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Biomedical subjects

K F Tabbara

Publications and source records attributed to K F Tabbara.

At least 19 recordsLinked to original sources
PubMed2001

Tear tryptase in vernal keratoconjunctivitis.

OBJECTIVES: To determine the tear level of tryptase (a marker of mast cell activation) in vernal keratoconjunctivitis (VKC) before and after treatment. In addition, eosinophil counts in conjunctival scrapings and ocular surface temperature before and after treatment were studied. PATIENTS AND METHODS: A total of 20 patients, 7 years or older with VKC, were included in this study. Tear samples for tryptase determination were collected before and 2 weeks after treatment with 4% disodium cromoglycate eyedrops and 0.1% fluorometholone eyedrops. In addition, conjunctival scrapings were obtained for microscopic evaluation, and measurement of the ocular surface temperature was performed before and 2 weeks after treatment. One patient was excluded because the patient did not receive topical treatment. Control tear samples were collected from 20 normal control patients for tryptase determination. RESULTS: There were 19 patients with VKC (17 males, 2 females). The age range was 7 to 17 years with a mean age of 9 years. The mean number of eosinophils prior to initiation of therapy was 11.37 eosinophils with a range of 1 to 34 per high-power field. Following treatment, the mean number of eosinophils was 3.42 eosinophils per high-power field with a range of 0 to 11 (P<.01). The mean ocular surface temperature for the right eye before treatment was 35.56 degrees C (range, 34.46 degrees C-36.50 degrees C) and after treatment was 33.53 degrees C (range, 31.13 degrees C-35.40 degrees C). For the left eye, the mean ocular surface temperature before treatment was 35.49 degrees C (range, 34.86 degrees C-36.16 degrees C) and after treatment was 33.88 degrees C (range, 32.40 degrees C-35.53 degrees C). The ocular surface temperature was found to decrease significantly following treatment (P<.001). The levels of tryptase in tears of patients with VKC were determined before and after treatment. The mean level was 16.77 ng/mL (range, <5-115 ng/mL). Following treatment with topical 4% disodium cromoglycate and 0.1% fluorometholone eyedrops, the mean level of tryptase decreased to 7.29 ng/mL (range, <5-44.1 ng/mL) (P<.05). CONCLUSIONS: Patients with severe VKC had high levels of tryptase in tears. Following treatment, the level of tryptase in tears decreased significantly.

Adolescent↗
PubMed2001

Revised diagnostic criteria for Vogt-Koyanagi-Harada disease: report of an international committee on nomenclature.

PURPOSE: To present revised criteria for the diagnosis of Vogt-Koyanagi-Harada disease, a chronic, bilateral, granulomatous ocular and multisystem inflammatory condition of unknown cause. METHODS: Diagnostic criteria and nomenclature were subjects of discussion at the First International Workshop on Vogt-Koyanagi-Harada Disease on October 19-21, 1999, at the University of California, Los Angeles, Conference Center, Lake Arrowhead, California. A committee appointed by the workshop participants was charged with drafting revised criteria for Vogt-Koyanagi-Harada disease, based on discussions held during the conference. This article is the consensus committee report. RESULTS: New criteria, taking into account the multisystem nature of Vogt-Koyanagi-Harada disease, with allowance for the different ocular findings present in the early and late stages of the disease, were formulated and agreed upon by the committee. These criteria are based on additional knowledge and experience of experts in the field and are believed to reflect disease features more fully than previously published criteria. CONCLUSIONS: The revised definition of Vogt-Koyanagi-Harada disease, with expanded diagnostic criteria, will facilitate performance of studies involving homogeneous populations of patients, at various stages of disease, that address unanswered questions regarding treatment and disease mechanisms.

California↗
PubMed2001

Trachoma: a review.

