Ultra-widefield fundus fluorescein angiography in the diagnosis and management of retinal vasculitis.

PurposeTo quantify the additional information provided by ultra-widefield fluorescein angiography, compared with 7-field standard imaging, in patients with retinal vasculitis (RV).Patients and methodsRetrospective case series of 106 patients.ResultsRetinal vascular pathology was identified by UWF FFA, but not by standard ETDRS 7-field area, in 62 patients (58.5%) and in 79 eyes (43.4%). The pathology included active RV (47 eyes, 25.8% of eyes); retinal ischaemia, or infarction (53 eyes, 29.1%); and retinal neovascularization (7 eyes, 3.8%). A change to management was made in 36 patients (34%). Of these, 21 (20% of all patients undergoing angiography) were made after the identification of retinal vascular pathology, which was found only on UWF FFA, outside the ETDRS area.ConclusionUltra-widefield fluorescein angiography has clear advantages over standard multi-field imaging. It is currently the standard method of assessment for RV in this centre.

Electronic retinal implants and artificial vision: journey and present.

Retinitis pigmentosa and age-related macular degeneration are two significant causes of severe visual dysfunction. In both, the retinal photoreceptors degenerate, preventing successful conversion of light into electrical energy that is interpreted in the visual cortex as visual function. Artificial vision or visual function began over two centuries ago with the idea of creating artificial light pulses, or phosphenes, through cortical stimulation. The pursuit is now on to improve artificial visual function. Two retinal implants appear the most likely to succeed in the future having undergone multicentre human trials: the Argus II electronic epiretinal device (Second Sight Medical Products, CA, USA) and Alpha-IMS electronic subretinal device (Retina Implant AG, Germany). The trial results to date are encouraging with visual improvement and acceptable safety profiles reported for both devices. At present, the visual function generated by either device does not offer high enough resolution or acuity for a patient to regain a fully functional life. Despite this, both devices not only have the potential, but have actually improved the vision-related quality of life in a significant number of patients implanted. With this in mind, the economic argument is clear. Provided device-life is long enough, its cost should be acceptable for the obtained improvement in the quality of life. The aim of this Review Article is to assist those readers that may be considering offering any of these devices as a treatment for blindness in Retinitis Pigmentosa.

Pascal panretinal laser ablation and regression analysis in proliferative diabetic retinopathy: Manchester Pascal Study Report 4.

AIMS: To quantify the 20-ms Pattern Scan Laser (Pascal) panretinal laser photocoagulation (PRP) ablation dosage required for regression of proliferative diabetic retinopathy (PDR), and to explore factors related to long-term regression. METHODS: We retrospectively studied a cohort of patients who participated in a randomised clinical trial, the Manchester Pascal Study. In all, 36 eyes of 22 patients were investigated over a follow-up period of 18 months. Primary outcome measures included visual acuity (VA) and complete PDR regression. Secondary outcomes included laser burn dosimetry, calculation of retinal PRP ablation areas, and effect of patient-related factors on disease regression. A PDR subgroup analysis was undertaken to assess all factors related to PDR regression according to disease severity. RESULTS: There were no significant changes in logMAR VA for any group over time. In total, 10 eyes (28%) regressed after a single PRP. Following top-up PRP treatment, regression rates varied according to severity: 75% for mild PDR (n=6), 67% for moderate PDR (n=14), and 43% in severe PDR (n=3). To achieve complete disease regression, mild PDR required a mean of 2187 PRP burns and 264 mm(2) ablation area, moderate PDR required 3998 PRP burns and area 456 mm(2), and severe PDR needed 6924 PRP laser burns (836 mm(2); P<0.05). CONCLUSIONS: Multiple 20-ms PRP treatments applied over time does not adversely affect visual outcomes, with favourable PDR regression rates and minimal laser burn expansion over 18 months. The average laser dosimetry and retinal ablation areas to achieve complete regression increased significantly with worsening PDR.

High-resolution hyperspectral imaging of the retina with a modified fundus camera.

