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Biomedical subjects

D P Edward

Publications and source records attributed to D P Edward.

At least 19 recordsLinked to original sources
PubMed2005

Endophthalmitis associated with the Ahmed glaucoma valve implant.

AIM: To investigate the rate, risk factors, clinical course, and treatment outcomes of endophthalmitis following glaucoma drainage implant (GDI) surgery. METHODS: A computerised relational database search was conducted to identify all patients who were implanted with Ahmed glaucoma valve (AGV) and developed endophthalmitis following surgery at the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia, between 1 January 1994 and 30 November 2003. Only medical records of the patients who developed endophthalmitis were retrospectively reviewed. RESULTS: 542 eyes of 505 patients who were on active follow up were included in the study. Endophthalmitis developed in nine (1.7%) eyes; the rate was five times higher in children than in adults. Delayed endophthalmitis (developed 6 weeks after surgery) occurred in eight of nine eyes. Conjunctival erosion overlying the AGV tube was present in six of nine eyes. Common organisms isolated in the vitreous included Haemophilus influenzae and Streptococcus species. Multiple regression analysis revealed that younger age and conjunctival erosion over the tube were significant risk factors associated with endophthalmitis. CONCLUSION: Endophthalmitis is a rare complication of GDI surgery that appears to be more common in children. Conjunctival dehiscence over the GDI tube seems to represent a major risk factor for endophthalmitis. Prompt surgical revision of an exposed GDI tube is highly recommended.

Adult↗
PubMed2005

Histopathological and immunohistochemical studies of lenticules after epikeratoplasty for keratoconus.

AIMS: To examine histopathological and immunohistochemical changes in lenticules and host of corneal buttons from patients who previously underwent epikeratoplasty for keratoconus. METHODS: 12 penetrating keratoplasty specimens from patients with keratoconus who had previously undergone epikeratoplasty, eight keratoconus, and seven normal corneas were examined. Immunostaining for Sp1, alpha1-proteinase inhibitor (alpha1-PI), and alpha2-macroglobulin (alpha2M) were performed. RESULTS: In nine of the 12 lenticules, the keratoconus-like disruptions were found in Bowman's layer. Peripheral and posterior keratocyte repopulation of the lenticules was observed in all cases. Keratocyte repopulation in the anterior and mid-stromal regions of the lenticules appeared related to the time since epikeratoplasty. Sp1 nuclear staining of the basal and wing epithelial cells was more intense in lenticules and keratoconus corneas than in normal corneas. Lenticular, host, and keratoconus keratocytes showed positive Sp1 staining, whereas staining was absent in normal corneas. Compared to normal corneas, alpha1-PI and alpha2M immunostaining was lower in the lenticules, host, and keratoconus specimens. CONCLUSIONS: The epithelial cells and keratocytes repopulated in the lenticules retain keratoconus-like biochemical abnormalities such as upregulation of Sp1 and downregulation of alpha1-PI and alpha2M. The authors speculate that both keratocytes and the corneal epithelium may participate in the development of keratoconus.

Adolescent↗
PubMed2005

Expression of growth differentiation factor-5 and bone morphogenic protein-7 in intraocular osseous metaplasia.

BACKGROUND/AIMS: Intraocular bone is seen in a wide spectrum of ocular disorders. The pathogenetic mechanisms of bone formation in the eye are unclear. Growth differentiation factor-5 (GDF-5), bone morphogenic protein-7 (BMP-7), and transforming growth factor beta-1 (TGF beta1) are multifunctional cytokines that have important roles in bone formation. Immunohistochemistry was used to localise GDF-5, BMP-7, and TGF beta1 in the human eye to determine their role in intraocular bone formation. METHODS: Paraffin embedded sections from human eyes included fetal eyes (n = 5), normal adult eyes (n = 4), eyes with osseous metaplasia (n = 8), and eyes with focal fibrous metaplasia of the retinal pigment epithelium (RPE) without osseous metaplasia (n = 2). Immunohistochemistry was performed using indirect immunofluorescence with antibodies to GDF-5, BMP-7, and TGF beta1. The staining intensity was evaluated semiquantitatively in the RPE, retina, ciliary epithelium, and cornea; and analysed statistically. RESULTS: When compared with normal adult eyes, which showed no RPE immunoreactivity, the RPE metaplasia surrounding areas of osseous metaplasia showed mild GDF-5 and moderate BMP-7 (p = 0.004) intracytoplasmic immunoreactivity. In contrast, trace GDF-5 and mild BMP-7 staining was seen in zones of RPE fibrous metaplasia in areas not associated with osseous metaplasia. Mild intracytoplasmic TGF beta1 expression was seen in the RPE metaplasia surrounding the bone when compared with adult eyes. Both fetal and adult eyes showed trace to mild GDF-5 and BMP-7 labelling of the non-pigmented ciliary epithelium which was increased in the eyes with osseous metaplasia. In eyes with osseous metaplasia, a significant decrease in GDF-5 and BMP-7 labelling was noted in fetal keratocytes (p = 0.0159 for both antibodies) when compared to adult eyes. Also, a significant decrease in BMP-7 labelling was seen in keratocytes in eyes with osseous metaplasia (p = 0.0162). CONCLUSIONS: The increase in GDF-5, BMP-7, and TGF beta1 immunoreactivity in zones of RPE metaplasia in eyes with osseous metaplasia suggests that these proteins have an important role in intraocular ectopic bone formation.