Trachoma is a leading cause of preventable blindness worldwide. The disease is caused by an intracellular epithelial gram-negative bacterium, Chlamydia trachomatis. The presence of children, overcrowding, and the lack of water in the household are factors that predispose to the transmission of the disease. The disease may remain asymptomatic but some patients many complain of redness, irritation, and ocular discharge. The principal initial clinical manifestation is a follicular conjunctivitis that may lead to conjunctival scarring, entropion, trichiasis, corneal thinning, and ulceration. Some patients develop corneal scars that lead to loss of vision. Despite the remarkable progress in our understanding of Chlamydial infections, the basic mechanisms involved in tissue damage and scarring remain to be elucidated. There are several effective therapeutic modalities for trachoma. Azithromycin oral single dose was found to be safe and effective in children with active trachoma. Conjunctival biopsy specimens obtained from adult patients receiving a single oral dose of azithromycin showed sustained high levels of azithromycin (above MIC of chlamydia) for up to 2 weeks after intake. These prolonged high levels of azithromycin in the conjunctival tissue following a single oral dose makes the drug suitable for the treatment of endemic trachoma.

Administration, Oral↗
PubMed2001

Toxoplasmosis in a group of glucose-6-phosphate dehydrogenase deficient patients.

OBJECTIVE: This was a retrospective study that aimed at evaluating the relative risk of Toxoplasma infection in patients with glucose-6-phosphate dehydrogenase deficiency as compared to a control group with no glucose-6-phosphate dehydrogenase deficiency. METHODS: Ninety-one blood donor volunteers had serology testing from Toxoplasma gondii and were screened for glucose-6-phosphate dehydrogenase deficiency by a qualitative method using fluorescent spot test. They were all males and their ages ranged from 17 to 52 years. RESULTS: Fifty-three persons (58%) were glucose-6-phosphate dehydrogenase deficient and 38 (42%) were glucose-6-phosphate dehydrogenase normal. In the glucose-6-phosphate dehydrogenase deficient group, 31 (58.5%) had positive titers for Toxoplasma; while in the glucose-6-phosphate dehydrogenase normal group 9 persons (24%) had positive titers for Toxoplasma. The relative risk of infection was 2.5 times more in the glucose-6-phosphate dehydrogenase deficient group, a statistically significant difference with a p value of 0.002. CONCLUSION: Glucose-6-phosphate dehydrogenase deficiency seems to increase the risk for Toxoplasma infection by 2.5 fold probably due to decreased killing effect, of phagocytic cells.

Adolescent↗
PubMed2000

Anterior uveitis following combined vaccination for measles, mumps and rubella (MMR): a report of two cases.

PURPOSE: To describe two children who developed anterior uveitis after vaccination for common childhood diseases. METHODS: A retrospective study of two Saudi patients who were seen at The Eye Center, Riyadh, Saudi Arabia. RESULTS: Aged 12 and 14, respectively, the two patients developed anterior non-granulomatous uveitis 6 and 4 weeks after having the combined vaccination for measles, mumps and rubella (MMR). No other definite cause of uveitis was detected from history or from laboratory work up. Both patients responded to traditional regimens of uveitis therapy. However, they required a treatment period of several months. CONCLUSION: Anterior uveitis may occur following MMR vaccination. Cases of vaccination thus require ophthalmic awareness if visual symptoms or a painful red eye develop.

Administration, Topical↗
PubMed2000

Sjögren syndrome.

Sjögren syndrome is a chronic systemic disease characterized by polyglandular tissue destruction leading to keratoconjunctivitis sicca (KCS) and xerostomia. Patients with primary Sjögren syndrome show evidence of KCS and xerostomia, whereas patients with secondary Sjögren syndrome suffer from KCS, xerostomia, and an autoimmune disease, most commonly rheumatoid arthritis. Certain factors cause autoimmune dysregulation leading to destruction of the acinar cells and ductal epithelia with subsequent dry eyes and dry mouth. Activated lymphocytes in patients with autoimmune diseases appear to have selective homing into the lacrimal and salivary glands leading to tissue damage. Understanding the factors involved in the immune dysregulation may improve our diagnostic and therapeutic approaches in Sjögren syndrome. Current therapeutic measures include means to increase secretion, relieve symptoms, and repair damage of the ocular surface.

