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Biomedical subjects

A A McNab

Publications and source records attributed to A A McNab.

At least 19 recordsLinked to original sources
PubMed2003

A technique for reconstruction of upper lid marginal defects.

BACKGROUND/AIMS: Reconstruction of large full thickness upper lid defects that cannot be closed directly often rely on utilising the lower lid. An example is the Cutler Beard procedure. A one stage technique for repair of large horizontal upper lid defects utilising local posterior and anterior lamella advancement flaps is described and the results reported. METHOD: Eight cases with upper lid defects repaired utilising this technique were reviewed retrospectively. The procedures were carried out by one surgeon. The upper lid lesions were removed under frozen section control. The mean follow up time was 35 months. RESULTS: All patients had a good cosmetic result. One patient had a recurrence of the upper lid lesion. Two patients complained of corneal irritation from lanugo hairs. The technique was modified to prevent this complication. CONCLUSIONS: Large upper lid marginal defects can be readily repaired using the technique described with local advancement flaps with no significant complications.

Aged↗
PubMed2001

Orbital and optic nerve trauma.

The ability to measure orbital volume expansion and correlate this with later enophthalmos has advanced radiological assessment of patients with orbital floor fractures. Attempts have also been made to classify orbital floor fractures on the basis of their configuration on CT scan and to correlate this with outcome in terms of ocular motility. A small subset of relatively undisplaced floor fractures with tight entrapment of tissues occurring most commonly in young patients has been identified, and early surgical intervention has been recommended for these. The range of alloplastic materials available for orbital rim and wall fractures has increased, and complications related to various alloplastic implants continue to be reported. Optic nerve trauma has received considerable attention but remains a difficult management area. Recent literature on this subject shows no definite benefit for optic nerve decompression or high dose corticosteroids, although no prospective randomized study has been possible.

Humans↗
PubMed2001

Nontraumatic subperiosteal orbital hemorrhage.

PURPOSE: Nontraumatic subperiosteal orbital hemorrhage (NTSOH) has been reported rarely in association with sudden elevation of cranial venous pressure, generalized diseases with bleeding diatheses, and paranasal sinusitis. To define more clearly the clinical and imaging characteristics of NTSOH, we evaluated nine cases seen by the authors and reviewed previous case reports. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Nine patients (10 eyes) with NTSOH. INTERVENTION: All patients underwent computed tomography scans of the orbits. Patients with typical clinical and imaging features and normal visual function were observed. Those with an uncertain diagnosis or visual compromise underwent surgical drainage of the hematoma. MAIN OUTCOME MEASURES: Resolution of proptosis, diplopia, lid swelling, and ptosis. RESULTS: Nine patients ranging from birth to 73 years of age were identified. All were females. The lesions were located superiorly in eight patients (one patient had bilateral lesions) and medially in one patient. Most were associated with sudden elevation in venous pressure (vomiting, strangulation, straining), and most required no surgical intervention. The bilateral case occurred in the setting of disseminated intravascular coagulation and was the only case associated with visual loss possibly resulting from ischemic optic neuropathy. CONCLUSIONS: Nontraumatic subperiosteal orbital hemorrhage may occur at any age, usually secondary to sudden elevation in venous pressure. It is nearly always superior. The clinical and radiologic features are sufficiently characteristic to allow conservative treatment in the absence of visual compromise.

Adult↗
PubMed2001

Australasian orbital and adnexal Wegener's granulomatosis.

OBJECTIVE: To report a retrospective case series of 29 Australian and New Zealand patients with orbital and adnexal Wegener's granulomatosis (WG). DESIGN: Retrospective case series. PARTICIPANTS: Twenty-nine cases of orbital and adnexal WG were identified. METHODS: A number of oculoplastic surgeons and other clinicians in Australia and New Zealand was asked about their experience with orbital and adnexal WG. Clinical data regarding these cases were conveyed by means of a questionnaire. Cases of ophthalmic WG without features of orbital or adnexal disease were excluded. MAIN OUTCOME MEASURES: Data obtained from the questionnaire includes age, gender, limited or generalized disease, antineutrophil cytoplasmic antibody (ANCA) status, symptoms and signs: nasolacrimal obstruction, sinusitis, fistula/orbital bone erosion, orbital mass/proptosis, extraocular muscle/diplopia, visual acuity reduction caused by optic nerve compression, orbital pain, lid edema/erythema, biopsy status, and treatment status. RESULTS: Twenty-nine patients with orbital and adnexal WG were identified and described. Symptoms included awareness of an orbital mass, epiphora, orbital pain and diplopia. Signs included an orbital mass or proptosis (69%), nasolacrimal duct obstruction (52%), limited ocular rotations (52%), lid erythema and edema (31%), bony destruction (21%), and reduced visual acuity (17%). Two patients had a persistent nasolacrimocanthal fistula. Cytoplasmic pattern antineutrophil cytoplasmic antibodies (c-ANCA) were present in 52% of patients, and in 9 of 10 patients with generalized disease. However, c-ANCA was positive in only 32% (6 of 19) of patients with limited WG. Perinuclear pattern antineutrophil cytoplasmic antibodies (p-ANCA) was positive in 10% of cases. CONCLUSIONS: To diagnose and treat ophthalmic WG effectively, the clinician must be aware of its protean orbital and adnexal manifestations. WG may occur with or without systemic involvement, and c-ANCA was negative in approximately half our cases. Our cases also demonstrated two orbital fistulae, an observation previously believed to be rare.

