COCNet Ophthalmology Intermedia

Ophthalmology INTERMEDIA

GLAUCOMA

Ulcer

You will find, in Ophthalmology, the original work of the month. It comes us from Thessalonique. This not randomised exploratory study compared 41 glaucomatous patients (of which nine had pseudoexfoliation) to a control group paired by age. Histological results of the biopsies made by endoscopy objectified an incidence of Helicobacter Pylori infection very significantly higher among glaucomatous patients. The most reasonable assumption is a predisposing common factor to both affections. However a possible pathogen role of Helicobacter Pylori in the glaucomatous disease, argued by the authors, is certainly not to draw aside and constitutes a base of future investigations.

Kountouras J, et al. Relationship between Helicobacter Pylori Infection and Glaucoma. Ophthalmology 2001;108:599-604.

hg (03/01)

CATARACTS

Smoker’s cataract

Smoking causes cataracts, a fact that has been established in several papers. During the course of a spectrophotometry study undertaken by the University of Ankara, copper, lead and cadmium concentrations were measured in 37 opacifled and 9 unaffected lenses, with a view to identifying some of the pathophysiological reasons underlying this fact. The main source of cadmium, which is present in blood and in the lens, is inhaled smoke and this is probably attributable to the widescale use of chemical fertilisers, Concentrations of these three elements were significantly higher amongst smokers and in cataracts. The positive correlation found between cadmium levels and those for the other two metals suggests that it encourages precipitation within the lens.

Cekic 0. Br.J.Ophthalmol 1998;82:186-8.

GLAUCOMA

Pigment dispersion: flattening of the iris

The concave profile assumed by the iris in certain pigment dispersion syndromes, increasing the degree of contact between the iris and the lens, could be treated by Nd:YAG laser iridotomy. In a study carried out in Milan, the researchers looked into the anatomical aspect of a well-known theory. Eyes presenting with pigment dispersion syndrome were examined using an ultrasound biomicro scope, along with controls. In 30 out of the 50 cases of pigment dispersion, the iris was concave. The corresponding figures for the controls were 2 out of 15 and there was increased contact between the iris and the lens in cases of dispersion syndrome. With a single exception, the iris reverted to a flat profile in all cases after iridotomy had been performed on 18 eyes. Iris/lens contact was iden tical for treated subjects and for normal eyes. However, whilst it may be effective in functional terms, does iridotomy have any effect on the course of the disease ?

Carassa R.G, et al. Br J Ophthalmol 1998;82:150-3.

NTG: lOP is under-estimated where the cornea is less thick

A paper published in Israel emphasises the way in which corneal thickness affects lOP measurements. The study involved 21 patients with NTG and 25 with P0-AG, along with 27 controls, The radius of currative was identical in all 3 groups. Corneal thickness in the NTG group was significantly less than in the other two groups.

Morad Y, et al. Am J Ophthalmol 1998;125:164-8.

Watch the disc closely

In the context of P0-AG, disk excavation, with acquired localised expansion, gives the patient a poorer prognosis. This is the conclusion reached in this retrospective study carried out by the Glaucoma Section at the Yale Eye Center, in which 25 subjects with acquired excavation expansion were compared with 24 glaucoma-sufferers who did not exhibit this disk appearance. They were matched by age, mean IOP, cup:disc ratio, peripheral deficit and length of monitoring. Details of the parameters being investigated were obtained by stereophotography and automated visual field measurement.

Ugurlu S, et al. Acquired Pit of the Optic Nerve A Risk Factor for Progression of Glaucoma. Am J Ophthal

RETINA

Macular holes: Keep the contralateral eye under observation

In a prospective study undertaken at the Moorfields Eye Hospital in London, the 5-year risk of a contralateral lesion, as determined using the Kaplan-Meier method, was estimated at 15.6%. A total of 114 patients, who presented initially with an idiopathic macular hole, took part in this study. ERG and EOG investigations were carried out, along with measurement of color sensitivity to contrast, the only parameter that could be considered predictive was a tritan deficit.

Ezra F, et al. Ophthalmology 1998;105:353-9.

REFRACTIVE SURGERY

Refractive surgery is programmed death for keratocytes

Keratocytic apoptosis is held to be the trigger factor in wound healing following refractive surgical procedures. It has undergone both qualitative and quantitative evaluation (research into DNA fragmentation and electron microscopy studies) in animal experimental work involving photorefractive keratectomy (PRK), transepithelial PRK and LASIK. transepithelial PRK provided the lowest levels of central corneal apoptosis and could prove a useful technique for dealing with severe myopia and for repeated intervention to deal with relapses.

Héléna MC, et al. Invest Ophthalmol Vis Sci 1998:276-83.

PRK: 6 years on

When the initial trials, involving 120 subjects, were being carried out in London, the excimer laser used in photorefractive keratectomy carried out ablation of small 4mm areas, giving correction of up to 7 dioptres. In this study involving 83 of the original subjects who are being followed up 6 years down the line, refraction was found to have stabilised after the first year and to have remained stable ever since.The principal complaint continued to be poor night vision, This being associated with The small scale of the photo-ablation operations that took place.

Stephenson C.G, et al. Ophthalmology 1998;105:273-81.

Endothelium maintained following LASIK

At the Emory Eye Center, over 100 eyes which had undergone LASIK surgery were analysed at Iwo weeks and three months after the procedure. No significant changes were found in the density or The morphology of cellular endothelium where ablation was carried out to a theoretical depth of 200 to 330µm, giving up to 1 4.5-dioptre correction. Yet another argument in favour of this technique will have to be confirmed in the long term.

Jones SJ, Azar 90, Cristol SM, et al. Am J Ophthalmol 1998;125:465-71.

hg (08/98)

BOOKS

An original work

In the majority of societies, the eye and vision provide one of the central planks upon which knowledge is based. It is in this context of the general history of the visual sense that Théétète Editions have published this particularly original piece of work by the ophthalmolo gist and painter, Dr Romano.
Under the title "The Eye of the Gods", the author takes a detailed look at mythology using the texts of Homer and Hesiod, searching for any pointers which will help to identify The major brushstrokes in the visual concept amongst the ancient Greeks.

Romano. L'œil des dieux. Théétète ed.

Source Ophthalmo NEWS 10/98 - 21