Treatment decisions of UK hospital optometrists and ophthalmologists in patients with nAMD: a vignette study.

PURPOSE: A vignette study to examine treatment decisions made by UK hospital optometrists in patients with neovascular age-related macular degeneration (nAMD) and the effect of optometrists' experience on agreement. METHODS: Patients with nAMD attending Manchester Royal Eye Hospital, Manchester, UK were identified as potential candidates for the case series of vignettes. The cases were chosen to reflect a varied case-mix with respect to difficulty as well as ensuring good quality of the images. Each vignette included a history summary consisting of the number of previous injections given and visual acuity measurements at baseline, the previous visit, and the current visit. Images were compiled to show baseline fundus photographs and ocular coherence tomography (OCT) images with the current visit images on which the treatment decision was to be made along with the images from the previous visit. Hospital optometrists were recruited and asked to complete the series of vignettes, deciding if treatment was required at that visit and how confident they felt with that decision. Their responses were compared to the reference standard created by a consensus of consultant ophthalmologists with a sub-speciality interest in medical retina. RESULTS: Regarding treatment decision for optometrists, the percentage correct value was 75% with the sensitivity being 75.6% (95% CI 70.1-80.3) and the specificity as 75.1% (95% CI 72.1-77.8). No statistically significant difference was found between differing levels of experience. However, there was a significant difference in confidence levels between groups. Potentially sight threatening decisions accounted for 6.4% of the optometrists' decisions, 3.5% were made with a high confidence rating suggesting no discussion with an ophthalmologist was required. CONCLUSIONS: Although the optometrists showed modest agreement with the reference standard in a series of cases that have higher than average complexity, the optometrists showed a similar amount of variability within their treatment decisions compared to the reference standard. The optometrists were therefore not inferior in their performance compared to the ophthalmologists and this can be seen as supporting evidence for their extended role within this clinical area. Experience did not have an effect on 'correct' treatment decisions although there was a statistically significant effect on increasing confidence of treatment decision.

Optos-guided pattern scan laser (Pascal)-targeted retinal photocoagulation in proliferative diabetic retinopathy.

PURPOSE: To investigate the clinical effects and safety of targeted pattern scan laser (Pascal) retinal photocoagulation (TRP) in proliferative diabetic retinopathy (PDR). METHODS: Prospective and non-randomized study of 28 eyes with treatment-naive proliferative diabetic retinopathy (PDR). Single-session 20-ms-Pascal TRP strategy applied 1500 burns to zones of retinal capillary non-perfusion and intermediate retinal ischaemia guided by wide-field fluorescein angiography (Optos). Main outcome measures at 12 and 24 weeks included; PDR grade (assessed by two masked retina specialists); central retinal thickness (CRT); mean deviation (MD) using 24-2 Swedish interactive threshold algorithm (SITA)-standard visual fields (VF); and ETDRS visual acuity (VA). RESULTS: Following primary TRP, there was PDR regression in 76% of patients at 12 weeks (κ = 0.70; p < 0.001). No laser re-treatment was required at 4 weeks, and 10 eyes underwent repeat TRP at 12 weeks. Wide-field Optos angiography at 24 weeks showed complete disease regression in 37% and partial regression in 33%. Additional panretinal laser photocoagulation (PRP) was planned for active PDR in 30%. There were significant reductions in CRT over time (10.4 µm at 12-weeks, p = 0.007; 12.1 µm at 24-weeks, p = 0.0003). The MD on VFs improved after 12 weeks (+1.25 dB; p = 0.015) and 24 weeks (+1.26 dB, p = 0.01). The VA increased by +3 letters at 24 weeks (95% CI, 1.74-5.01; p < 0.0001). CONCLUSIONS: This pilot study reports that Optos-guided Pascal 20-ms TRP using 1500 burns for treatment-naive PDR is a promising procedure with favourable safety profile.

Pilot randomised clinical trial of Pascal TargETEd Retinal versus variable fluence PANretinal 20 ms laser in diabetic retinopathy: PETER PAN study.

PURPOSE: To investigate the short-term effects of high-density 20-ms laser on macular thickness using Pascal-targeted retinal photocoagulation (TRP) and reduced fluence/minimally-traumatic panretinal photocoagulation (MT-PRP) compared to standard-intensity PRP (SI-PRP) in proliferative diabetic retinopathy (PDR). METHODS: Prospective randomised clinical trial. Treatment-naive PDR was treated with single-session 20-ms Pascal 2500 burns photocoagulation randomised to one of three treatment arms (TRP:MT-PRP:SI-PRP). Primary outcome measure was change in central retinal thickness (CRT) on OCT. Secondary outcomes at 4 and 12 weeks post-laser included: OCT peripapillary nerve fibre layer (NFL) thickness; PDR disease regression on Optos angiography; SITA-Std visual fields (VF); and, visual acuity (VA). RESULTS: 30 eyes of 24 patients were studied, ten eyes/arm. At 12 weeks, there were significant reductions in CRT after TRP (9.6 µm; 95% CI, 1.84 to 17.36; p=0.021) and MT-PRP (17.1 µm; 95% CI, 11 to 23.2; p=0.001), versus SI-PRP (+5.9 µm; 95% CI, -6.75 to 18.55; p=0.32). PDR regression was similar between groups (TRP 70%; MT-PRP 70%; SI-PRP 90%; κ=0.76). No significant changes in VA and NFL thickness developed between groups. The VF mean deviation scores increased significantly in all groups at 12 weeks ([TRP, +0.70dB; 95% CI, 0.07 to 1.48; p=0.07], [MT-PRP, +0.63dB; 95% CI, 0.12 to 1.15; p=0.02], [SI-PRP, +1.0dB; 95% CI, 0.19 to 1.74; p=0.02]). There were no laser-related ocular complications. CONCLUSIONS: This pilot study reports that high-density 20-ms Pascal TRP and MT-PRP using 2500 burns did not produce increased macular thickness or any ocular adverse events during the short-term.

