Osteoradionecrosis of the exenterated orbit.

Osteoradionecrosis (ORN) occurs in an estimated 2% of head and neck-irradiated patients. It is seen most commonly in the mandible with other reported sites including the maxilla, temporal bone, clavicle, and vertebrae. It is defined as an area of exposed devitalised irradiated bone, with failure to heal during a period of at least 3 months, in the absence of local neoplastic disease. We report 2 cases of ORN following postoperative radiotherapy given to patients who had undergone an orbital exenteration. ORN can develop spontaneously in one-third of cases, although in the majority of patients, it is induced by secondary trauma. Radiotherapy induces an endarteritis in the small blood vessels of bone, thus favouring the generation of small thrombi that obliterate the vascular lumen and interrupt tissue perfusion. Likewise, irradiation impairs the function of osteoblasts, manifesting as osteopenia, with impairment of the repair and remodelling capacity of bone. Prior radiation exposure can thus decrease bone vascularity and injure its reserve reparative capacity. It is important to differentiate ORN from local recurrence of malignancy, bone metastasis, radiation-induced sarcoma, and infection. CT and MRI are effective diagnostic tools. Clinical management of ORN is complex and unsatisfactory. Treatment remains difficult, and prevention is paramount. A history of radiotherapy should alert clinicians to detect bone exposure or excessively prolonged socket healing. Early diagnosis with a high index of suspicion can achieve higher control rates with conservative management. Our case series reports a rare, previously unreported, but important complication of radiation therapy of the exenterated orbit.

PAX6 mutation in association with ptosis, cataract, iris hypoplasia, corneal opacification and diabetes: a new variant of familial aniridia?

BACKGROUND: We report a family with ptosis, cataract, iris hypoplasia and gradual corneal opacification occurring in association with a PAX6 mutation. DESIGN: Case-series. PARTICIPANTS: Fourteen family members - 8 affected, 6 unaffected controls. METHODS: All participants underwent ophthalmological assessment, including best-corrected visual acuity, slit-lamp-examination, pachymetry, endothelial cell-count, tonometry and dilated fundoscopy. All subjects underwent anthropometry and assessment of glycaemic status. Genetic analysis of the PAX6 gene was performed. MAIN OUTCOME MEASURES: Presence of ptosis, corneal, iris and lenticular changes, gycaemic and PAX6 status. RESULTS: All eight affected subjects had ptosis with reduced levator function, anterior polar cataracts, and corneal changes of variable severity - two patients had undergone penetrating keratoplasties, with graft histology revealing conjunctival cells on the cornea and severe fibroinflammatory change. Five patients had iris hypoplasia. One patient had aphakic glaucoma and another had hypoplastic optic discs. Four of the six controls had no ocular features of this syndrome, and two had isolated mild ptosis. There was no difference in height or body mass index between cases and family controls (p > 0.05), but Haemoglobin A1c was greater in the cases (median [interquartile range] 5.6(0.8) vs 5.1(0.3), p = 0.028). Genetic analysis confirmed a pathogenic PAX6 mutation in exon 12 (c1439delC) in all eight patients, but none of the controls. CONCLUSION: This is the first report of this particular constellation of ocular signs occurring in association with a PAX6 mutation. There was no association with anthropometric features, but affected subjects had worse glycaemia than controls, which may be related to the known role of PAX6 in development of the pancreas.

Permacol in eyelid reconstruction -- a novel use.

BACKGROUND: Reconstruction of a full-thickness lower eyelid defect is not an uncommon procedure and requires repair of both the anterior and posterior lamella. The modified Hughes procedure is commonly used for large defects, however this requires a second procedure and since the flap must be left in place for at least 3 weeks prior to the second-stage separation, it is not suitable for patients with only eyes or of amblyogenic age. In such situations, a free tarsoconjunctival graft from the opposite upper eyelid or a mucoperiosteal graft from the hard palate is more appropriate. These have the advantage of being autologous tissue with excellent recipient tolerance, however, they are not without drawbacks, including donor site scarring, limited availability and prolonged operating time. In order to avoid donor-site morbidity, several substitutes on the market can be used to replace autologous grafts. Permacol is a relatively new biomaterial made from acellular cross-linked porcine dermal collagen with a structural architecture very similar to that of human dermis. METHODS: The authors present the first report of the use of Permacol to replace tarsus in the reconstruction of a full-thickness lower eyelid defect. RESULTS: Permacol seems to be far superior to other commercially available tissue substitutes because of its increased tensile strength, rigidity, durability, predictability of structure and robust behaviour. It is well incorporated by the body, and it serves as an excellent matrix for tissue ingrowth. CONCLUSION: We feel it is a very good autologous graft substitute in eyelid reconstructive surgery and achieved satisfactory functional and aesthetic results.

