Pioneers of a new frontier

Dr Jennifer Craig of the University of Auckland, currently in the UK, opened the programme with a review of patients' expectations of refractive surgery. Professional advice, she said, was a much stronger motivational factor in a patient's decision to opt for surgery than it was with contact lenses and patients often looked to their optometrists for information.

Visual outcome, appearance, convenience, comfort, safety and cost were the key considerations when deciding on surgery, all of which had positives and negatives. Visual outcome was still improving but overall satisfaction was high. Freedom from spectacles was a major reason for undergoing surgery, but partial correction might be acceptable to those with high preoperative refractive error.

Interest in surgery was often prompted by discomfort with contact lenses, Craig said, yet transient dry eye lasting three months or more after treatment occurred in around half of Lasik patients.

Although the safety of refractive surgery had improved in the last decade, the risk of a complication affecting best corrected VA remained at 1 per cent to 5 per cent. The cost of surgery varied widely and often reflected the level of pre and postoperative care provided.

Cornea 'Sacrosanct'

'Why risk the cornea?' was the question posed by consultant ophthalmologist John Bolger.

In ocular surgery, a poorly constructed or positioned incision could induce refractive changes which made life miserable for the patient and for the optometrist, he argued. Using videos of various refractive procedures, along with pre and postoperative topographic maps, he showed the disadvantages of corneal incisions and suggested other methods of achieving often better results. Limbal relaxing incisions, for example, had replaced arcuate keratotomy in the attempt to reduce congenital astigmatism during cataract surgery, but could have serious and irreversible effects on the cornea. For Bolger, the cornea was sacrosanct and should never be included in surgery, except where the offending pathology lay within it.

South African ophthalmologist Jan Venter has performed more than 7,000 Lasik procedures and most recently has introduced implantation procedures to the Optimax group of laser eye clinics in the UK.

Opening his lecture, he said that refractive surgery had become the most common surgical procedure in the world, but problems remained with corneal procedures that could be overcome with recently introduced technologies. In line with the current trend, phakic intraocular lenses (IOLs) were Venter's preferred option for correcting high myopia, hyperopia and astigmatism. The projection for refractive IOLs in Europe in 2008 was 100,000 procedures per year.

Intacs intracorneal rings were indicated for use in patients with keratoconus where contact lenses were no longer suitable and were often the best procedure to stabilise the cornea and improve vision. Venter's study showed that one Intacs ring was as safe and effective as two rings in decreasing corneal steepening and improving VA.

His evaluation of wavefront-guided Lasik using a Nidek system showed the technique was predictable, effective and stable, but the best results were in patients with greater high-order aberrations. Not all eyes needed or benefited from wavefront treatment, he said. Femtosecond laser ablation for Lasik flap creation created more consistent flap thickness and had fewer complications than microkeratomes and provided better visual outcomes in most patients. Venter concluded that refractive surgery had come of age. With only 1 per cent to 2 per cent market penetration in the developed world, there was room for further growth, particularly in the UK where he estimated the current penetration was 0.6 per cent.

Plugging the gaps

The next session opened with optometrist David Austen's presentation on managing the dry eye patient, and, in particular, the use of punctum plugs. This option was indicated to relieve post-Lasik or seasonal dry eye, chronic dry eye associated with systemic conditions or medication, and to enhance the effect or prevent drainage of topical medications.

Plugs could be temporary or permanent and came in extra-canalicular and intra-canalicular designs. Collagen plugs were used for diagnosis and PCL plugs for temporary occlusion. Silicone or thermoplastic plugs were for extended occlusion. Despite video footage that suggested otherwise, Austen said that they were easy to insert and remove and, in the case of intra-canalicular designs, relatively comfortable for the patient.

'Is the solution the solution or the problem?' was the intriguing title for optometrist Caroline Christie's review of recent developments in lens care products and current thinking on their role in ocular signs and symptoms. Two-step peroxide had long been seen as the 'gold standard' for soft lens disinfection but the problem of residual peroxide and lack of convenience had led to its gradual withdrawal. One-step peroxide was popular with some practitioners although these systems had reduced efficacy, did not allow continuous disinfection and surfactant was still required. New non-preserved chlorite-containing solutions were promoted as peroxide systems, but the low level of peroxide was incorporated for its stabilising properties, rather than as a primary disinfectant.