PURPOSE: to examine the practical feasibility of developing a hyperspectral camera from a Zeiss fundus camera and to illustrate its use in imaging diabetic retinopathy and glaucoma patients. METHODS: the original light source of the camera was replaced with an external lamp filtered by a fast tunable liquid-crystal filter. The filtered light was then brought into the camera through an optical fiber. The original film camera was replaced by a digital camera. Images were obtained in normals and patients (primary open angle glaucoma, diabetic retinopathy) recruited at the Manchester Royal Eye Hospital. RESULTS: a series of eight images were captured across 495- to 720-nm wavelengths, and recording time was less than 1.6s. The light level at the cornea was below the ANSI limits, and patients judged the measurement to be very comfortable. Images were of high quality and were used to generate a pixel-to-pixel oxygenation map of the optic nerve head. Frame alignment is necessary for frame-to-frame comparison but can be achieved through simple methods. CONCLUSIONS: we have developed a hyperspectral camera with high spatial and spectral resolution across the whole visible spectrum that can be adapted from a standard fundus camera. The hyperspectral technique allows wavelength-specific visualization of retinal lesions that may be subvisible using a white light source camera. This hyperspectral technique may facilitate localization of retinal and disc pathology and consequently facilitate the diagnosis and management of retinal disease.

Pain responses of Pascal 20 ms multi-spot and 100 ms single-spot panretinal photocoagulation: Manchester Pascal Study, MAPASS report 2.

AIMS: To evaluate pain responses following Pascal 20 ms multi-spot and 100 ms single-spot panretinal photocoagulation (PRP). METHODS: Single-centre randomised clinical trial. 40 eyes of 24 patients with treatment-naive proliferative diabetic retinopathy randomised to 20 and 100 ms PRP under topical 0.4% oxybuprocaine. A masked grader used a pain questionnaire within 1 h (numerical pain score (NPS)) and 1 month after treatment (numerical headache score (NHS)). Primary outcome measure was NPS immediately post-PRP. Secondary outcome measures were mean NHS scores and levels of photophobia reported within 4 weeks of primary PRP. RESULTS: Mean laser fluence was significantly lower using 20 ms PRP (4.8 J/cm²) compared to 100 ms PRP (11.8 J/cm²); p < 0.001). Mean NPS scores for treatment were 2.4 (2.3) (mild) for 20 ms PRP group compared to 4.9 (3.3) (moderate) in 100 ms PRP group-a significant difference (95% CI 4.3 to 0.68; p = 0.006). Mean NHS score within 1 month was 1.5 (2.7) in 20 ms PRP group compared to 3.2 (3.5) in the 100 ms PRP group (p < 0.05). The median duration of photophobia after 20 ms PRP was 3 h, and significantly less compared to 100 ms PRP after which 72 h of photophobia was reported (p < 0.001). CONCLUSIONS: Multi-spot 20 ms PRP was associated with significantly lower levels of anxiety, headache, pain and photophobia compared to 100 ms single-spot PRP treatment. Possible reasons include lower fluence, shorter-pulse duration, and spatial summation of laser nociception with multi-spot Pascal technique.

Effects of conventional argon panretinal laser photocoagulation on retinal nerve fibre layer and driving visual fields in diabetic retinopathy.

AIMS: To determine the effects of argon green panretinal laser photocoagulation on retinal nerve fibre layer thickness, threshold visual fields, and Estermann full-binocular visual fields over time in diabetic retinopathy. METHOD: Prospective, pilot clinical study. Time-domain optical coherence tomography (TD-OCT) of the optic nerve head and 24-2 SITA-Fast Humphrey/Estermann visual fields (HVF, EVFs) recorded at baseline, 10 weeks, and 6 months post laser. Quantitative field analysis of central 10 degrees, 24 degrees, and binocular visual fields. RESULTS: A total of 10 eye samples were subjected to uncomplicated multiple-session 100 ms panretinal laser using 2000 burns, 300-microm spot, and mean power of 136 mW (SD+/-39.3). TD-OCT detected and quantified an increase in mean retinal nerve fibre layer thickness at 10 weeks (+8 microm; P<0.05) and progressive thinning at 6 months (-4 microm; P<0.05) compared with baseline. Mean threshold sensitivities, and 10 degrees and 24 degrees HVF improved at both time points in the majority (9 of 10 and 8 of 10) of patients. EVFs showed no significant change with treatment. CONCLUSIONS: This pilot study shows that conventional argon laser panretinal photocoagulation may increase the retinal nerve fibre layer thickness in the short term, presumably related to laser-induced axonal injury, with progressive thinning of nerve fibre layer over the long term. The 10 degrees and 24 degrees visual fields improved significantly after laser with no adverse effects on the UK standard driving fields.

Fundus autofluorescence and Fourier-domain optical coherence tomography imaging of 10 and 20 millisecond Pascal retinal photocoagulation treatment.

