OPT 329 Retinal Lasers/Injections

laser energy absorbed by the tissue creates heat and denatures proteins = kill off some areas of retina to save other areas

What is photocoagulation?

putting energy into eye for therapeutic effect (decrease exudate/fluid, make RPE work more effectively, etc) without damaging retina

What is a subthreshold laser?

Xenon arc = not a true laser, just an intense light source = not much control over therapeutic effect and lots of S/E such as CNV, peripheral vision loss

What was the first retinal laser used in the 50s?

1960s

When were the Ruby red (694nm) and Argon blue-green (488nm, 514nm) lasers introduced?

multiple burns at once

more uniform distribution and control of burn spots (still some damage tho)

higher intensity burns for shorter duration

What is the PASCAL 532nm freq-doubled Nd:YAG laser from 2006?

macular edema = DME, ME from BRVO

CSR

macroaneurysms = arterial, Coat's

CNV

What do we use focal laser for? 4 things.

focal/grid Argon laser for ME decreased risk of vision loss by 50%

also established definition of CSME

What were 2 outcomes of the ETDRS 1989 study?

BVOS found laser was helpful in BRVO

CVOS found no benefit in CRVO

How did the outcomes of the BVOS and CVOS studies differ?

anti-VEGF (PROTOCOL I supported it as better than laser)

steroids

vitrectomy

What are some alternative tx for macular edema?

diffuse mac edema is difficult to tx with laser

proximity to fovea = don't want to damage central VA

fixation/cooperation

What are 3 limitations to laser for mac edema?

non-urgent (2 week) referral = not as urgent bc PR's are not damaged as easily here

f/u 4-6 weeks after

What is the referral and f/u timeline for macular edema tx with laser/anti-VEGF?

3-6 mos = monitor bc anything that damages outer retina can lead to CNVM

How long do we want to wait between repeating focal laser for macular edema?

recurrence/worsening of fluid

CNV from laser scars or the underlying disease

additional complications of the underlying disease (e.g. neo)

What are we looking for at the post-laser f/u for mac edema?

proliferative retinopathies:

PDR is most common

CRVO

BRVO

sickle cell retinopathy

OIS

ROP

When do we perform panretinal photocoagulation (PRP)?

destroys retinal tissue = reduces oxygen demand = less VEGF released = neovasc involutes

What is the MOA of PRP?

beneficial to prevent vision loss but benefits don't outweigh S/E until high risk PDR:

NVD at least 1/4 disc areas in size

NVD with pre-retinal heme or vitreous heme

NVE greater than 1/2 disc areas with preretinal or vitreous heme

What did the Diabetic Retinopathy Study (1979) find about using PRP for high risk PDR?

consider PRP in severe NPDR and PDR

What did the ETDRS study (1989) find about using PRP for DR?

ranibizumab anti-VEGF alone can work but need more appts, more f/u, etc.

What did Protocol S suggest about PRP vs anti-VEGF for DR?

Eylea anti-VEGF for moderately severe to severe NPDR

What did PANORAMA suggest about anti-VEGF for DR?

as the neo involutes, there can be hemes

Why are vitreous hemes sometimes a side effect of PRP?

98%

What % of pts with diabetic retinopathy that simply attend appt's will not suffer severe vision loss (not even considering how they control their DM)?

patient cooperation, fixation

media opacity = cortical cataract, hemorrhage

too much treatment/scarring

What are some limitations to performing PRP?

non-urgent (2 week) referral = not as urgent

f/u 4-6 weeks after

can extend out 4-6 mos if PDR quiescent

What is the referral and f/u timeline for proliferative retinopathy treated with PRP?

emergent = refer asap

What is the referral and f/u timeline for neovascular glaucoma treated / iris neo?