The latest multipurpose solutions (MPS) contained surfactants, wetting agents and lubricants in the formulation to improve comfort. It was not the disinfection efficacy per se but additional ingredients that had proved to be the problem with ReNu MoistureLoc. 'Rub and rinse' was set to be the hot topic in 2007 in the wake of the outbreak of fungal keratitis and withdrawal of MoistureLoc, and it was likely that 'no rub' indications would be removed from product packaging.

Although compliance was clearly an issue, not all MPS were equally effective against all pathogens and the testing of products by different laboratories sometimes produced differing results.

In the case of MoistureLoc, efficacy against Fusarium solani and Staph aureus was reduced when the water content of the solution was depleted by evaporation or topping up. The combination of a high polymer content and poor patient habits led to a reduced margin of efficacy. Fusarium in the resulting film could survive even when challenged by 'full-strength' MoistureLoc. However, it was important to keep this experience in perspective. There had been fewer than 300 associated episodes of fungal infection worldwide among around 5 million users, representing an event rate of 0.6 per 1,000.

Silicone hydrogel lenses were originally designed for continuous wear, so manufacturers had been slow to develop solutions for them. Studies led by, among others, Jones, Andrasko and Nichols, had shown compatibility problems with certain lens/care product combinations but, in general, levels of staining were low. New products were emerging that would be better suited to silicone hydrogels and solution selection would become an important part of the fitting process. The effect of solutions on corneal sensitivity was another area for future research.

Dry but why?

In her second presentation, Dr Jennifer Craig reviewed the latest research into dry eye and tear film management. The term 'dry eye' was no longer restricted to the patient with deficient tear quantity the problem might be with the quality of the tear film, or with the ocular surface, causing an evaporative rather than aqueous-deficient dry eye.

An array of artificial tear supplements, anti-inflammatory agents, oral medications and lid hygiene products were available, reflecting the multifactorial nature of dry eye and the need for a multifaceted approach to its management. Among recent developments in anti-inflammatories was cyclosporine, marketed as Restasis in the US but as yet unavailable in the UK, which was effective in moderate-to-severe dry eye patients. Topical androgen therapy to modulate hormone deficiency, secretagogues to stimulate tear production, and autologous serum derived from patients' own blood were just some of the therapeutic approaches taken, in this active area of research. Dr Craig's view was that more effective topical formulations were needed, not just whole body treatments.

For Canadian tear specialist Dr Barbara Caffery, nutrition and lifestyle were key factors in dry eye disease. Stopping smoking, increasing vitamin intake, reducing trans fatty acids and increasing dietary omega-3 fatty acids were her suggested approaches to reducing inflammation, which she argued was 'a large part' of dry eye disease. Nutritional supplements, topical nutrients, drinking more water and regular exercise were all measures that could theoretically have an effect. But there seemed to be little in the literature relating specifically to the anterior eye to support these theories.

Dr Caffery returned to the stage later in the evening to deliver the 3rd BCLA Pioneers' Lecture on the topic of 'Dry eye, Sjögren's syndrome and autoimmune disease'. For her PhD thesis she had described more than 200 cases of Sjögren's, a serious and debilitating disease that remains under-recognised by clinicians and made a fascinating subject for this lecture. One of the difficulties in diagnosis was the variety of forms the syndrome could take, such that patients might be referred to rheumatologists, ophthalmologists, optometrists and dentists. The classic symptoms to watch out for were dry, irritated eyes, a dry mouth and fatigue among predominantly middle-aged and post-menopausal women. At the least, these symptoms interfered with their work and social lives and, at worst, they were at 40 times greater risk of lymphoma tumours.

History and symptoms, Schirmer tear tests and slit-lamp examination were the clinician's main diagnostic tools. Dry eye symptoms for at least three months, a dry mouth, Schirmer scores of 5mm or less in 5 minutes, and Rose Bengal or fluorescein staining scores of 4/9 or more in at least one eye were the criteria that could most easily applied in everyday practice. Positive serum findings and salivary gland biopsy were more definitive tests.

One of the highlights of the day was John De Carle's acceptance speech as he was awarded honorary life membership of the BCLA for his contribution to contact lenses and to the association.

De Carle is perhaps best known as an early pioneer of extended wear. Among many amusing anecdotes from a career in contact lens practice and research spanning 60 years, was visiting Woolworths to measure marbles that he could use as moulds for early corneal lenses. Another was the problem of explosions when heating polymer in the kitchen of his north London flat, to supply CooperVision with material for its first soft lenses.

On a sombre note, the evening meeting also included a tribute by the association's honorary meetings secretary Nigel Burnett Hodd to his friend and colleague Ron Loveridge, president of the BCLA from 1993-94, who died that week.