Cardiac pacemakers and electrocautery in ophthalmic surgery.

The aging of the population and our ability to care for a patient with increasingly complex disease suggest that we will be caring for many more patients with pacemakers and implantable cardioverter-defibrillators. Using surgical diathermy or electrocautery on these patientscan present the additional risk of electrical interference and appropriate precautions need to be considered. We summarise the different type of pacemakers and electrocautery, and how electrocautery can interfere with such devices. We discuss the relevant issues that should be considered when these patients undergo assessment for surgery and their intra- and post-operative management, including the use of magnets.

Orbital apex syndrome from blunt ocular trauma.

Orbital apex syndrome (OAS) is a rare condition due to a range of pathological processes around the optic nerve foramen and the superior orbital fissure causing characteristic functional loss. It is a rare complication of trauma and results from penetrating injuries as well as those involving bony fractures. We present a case of OAS from non-penetrating ocular trauma without bony involvement.

Comparison of dacryocystography and lacrimal scintigraphy in the investigation of epiphora in patients with patent but nonfunctioning lacrimal systems.

PURPOSE: To assess and compare dacryocystography and lacrimal scintigraphy in the management of patients with epiphora and patent but nonfunctioning lacrimal systems. METHODS: Data were collected retrospectively over a 3-year period from all patients having both dacryocystography and lacrimal scintigraphy for epiphora where clinical examination indicated delayed tear clearance but the lacrimal system was patent. Both investigations were evaluated for presence, site, and severity of delayed clearance. Dacryocystograms were also evaluated for reflux and anatomical abnormalities. The findings were assessed in a masked fashion and compared with the clinical examination. RESULTS: More than 200 lacrimal systems in 107 patients were examined. An abnormality was present in one or both investigations in 92% of systems. There was greater agreement between clinical evaluation and scintigraphy than for dacryocystography. Abnormalities were detected with scintigraphy and dacryocystography in 78% and 56% of systems (25% delay, 11% anatomical abnormalities, and 20% both), respectively. Overall agreement was 52%. Disagreement occurred mainly with a normal dacryocystogram and abnormal scintigram. There was agreement for site of blockage in 59%; however, scintigraphy detected a block at a more proximal level in 38%. CONCLUSIONS: In the investigation of epiphora in patients with apparent outflow obstruction but patent lacrimal systems, both dacryocystography and scintigraphy are often abnormal. The authors' study shows that scintigraphy is the more sensitive test, correlating more closely with the clinical examination and often detecting more proximal and severe obstruction, and appears to be the investigation of choice in these patients.

Optic disc and visual field progression in ocular hypertensive subjects: detection rates, specificity, and agreement.

PURPOSE: To examine the detection rates, specificity, and agreement between visual field (VF) progression and Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, GmbH, Heidelberg, Germany) rim area (RA) progression in subjects with ocular hypertension (OHT). METHODS: One hundred ninety-eight OHT and 21 control subjects were examined prospectively (1994-2001) with regular Humphrey VF (Carl Zeiss Meditec, Inc., Dublin, CA) and HRT testing. Point-wise linear regression (PLR) of sensitivity/time was used to assess VF progression, using standard and three-omitting (less stringent and stringent) criteria. The change in HRT-detected progression was assessed by linear regression of sectoral RA/time, defined as slope>1%/year, with significance level tailored according to series variability. Less stringent and stringent criteria were tested. Specificity was estimated by the proportions of control subjects with disease progression and significantly improving subjects (all). Agreement between disc and field progression in the subjects with OHT was assessed with specificities matched for both VF and HRT. RESULTS: Specificity for VF PLR was estimated to be 85.7% to 95.4% when standard criteria were used, and for RA/time to be 88.1% to 90.5% with the less-stringent criteria. In this comparison, 21.2% progressed by RA alone and 20.2% by VF alone, and 12.1% progressed by both RA and VF. Specificity was estimated to be 95.2% to 98.2% for both VF PLR and RA/time, using the three-omitting criteria and the stringent RA/time criteria, respectively. In this comparison, 8.6% progressed by RA alone, 15.1% by VF alone, and 3.5% by both RA and VF. CONCLUSIONS: A relatively high frequency of detected disease progression was observed with either method, with progression by VF occurring at least as frequently as progression by RA. Poor agreement between RA and VF progression was observed regardless of the specificity of the progression criteria. The results indicate that, in patients with ocular hypertension, monitoring of both VF and optic disc is necessary, as agreement between optic disc and VF progression is the exception rather than the rule.