Adult↗
PubMed2001

Acute endogenous endophthalmitis due to Bartonella henselae.

A 45-year-old man presented with progressively worsening vitreitis of 1 week's duration. Treatment for cat-scratch disease 3 years prior to presentation and persistent vitreitis led to vitrectomy, and analysis of the vitrectomy specimen revealed inflammatory cells and necrotic debris; polymerase-chain-reaction analysis of the vitreous fluid sample, done by use of a novel heminested protocol, demonstrated the presence of Bartonella henselae DNA. Treatment with doxycycline led to improvement in the intraocular inflammation but resulted in a poor visual outcome.

Acute Disease↗
PubMed2000

Matrix metalloproteinases and tumor necrosis factor alpha in glaucomatous optic nerve head.

OBJECTIVE: To study expression and location of matrix metalloproteinases (MMPs) and tumor necrosis factor alpha (TNF-alpha) in glaucomatous optic nerve heads, which are known to be secreted in response to a variety of neuronal injury. METHODS: Four postmortem eyes from patients with primary open-angle glaucoma, 7 eyes from patients with normal-pressure glaucoma, and 4 eyes from age-matched normal donors were studied by immunohistochemistry. The sections of the optic nerve heads were examined after immunostaining with antibodies to MMPs (MMP-1, MMP-2, and MMP-3), TNF-alpha, or TNF-alpha receptor 1. RESULTS: The intensity of the immunostaining and the number of stained cells for MMPs, TNF-alpha, or TNF-alpha receptor 1 were greater in the glaucomatous optic nerve heads, particularly in eyes with normal-pressure glaucoma compared with age-matched controls. Positive immunostaining was observed in all regions of the glaucomatous optic nerve heads, but most prominently in the postlaminar region. Immunostaining was observed mainly in glial cells and their processes around the axons and blood vessels and in pial septae. CONCLUSION: There is increased immunostaining for MMPs, TNF-alpha and TNF-alpha receptor 1 in the glaucomatous optic nerve head, which suggests increased expression of these proteins in glaucoma and thereby implies a role in the tissue remodeling and degenerative changes seen in glaucomatous optic nerve heads. CLINICAL RELEVANCE: The MMPs and TNF-alpha may be components of astroglial activation that occurs in glaucomatous optic nerve heads. The biological alterations in the expression of these proteins may play a role in the progression of glaucomatous optic neuropathy.

Aged↗
PubMed2000

Thickness of the peripapillary retina in healthy subjects with different degrees of ametropia.

PURPOSE: To evaluate the thickness of the peripapillary retina in healthy subjects with different degrees of ametropia. DESIGN: Cross-sectional study. PARTICIPANTS: Forty-three healthy normal subjects, ages 15 to 64 years (38+/-15 years) were recruited. METHODS: The method of retinal thickness mapping was applied to generate serial optical section images in the temporal peripapillary retinal area. The digitized images were analyzed to detect the separation between the vitreoretinal and chorioretinal interfaces. The separation was converted to absolute thickness by taking into account the magnification of the optical system and the optical dimensions of the eyes. MAIN OUTCOME MEASURES: The refractive error of the eyes ranged from +8.25 to -12.75 diopters (spherical equivalent). The axial length of the eyes ranged from 19.3 to 27.35 mm. The retinal thickness in a 2- x 2-mm temporal peripapillary retinal area was determined. RESULTS: The separation between the retinal interfaces decreased with increasing axial length (P<0.001). The thickness in the temporal peripapillary retinal area was not significantly correlated with the axial length of the eye (P = 0.3). A lack of statistically significant difference between the average thickness in the hyperopic, emmetropic, and myopic eyes (P> or =0.06) was found. CONCLUSIONS: The average thickness in the temporal peripapillary retinal area was not influenced by the axial length of the eye, when the magnification of the optical system and the optical dimension of the eyes were taken into consideration.