Autoimmunity↗
PubMed2000

Extended wear contact lens related bacterial keratitis.

AIMS: To report the clinical findings and visual outcome of patients with extended wear contact lens (EWCL) related bacterial keratitis. METHODS: 11 cases with EWCL related bacterial keratitis were included. Corneal scrapings were obtained for cytology and cultures. RESULTS: Nine patients had unilateral bacterial keratitis and two patients showed bilateral involvement. Corneal scrapings revealed Pseudomonas aeruginosa in seven patients, Staphylococcus aureus coagulase positive in one patient, and Staphylococcus epidermidis in three patients. CONCLUSION: EWCLs may be associated with bacterial keratitis and may result in visual loss. Dispensing contact lenses by optometrists should be performed in consultation with ophthalmologists.

Adolescent↗
PubMed2000

Infectious uveitis: a review.

Uveitis may be caused by infectious or non-infectious disorders. Although most cases of uveitis are considered to be immune-mediated disorders, certain forms of uveitis are caused by infectious agents. The disease may become latent, smoldering and chronic and may mimic other causes of auto-immune uveitis. While auto-immune or immune-mediated disorders causing uveitis respond to steroids or immunosuppressive therapy, such treatment may prove to be devastating in certain infectious diseases causing uveitis. It is, therefore, highly desirable to identify cases of chronic uveitis caused by infectious diseases in order to initiate specific and appropriate antimicrobial therapy. The diagnosis of infectious uveitis can be established in most cases based on age and sex of the individual, mode of onset the morphology of the lesion, the laterality, and the association with other systemic infectious diseases. Laboratory tests in these disorders and imaging techniques are used to refine the diagnosis. In this review, bacterial, fungal and parasitic infections leading to uveitis are discussed. Clinical findings, laboratory diagnosis and management are elucidated.

Adolescent↗
PubMed1999

Corneal haze among blue eyes and brown eyes after photorefractive keratectomy.

BACKGROUND: To compare the incidence and severity of corneal haze after photorefractive keratectomy (PRK) among white patients with blue eyes and Saudi patients with brown eyes. DESIGN: Retrospective, nonrandomized, comparative trial. PARTICIPANTS: A total of 150 patients (71 females and 79 males) were included in this study. Two hundred sixty-six eyes of 150 patients were subjected to PRK. One hundred blue eyes of 50 white patients and 166 brown eyes of 100 Saudi patients were included in this study. METHODS: Two hundred sixty-six eyes of 150 patients were subjected to PRK with the Chiron Technolas Keracor 117C for the correction of myopia and astigmatism. MAIN OUTCOME MEASURES: All patients had complete ophthalmologic examinations, visual acuity testing, intraocular pressure, pachymetry, corneal haze assessment (0-4+), and computerized corneal topography. RESULTS: There were 266 eyes of 150 patients with 100 blue irides and 166 brown irides. The spherical equivalent was -0.50 diopter (D) to -8.75 D. The mean postoperative spherical equivalent at 6 months was -0.063 D (standard deviation [SD], +/-0.595) in blue eyes compared to -0.28 D (SD, +/-0.683) in brown eyes (P = 0.006). Ninety-five (95%) of 100 of the blue eyes achieved +/- 1 D of attempted correction compared to 148 (89.2%) of the 166 brown eyes. All patients with blue eyes had a visual acuity of 20/30 or better compared to 153 (92.2%) of the 166 brown eyes (P = 0.009). Forty-eight (18.04%) eyes had minimal to mild haze, 3 (1.12%) eyes had moderate haze, and 2 (0.75%) eyes had severe haze. The incidence of corneal haze among brown eyes was 48 (28.9%) of 166 eyes compared to 5 (5%) of 100 in blue eyes (P < 0.001). The difference remained significant after adjustment for age and gender with a P value of 0.0283. The relative risk for developing haze in brown eyes was found to be 7.72. CONCLUSION: The incidence of corneal haze after PRK was significantly higher among Saudi patients with brown irides than among white patients with blue irides. This suggests that racial factors may play a role in the development of corneal haze.