External dacryocystorhinostomy for the treatment of epiphora in patients with patent but non-functioning lacrimal systems.

AIMS: To assess the outcome of external dacryocystorhinostomies (DCRs) in patients with patent but non-functional lacrimal drainage systems and to identify any preoperative clinical or dacryocystography (DCG) and lacrimal scintigraphy (LS) factors associated with successful surgery. METHODS: A retrospective study of 46 DCRs with silicone intubation performed for patients with epiphora associated with a clinically patent lacrimal drainage system. All patients underwent preoperative DCG and LS which were evaluated for presence, site and severity of delayed clearance. DCGs were also evaluated for reflux and anatomical abnormalities. Postoperative success was determined by subjective resolution of epiphora. Patients with persistent symptoms were offered Lester Jones Tube (LJT) insertion after establishment of a patent anastomosis to syringing and normal ostium on nasal endoscopy. Statistical analysis was performed using the chi2 and Fisher exact tests to determine whether there was any association between surgical outcome and preoperative resistance to lacrimal syringing, DCG and LS findings. RESULTS: 29 cases (63%) reported subjective surgical success after 11 months' average follow-up. There was a statistically significant association between increased resistance to syringing preoperatively and successful DCR (p=0.012). Of the 17 eyes that failed, all had patent anastomoses, and seven went on to have LJT insertion with complete resolution of symptoms. CONCLUSION: The majority of patients with patent but non-functional lacrimal drainage systems will be helped by DCR surgery, with greater success rates in those with significant reflux on preoperative syringing. For patients with residual epiphora, functional success can reach 100% with subsequent LJT insertion.

Visual function following transpupillary thermotherapy with adjusted laser parameters for the treatment of exudative age-related macular degeneration: a pilot study.

PURPOSE: To evaluate the efficacy of transpupillary thermotherapy (TTT) using adjusted laser parameters for the treatment of choroidal neovascularization (CNV) secondary to age-related macular degeneration. METHODS: TTT was performed on patients with CNV using a diode laser (810 nm) for 60 s in a subthreshold manner. Power settings were varied between 460 and 1200 mW, depending on lesion size, presence of pigment epithelial detachment and the amount of fundal pigmentation and subretinal fluid. LogMAR visual acuity, contrast sensitivity (Pelli-Robson) and metamorphopsia (Amsler chart) were assessed prior to and 6 months following treatment. Subjects also self-administered the National Eye Institute 25-Item Visual Function Questionnaire. RESULTS: Thirty occult/minimally classic and eight predominantly classic membranes were treated with TTT. At 6 months, absence or significant reduction of fluorescein leakage was observed in 20 (53%) patients. Stabilization of vision (loss of less than 15 letters) was observed in 25/30 (83%) eyes with occult/minimally classic CNV and 5/8 (63%) eyes with predominantly classic CNV. Improvement of contrast sensitivity was noted in 15 (35%) eyes, in 10 (26%) eyes it remained unchanged and in 13 (34%) eyes it deteriorated. There was no statistically significant effect of TTT on the National Eye Institute 25-Item Visual Function Questionnaire composite or subscale scores. CONCLUSIONS: TTT using adjusted parameters depending on fundal characteristics appears to be effective in stabilizing subjective and objective visual ability in a considerable number of patients with subfoveal CNV due to age-related macular degeneration. Larger-scale studies are required to confirm the benefit of this technique as opposed to the natural history of occult CNV.