Dr Laura Downie
BOptom PhD(Melb) PGCertOcTher FACO FAAO DipMus(Prac) AMusA
Study shows optometrist referrals are more comprehensive and legible than referrals written by ophthalmologists
When researchers in Canada conducted a cross-sectional study to assess the quality of referral letters to glaucoma specialists, they found that optometrist referrals contained more information and were relatively more legible than those of ophthalmologists. They also found that many clinicians often omitted vital information.
The study involved a survey of 135 glaucoma specialists and an audit of 200 consecutive referrals to a tertiary glaucoma unit. The survey asked respondents to detail what they considered the most important data to be included in a glaucoma referral. The referral letters were assessed with regard to their content on the basis of the survey results and information in current Canadian glaucoma guidelines.
Of the 200 referral letters, 46 per cent were from ophthalmologists, 42 per cent from optometrists, 10 per cent from family medical doctors and two per cent from other sources.
The top five most important data that glaucoma specialists suggested for inclusion in a referral letter for progressive glaucoma were serial visual fields (VFs), current glaucoma therapy, current intraocular pressure (IOP), maximum IOP and serial disc imaging.
Approximately one-quarter of referrals were illegible (18 per cent from ophthalmologists vs six per cent from optometrists, p < 0.01). Optometrists were more likely than ophthalmologists to provide visual acuity, IOP, refraction and VF details (p < 0.01 for each). Only 24 per cent of referrals for glaucoma progression included more than 10 of 14 information points suggested by glaucoma guidelines and 34 per cent included fewer than eight of 14 points.
Overall, optometrist referrals were more comprehensive and more legible than ophthalmologist referrals. Referrals to glaucoma specialists frequently did not include important information. The authors suggested that practitioners would benefit from having a check-list of clinical details when referring patients for specialist glaucoma care that includes maximum and current IOP, disc evaluation, serial VFs and serial disc imaging.
Ophthalmology 2014; 121: 1: 126-133
In vivo test confirm viability of drug-eluting contact lens
The concept of utilising contact lenses as a means of ocular drug delivery was proposed nearly 50 years ago but successfully achieving controlled release of therapeutic agents has remained a considerable challenge.
A recent paper described a drug-eluting contact lens designed for prolonged delivery of latanoprost for glaucoma treatment. The contact lens was created by encapsulating latanoprost-poly(lactic-co-glycolic acid) films in methafilcon by ultraviolet light polymerisation. In vitro and in vivo studies showed an early burst of drug release, followed by sustained release for at least one month.
Using an in vivo animal model, a single contact lens was able to achieve latanoprost concentrations in the aqueous humour that were comparable to those achieved with topical latanoprost eye-drops. The contact lens was reported to appear safe both in cell culture and animal studies.
The authors proposed that this contact lens design may offer a viable alternative to the current treatment of glaucoma with topical eye-drops and may also serve as an ocular drug delivery platform for treating other ocular diseases.
Biomaterials 2014; 35: 1: 432-439
Quality of social media for patients with glaucoma highly variable
Analysis confirms that social media platforms may be a useful adjunct to current ophthalmic care models by providing a supportive and educational online community—provided that their limitations are understood.
Researchers in the United Kingdom assessed the ophthalmic content of five social media platforms: the International Glaucoma Association (IGA) forum, Facebook, Twitter, YouTube and PatientOpinion.org.uk. A total of 3,785 items were scraped from the sites, collated and analysed using simple thematic analysis by two coders.
A total of 14 themes were identified. The most commonly discussed topics included treatments, care experiences, promotions and support. Unmoderated sites were found to contain misleading information. Complementary therapies and treatments with a poor evidence base were presented more positively than established, evidence-based treatments.
The authors concluded that while online forums provide patients with a space to air questions, grievances and suggestions, and to offer mutual support, there is a risk of exposure to misleading content which is heightened in unmoderated sites.
Ophthalmic Physiol Opt 2014; 34: 1: 46-52
IOP changes in medically-versus surgically-treated eyes
A study comparing posture-induced intraocular pressure (IOP) changes in (non-operated) medically-treated eyes versus previously trabeculectomised eyes with open angle glaucoma suggests that trabeculectomy may not only decrease IOP but may also reduce postural-related IOP deviations, compared with medical glaucoma intervention.
Post-trabeculectomised open angle glaucoma eyes with a cystic filtering bleb (n = 51) and medically-treated OAG eyes (n = 51) with a baseline IOP less than 12 mmHg were studied using Goldmann tonometry. IOP was measured in the sitting and lateral decubitus position (upper eye after five minutes) using an iCare rebound tonometer.
The study authors found that there was no significant difference in IOP between groups at baseline using Goldmann tonometry (p = 0.892) or in the sitting position using the iCare tonometer.
