Evidence to know Flashcards
MPS
Macular Photocoagulation study: Purpose: To evaluate laser treatment of CNV through three sets of RCTs 1) Argon for extrafoveal CNV in the prevention or delay of central vision loss in three underlying conditions (AMD, POH, and INVM) 2) Kryton red photocoag for parafoveal CNV beneficial in the prevention or delay of visual acuity in patients with three underlying conditions (AMD, POH, and INVM; each with separate trials). 3) Does laser photocoagulation prevent or delay of further visual acuity loss in patient with new or recurrent CNV under the center of the FAZ. In each RCT of each MPS group, focal laser photocoagulation was compared to observation without treatment - Visual symptoms attributable to macular lesion (e.g. decreased VA, Amsler grid distortion) - Visible, well-demarcated hyperfluorescence consistent with classic CNV on FA - Eligibility criteria for each condition: o AMD: >50 years old, drusen in macula in >1 eye o POH: >18 years old, one characteristic histo spot in >1 eye o INVM: >18 years old, no evidence of AMD, POH, angioid streaks, high myopia, DR, or other identifiable cause of CNV - Additional eligibility criteria for each study: o Argon Study: Clinical serous RD with diffuse area of leakage and discrete extrafoveal CNV, VA>20/100 in study eye o Krypton Study: CNV with blood/pigment extending into the CNV; posterior border of CNV extend as close as 1 micron to FAZ center; VA>20/400 o Foveal Study: AMD patients only. FA showing leaking CNV extending under center of FAZ, or CNV consisting of old laser treatment scar and contiguous leaking CNV within 150 microns from center of FAZ. New, never-treated subfoveal lesions 20/230. Results: Argon Study: All trials (AMD, POH, INVM) halted early due to dramatic reduction in severe VA loss with argon laser treatment Krypton Study: Beneficial effect for krypton red laser treatment in eyes with AMD, most pronounced in normotensive patients (not apparent among pts with HTN). POH patients with significant benefit from krypton red laser Results in INVM patients were intermediate between AMD and POH. Foveal Study: Generally, eyes with AMD and subfoveal CNV benefitted from laser Initially, laser-treated eyes had immediately lost more vision than observed eyes; this loss was similar to the untreated group at 12 months Conclusions: For patients with well-demarcated classic CNV from AMD, POH, or INVM, treatment with laser photocoagulation, performed according to MPS guidelines, had better visual prognosis Likewise, patients with extrafoveal and juxtafoveal CNV from AMD, POH, or INVM had better visual prognosis with laser photocoagulation. Eyes with AMD and subfoveal CNV: Eyes with smaller lesion and worse initial VA had greater and earlier benefits of laser treatment Eyes with large subfoveal CNV lesions and good initial VA are not good candidates for focal laser photocoagulation
DRS
Diabetic Retinopathy Study (DRS) Does PRP (argon or xenon arc) prevent severe vision loss in eyes with diabetic retinopathy? Patients were included in the study if they had PDR in at least one eye or severe NPDR in both eyes, and had VA of 20/100 or better in each eye. Severe NPDR was defined as the presence at least 3 of the following: 1. Cotton wool spots 2. Venous beading 3. Intraretinal microvascular abnormalities (IRMA) in at least 2 contiguous overlapping photographic fields 4. Moderate-to-severe retinal hemorrhages and/or MA’s Patients were excluded if they had undergone previous PRP or had a macula-threatening TRD. This was a randomized, prospective multicenter clinical trial. 1742 study subjects were enrolled. One eye from each subject was randomly assigned to PRP and the other eye assigned to no PRP. The PRP eyes were randomized to either argon blue-green laser (800-1600, 500 micron spots) or xenon arc (200-400, 4.5 degree spots). The primary outcome measure was severe vision loss, defined as VA < 5/200 on two consecutive follow-up exams, 4 months apart. RESULTS: PRP reduced the risk of severe vision loss by at least 50% as compared to untreated control eyes. The greatest benefit was seen in eyes with high-risk PDR. Study follow-up was over 5 years. High-risk PDR was defined as any one of the following: 1. NVD ≥ 1/3 disc area 2. Any NVD with vitreous hemorrhage 3. NVE ≥ ½ disc area with vitreous hemorrhage High-risk PDR was also defined as three or more of the following high-risk characteristics (HRC’s): 1. Presence of vitreous hemorrhage or pre-retinal hemorrhage 2. Presence of any active neovascularization 3. Location of neovascularization on or within one disc diameter of the optic disc 4. NVD > 1/3 disc area or NVE > ½ disc area Eyes with high-risk PDR had significantly greater risk of severe visual loss and demonstrated the greatest benefit from PDR. No clear benefit was demonstrated for PRP in eyes with severe NPDR or in eyes with PDR without high-risk characteristics. Risks of treatment include small reductions in visual acuity or visual field. Harmful effects of argon laser treatment were less than those seen with xenon arc treatment. In the argon laser treatment group, a decrease in VA of 1 or more lines was seen in 11% of eyes; visual field loss was seen in 5%. CONCLUSIONS: PRP reduces the risk of severe vision loss compared with no treatment in eyes with high-risk PDR. Eyes with high-risk PDR should receive prompt treatment with PRP. Eyes with two or fewer high risk characteristics (HRC’s) still benefit from PRP, but the benefit is small and risks of treatment may outweigh the benefits. However, consider earlier treatment with PRP for older-onset diabetic patients.
