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Biomedical subjects

P Brittain

Publications and source records attributed to P Brittain.

6 recordsLinked to original sources

Spontaneous bony orbital auto-decompression in thyroid ophthalmopathy.

Orbital 'auto-decompression' in TED (thyroid eye disease) is a well recognised phenomenon in older patients where lax orbital septa allow proptosis to decompress the orbit. Bony 'auto-decompression' in TED is a different entity which to the best of our knowledge has not been previously reported. We describe such a case which presented spontaneously, in the absence of trauma or bony pathology, and discuss possible causes.

Female↗

Corneal toxicity secondary to inadvertent use of benzalkonium chloride preserved viscoelastic material in cataract surgery.

AIMS: To study the long term toxic effects of intraocular benzalkonium chloride (BAC). METHODS: 19 patients exposed to intraocular BAC preserved viscoelastic during cataract surgery in February 1999 developed severe striate keratopathy immediately postoperatively. 16 patients, including two who underwent penetrating keratoplasty, were studied in the period April to June 2000. Ocular symptoms, visual acuity, biomicroscopy, intraocular pressure, dilated funduscopy, specular endothelial microscopy, and corneal pachymetry findings were recorded. The corneal and iris specimens of the two patients who underwent keratoplasty were studied by light, transmission, and scanning electron microscopy. RESULTS: Six males and 10 females, aged 64-98 years, were studied 14-16 months postoperatively. All patients were symptomatic. 12 patients had best corrected visual acuity of 6/12 or better and four patients of between 6/18 and 6/60. Five patients had corneal epithelial oedema and 11 had Descemet's membrane folds. The central corneal thickness, 620 (SD 71) microm, in affected eyes was significantly higher (p<0.005, two tailed paired t test) than that of the contralateral eyes, 563 (SD 48) microm. The endothelial cell density was significantly lower (p<0.0001, two tailed paired t test) in affected eyes: 830 (SD 280) cells/mm2 v 2017 (SD 446) cells/mm2. The mean average cell area was significantly higher in the BAC treated eyes: 1317 (SD 385) microm2 v 521 (SD 132) microm2. There was no significant difference in the coefficient of variation of cell size between the two eyes (p=0.3, two tailed paired t test). Two corneal specimens displayed morphological features of bullous keratopathy and other non-specific abnormalities. Extracellular melanosomes were present in a portion of the iris of one case. CONCLUSION: BAC is toxic to the corneal endothelium when used intraocularly, leading to severe striate keratopathy. This cleared in most cases but left varying degrees of residual stromal thickening in all eyes. If penetrating keratoplasty is required the results are excellent.

Aged↗

Retrobulbar phenol injection in blind painful eyes.

Retrobulbar phenol injection was used as a neurolytic to manage blind chronically painful eyes in ten patients. The cause of the blind painful eye was absolute glaucoma in eight of the ten eyes. We used 1.5mL of 1:15 (6.7%) aqueous phenol solution in each case. None of the patients experienced any pain from the injection. Seven patients obtained complete pain relief after the procedure, and one patient had some improvement. We found a range of duration of pain relief of 4.5 to 48 months (mean, 15 months), which compares favorably with retrobulbar alcohol injection. We believe retrobulbar phenol injection is preferable to alcohol. It has the advantage of being less painful during injection because of its local anesthetic properties.

Adult↗

Alteration of the stromal architecture and depletion of keratan sulphate proteoglycans in oedematous human corneas: histological, immunochemical and X-ray diffraction evidence.

The structure and content of the extracellular stromal matrix of several oedematous human corneas was investigated using electron microscopy, X-ray diffraction and biochemical techniques. Electron microscopy revealed the presence of wavy lamellae and various sized collagen-free 'lakes' within the stroma of the oedematous corneas, with their posterior sections containing by far the largest 'lakes'. The existence of 'lakes' was supported by the equatorial X-ray diffraction evidence. Staining the oedematous corneas with Cuprolinic blue prior to electron microscopical and meridional X-ray diffraction studies demonstrated a loss of stromal proteoglycans normally associated with collagen. Immunochemical evidence demonstrated reduced levels of antigenic keratan sulphate in the oedematous corneas while biochemical techniques revealed constant chondroitin sulphate levels in the same corneas.

Chondroitin Sulfate Proteoglycans↗