Adolescent↗
PubMed2001

Fulminant orbital cellulitis with complete loss of vision.

Bacterial orbital cellulitis is a condition that rarely presents with complete loss of vision. A case is reported of a 69-year-old man who presented with fulminant onset of proptosis, significant ophthalmoplegia and no perception of light. Computed tomography showed no evidence of paranasal sinus disease. Despite treatment with intravenous flucloxacillin, ceftriaxone and metronidazole, and later, penicillin after Streptococcus pyogenes was grown from tissue culture, there was no improvement in vision; however ocular motility returned to normal.

Aged↗
PubMed2001

A prospective randomized study comparing division of the pedicle of modified hughes flaps at two or four weeks.

PURPOSE: To compare the incidence of upper and lower eyelid malposition or other complications when the pedicle in modified Hughes flap repair of the lower eyelid is divided at 2 versus 4 weeks. METHODS: A prospective randomized study. Data were collected on patient age and sex, horizontal tumor dimension, upper and lower eyelid position before surgery and 3 months after division of the pedicle, and any complications. RESULTS: Complete data from 60 patients were collected, with 32 patients in the 2-week group and 28 patients in the 4-week group. The two groups were not significantly different in terms of sex, age, or tumor dimensions. In the 2-week group, the upper eyelid was within 1 mm of its preoperative position at 3 months in 25 of 32 patients (78.1%) and in 26 of 28 (92.8%) in the 4-week group. The lower eyelid was within 1 mm of its normal position in 27 of 32 patients in the 2-week group (84.4%) versus 25 of 28 (89.3%) in the 4-week group. Statistical analysis showed no significant difference between the 2- and 4-week groups for upper and lower eyelid position at 3 months. Other complications were uncommon and evenly spread between the two groups. CONCLUSIONS: A modified Hughes flap pedicle may be divided at 2 weeks with no increased incidence in upper or lower eyelid malposition or other complication.

Adult↗
PubMed2000

Secondary haemorrhage after dacryocystorhinostomy.

OBJECTIVE: To describe the incidence, clinical features, possible risk factors and outcome of patients suffering secondary haemorrhage after dacryocystorhinostomy (DCR). METHODS: Records of all patients undergoing external DCR by one surgeon (AAM) over a 6-year period were analysed retrospectively. RESULTS: After 293 DCR operations in 260 patients, 10 patients had a secondary haemorrhage (one after bilateral DCR), usually between days 4 and 10 post-operatively (mean 6.8 days). Six of the 10 were hospitalized for 2-5 days (mean 2.8 days), all of whom had nasal packing, intravenous antibiotics and intravenous fluids; none required blood transfusion. Three patients had immune system defects, three had used non-steroidal anti-inflammatory drugs (NSAID) and four had no obvious risk factors. All 10 had a successful outcome following DCR (compared to an overall failure rate of 25/293 (8.5%): 16 anatomical and nine functional). CONCLUSIONS: Secondary haemorrhage after DCR was found to occur after 3.8% of DCR. Risk factors include being immunocompromised and taking NSAID prior to surgery. The haemorrhage did not adversely affect surgical outcome.

Adolescent↗
PubMed2000

Reversal of floppy eyelid syndrome with treatment of obstructive sleep apnoea.