TAP +VIM + VIP
Treatment of AMD with PDT: AMD and subfoveal classic CNV and vision 20/50 - 20/200. q3mos visits. Stable or improved vision at 12 mos: 61% treated 46% placebo, 24mos 53% treated 37% placebo Study showed that predominantly classic lesions derived greatest benefit. VIM: Visudyne in minimally classic CNVM
VIP: PDT for all types of CNVM
Defn: Classic CNVM
IVFA description: area of bright fairly uniform hyper fluorescence early in FA that inesifies throughout transit and leaks late obscuring the boundaries of the lesion
Defn: Predominantly Classic CNVM, minimally classic and occult with no classic.
Predom Classic: Classic CNV occupies more than 50%, Minimally classic: 1-49% is classic occult with no classic: duh.
Defn: Occult CNVM
2 types: Fibrovascular PED: irregular elevation of RPE with stippled or granular fluorescence. progressive leakage from lesion in a stipped fashion that is not as uniform as classic CNV. Late leakage from an undetermined source refers to regions not associated with other CNV on FA that leak late.
MARINA
Monthly ranabizumab
ANCHOR
Comparison of lucentis to PDT for predominantly classic CNVM.
CVOS
DRVS
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BVOS
The Branch Vein Occlusion Study (BVOS) was a multi-center, randomized, controlled trial to determine the efficacy of: (1) Argon macular grid laser in treating macular oedema secondary to branch vein occlusion (reference 1) (2) Sectoral argon scatter PRP in the distribution of the vein occlusion for prevention of neovascularisation and vitreous haemorrhage (reference 2) Outcome 1 - Efficacy of Macular Grid Laser: Results were published in American Journal of Ophthalmology (see reference 1). Patients were included if there was documented branch vein occlusion, visual acuity was 20/40 or less and there was angiographic evidence of macular oedema. Patients were randomly assigned to treatment or control (no treatment) arms. In the treatment group, burns of 50-100 micrometers in diameter with exposure of 0.05 to 0.1 seconds were applied in a grid pattern to the macula - with burns no closer to the fovea than the edge of the foveal avascular zone and extending no further than the arcades. Repeat treatments were performed as necessary. The primary outcome was the percentage of patients gaining at least 2 lines of Snellen acuity from baseline and maintaining this improvement for 2 consecutive visits. The results: 139 eyes included in study with a mean follow-up of 3 years. The gain of at least two lines of visual acuity from baseline maintained for two consecutive visits was significantly greater in treated eyes (P = .00049, logrank test). The results of the BVOS trial established macular grid laser as the Gold-Standard treatment for macular oedema due to branch retinal vein occlusions for the better part of 2 decades. Recent evidence suggests that newer treatment modalities - such as intra-vitreal steroids and anti-VEGF agents - may be more efficacious than laser in this condition. Outcome 2 - Efficacy of Sectoral PRP: Results were published in the Archives of Ophthalmology (reference 2). Patients were included if they had documented branch vein occlusion with or without neovascularisation and were randomly assigned to treatment or control groups. In the treatment group, sectoral PRP was performed in the region of distribution of the affected vein. 100 to 400 laser burns were applied with spot size 200 to 500 microns in diameter and exposure 0.1 to 0.2 seconds, avoiding the fovea and optic disc. The results were as follows: In the 319 eyes without neovascularisation, treated eyes developed significantly less neovascularisation.
What is PDT and how does it work
photodynamic therapy 2 step process involving the administration of a photosensitizing drug(vertporfin) followed by application of light to a particular tissue.
A laser with a wavelength appropriate for the particular drug causes exitation of the vertporfin molecule which subsequently excited nearby oxygen molecules creating free radicals which result in thrombosis and coagulation of vasculature.
AREDS
C(500), E(400), Beta catorene(15mg) Zinc (80mg *now down to 25mg, and 2 mg Copper) Now with AREDS 2 they have added Lutein 10mg and Xeaxanthin 2 mg (also, in AREDS 2, Beta carontene was removed and Omega-3s (350 DHA and 650 EDA) were not found to be helpful)
What is moderate vision loss (ADREDS)
ETDRS - 3 lines or 15 letters
What is High risk (AREDS)
Intermediate AMD in both eyes or advanced AMD in one eye - these people should be on vitalux
Define Mild AMD
Many small drusen or some intermediate drusen mild pigmentary change
Define intermediate AMD
Lots of intermediate drusen and non central GA
Advanced AMD
vision loss 20/32 due to AMD either CNV or central GA
What are the three FA findings in CSCR
smoke stack , diffuse, expansile dot.
Expansile dot is the most common and smoke stack only occurs 10-15% of the time
What features make you suspicious that a nevus will evolve into melanoma
orange pigment, symptomatic, thickness > 2mm, juxtapapillary, SRF, visual symptoms.
Atypical serpiginous with variable FAF what should you rule out
TB (tuberculin-like-serpiginous)
ETDRS - what are the two outcomes
Does scatter photocoag reduce progression of retinopathy?
No
Does focal laser improve macular edema.
Treat CSME with focal laser reduces moderate vision loss by 50%,
Define CSME
Any thickening within 500um, HE within 500um assoc c/ thickening, thickening of 1 disc are within 1dd of the fovea
What arden ratio defines Best’s
1.5