Adolescent↗
PubMed1999

The long term effects of unilateral corneal scars.

The main purpose of this study was to evaluate the long term effects of unilateral dense central corneal scars on the axial length and development of lens opacities. We included 12 patients with unilateral dense central corneal scars of early onset before the age of seven years. This study served as naturally-controlled experiment and demonstrated a statistically significant increase in ocular axial length and decrease in the incidence of cataract in the eye with central corneal scar. Visual deprivation induced by unilateral central corneal scars occurring in early childhood leads to increase in the ocular axial length, and decrease in the incidence of cataract.

Aged↗
PubMed1999

HLA class I and II typing of the patients with Behçet's disease in Saudi Arabia.

Thirteen Saudi Arabian patients with Behçet's disease (BD) were typed for HLA-A and -B alleles by the conventional serologic typing and for HLA-DRB1, -DQB1 and -DPB1 alleles by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. As a result, the phenotype frequency of the B51 antigen was significantly increased in the patient group as compared to the ethnically matched control group (76.9% in patients vs. 22.20% in controls), but no significant difference was observed in HLA-A, -DRB1, -DQB1 or -DPB1 alleles between the patients and controls, as previously observed in Japanese BD. Further, by HLA-B51 allelic genotyping performed by the polymerase chain reaction-sequence specific primers (PCR-SSP) method, all of the B51-positive patients and controls were found to carry one particular allele, B*5101, except one patient with B*5108.

Behcet Syndrome↗
PubMed1999

Efficacy of nedocromil 2% versus fluorometholone 0.1%: a randomised, double masked trial comparing the effects on severe vernal keratoconjunctivitis.

AIMS: To compare the efficacy of topical nedocromil 2% with fluorometholone 0.1% in vernal keratoconjunctivitis (VKC). METHODS: In a double masked random design, 24 patients with severe vernal keratoconjunctivitis were placed at random on nedocromil 2% eye drops in one eye and fluorometholone 0.1% in the fellow eye. At the end of the 2 week treatment period, the patient crossed over the eye drops (if asymptomatic in one eye), or continued with nedocromil sodium in both eyes (if asymptomatic in both eyes). All patients were examined weekly and ocular surface temperature recorded for a period of 6 weeks. RESULTS: Improvement in the watering, discharge, conjunctival hyperaemia, papillary hypertrophy, and Trantas' dots was noted in both groups, but overall fluorometholone was significantly more effective than nedocromil. Eyes treated with fluorometholone showed a significant decrease in ocular surface temperature compared with nedocromil treated eyes (p = 0.03). CONCLUSIONS: Both nedocromil and fluorometholone were effective in ameliorating the signs and symptoms of vernal keratoconjunctivitis. No adverse effects were noted in the nedocromil group.

Adolescent↗
PubMed1999

Ocular complications of vernal keratoconjunctivitis.