Adolescent↗
PubMed1999

Effect of melanin on traumatic hyphema in rabbits.

OBJECTIVE: To investigate the role of melanin in influencing the clearance of traumatic hyphema and in the incidence of rebleeds following the hyphemas. METHODS: Hyphemas were induced in 30 eyes of New Zealand white albino rabbits using an Nd:YAG laser. A total of 3.75 mg of synthetic melanin suspended in 0.1 mL of balanced salt solution was introduced into the anterior chambers of 16 animals. A total of 0.1 mL of balanced salt solution was injected into 14 control eyes. Hyphema levels were measured by a masked observer (V.D.B.) daily for 15 days. Pairs of animals were sacrificed at 1, 3, 5, 10, and 15 days and the eyes studied histologically. RESULTS: Hyphemas were consistently produced in all eyes with mean+/-SD levels of 1.44+/-0.22 mm and 1.57+/-0.24 mm in the melanin-treated and control eyes, respectively. The clearance of hyphemas in the melanin-treated eyes was significantly prolonged throughout the study (P<.001). The rate of rebleed in the melanin-treated group was 18.8% and in the control group was 7.1% (P<.01). Histologically, both groups showed variable degrees of blood in the anterior chambers and trabecular meshwork. In addition, the melanin-treated eyes showed free melanin, melanin-laden macrophages, and an inflammatory response in the anterior chamber and trabecular meshwork that was greater than that in the control eyes. Melanin-treated eyes with rebleeds showed organized hemorrhage with neovascularization. CONCLUSIONS: The presence of melanin results in a significantly prolonged course of hyphemas and may influence the rate of rebleeds. Occlusion of the trabecular meshwork with melanin-laden macrophages and inflammation may be the mechanisms responsible for these effects. CLINICAL RELEVANCE: The release of melanin into the anterior chamber during ocular trauma may be partly responsible for the susceptibility of darker-pigmented individuals to more serious complications following a traumatic hyphema.

Animals↗
PubMed1999

Benign lymphoid hyperplasia of the conjunctiva in children.

Benign lymphoid hyperplasia of the conjunctiva occurs infrequently in children, and its presentation, clinical course, and appropriate management are not well established. We describe 2 children with nasal conjunctival masses that on pathological examination demonstrated benign lymphoid hyperplasia. Local irradiation of residual tissue was deferred, and the lesions remained stable for 1 year in one case and for 3 1/2 years in the other case. No systemic involvement had occurred. Although the natural history of extranodal lymphoid hyperplasia in children is poorly documented, most cases of nodal lymphoid hyperplasia in children are at very low risk of malignant transformation. Careful observation for local and systemic disease is indicated for ocular adnexal lymphoid hyperplasia in children until a more complete understanding of its natural history is available.

Antigens, CD20↗
PubMed1999

Serum autoantibodies to optic nerve head glycosaminoglycans in patients with glaucoma.

BACKGROUND: Serum autoantibodies that cross-react with glycosaminoglycans have been proposed to play a significant role in specific tissue injury in patients with systemic autoimmune diseases. OBJECTIVE: To investigate whether serum immunoreactivity to glycosaminoglycans is present in patients with glaucoma who have aberrant serum autoantibodies to DNA, RNA, nuclear proteins, or retinal proteins, as proteoglycans and their glycosaminoglycan side chains are important components of the optic nerve head and its vasculature. METHODS: We performed Western blotting using patient serum samples and human optic nerve head homogenates that were treated with or without specific glycosaminoglycan degrading enzymes. Monoclonal antibodies that recognize different determinants of glycosaminoglycans were used to identify specific substrate antigenicity. We compared the serum immunoreactivity to glycosaminoglycans in 60 age-matched patients with normal-pressure glaucoma, 36 patients with primary open-angle glaucoma, and 20 control subjects by enzyme-linked immunosorbent assay. In addition, immunohistochemistry was performed to compare the distribution patterns of glycosaminoglycans in the optic nerve head of postmortem eyes of age-matched patients with normal-pressure glaucoma, primary open-angle glaucoma, and control subjects. RESULTS: Western blotting demonstrated that serum samples from patients with glaucoma who have circulating autoantibodies can recognize optic nerve head proteoglycans, including chondroitin sulfate and heparan sulfate. The level of serum autoantibodies binding purified chondroitin sulfate and heparan sulfate glycosaminoglycans in an enzyme-linked immunosorbent assay was approximately 100% higher in patients with normal-pressure glaucoma than that in control subjects and approximately 50% higher than that in patients with primary open-angle glaucoma. We also observed increased immunostaining of glycosaminoglycans in the optic nerve head of eyes with glaucoma, particularly those with normal intraocular pressure, compared with control eyes. CONCLUSION: There are increased levels of autoantibodies recognizing glycosaminoglycans of the optic nerve head in the serum samples of some patients with glaucoma. CLINICAL RELEVANCE: These autoantibodies may increase the susceptibility of the optic nerve head to damage in these patients by changing the functional properties of the lamina cribrosa, its vasculature, or both.

