Southern Regional Congress 2017 Part 2

Keynote speaker Dr Ben Gaddie, an optometrist from Louisville in the US, tackled the thorny issues of dry eye and Meibomian gland dysfunction (MGD), issues that often arise concurrently. According to Gaddie, wider progress on the clinical front has been limited by the complexity of guidelines offered by the American Optometric Association (AOA), the latest iteration of the DEWS (international dry eye workshop) series of working committees, and other sources of ‘guidelines’. He described th as “too complex and of little practical use,” especially some of the advice offered by ‘experts’ which he described as “not especially useful.”Part of the DEWS series involved a day-and-a-half of discussion and debate between eyecare practitioners and the supporting industry, at which it was agreed that the eyes may not necessarily be ‘dry’, rather they may be causing symptoms of irritation, burning, stinging, etc. While 70% of those offering dry eye care are likely to recommend some form of treatment for symptomatic patients, just 25% of ‘community’ optometrists did so. This situation has been exacerbated by a general lack of awareness concerning the guidelines.Diabetes, allergies, CL wear, medications (especially antihistamines, decongestants, antidepressants, and antihypertensives), increasing age, and use of digital devices – which depress the blink rate by a factor of 10 and are used on average 10 hours a day – all raise the risk of contracting dry eye. Suitable screening questions include: ‘Do your eyes feel dry or uncomfortable?’, ‘Are you bothered by changes in your vision throughout the day?’, ‘Are you bothered by red eyes?’, and ‘Do you ever use, or feel the need to use, suitable eye drops?’{{quote-A:R-W:450-I:2-Q: Gaddie believes that most dry eye has an evaporative component from a faulty lipid or mucin layer, or perhaps both.”-WHO: Dr Ben Gaddie, Optometrist from Louisville}}Factors that warrant consideration include the condition and appearance of the eyelids, the presence of any staining of the ocular surface, and an assessment of the stability of the tear film.Gaddie believes that most dry eye has an evaporative component from a faulty lipid or mucin layer, or perhaps both. He and others also believe that there is an inflammatory component to dry eye. The most recent DEWS report included a new and more complex definition of MGD, describing it as a chronic abnormality of the Meibomian glands, characterised by obstruction of the duct outlet and accompanied by changes in the gland’s secretions.Gaddie discussed the possibility of using some existing therapeutic agents ‘off-label’, such as steroid/antibiotic combinations, topical antibiotics, and manual or automated therapeutic gland manipulation. For example, the LipiFlow syst – whose long-term efficacy he confirmed in a bar chart subsequently – resulted in a 3x improvent in gland secretion and a 50% reduction in symptoms. However, side effects of pharmacological treatments, such as raised IOP, need careful monitoring.Omega-3 supplentation was suggested as a way of improving the quality of the meibum secreted by the Meibomian glands. Gaddie quoted the findings of Lp et al. (2012) and said 14% of dry eye cases were due to aqueous deficiency, 86% MGD, and only 1% ‘other’. He also noted that completeness (lids touching each other in the closed position) of each blink was important to the secretory discharging process and significant failure can lead to atrophy of the glands. He went on to detail the usefulness of the new dichotomous InflammaDry MMP-9 detection test, but whether that test ever becomes available in Australia rains unknown.Theoretically, the most obvious indicator, albeit not diagnostic, is tear osmolality. However, quantifying that parameter can be costly and osmometers are not a common feature in general practice. In discussing treatment options, not all of which are available locally, Gaddie made the point that no treatment was a matter of 3–4 days only. Rather, regular repeat treatment and review was necessary at 6–8 week intervals.He summarised what is and is not known about MGD, which he described as being “extrely common”. While the presence of Dodex spp. was implicated, its prevalence or how much Dodex is required to produce symptoms is not well understood. Roseacea is a common cause of MGD and Dodex is a common cause of roseacea, and what was commonly thought of as blepharitis is probably the result of Dodex infestation.Another issue raised by Gaddie was that ocular allergy overlaps dry eye and MGD. Lid disease was given as a common cause of evaporative dry eye. Other unknowns include; the symptom level at which treatment is warranted; the breakdown of lipid or mucin aetiologies of dry eye; and effective and enduring treatments for MGD and Dodex. Importantly, cylindrical dandruff on lash filaments was said to be pathognomic of a Dodex infestation. While total elimination of Dodex was desirable, such an outcome is unrealistic. Instead, a large reduction in the ‘load’ of the arachnid was said to be a more realistic goal.Solving everyday BV problsMr Tim Fricke, a Melbourne-based international humanitarian optometrist, tackled recurring probls related to binocular vision (BV), specifically, non-strabismic accommodation-convergence probls. He described optometry as a pluralist profession, as its BV approaches can take the form of ‘conventional wisdom’, a behavioural approach, or evidence-based practice. Fricke chose the latter as the basis of his presentation and the one most likely to result in the correct intervention.The results of the Convergence Insufficiency Treatment Trial (CITT) showed that the use of a symptom survey was successful in detecting convergence insufficiency (CI) in children. To assess vergence facility, Gall et al. (1998) showed that a combination of 12 Base Out prism with three Base In prism was best and if the subject cannot sustain 15 cycles of prism introduction per minute they should be considered to have CI. Phoria measurents have been shown to be more repeatable if either a modified Thorington technique or a Prentice Phoria Card is used, whereas alternatives such as a Maddox rod or Maddox wing did not perform as well.Regardless of the method used, variations in phoria measurents must be expected. Quoting Dr Charles Sheard (circa 1930), Fricke said binocular fusion and visual comfort were enhanced when the base-out reserve is ≥2x any exo deviation. The amount of prism to be prescribed was suggested to be a quarter of the recovery value as determined in a blur, break [diplopia], recovery cycle.Shifting focus to accommodation and the potential use of a near addition, Fricke followed the research of Brautaset et al. (2009–2010) in Sweden and concluded that +1.00 D add was superior to +2.00, although both improved near vision comfort. The smaller add was found to improve accommodation skills whereas the higher add did not. Citing research by Horwood and Toor (2014), Fricke recommended that vergence be exercised independent of accommodation or proximity, and also accommodation independent of vergence or proximity. However, the concurrent exercising of both convergence and accommodation and proximity, as occurs in the traditional pencil-to-nose exercise for a deficient NPC, does not work.Interestingly, those who applied greater effort to suitable exercises were rewarded with better outcomes. A similar finding was correlated with instructor effort and diligence, suggesting that practitioners lacking enthusiasm and direct involvent are likely to be met with poorer outcomes. Therefore, it is important that only one facility (convergence, accommodation, or proximity) at a time be exercised, while practitioner and patient enthusiasm is required for an optimum outcome. Several studies suggest that home therapy executed properly is just as effective as in-office procedures.In a summary of prescribing prism, the CITT results suggest that base-in relief in children does not help, but may be of use in adult cases of CI. A possible exception is in cases of hyperopes with CI in whom the use of more plus power might make any pre-existing CI worse. Some base-in relief may be required.Also, improved vision and comfort resulting from successful treatment of CI has been shown to decrease adverse acadic behaviours and parental concerns associated with reading and schoolwork.