PURPOSE: To describe the beneficial effects of treatment of obstructive sleep apnoea on the symptoms and signs of floppy eyelid syndrome. METHOD: A case of sleep apnoea with associated floppy eyelid syndrome is reported. RESULTS: A 32-year-old man presented with left floppy eyelid syndrome and a known diagnosis of obstructive sleep apnoea. He underwent treatment for 4 years with continuous positive airways pressure by mask during sleep and the symptoms and signs of his floppy eyelid syndrome disappeared. CONCLUSION: Treatment of obstructive sleep apnoea may reverse the changes of floppy eyelid syndrome.

Adult↗
PubMed2000

Sino-orbital fistula: two case reports.

A fistula between the paranasal sinuses and the orbit as a late complication of orbital fractures is rare and may present with intermittent symptoms due to air passing into the orbit. A case note review of two patients with sino-orbital fistula is presented. Two patients, 23- and 30-year-old males, presented with intermittent symptoms of globe displacement, diplopia or discomfort months after repair of an orbital floor fracture with a synthetic orbital floor implant. The symptoms occurred after nose blowing. They were both cured by removal of the implant and partial removal of the tissue surrounding the implant. A sino-orbital fistula may complicate the otherwise routine repair of an orbital floor fracture, but may be cured by removal of the implant and part of the surrounding pseudocapsule.

Adult↗
PubMed1999

Lacrimal gland abscess: two case reports.

BACKGROUND: Bacterial dacryoadenitis is rare and suppuration leading to abscess formation within the lacrimal gland has been very rarely reported in the antibiotic era. METHODS: The medical records and investigation results, including computed tomography (CT), of two patients with lacrimal gland abscess were reviewed. RESULTS: Two cases of lacrimal gland abscess, one a 28-year-old male and the other a 64-year-old female, are described. Both demonstrated a characteristic low-density area within an enlarged lacrimal gland on CT. The first case had been treated with antibiotics and the abscess, when drained, was sterile. The second case settled spontaneously. Neither patient suffered any sequelae of dry eye. CONCLUSIONS: Although rare, lacrimal gland abscess may still occur and may require surgical drainage if spontaneous resolution does not occur.

Abscess↗
PubMed1999

Subconjunctival fat prolapse.

PURPOSE: Subconjunctival orbital fat prolapse has been rarely described in the literature and is frequently confused with other conjunctival tumours, such as dermolipoma. The purpose of the present study was to describe the clinical features and treatment of a series of patients with subconjunctival orbital fat prolapse. METHODS: Review of clinical records. RESULTS: Twelve patients with subconjunctival orbital fat prolapse were identified. Eight had a superotemporal prolapse and five of these were bilateral. All but one were male and most were elderly and tended to be obese. Five of these patients underwent surgical excision of the prolapsed fat for symptoms of discomfort or for cosmesis. Four atypical unilateral cases were seen in younger patients with fat prolapse occurring superonasally in three and inferiorly in one. In one case there was a history of trauma CONCLUSIONS: Subconjunctival orbital fat prolapse typically occurs superotemporally in obese elderly males and is easily differentiated from other lesions, such as dermolipoma. The prolapsed orbital fat may be excised via the conjunctiva.

Adipose Tissue↗
PubMed1999

Late infection of hydroxyapatite orbital implants.

BACKGROUND: Exposure and minor complications of hydroxyapatite orbital implants are common. Infection appears to be rare and fibrovascular ingrowth into hydroxyapatite implants may make infection and extrusion less likely than with other types of orbital implant. METHODS: We describe three cases of chronic low-grade infection of hydroxyapatite implants, occurring late after apparently uncomplicated surgery, with tiny or inapparent areas of conjunctival loss or exposure. RESULTS: Two of the three cases grew Staphylococcus oureus on culture. All three implants ultimately needed to be removed. A characteristic histological pattern was seen, with abrupt transition between vascularized and abscessed implant. CONCLUSIONS: Chronic infection of hydroxyapatite implants can occur late, in the absence of large conjunctival defects, or other obvious risk factors. While exposure of the implant to pathogens through a breach in the conjunctiva may have been a factor, it appeared that the infection may have arisen in an avascular portion of the implant prior to the conjunctival breakdown in one or more of these cases.

Aged↗
PubMed1999

Current treatment and outcome in orbital cellulitis.

