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Dive into the research topics where Alan A. McNab is active.

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Featured researches published by Alan A. McNab.


British Journal of Ophthalmology | 2002

Squamous cell carcinoma of the conjunctiva: a series of 26 cases

Penelope McKelvie; Mark Daniell; Alan A. McNab; Michael S. Loughnan; John D Santamaria

Aim: To retrospectively study 26 patients with squamous cell carcinoma (SCC) of the ocular surface to determine pathological and clinical characteristics of tumour associated with outcome. Methods: Patients with conjunctival SCC from St Vincents Hospital and the private ophthalmology practices of the authors were reviewed. Results: Patents were usually male (77%), elderly (69% > 60 years of age), with most lesions (81%) occurring at the limbus. Seven patients (27%) suffered recurrent ocular surface squamous neoplasia (OSSN) within 4–15 months and two of these patients (8%) died of metastatic disease. Intraocular invasion was noted in three patients (11%), while corneal and/or scleral invasion was found in eight (30%). Orbital invasion was noted in four patients (15%). Six required orbital exenteration. Preoperative impression cytology of five patients with minimally invasive disease showed OSSN in four (80%). In situ carcinoma could not be differentiated from minimally invasive disease using impression cytology. Preoperative diagnosis of SCC was made in 35% of cases. Clinical accuracy was higher for larger lesions (>10 mm) and those with hyperkeratosis. Conclusions: Conjunctival SCC occurs in sun damaged ocular surface, usually at the limbus in elderly men. Recurrence of OSSN is common with significantly increased risk for older patients, lesions of large diameter, high proliferation index (Ki-67 score), and positive surgical margins. Orbital exenteration may be required for control of local disease and death from metastatic disease occurs in a small percentage of patients.


Ophthalmology | 2002

Clinical features and management of intraorbital foreign bodies

Timothy P. Fulcher; Alan A. McNab; Timothy J. Sullivan

PURPOSE To review the clinical features and management of patients with intraorbital foreign bodies. DESIGN Noncomparative interventional case series. PATIENTS AND METHOD Forty patients seen at two regional orbital surgery departments with intraorbital foreign bodies were reviewed. MAIN OUTCOME MEASURES Visual acuity, surgical interventions, and complications. RESULTS Seventy-three percent of patients were younger than 30 years old. There were 22 metallic, inorganic; 5 nonmetallic, inorganic; and 13 organic intraorbital foreign bodies (IOrbFb) in this series. Thirty patients were seen at the time of injury, and 10 patients were seen in a delayed setting with orbital complications. Thirty-four patients had surgical removal of their IOrbFb either because of complications or easy surgical access. Six patients had no surgery because of posteriorly located inorganic foreign bodies. Thirteen patients had resultant blind eyes; 12 of these were blind from the initial trauma. CONCLUSIONS Loss of vision in conjunction with IOrbFbs is usually a result of the initial trauma. All patients should have antibiotic therapy because of the high incidence of secondary orbital infections. Computed tomography is the best initial mode of imaging. Surgical removal is indicated for all organic IOrbFbs. Inorganic IOrbFbs should be removed if causing complications or if located anteriorly after discussion of potential surgical complications with the patient. Posteriorly located inorganic IOrbFbs should be left alone, unless they are causing significant orbital complications.


Clinical and Experimental Ophthalmology | 2001

Ocular adnexal lymphoproliferative disease: a series of 73 cases

Penelope McKelvie; Alan A. McNab; Ian C. Francis; Richard M. Fox; Justin O'Day

Background: This study involved 73 patients with lymphoproliferative lesions of the ocular adnexa. The lesions were categorized using the Revised European American Lymphoma classification of lymphoid tissues and analysed to determine the frequency and prognostic impact of tumour type, location, stage and patients age and sex.


Ophthalmic Plastic and Reconstructive Surgery | 1997

Floppy Eyelid Syndrome and Obstructive Sleep Apnea

Alan A. McNab

Floppy eyelid syndrome (FES) usually affects middle-aged obese men, presenting as a unilateral or bilateral chronic papillary conjunctivitis. The upper eyelid is lax, floppy, and easily everted. The laterality corresponds to the side the patient sleeps on. An association with obstructive sleep apnea (OSA) has been suggested. A personal series of 17 new cases is presented, and 79 previously reported cases are reviewed to give a detailed description of the syndrome. In addition to the classical presentation, patients may present with upper lid ptosis, lash ptosis or trichiasis, lower lid ectropion or rarely entropion, or corneal complications. Eight patients with FES were investigated for OSA. Twenty other patients with known OSA were examined for FES and other possibly associated ocular features. All eight patients referred for sleep studies were found to have OSA. One of the 20 patients with known OSA was found to have FES, and two had features of early asymptomatic FES. One patient with FES and OSA had normal tension glaucoma. Patients with FES should be considered for sleep studies because of the known morbidity of OSA. Simple screening of patients with OSA may detect FES and avoid late corneal complications that can compromise vision.


