby straightening the curvature of the cornea and reducing refractive power. As early diagnosis and treatment are very important, paediatric ophthalmologists should remember to rule out MPS I-H in children with corneal opacities.

Child↗
PubMed1988

Effect of ketorolac on Pseudomonas aeruginosa ocular infection in rabbits.

Corticosteroids can exacerbate bacterial ocular infections, even in the presence of antibiotics. Ketorolac tromethamine is a new non-steroidal compound being considered as an anti-inflammatory ophthalmic drug. In this study, rabbits ocularly infected with Pseudomonas aeruginosa were treated topically with 0.4 percent tobramycin sulfate 4 times daily for 7 days to control infection. At the same times, either 0.5 percent ketorolac, 0.1 percent dexamethasone or vehicle was also given topically. Animals were scored for severity of both conjunctivitis (maximum severity rates score of 10) and corneal opacity (maximum of 4) using the Draize scale. Severity of the infection was determined by counting the number of punctate lesions which developed on the cornea. Nine days after treatment ended, the number of these lesions was the same for ketorolac as for the vehicle (respectively, 16.7 +/- 3 and 13.8 +/- 3, mean +/- SE, n = 24), indicating no exacerbation of the infection, whereas with dexamethasone these parameters increased (30.2 +/- 4, n = 24). During treatment, ketorolac reduced conjunctivitis (1.8 +/- 0.2, n = 120) when compared with the vehicle (2.9 +/- 0.2, n = 120), whereas dexamethasone did not (3.8 +/- 0.2, n V 120); neither ketorolac nor dexamethasone reduced corneal opacity (respectively, 2.3 +/- 0.05 and 2.6 +/- 0.1, n = 24) compared with vehicle (2.2 +/- 0.05, n = 24). After treatment, both conjunctivitis and corneal opacity became more severe only in dexamethasone treated eyes (respectively, 4.4 +/- 0.2, n = 120 and 3.0 +/- 0.02, n = 24). Thus, ketorolac appears to be an anti-inflammatory agent that does not worsen bacterial ocular infection.

Administration, Topical↗
PubMed1991

Clinical use of the 193-nm excimer laser in the treatment of corneal scars.

Phototherapeutic keratectomy using a 193-nm excimer laser was performed at four centers on 33 sighted patients with corneal opacity and/or irregular astigmatism. Pathologic conditions included anterior stromal and superficial scarring from postinfectious and posttraumatic causes, including inactive herpes simplex virus, anterior corneal dystrophies, recurrent erosions, granular dystrophy, and band keratopathy. Most patients received peribulbar anesthesia and underwent removal of the epithelium prior to laser ablation. A majority of patients had a reduction in the amount of corneal scarring and approximately half had improved visual acuity. No intraocular reaction or changes in endothelial counts were seen, and some patients avoided the need for penetrating keratoplasty. Reepithelialization usually occurred within 4 or 5 days and we noted no significant scarring secondary to use of the laser. It was difficult to eliminate preexisting irregular astigmatism despite the use of surface modulators, such as methylcellulose. A hyperopic shift secondary to corneal flattening was encountered in approximately 50% of the patients. A combination of myopic ablation, followed immediately by a secondary hyperopic steepening, may minimize this refractive change. The 193-nm excimer laser is an effective new tool in the treatment of selected patients with superficial corneal opacity from a variety of conditions.

Adult↗