Pythium insidiosum keratitis

A case of Pythium insidiosum keratitis is described. It is an unusual organism that is difficult to isolate. Cases in animals and humans have been reported from tropical and subtropical parts of the world but this is the first case from a temperate region and was acquired from a hot pool. Although resembling a fungus, it is insensitive to all antifungals and requires wide surgical excision for cure.     

Subretinal new vessel recurrence in age-related macular degeneration

Laser photocoagulation with argon or krypton is currently used to treat selected patients with age-related macular degeneration and sudden visual loss from subretinal new vessel formation. In 102 consecutive cases, treated over two years, closure of the vessels was achieved without additional major visual loss in 79% when assessed at two months. Early failure occurred in 21% and was due either to selection of cases with central location or failure to close the new vessel. Later failures due to recurrent subretinal new vessel formation or progression of other macular degenerative changes has occurred in a further 28% so far. Although controlled clinical trials show a significant benefit of treatment, the overall impact of these few successes on the population with macular degeneration is small. Further understanding of the mechanism of subretinal new vessel formation is urgently required. Areas under investigation include the response of injured retinal pigment epithelium, choroid and retina and cellular production of facilitatory factors including proteases and fibronectin.     

Topical antibiotic prophylaxis for cataract surgery: a controlled trial of fusidic acid and chloramphenicol

The effectiveness of topical fusidic acid 1%, in a viscous drop base, to reduce or eliminate ocular microflora in patients undergoing cataract surgery has been studied. Forty-two patients received fusidic acid on a double-blind basis and for comparison 21 patients were similarly assessed with topical chloramphenicol. A further 17 patients received no treatment other than subconjunctival cephazolin administered to all operated eyes at the time of surgery. Quantitative bacterial counts from the conjunctivae and lash lines of each patient were made 24 hours before surgery, on the morning of operation and again 48 hours after surgery. With a regimen of five administrations on the day prior to surgery, neither topical fusidic acid 1.0% nor chloramphenicol 0.5% produced clinically or statistically significant reductions of the ocular microflora. In contrast perioperative subconjunctival cephazolin effectively reduced or eliminated lid and conjunctival microflora following surgery. This study indicates that the effectiveness of a topical antibiotic preparation for overt ocular infection cannot be directly extrapolated to the effect on resident ocular microflora, at least with short-term use for presurgical prophylaxis.     

Exudative macular degeneration and intravitreal triamcinolone: 18 month follow up

Purpose: To evaluate the safety and efficacy of intravitreal triamcinolone after 18 months of follow up in patients with age-related macular degeneration and subfoveal or juxtafoveal choroidal neovascularization considered unsuitable for laser photocoagulation. Methods: Thirty eyes of 28 patients, referred from general eye clinics as well as the private clinic of one of the authors to a hospital-based retinal out-patient clinic, were treated with an intravitreal injection of triamcinolone (4mg). The primary outcome measure was the proportion of eyes with loss of six or more lines on a Bailey-Lovie Chart. The incidence of adverse events associated with treatment was also observed. Results: Of the 20 eyes with initial visual acuity (VA) of 6/60 or better, the vision was maintained (± 1 Bailey-Lovie lines) in 11 eyes (55%), while six eyes (30%) suffered severe visual loss (six or more lines). The VA improved by five to six lines in three of 10 eyes with initial vision of 3/60 or worse. Three of four eyes receiving a second injection suffered either progressive cataract or elevated intra-ocular pressure (IOP) requiring cataract surgery and/or filtering surgery. One of 26 eyes (3%) receiving a single injection showed progression of cataract and elevation of IOP within 6 weeks of treatment and required anti-glaucoma medication for 6 weeks. Progression of nuclear sclerosis 8–12 months after treatment was observed in six of 26 eyes (23%) receiving a single injection. Conclusions: The results of the present study suggest that a single intravitreal injection of 4 mg triamcinolone is reasonably well tolerated by the human eye. The rate of development of severe visual loss was less than reported for historical controls. Because the results are preliminary and uncontrolled, the treatment should not be used routinely until its benefit to patients is established by a prospective, randomized controlled study.     

Penetrating eye injury from a rigid infant pacifier

Background: The use of infant pacifiers (dummies) is common in Australasian communities and has been reported to be associated with various injuries, but to date ocular trauma has not been reported.
Case report: A 14-month-old child sustained a penetrating eye injury from the infant pacifier that was in his mouth during a minor fall. Only a lid laceration was detected at the time. One week later he presented with mydriasis, heterochromia and a poor red reflex. Diagnosis of a penetrating eye injury was made by examination under anaesthesia, with B-scan ultrasonography demonstrating hypotony but no retinal detachment or intraocular foreign body. Funduscopy revealed a small inferior vitreous haemorrhage. Exploration of the globe adjacent to the lid wound showed a 6 mm laceration through the sclera plugged with prolapsed vitreous.
Conclusion: Serious ocular injury may result after a minor fall with some designs of rigid infant pacifiers. Heterochromia and anisocoria noted by the mother heralded more serious ocular injury in this case. The delay in diagnosis of this injury emphasises the importance of ocular examination to exclude eye trauma when injuries occur around the orbit.     

BLINDNESS IN NEW SOUTH WALES An estimate of the prevalence and some of the contributing causes

The information available on the prevalence of blindness in Australia is examined in an attempt to estimate the number of blind people in New South Wales. Records of the causes of blindness made by the authors at the Royal Blind Society's Low Vision Clinic arethen examined to estimate their relative significance.
If blindness is to be prevented, a more detailed analysis of causes will be needed. This could be obtained by examination and coding of the records for Disability (Blind) Pensions at the Department of Social Security.
There are at least seven thousand people blind, out of a total population of 5,145,900. Macula pathology contributes 37.2% and 81.5% of those affected are over 60 years old. Diabetes is responsible for approximately 10%. Genetically determined disease causes 25% between ages 16 and 60 years.
Blindness in Aboriginals is not discussed.     

OCULAR RIGIDITY AND INTRAOCULAR PRESSURE IN KERATOCONUS

Eighty-five patients with keratoconus and 20 normal controls were studied. Ocular rigidity, calculated using the Friedenwald nomogram, correlated with corneal thinning (p < 0.001) and area of cone (p = 0.05). Schiøtz pressures with increasing weights fell more than normal in Grades 0 to 3 keratoconus, but returned to normal following corneal grafting, as did ocular rigidity. Goldmann applanation pressures were low over the apex of the cone, varying most in eyes with lowest ocular rigidity and with greatest corneal thinning, but also in large sagging cones which had only minimal corneal thinning. Pressures by Mackay-Marg tonometry were normal in keratoconus. The axial length of eyes with keratoconus even after corneal grafting was longer than normal and correlated with myopia. It is concluded that abnormalities of ocular rigidity, Schiøtz and Goldmann pressures in keratoconus are determined by abnormal corneal rigidity. If corneal rigidity is low or corneal thinning is present, Goldmann applanation pressures are falsely low and Mackay-Marg tonometry more closely approximates the true intraocular pressure. The cone develops by stretching with limited loss of tissue and the lower rigidity and reduced apical stress decrease the likelihood of rupture.