Ophthalmology | 1997

Perineural Spread of Cutaneous Squamous Cell Carcinoma via the Orbit: Clinical Features and Outcome in 21 Cases

Alan A. McNab; Ian C. Francis; Ross Benger; John Crompton

OBJECTIVE To describe the clinical features, treatment, and outcome of a series of patients with perineural spread (PNS) of cutaneous squamous cell carcinoma (SCC) via the orbit. DESIGN A cohort study. PARTICIPANTS Twenty-one patients identified with PNS of cutaneous SCC via the orbit. INTERVENTION Patients were treated with various combinations of conservative or radical surgery, external beam radiation therapy, and chemotherapy. RESULTS Of 21 cases, 17 (81%) were male. Age at presentation with PNS ranged from 38 to 82 years (median, 66 years). The forehead and eyebrow were the most common site of the primary lesion. All but one had altered or decreased sensation, but only nine presented with pain. Fourteen (67%) had ophthalmoplegia at presentation, and 14 (67%) had evidence of PNS involving branches of the facial nerve. Despite combinations of radical surgery, conservative surgery, and radiation therapy, no method of treatment appeared more effective, and 14 patients died from 9 months to 5 years after presentation with PNS (median, 3 years), usually from local and intracranial disease. Two survived to 14 and 18 years, one is alive at 3 years with recurrent local and distant disease, and four are alive without evidence of disease at 2, 3, 4 and 12 months after radiation therapy. CONCLUSIONS Perineural spread of cutaneous SCC via the orbit carries a poor prognosis. Early radiation therapy may offer the best form of palliation. The role of radical surgery probably is limited once orbital involvement is apparent, as the cavernous sinus and facial nerve branches usually are involved.


British Journal of Ophthalmology | 1989

Primary optic nerve sheath meningioma.

J E Wright; Alan A. McNab; W I McDonald

Fifty patients with optic nerve sheath meningiomas have been reviewed with a follow-up of up to 15 years. The median age at onset of their symptoms was 40.0 years. The majority were middle aged females with a slowly progressive lesion. More aggressive lesions were encountered in a younger, predominantly male group of patients with frequent intracranial involvement. Our experience indicates that a more aggressive surgical approach to these lesions is needed to prevent this sequence of events. Meningiomas in older individuals often do not need treatment, though radiotherapy can be beneficial.


Ophthalmology | 2001

Australasian orbital and adnexal Wegener’s granulomatosis

Thomas L Woo; Ian C. Francis; Geoffrey A. Wilcsek; Minas T. Coroneo; Alan A. McNab; Timothy J. Sullivan

OBJECTIVE To report a retrospective case series of 29 Australian and New Zealand patients with orbital and adnexal Wegeners 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.


Aesthetic Plastic Surgery | 2007

Age-Related Changes of the Orbit and Midcheek and the Implications for Facial Rejuvenation

Bryan C. Mendelson; Winfield Hartley; Mark Scott; Alan A. McNab; Jay W. Granzow

BackgroundAging of the midface is complex and poorly understood. Changes occur not only in the facial soft tissues, but also in the underlying bony structure. Computed tomography (CT) imaging was used for investigating characteristics of the bony orbit and the anterior wall of the maxilla in patients of different ages and genders.MethodsFacial CT scans were performed for 62 patients ranging in age from 21 to 70 years, who were divided into three age groups: 21–30 years, 41–50 years, and 61–70 years. Patients also were grouped by gender. The lengths of the orbital roof and floor and the angle of the anterior wall of the maxilla were recorded on parasagittal images through the midline of the orbit for each patient.ResultsThe lengths of the orbital roof and floor at their midpoints showed no significant differences between the age groups. When grouped by gender, the lengths were found to be statistically longer for males than for females. The angle between the anterior maxillary wall and the orbital floor was found to have a statistically significant decrease with advancing age among both sexes.ConclusionBony changes occur in the skeleton of the midcheek with advancing age for both males and females. The anterior maxillary wall retrudes in relation to the bony orbit, which maintains a fixed anteroposterior dimension at its midpoint. These changes should be considered in addressing the aging midface.


Ophthalmology | 2001

Nontraumatic subperiosteal orbital hemorrhage

Maged L Atalla; Alan A. McNab; Timothy J. Sullivan; Brian Sloan

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.


Orbit | 2009

Orbital Metastasis: Clinical Features, Management and Outcome

Alejandra A. Valenzuela; Curtis W. Archibald; Ben Fleming; Lorraine Y. Ong; Brett O'Donnell; John J. Crompton; Dinesh Selva; Alan A. McNab; Timothy J. Sullivan

Purpose: To review the clinical features, treatment, outcome and survival of metastatic tumors of the orbit. Materials and Methods: Retrospective, non-comparative, chart review of 80 patients with orbital metastasis treated in four tertiary orbital centres in Australia. Results: The study included 80 patients of which, 44 were male with a mean age of 60 years. Orbital involvement commonly presented late in a multisystemic disease; however, the orbit was the first presentation in 15% of the cases. Diplopia (48%), pain (42%), and visual loss (30%) were the commonest symptoms at presentation; whereas proptosis (63%), strabismus (62%), and visual loss (41%) were the most frequent clinical signs. Computed tomography commonly showed a solid enhancing mass (42 cases) located within the orbital fat (43%), or enlarging an extraocular muscle (28%). Breast carcinoma (29%), melanoma (20%), and prostatic cancer (13%) were the most frequent histological types. Treatment was often multi-disciplinary and modalities included radiotherapy, chemotherapy, hormone therapy, surgery, and immunotherapy. Survival was limited to 1.5 years after diagnosis independent of the histological type, with 29% of patients alive after 17 months follow-up. Conclusions: A high index of suspicion and appropriate intervention with histological diagnosis can help in the management and quality of life in patients with metastatic orbital disease. Overall survival is limited and we encountered statistical limitations proving differences in the survival based on the sub-type of primary tumour involved. Metastatic orbital melanoma presented a higher incidence when compared with previous studies, probably due to the increase frequency of skin found in the Australian population.

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Dinesh Selva

Royal Adelaide Hospital

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Timothy J. Sullivan

Royal Brisbane and Women's Hospital

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Penny McKelvie

St. Vincent's Health System

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Brett O'Donnell

Royal North Shore Hospital

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Garry Davis

University of Adelaide

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Alejandra A. Valenzuela

Royal Brisbane and Women's Hospital

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Penelope McKelvie

St. Vincent's Health System

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J E Wright

Moorfields Eye Hospital

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