Can genetic risk information for age-related macular degeneration influence motivation to stop smoking? A pilot study

AIMS

Smoking can increase the risk of macular degeneration and this is more than additive if a person also has a genetic risk. The purpose of this study was to examine whether knowledge of genetic risk for age-related macular degeneration (AMD) could influence motivation to quit smoking.

METHODS

A questionnaire-based study of hypothetical case scenarios given to 49 smokers without AMD. Participants were randomly allocated to a generic risk, high genetic risk, or low genetic risk of developing AMD scenario.

RESULTS

Forty-seven percent knew of the link between smoking and eye disease. In all, 76%, 67%, and 46% for the high risk, generic, and low risk groups, respectively, would rethink quitting (P for trend = 0.082). In all, 67%, 40%, and 38.5%, respectively, would be likely, very likely, or would definitely quit in the following month (P for trend = 0.023). Few participants (<16% of any group) were very likely to or would definitely attend a quit smoking session with no difference across groups. In all, 75.5% of participants would consider taking a genetic test for AMD.

CONCLUSION

In this pilot study, a trend was seen for the group given high genetic risk information to be more likely to quit than the generic or low genetic risk groups. Participants were willing to take a genetic test but further work is needed to address the cost benefits of routine genetic testing for risk of AMD. More generic risk information should be given to the public, and health warnings on cigarette packets that 'smoking causes blindness' is a good way to achieve this.

The prevalence and associated features of posterior embryotoxon in the general ophthalmic clinic

PURPOSE

To estimate the prevalence of posterior embryotoxon (PE) in the general ophthalmic clinic and to identify any features of PE that suggest that it is pathological rather than physiological.

METHODS

Over 700 consecutive patients of all ages were examined with the slit lamp during their routine eye clinic appointment. Patients with posterior embryotoxon were invited to return for full ocular examination including keratometry, corneal topography, and gonioscopy.

RESULTS

In all, 49 out of 723 patients were found to have PE. This gives a prevalence of 6.8% with an age range of 18 months to 95 years. There was a higher prevalence in the younger age group of 22.5% (age range 18 months to 20 years) compared to 5.9% in the older age range (21-95 years). A total of 29 patients with PE returned for further examination. Six patients had glaucoma (two with Axenfeld's syndrome and one with aniridia), and one had ocular hypertension. In all, 20 patients had bilateral PE on slit-lamp examination, which increased to 24 with gonioscopy. The majority of the PE was seen temporally (97.9%) and limited to a few clock hours. Gonioscopy showed that eight patients with PE had associated inferior pigmentation of schwalbes line.

CONCLUSION

This large series found the prevalence of PE the general ophthalmic clinic to be 6.8%. Its presence should prompt careful anterior segment examination, including gonioscopy, to identify any associated abnormalities that may carry a risk of glaucoma. Children should also be assessed for any associated systemic or genetic abnormality.

Nd:YAG laser treatment for premacular subhyaloid haemorrhage

PURPOSE

Premacular subhyaloid haemorrhage produces sudden, profound visual loss which may be prolonged if untreated. Nd:YAG laser treatment can create a posterior hyaloidotomy enabling rapid diffusion of subhyaloid haemorrhage into the vitreous gel. This study was performed to assess the results of Nd:YAG laser hyaloidotomy and to compare the outcome with similar conservatively managed cases.

METHODS

Nd:YAG laser hyaloidotomy was performed in 6 patients with premacular subhyaloid haemorrhage. The aetiologies were Valsalva retinopathy, macroaneurysm, branch retinal vein occlusion, proliferative diabetic retinopathy (2 cases) and idiopathic. Four patients with premacular subhyaloid haemorrhage were managed conservatively. The aetiologies were Valsalva retinopathy (2 cases), macroaneurysm and proliferative diabetic retinopathy.

RESULTS

Nd:YAG laser hyaloidotomy achieved rapid resolution of subhyaloid haemorrhage in all treated patients. Visual acuity improved to 6/9 or better in 4 patients, but was limited by ischaemic diabetic retinopathy in 2 patients. No patient had evidence of damage to the retina or choroid from treatment. Among the conservatively managed cases, 3 patients had slow resolution of the subhyaloid haemorrhage over 3-6 months. One patient with diabetic retinopathy demonstrated little improvement at 18 months.

CONCLUSION

Nd:YAG laser hyaloidotomy is a safe and effective procedure. It achieves rapid resolution of premacular subhyaloid haemorrhage with restoration of visual function, preventing the need for vitreoretinal surgery.