Antibodies, Monoclonal↗
PubMed1999

Bilateral orbital emphysema from compressed air injury.

PURPOSE: To describe a patient who developed bilateral subconjunctival and orbital emphysema after an automobile tire explosion. METHOD: Case report. RESULTS: A 60-year-old man sustained bilateral ocular injury after a tire explosion. Ophthalmic examination disclosed bilateral subconjunctival air, with no visible conjunctival laceration. Computed tomography showed orbital emphysema, with no evidence of orbital fracture. Follow-up examination 2 weeks after the injury disclosed resolution of the subconjunctival air. Best-corrected visual acuity in the right eye was decreased after the explosion but improved to the baseline level of 20/40 2 weeks after the injury. CONCLUSION: Subconjunctival and orbital emphysema can occur from high-pressure air injury in the absence of an obvious entry site.

Air↗
PubMed1999

Lacrimal gland tumors and simulating lesions. Clinicopathologic and MR imaging features.

The lacrimal gland region can be involved in a wide spectrum of orbital pathology, including inflammatory, lymphoproliferative, and epithelial tumors. This article focuses on benign and malignant epithelial tumors of lacrimal gland and simulating lesions. The clinical presentations, MR imaging, and pathologic findings of lacrimal gland tumors are reviewed.

Dacryocystitis↗
PubMed1999

Ocular amyloidosis and secondary glaucoma.

OBJECTIVE: To report the clinical and histopathologic findings in two cases of secondary glaucoma associated with amyloidosis. DESIGN: Two case reports. METHODS: Retrospective review of clinical findings, course, and treatment of the two patients. The histopathologic findings from available biopsy material were also reviewed. MAIN OUTCOME MEASURES: Intraocular pressure (IOP), visual field changes, and surgical outcome. RESULTS: The first case describes a 76-year-old woman with orbital amyloidosis who developed gradual unilateral elevation of IOP that was poorly responsive to medical therapy and underwent filtration surgery. Episcleral venous pressure was elevated on the affected side, and histopathologic analysis of the conjunctival tissue confirmed perivascular amyloid deposits, further suggesting raised episcleral venous pressure to be a possible mechanism of glaucoma. The second case describes a 47-year-old white woman with familial amyloid neuropathy with a transthyretin cys-114 mutation. The association of glaucoma with this mutation has not been described previously. Persisting elevation of IOP in one eye was initially responsive to topical antiglaucoma medications but eventually required filtration surgery. Amyloid particles were found in the aqueous and on the lens surface. Histopathologic analysis of the aqueous and sclerectomy specimens demonstrated amyloid, suggesting outflow obstruction as a possible mechanism of glaucoma. Conjunctival buttonholing complicated filtration surgery in both cases, and the leaks eventually resolved with good control of IOP. CONCLUSIONS: Amyloid associated with glaucoma may involve different pathophysiologic mechanisms. The elevated IOP may not respond well to medical therapy. Cautious surgical manipulation of the conjunctiva is warranted in these cases.

Aged↗
PubMed1999

Mucoepidermoid carcinoma of the eyelid skin.

PURPOSE: Mucoepidermoid carcinoma involving the eye or its adnexa generally arises from the conjunctiva. We describe a nodular lesion of the lower eyelid skin with histologic features consistent with low-grade mucoepidermoid carcinoma. METHOD: Case report. RESULTS: By histology, the tumor demonstrated areas of squamous cell carcinoma and scattered islands of mucin-secreting cells. Histochemistry showed hyaluronidase-resistant mucin and intense immunoreactivity with an antibody against carcinoembryonic antigen suggesting that the tumor originated from acrosyringeal structures. CONCLUSIONS: To our knowledge, this is the first report of a mucoepidermoid carcinoma arising from sweat glands in the eyelid skin.

Aged↗