BACKGROUND: The objective of this study was to assess the ocular complications and visual loss among patients with severe vernal keratoconjunctivitis (VKC). METHODS: A total of 58 consecutive patients (52 boys and 6 girls aged 8 to 17 [mean 12.2] years) with severe active VKC were examined at two tertiary care facilities in Riyadh, Saudi Arabia, between 1995 and 1997. Patients were deemed to have severe VKC if they had had symptoms for at least 2 years, had diffuse palpebral conjunctival edema and thickening with papillary hypertrophy (P3) and giant papillary conjunctivitis, and had limbal infiltration of 180 degrees or more. Visual acuity was measured with the standard Snellen visual acuity chart. Visual impairment was assessed by means of the World Health Organization criteria for visual disabilities. Visual loss was defined as either blindness or visual impairment. RESULTS: Twelve patients (21%) had a best corrected visual acuity in one or both eyes of 20/200 or less, 20 (34%) had 20/50 to 20/200 vision, and 26 (45%) had 20/20 to 20/50 vision. The ocular complications that led to visual loss among 32 patients included steroid-induced cataract (8 patients), steroid-induced glaucoma (4), central corneal scars (7), irregular astigmatism (4), keratoconus (3) and limbal tissue hyperplasia (3). Of the 32 patients 12 had dry eye syndrome, which may have contributed to the visual loss. INTERPRETATION: Severe VKC in developing countries is a potentially blinding disease. Visual loss may be due to corneal complications, including corneal scars, astigmatism and keratoconus, as well as complications of the unsupervised use of topically administered corticosteroids.

Adolescent↗
PubMed1998

Ocular levels of azithromycin.

OBJECTIVE: To assess azithromycin levels in human serum, aqueous humor, tear fluid, and conjunctival tissue specimens after administration of a single 1-g oral dose of azithromycin. METHODS: Sixty patients undergoing cataract surgery were included in this analysis. Serum, aqueous, and tear specimens were collected 3, 6, and 12 hours and 1, 2, 3, and 4 days after azithromycin administration. Conjunctival tissue biopsy specimens were collected 1, 2, 3, 4, 6, 8, 10, 12, and 14 days after azithromycin administration. All specimens were subjected to analysis by high-performance liquid chromatography-mass spectrometry. RESULTS: Azithromycin concentration ranges during the specified sampling times were as follows: serum, 21 to 974 ng/mL; tear, 82 to 2892 ng/mL; aqueous, 10 to 69 ng/mL; and conjunctival, 0.7 to 32 micrograms/g. Levels above the 90% minimal inhibitory concentration (MIC90) for Chlamydia trachomatis were detected after 4 days in all tear samples and after 14 days in all conjunctival tissue specimens following oral azithromycin administration. CONCLUSION: We demonstrated prolonged high levels of azithromycin in drug-targeted ocular tissue. Prolonged high concentrations of azithromycin in conjunctival tissue make this drug suitable for treatment of conjunctivitis caused by chlamydiae and other susceptible organisms.

Administration, Oral↗
PubMed1998

Hospital construction-associated outbreak of ocular aspergillosis after cataract surgery.

OBJECTIVE: This study aimed to report an outbreak of Aspergillus endophthalmitis after cataract extraction during hospital construction. DESIGN: The study design is a case series of an outbreak of Aspergillus endophthalmitis. PARTICIPANTS: Five patients in whom Aspergillus endophthalmitis developed during a period of hospital construction in Jeddah, Saudi Arabia, participated. Severe postoperative uveitis occurred in all five patients and failed to subside with topical steroid therapy. The patients were referred to the King Khaled Eye Specialist Hospital for treatment. The causative organism was identified as Aspergillus fumigatus in each case. INTERVENTION: All five patients were subjected to aqueous or vitreous tap. Three patients had vitrectomy. Patients were given systemic, periocular, and intravitreous antifungal agents. MAIN OUTCOME: The final outcome in each patient was evisceration or enucleation, despite an intensive course of antifungal therapy. RESULTS: There were five patients, three females and two males, ranging in age from 51 to 65 years. Postoperative signs of infection developed in the patients 4 to 15 days after surgery. In all five cases, cultures of aqueous or vitreous grew A. fumigatus. CONCLUSION: Aspergillus endophthalmitis is a serious and devastating complication of ocular surgery. The outbreak, herewith, may have been related to hospital construction. The infection can be prevented, notably, by proper maintenance of old, "sick" buildings and by following certain procedures during hospital construction.

Aged↗