KEYNOTE SPEAKERS
Ho Wah Ng	Richard Lindsay	Tim Fricke	Jessica Chi

Silicone hydrogels in CL practiceExperienced Melbourne CL practitioner and sometime acadic Mr Richard Lindsay offered advice on the role of SiHy CLs in CL practice. He gave a brief overview of the history of the CL category, the various generations of materials, and the relationship between water content and Dk. He also revealed the broad range of BVPs now available and the expanding availability of daily disposable (DD) SiHy CLs, which now account for about 40% of the soft CL market. The Australian and NZ experience is that more than 75% of the soft CL market is SiHys. Although he is not convinced with custom SiHy CLs, sometimes his hand is forced, in which case he preferred the Contamac 74 material.Replacent rates are still subject to a wide range of opinions but Lindsay noted that the two-week category was in decline. However, when a one-month replacent rate is envisaged, he finds that some wearers struggle to make it that far. That being the case, his first suggestion is the routine use of a peroxide care syst.Quoting data from Nathan and Suzanne Efron, the break-even point for DDs versus other replacent modalities is now around 3–4 days per week, fewer uses and the DD work out more economical, more days of use see non-DD replacent more economical. DD CLs still have cost and environmental (packaging) considerations, but Lindsay did say that the decision to use DD CLs was the patient’s and not the practitioner’s, unless there was some pressing clinical reason for daily replacent of CLs.According to Lindsay, J&J’s one-day Oasys handles well, offers two BOZRs, and has torics in the pipeline. He also suggested fitting the flatter option in a CL series if dry eye or tear film issues are present as the flatter fit offers greater tear exchange. Other general advice included the fact that a CL material’s Young’s Modulus affects its fitting, mucin balls and SEALs are rarely seen with current SiHy CLs, most of the earlier lens care product compatibility issues have been resolved, and – despite all the advances in materials, CL designs, and physiological performances on offer – extended wear (EW) of SiHy and other CLs still has an attendant heightened, albeit low, risk of microbial keratitis (MK).{{quote-A:L-W:450-I:7-Q: Lindsay’s advice was to start with a spherical SIHY CL because the deformability of the diseased cornea prevents the prediction of final outcomes. -WHO:Mr Richard Lindsay, Melbourne CL practitioner}}If CL papillary conjunctivitis (CLPC) occurs in SiHy CL wearers, generally it is a milder form of that experienced with conventional hydrogel CLs. Also, if CLPC does occur, it is usually possible to continue CL wear with the aid of a topical mast cell stabiliser.Although continuous wear (CW) and EW are not popular with practitioners, flexi wear was suggested as a compromise that might have a lower risk of adverse events. It has been shown that SiHy CLs still have a greater risk of corneal inflammatory events (CIEs), however, SiHy CLs decrease the so-called myopic creep and cause fewer epithelial adhesions. They have also proved their worth in early keratoconus and as the foundation of a piggy-back CL syst.In keratoconus, Lindsay’s advice was to start with a spherical SiHy CL because the deformability of the diseased cornea prevents the prediction of final outcomes and often bears only a passing relationship to the vertex distance-corrected spectacle Rx. Relatively large unexpected changes in the spherical component of the spectacle Rx should be expected due to the conformability of the abnormal cornea.When fitting post-RK patients he recommended the use of high-modulus materials and flat fits. Regardless, neovascularisation of the RK incisions rains a probl. Conversely, he recommended a low modulus material and a steep fit if a proud graft was being fitted.Generally, in his experience, SiHy CLs can be fitted over corneal grafts successfully. However, if fluting occurs or a satisfactory fit cannot be achieved, the use of custom SiHy CLs might be required. SiHy CLs also have therapeutic uses in cases such as bullous keratopathy, Steven- Johnson syndrome, Thygeson’s SPK, RCE, etc. Finally, for EW, Lindsay recommended the use of a low modulus material and a loose fit.

More reading: Southern Regional Congress 2016: 950 delegates surprises organisers Part 1