The impact of axial length on retinal tamponade for gas, silicone oil, and heavy silicone oil, using an in vitro model.

BACKGROUND: To investigate whether ocular axial length influences the tamponade efficacy of three commonly used agents: gas, silicone oil, and heavy silicone oil. METHODS: A series of filling experiments was conducted using 19-mm and 25-mm surface-modified spherical model eye chambers to mimic the vitreous cavity. For each agent, tamponade efficacy was assessed across a range of percentage fills, and comparison was made between the two model eye chambers. The behavior of each tamponade agent was quantified by measuring (1) the maximum height of the tamponade bubble, and calculating (2) the arc of retinal contact subtended by the tamponade bubble. RESULTS: Polynomial regression analysis found no statistically significant difference between the regression models for the different-sized model eye chambers for bubble height or arc of retinal contact subtended. This applied to all of the tamponade agents under investigation. CONCLUSIONS: Across the range of cavity sizes under investigation, no significant difference in tamponade efficacy (as reflected by the measured dimensions of the tamponade bubble) was identified.

Fourier-domain optical coherence tomography imaging of gas tamponade following macular hole surgery.

In this prospective study, the authors report fourier-domain optical coherence tomography (FD-OCT) imaging of gas-inner retinal tamponade following surgery for full-thickness macular hole and evaluate postoperative posturing based on FD-OCT findings. Patients underwent FD-OCT 1 day after pars plana vitrectomy, internal limiting membrane peel, and gas injection. Three-dimensional FD-OCT and high-resolution line scans demonstrated gas-inner retinal tamponade across the macula with the apex of tamponade located at the fovea. Inner and outer retina landmarks could be accurately identified along the curvature of the eye using FD-OCT in x-, y-, and z-planes. No patients required face-down positioning postoperatively based on FD-OCT findings. Satisfactory gas-inner retinal tamponade with 75% fill of any gas agent in the upright position was observed. Full-thickness macular hole closure was successful in 90% at 1 day, 2 weeks, and 12 weeks postoperatively. These FD-OCT findings may support decisions to not require face-down positioning postoperatively.

Barely visible 10-millisecond pascal laser photocoagulation for diabetic macular edema: observations of clinical effect and burn localization.

PURPOSE: To investigate the morphologic features and clinical efficacy of barely visible Pascal (Optimedica Corporation) photocoagulation burns in diabetic macular edema (DME) using Fourier-domain optical coherence tomography (FD OCT) and fundus autofluorescence (AF). DESIGN: Interventional case series. METHODS: Retrospective evaluation of 10 eyes with newly diagnosed DME that underwent barely visible Pascal photocoagulation using an array of 10-microm, 10-millisecond photocoagulation burns. FD OCT and camera-based AF was performed at baseline and at 1 hour, 2 weeks, 4 weeks, and 12 weeks after laser. Changes in retinal thickening after laser treatment were measured using retinal thickness maps within the treated sector and the central foveal subfield. RESULTS: At 1 hour after treatment, burns were visualized partially with clinical biomicroscopy. AF demonstrated spots lacking autofluorescence that confirmed effective laser uptake within the Pascal arrays. Sequential changes in hyperreflectivity on FD OCT correlated with morphologic alterations seen on AF. Burns became increasingly hyperautofluorescent between 2 and 4 weeks. There were significant reductions in the retinal thickness within treated sectors on FD OCT at 2 weeks (26 +/- 32 microm; P = .012) and 3 months after laser (20 +/- 21 microm; P = .02) compared with baseline. Clinical biomicroscopic reduction of DME was the most common finding in 80%. CONCLUSIONS: Barely visible 10-millisecond Pascal laser seems to produce an effect at the level of the inner and outer photoreceptor segments and apical retinal pigment epithelium, with minimal axial and lateral spread of burns. FD OCT confirmed spatial localization of AF signal changes that correlated with laser burn-tissue interactions over 3 months. The technique of lower-fluence barely visible 10-millisecond laser may reduce retinal edema within affected sectors and effectively treat DME with minimization of scar formation.

