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The amniotic membrane remains a useful tool in the treatment of several ophthalmic conditions, especially those related to the ocular surface. However, the 'success' reported in individual case reports and case series is not substantiated in the few published randomised controlled trials. More often than not, it is not as good as existing alternative options and, at best, is as good but with probably an increased cost. The variable outcomes could be related to inter and intra donor variations in the membrane and the depletion or alterations in its constituents subsequent to processing and storage. The membrane thus is a fairly 'non-standardised product' making comparisons of different applications and indications difficult. The potential for 'epidemic' infections, such as HIV, hepatitis B and C, is a serious issue as, in many parts of the world, fresh unquarantined membrane, at times with no tests for the above infectious agents, is being used. The exact mechanism of action of the membrane is not known but the consensus is that it acts as a substrate or scaffold for host cells to populate and thus facilitate healing and repair. The development of a standard 'synthetic membrane' using collagen or polymer matrices impregnated with putative beneficial ingredients, such as growth factors and antimicrobials, is being considered and may prove to be a step in the right direction.

Aim: To assess microbial contamination of 20% autologous serum (AS) eye drops used in a hospital inpatient setting., Method: 14 patients received autologous serum drops from 4 to 14 days with a cumulative total of 67 days. For each day the first and last drop (total 134 samples) was cultured on broth and blood agar., Results: Four patients (9 samples) grew Staphylococcus epidermidis only. One patient (1 sample) showed Staphylococcus epidermidis and a scanty growth of viridans streptococci in the same sample, and on different days the same patient grew Staphylococcus aureus in one sample and Staphylococcus epidermidis in another sample. One patient (1 sample) grew micrococcus. There was no clinical or microbial evidence of infection in any of these six patients., Conclusion: This study shows that autologous serum drops can be safely used in an inpatient setting, under a strict protocol of preparation and storage, without significant risk of bacterial contamination and consequent infection.

Aim: To report the outcome of a series of patients with stem cell deficiency who underwent allo-limbal transplantation and to describe a technique for this procedure., Methods: Six consecutive patients underwent allo-limbal stem cell transplantation. The primary diagnosis included alkali burn (n = 2), trachoma (n = 1), chronic rosacea blepharitis and kerato-conjunctivitis (n = 1), aniridia (n = 1), and Stevens-Johnson syndrome (n = 1). The limbal rim consisted of peripheral cornea and perilimbal sclera. FK-506 was used postoperatively for immunosuppression., Results: The length of follow up ranged from 3 to 24 months (mean follow up 11.8 (SD 9.3) months). The outcome was considered satisfactory in five of six cases. The corneal surface was completely epithelialised within 2 weeks, and there was a substantial improvement in vision and symptoms. One patient had recurrent epithelial defects related to eyelid abnormalities. No side effects associated with systemic immunosuppression were noted., Conclusion: Allo-limbal transplantation, with systemic immunosuppression with FK-506 is useful in reconstruction of the ocular surface with improvement in vision in patients with severe stem cell deficiency.

Aims: To develop a diagnostic algorithm using rim/disc area asymmetry ratio (RADAAR) to discriminate between normal and glaucomatous eyes using the Heidelberg retina tomograph (HRT). Methods: RADAAR was calculated by dividing rim/disc area ratio of the larger disc by that of the smaller disc. RADAAR normal tolerances in each disc sector were generated using 611 population based normal elderly individuals (mean age 72.5 years). Overall status for each individual was equal to the worst disc sector. Sensitivity was assessed in 45 patients with open angle glaucoma. Results: RADAAR variance was significantly greater in glaucoma compared with normality in all disc sectors (p<0.001). Normal RADAAR limits were not dependent on age or sex. Overall, at the 99th percentile limit, the diagnostic algorithm's specificity was 95. % with a sensitivity of 55.6%. Males with glaucoma showed greater RADAAR variance than females. Corresponding sensitivity of the diagnostic algorithm was 63.0% and 44.4% in males and females respectively, although this difference was not statistically significant (p=0.43). Conclusion: The RADAAR diagnostic algorithm detected glaucoma with moderate sensitivity but was limited by significant numbers of glaucoma patients with symmetrical optic disc changes. RADAAR may have greater sensitivity in males than in females although this requires confirmation in further studies. [ABSTRACT FROM AUTHOR]

Background/aim: To compare intraocular pressure (IOP) measurements taken by the Goldmann applanation tonometer, the Tono-Pen and the ocular blood flow pneumotonometer in eyes with varying central corned thickness (CCT) due to penetrating keratoplasty (PK), keratoconus (KC), and Fuchs' endothelial dystrophy (FED). Methods: IOP was measured with the Goldmann applanation tonometer, Tono-Pen XL, and OBF pneumotonometer in 127 eyes with the following corned abnormalities. There were 56 eyes that had undergone PK, 37 eyes with KC, and 34 eyes with FED. CCI was measured using an ultrasound pachymeter after IOP determinations had been made. Results: Mean IOP measurements in all three patient groups were significantly higher when measured by OBF pneumotonometer. Linear regression analysis showed that patients with FED had a significant increase in IOP with increasing CCT of 0.18 mm Hg/10 μm using the Goldmann tonometer, 0.15 mm Hg/10 μm with the Tono-Pen, and 0.26 mm Hg/10 μm with the OBF pneumotonometer. In patients with KC and after PK, linear regression analysis did not show a significant effect of CCT on IOP. A multivariate linear regression model controlling for age, sex, graft size, and patient group, showed that the effect of CCT on IOP for Tono-Pen (0.13 mm Hg/10 μm CCT) and Goldmann (0.14 mm Hg/10 μm CCT) were significantly lower than for the OBF pneumotonometer (0.26 mm Hg/10 μm CCT). Conclusion: This study found that mean IOP measurements using the OBF pneumotonometer were significantly higher than those made using the Goldmann applanation tonometer or Tono-Pen in eyes with a variety of cornel pathologies. The OBF pneumotonometer was found to be mast affected by variation in CCT. For all three instruments, the relation between IOP and CCT depended on the corned pathology and was greatest for FED. [ABSTRACT FROM AUTHOR]

Aim: To report a novel technique using amniotic membrane to cover exposed glaucoma tube shunts. Methods: A consecutive series of three cases that underwent drainage tube shunt surgery with the Ahmed valve for intractable glaucoma. All three patients developed exposure of the tube secondary to necrosis of the overlying bovine pericardial patch and conjunctiva. Repair of the defect was carried out with a double layer of amniotic membrane, the inner one acting as a graft and the outer as a patch. Autologous serum was used to promote epithelial growth. Results: Successful lasting closure of the conjunctival defect was achieved in all cases. Conclusion: Erosion of the drainage tube following shunt surgery is a potentially serious problem. It can be successfully managed using a double layer of amniotic membrane. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor referring to a case of postoperative candida endophthalmitis.

Presents a letter to the editor referencing article related to pseudohypopyon.