BACKGROUND: Bacterial orbital cellulitis is an uncommon condition previously associated with severe complications. The purpose of this paper is to describe current investigations and treatment in orbital cellulitis, establish their effectiveness and to describe the incidence of complications and surgical intervention. METHODS: A chart review of all patients admitted to the Royal Victorian Eye and Ear Hospital and the Royal Children's Hospital, Melbourne with a diagnosis of orbital cellulitis for the period July 1993 to July 1997. RESULTS: A total of 52 patients fulfilling the diagnostic criteria for orbital cellulitis were identified. Paranasal sinus disease was the commonest predisposing cause, especially in the paediatric age group. Diagnosis was made clinically with radiological confirmation in all cases. Microbiological investigation and results varied. The commonest species isolated were Staphylococci and Streptococci. Three cases of mixed anaerobes and one of Clostridium were seen. Cultures from abscess cavities and infected sinuses gave the highest positive yield (50-100%). Blood cultures were taken in 26% of adults and in 56% of children; none was positive. Treatment was either by intravenous broad-spectrum antibiotics alone or with surgery to drain orbital abscesses, usually n conjunction with sinus surgery. No patient suffered permanent visual impairment other than one case of enucleation for endophthalmitis that had caused orbital cellulitis. There was one case of permanent ocular motility impairment, and one of meningitis. CONCLUSIONS: Despite its past history of severe morbidity and even mortality, adequately treated orbital cellulitis rarely has significant morbidity today. Paranasal sinus disease remains the commonest cause. Culture of infected paranasal sinuses or pus from abscesses is most likely to yield significantly positive results in this study. Blood cultures were not helpful.

Adolescent↗
PubMed1998

Lacrimal canalicular obstruction associated with topical ocular medication.

PURPOSE: To describe the association between the use of various types of topical ocular medications and acquired lacrimal canalicular obstruction in 14 patients. METHODS: The records of all patients in the author's practice with either lacrimal canalicular or punctal occlusion associated with the use of topical ocular medication were reviewed. RESULTS: Fourteen cases were identified. The obstructions occurred at any point from the punctum to the common canaliculus, but most commonly occurred 2-5 mm from the lacrimal punctum. There was an association with various degrees of clinically apparent subconjunctival scarring maximal at the inner canthus, rarely to a severe degree, with symblepharon, medial canthal keratinization and cicatricial medial entropion. In some cases, no subconjunctival scarring could be clinically detected. Topical medications used were often multiple and included prednisolone acetate/phenylephrine hydrochloride (n = 5), timolol maleate (n = 5), pilocarpine (n = 3), dipivefrine hydrochloride or adrenaline (n = 3), chloramphenicol (n = 3), tobramycin (n = 3), indomethacin (n = 2), ecothiopate iodide (n = 1), betaxolol (n = 1), dexamethasone (n = 1), tropicamide (n = 1) and the long-term use of naphazoline and various artificial tear preparations (n = 1). The duration of exposure ranged from 3 weeks to 20 years, with seven patients having used drops for 3-6 weeks. Seven patients had surgical repair, three by dacryocystorhinostomy (DCR) and glass by-pass tube (all successful), three by canalicular repairs (one failed) and one by DCR and canalicular repair that restenosed at the puncta, who then had successful punctoplasty and silicone intubation. CONCLUSIONS: Lacrimal canalicular obstruction may occur after relatively short-term exposure to topical ocular medications or as part of a more widespread cicatricial reaction in patients on long-term medication. While a direct causal relationship cannot be confirmed, there appears to be a strong association and the site of the obstructions makes other causes unlikely.

Administration, Topical↗
PubMed1998

Persistent infra-orbital nerve hyperaesthesia after blunt orbital trauma.

BACKGROUND: Hyperaesthesia involving the infra-orbital nerve is rarely associated with orbital floor fracture. METHODS: An 11-year-old boy and a 34-year-old man had persistent and severe hyperaesthesia in the distribution of the infra-orbital nerve 12 and 26 months, respectively, after blunt orbital trauma. RESULTS: Surgical decompression of the infra-orbital nerve resulted in rapid and complete resolution of the hyperaesthesia in both cases. CONCLUSION: Persistent hyperaesthesia of the infra-orbital nerve is another indication for exploration of the orbital floor following blunt orbital trauma.

Adult↗
PubMed1998

Orbital osteoma in Gardner's syndrome.

PURPOSE: To report the association of an orbital osteoma with Gardner's syndrome (familial polyposis coli leading to carcinoma, multiple osteomas and skin and soft tissue tumours). METHOD: A review of patient records. RESULTS: A 29-year-old male with known Gardner's syndrome presented with long-standing right proptosis due to an osteoma of the medial wall and roof of the orbit. He had previously had prophylactic colectomy and one other osteoma of the skull excised. CONCLUSION: Although orbital osteoma in the setting of Gardner's syndrome is rare, it should be recognized as an association because of the importance of the intestinal polyposis, which leads to carcinoma if untreated.

Adult↗