Single-session vs multiple-session pattern scanning laser panretinal photocoagulation in proliferative diabetic retinopathy: The Manchester Pascal Study.

OBJECTIVE: To investigate the effects of pattern scanning laser (Pascal; OptiMedica, Santa Clara, California) multispot panretinal photocoagulation given in a single-session (SS-PRP) vs single-spot multiple-session PRP (MS-PRP) on proliferative diabetic retinopathy (PDR). METHODS: Single-center, randomized clinical trial of 40 eyes. Proliferative diabetic retinopathy was treated with a 400-mum spot size in 1500 burns given either as Pascal in 20-millisecond SS-PRP or in 3 sessions (100-millisecond MS-PRP) during a 4-week period. Visual acuity, central subfield retinal thickness (CRT), and 24-2 Swedish interactive thresholding algorithm visual fields were recorded at baseline and 4 and 12 weeks. MAIN OUTCOME MEASURES: Central subfield retinal thickness, mean deviation, and PDR grade at 12 weeks. RESULTS: There was a significant increase in mean CRT with MS-PRP (22 mum at 4 weeks, 95% CI, -32.25 to -10.75; 20 mum at 12 weeks, 95% CI, -28.75 to -10.82; P < .001) and no significant increase in the SS-PRP group. The mean deviation increased significantly in the SS-PRP group after 4 weeks (0.73 dB, P = .048), with no significant changes in either group at other points. A positive effect on PDR was observed in 74% of eyes in the SS-PRP group vs 53% in the MS-PRP group (P = .31). Mean treatment time for SS-PRP was 5.04 minutes (SD, 1.5 minutes) compared with 59.3 (SD, 12.7 minutes) in the MS-PRP group (P < .001). CONCLUSIONS: There were no adverse outcomes (CRT, visual acuity, or visual field) from using multispot SS-PRP vs single-spot MS-PRP at 12 weeks postlaser, and treatment times were significantly shorter for multispot SS-PRP. Pascal SS-PRP was as effective as MS-PRP in the treatment of PDR. APPLICATION TO CLINICAL PRACTICE: Twenty-millisecond Pascal SS-PRP may be safely and rapidly performed in 1500 burns with a similar efficacy to conventional MS-PRP. TRIAL IDENTIFIER: Research and Development Office PIN R00037, Central Manchester University Hospitals Foundation Trust.

In vivo laser-tissue interactions and healing responses from 20- vs 100-millisecond pulse Pascal photocoagulation burns.

OBJECTIVES: To compare in vivo burn morphologic features and healing responses of Pascal 20- and 100-millisecond panretinal photocoagulation (PRP) burns in proliferative diabetic retinopathy. DESIGN: Prospective randomized controlled trial with 24 eyes assigned to either 20- or 100-millisecond Pascal PRP. Fundus autofluorescence and Fourier domain optical coherence tomography (FD-OCT) were performed 1 hour and 2 and 4 weeks after treatment. Main outcome measures included burn morphologic features on FD-OCT and greatest linear diameter (GLD) of laser burns as evaluated in 6 standard Early Treatment of Diabetic Retinopathy Study photographic fields using autofluorescence. RESULTS: The contemporaneous increase in autofluorescence is observed with increasing pulse duration. Differences in mean GLD between 100- and 20-millisecond burns were 63 mum at 1 hour and 198 mum at 4 weeks (P < .001 for both). At 4 weeks, all burns corresponded to defects at the junction of inner and outer segments of photoreceptors (JI/OSP) and apical retinal pigment epithelium. After 4 weeks, the GLD of 20-millisecond burns reduced significantly by 35% (P < .001), with no change in 100-millisecond burns. CONCLUSIONS: All burns initially appear as equivalent square-edged, columnar foci of hyperreflectivity in the outer retina. Pascal 20-millisecond burns progressively reduce in size, and this suggests a novel healing response localized to the JI/OSP and apical retinal pigment epithelium. The higher-fluence 100-millisecond burns develop larger defects due to thermal blooming and collateral damage.

Fourier-domain optical coherence tomography imaging of gas tamponade following macular hole surgery.

In this prospective study, the authors report fourier-domain optical coherence tomography (FD-OCT) imaging of gas-inner retinal tamponade following surgery for full-thickness macular hole and evaluate postoperative posturing based on FD-OCT findings. Patients underwent FD-OCT 1 day after pars plana vitrectomy, internal limiting membrane peel, and gas injection. Three-dimensional FD-OCT and high-resolution line scans demonstrated gas-inner retinal tamponade across the macula with the apex of tamponade located at the fovea. Inner and outer retina landmarks could be accurately identified along the curvature of the eye using FD-OCT in x-, y-, and z-planes. No patients required face-down positioning postoperatively based on FD-OCT findings. Satisfactory gas-inner retinal tamponade with 75% fill of any gas agent in the upright position was observed. Full-thickness macular hole closure was successful in 90% at 1 day, 2 weeks, and 12 weeks postoperatively. These FD-OCT findings may support decisions to not require face-down positioning postoperatively.