On average, a greater increase in IOP (+3.3 mmHg) was observed in the medically-treated group compared with the surgically-treated group (+1.00 mmHg, p < 0.001) for the lateral decubitus position.
Invest Ophthalmol Vis Sci 2014; Epub Jan 7 ahead of print
Habitual sleep positions may be associated with visual field loss
The results of a retrospective, cross-sectional study suggest that the sleep position habitually preferred by glaucoma patients may be associated with greater visual field loss.
The study sought to investigate the relationship between preferred sleeping position and asymmetric visual field loss, defined as a difference in mean deviation between eyes of at least 2dB, in open-angle glaucoma.
Patients (n = 692) with either bilateral normal tension glaucoma or high-tension glaucoma were consecutively enrolled. A questionnaire was used to determine preferred sleeping position.
Of the participants, 60.6 per cent with normal tension glaucoma and 66.5 per cent with high-tension glaucoma demonstrated asymmetric visual field loss between the two eyes. Among these normal tension glaucoma patients, approximately one-third preferred the lateral decubitus position; of these, 66 per cent preferred the worse-eye-dependent lateral decubitus position (p = 0.001).
Among the high-tension glaucoma patients, about one-quarter preferred the lateral decubitus position and of these 72 per cent preferred the worse-eye-dependent position (p = 0.013).
Am J Ophthalmol 2013; Epub Dec 14 ahead of print
Intraocular lens glistening in glaucomatous eyes
There is a relationship between the number of topical daily glaucoma medications that a patient uses and the degree of intraocular lens (IOL) glistening after cataract surgery, it has been shown.
The prospective study involved 67 consecutive glaucomatous eyes (47 patients) who previously had phacoemulsification with a hydrophobic acrylic IOL implanted in the capsular bag. IOL glistening was graded by severity: GO (< 50 micro-vacuoles per mm2), G1 (50-100 micro-vacuoles per mm2) and G2 (>150 micro-vacuoles per mm2). Eyes were examined for visual acuity, visual fields, contrast sensitivity and wave-front analysis of higher-order aberrations.
Grading of the degree of glistening was G0 for 39 per cent, G1 for 18 per cent and G2 for 43 per cent of eyes. The mean follow-up after cataract surgery was significantly higher for G1 and G2 groups compared with G0 eyes (p < 0.001). A higher number of topical glaucoma medications was associated with a higher IOL glistening grade (p < 0.05). G1 and G2 eyes had significantly lower mean contrast sensitivity at high spatial frequencies and significantly higher loss variance values on visual field testing (p < 0.05). There was no difference in visual acuity between groups (p > 0.05).
It was concluded that in glaucomatous eyes, IOL glistening increased with time and was significantly associated with the number of topical daily glaucoma medications being utilised. It was also suggested that because IOL glistening had some impact on visual performance, it should be a consideration in the management of glaucoma patients.
Acta Ophthalmol 2013; Oct 7 Epub ahead of print
FDT rates predictive of glaucoma progression
Rates of frequency doubling technology (FDT) pattern standard deviation (PSD) change were found to be predictive of the development of standard automated perimetry (SAP) visual field (VF) loss in patients suspected of having glaucoma.
The prospective, observational cohort study was conducted with the purpose of determining the utility of longitudinal frequency doubling technology (FDT) (Humphrey Matrix, Carl Zeiss Meditec Inc) to predict the development of glaucomatous visual field loss on standard automated perimetry (SAP) in glaucoma suspects.
This study included 587 eyes of 367 patients with suspected glaucoma (defined as IOP > 21 mmHg or an optic disc appearance suspicious of glaucoma, with normal or non-repeatable abnormal SAP) at baseline, selected from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES). The eyes had an average of 6.7 ± 1.9 FDT tests during a mean follow-up time of 73.1 ± 28.0 months. The study end-point was the development of three consecutive abnormal SAP test results.
Sixty-three (11 per cent) of eyes developed SAP visual field loss during follow-up. The mean rate of FDT pattern standard deviation (PSD) change in eyes that developed SAP visual field loss was 0.07 dB/year versus 0.02 dB/year in those that did not (p < 0.001). Baseline FDT PSD and slopes of FDT PSD change were significantly predictive of glaucomatous visual field progression, with hazard ratios of 1.11 per 0.1dB higher (95% CI: 1.04-1.18, p = 0.002) and 4.40 per 0.1 dB/year faster (95% CI: 1.08-17.96, p = 0.04), respectively.
The study authors concluded that longitudinal frequency doubling technology (FDT) evaluation may be useful for risk stratification for patients with suspected glaucoma.
Ophthalmology 2013; Epub Nov 26 ahead of print