AIM: To report the evolution of pattern scanning laser (Pascal) photocoagulation burns in the treatment of diabetic retinopathy, using Fourier-domain optical coherence tomography (FD-OCT) and fundus autofluorescence (AF), and to evaluate these characteristics with clinically visible alterations in outer retina (OR) and retinal pigment epithelium (RPE). METHODS: Standard red-free and colour fundus photography (FP), FD-OCT, and fundus camera-based AF were performed in 17 eyes of 11 patients following macular and panretinal photocoagulation (PRP). RESULTS: One hour following Pascal application, visibility of threshold burns on FP was incomplete. AF enabled visualisation of complete treatment arrays at 1 h, with hypoautofluorescence at sites of each laser burn. AF signals accurately correlated with localised increased optical reflectivity within the outer retina on FD-OCT. AF signals became hyperautofluorescent at 1 week, and corresponded on FD-OCT to defects at the junction of the inner and outer segments of the photoreceptors (JI/OSP) and upper surface of RPE. A 10 ms macular laser pulse produced a localised defect at the level of JI/OSP and RPE. Macular and 20 ms PRP burns did not enlarge at 1 year's and 18 months' follow-up respectively. CONCLUSIONS: We report the in vivo spatial localisation and clinical correlation of medium-pulse Pascal photocoagulation burns within outer retina and RPE, using high-resolution FD-OCT and AF. Ophthalmoscopically invisible and threshold Pascal burns may be accurately localised and mapped by AF and FD-OCT, with monitoring over time.

Initial experience with the Pascal photocoagulator: a pilot study of 75 procedures.

BACKGROUND: The Pascal is a semiautomated photocoagulator that delivers a pattern array of multiple burns in a rapid predetermined sequence with a single foot pedal depression. Each burn is reduced to 10 or 20 ms to achieve this. The authors report their early experience with this system. METHODS: 75 procedures done in 60 patients divided into four groups-group A, patients undergoing panretinal photocoagulation (PRP); group B, patients undergoing focal or modified grid macular laser; group C, patients undergoing macular grid and group D, patients undergoing retinopexy-were retrospectively studied. RESULTS: 31/34 procedures in group A, 24/26 procedures in group B, 5/7 procedures in group C and all eight patients in group D had successful outcomes. Significantly higher powers were required with the Pascal than with conventional laser (p<0.001) in eyes that underwent PRP and focal/modified grid macular treatment with both systems. Single session PRP was successfully performed in five patients, and five were successfully treated with a macular grid using pattern arrays only. No adverse events were noted. CONCLUSION: Although the shorter pulse duration of the Pascal necessitates the use of a higher power, it is not associated with adverse effects. The results here suggest that the Pascal photocoagulator is safe and effective, and offer several potential advantages related to the brief exposure time.

Retinal pigment epithelium translocation and central visual function in age related macular degeneration: preliminary results.

PURPOSE: To test the feasibility of a new surgical technique, and to assess visual function over the translocated retinal pigment epithelium (RPE) cells in patients operated upon for subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). MATERIALS AND METHODS: Six patients presenting previously untreated exudative AMD underwent surgical excision of the subfoveal CNV with RPE translocation and were followed from 1 to 10.5 months. The surgery consisted of a standard three port pars plana vitrectomy (TPPPV), excision of the CNV and RPE translocation. Pre and post-operative ocular examination included best-corrected visual acuity measurement, fundus color stereo photography and fundus fluorescein angiography. Optical coherence tomography (OCT) and confocal laser scanning ophthalmoscopy (cLSO) were performed post-operatively. A cross fixation target and a single-point flashing light were projected on different areas of the posterior pole using a cLSO. Photopic 10-2 perimetry, photopic fine matrix mapping, cLSO microperimetry were also performed pre and post-operatively in four patients. OCT cross-sectional scans and cLSO RPE autofluorescence were recorded to detect the presence of viable translocated RPE. Visual acuity, fixation, photopic 10-2 perimetry, photopic fine matrix mapping and cLSO microperimetry were tested for the presence of central visual function. RESULTS: RPE could be effectively translocated at the time of CNV removal from the edge of the RPE defect to a subfoveal location. OCT showed the translocated RPE as an area of increased optical reflectivity with optical shadowing external to it. cLSO showed autofluorescence of the translocated RPE. The cross fixation target was seen when projected on the translocated RPE. During eccentric fixation, the patients could see a flashing point-target projected on the translocated RPE. Photopic 10-2 perimetry, photopic fine matrix mapping and cLSO microperimetry showed presence of central visual function. CONCLUSIONS: The authors propose that translocation of RPE at the time of CNV removal, from the edge of the RPE defect to a subfoveal location, may have a role in the surgical management of AMD.