NVE

TRD

NVI

pre-retinal heme

vitreous heme

additional complications of disease (DME)

What are we looking for at the post-laser f/u for proliferative ret?

retinal holes/tears

subclinical RD

What do we use laser retinopexy for?

symptomatic horseshoe tear

symptomatic dialyses

traumatic retinal breaks

Dr. Haynes says refer if symptomatic, superior, CAT Sx soon

According to the AAO, what holes/tears should be referred for possible laser tx?

operculated holes (regardless of symptoms)

asymptomatic lattice +/- holes

asymptomatic horseshoe tear

asymptomatic atrophic holes

Dr. Haynes also says inferior holes, asymptomatic, pigmented is safe

According to the AAO, what holes/tears can be monitored only?

view

extent of subretinal fluid (should laser at edge of fluid!)

pt cooperation/fixation

What are some limitations to laser retinopexy?

6 mos to 1 year for atrophic holes, lattice degeneration, retinal tufts

What is the monitoring timeline for holes/tears?

non-urgent (1 month) for asymptomatic atrophic or operculated holes

urgent/emergent for symptomatic operculated hole or horseshoe tear

What is the referral timeline for laser retinopexy?

typically 1 month unless large tear, lots of fluid, difficult laser, high concern for additional breaks, etc.

What is the f/u timeline for laser retinopexy?

check laser uptake (2-6 mos)

look for additional holes/tears

assess fluid

What are we looking for at the post-laser f/u for laser retinopexy?

cool laser targets verteporfin dye to create an oxidative reaction

What is photodynamic therapy (PDT)?

CSR

polyploidal choroidal vasculopathy

vascular tumors = choroidal hemangioma, hemangioblastoma, metastatic tumors

What is photodynamic therapy (PDT) used for?

confirm the patient, eye, and medication

signed consent

topical numbing drops

betadine

lid speculum = L/L are main source of bacteria entering eye

What is the preparation for intravitreal injections?

3mm posterior to limbus

Where is the intravitreal injection placed on the eye?

eye rinse

check VA

check IOP

educate about symptoms requiring re-evaluation

recommend ATs

What is the post-op care for intravitreal injections?

betadine irritation/discomfort

What is the most common post-op complaint after injections?

floaters (often just the medication itself)

mild discomfort

subconjunctival heme

punctate keratitis

What are some other common S/E of intravitreal injections?

corneal abrasions

increased IOP

endophthalmitis from skin/eyelashes 3-4 days post-op = eye pain, soreness, blur, vitritis, AC rxn, hypopyon

CATs if Dr hits the lens

RD

inflam = sterile endophthalmitis reaction to meds, needle, etc.

What are some other uncommon S/E of intravitreal injections?

macular edema = DME, RVO

wet AMD

NPDR and PDR

other proliferative retinopathies

myopic CNV

What are some indications for using anti-VEGF?

Avastin (bevacizumab)

Which anti-VEGF medication is used off-label bc it's inexpensive?

in DR, VEGF is very high compared to levels in AMD

Why do on-label meds like Eylea, Lucentis, Beovu tend to work better for DR while they work just as good as off-label for AMD?

Avastin and Luctenis were similar to exudative AMD (which responds well to anything) but the benefit of name brand is they can go longer between injections

What did the CATT trial find about Avastin and Lucentis?

avoid permanent PR atrophy especially at the PIL

prevent exudates from depositing

While we consider location of edema, pt symptoms, VA, general level of retinopathy, BG control when deciding whether to tx mac edema, what are 2 big reasons we should treat it?

non-urgent (2 week) referral

f/u 4 weeks after if treated (4-8 if just monitoring)

What is the referral and f/u timeline for treating mac edema with anti-VEGF?

Lucentis has better visual outcomes, less VF loss compared to PRP (but higher tx burden)

What does Protocol S suggest for treating PDR with Lucentis?

Eylea for moderately severe to severe NDPR resulted in a 2 step reduction in DR severity, decreased risk of sight threatening complications or DME compared to no tx

What does PANORAMA suggest for treating PDR with Eylea?

non-urgent (2 week) referral for severe NPDR, PDR, other proliferative ret

emergent/urgent referral for NVG/NVI

What is the referral and f/u timeline for treating proliferative retinopathies with anti-VEGF?

choroidal breaks = laser scars

Histoplasmosis

AMD

myopic CNV

peripapillary CNV

angioid streaks

Best's disease

CSR

MacTel 2

What can cause a CNV?

PDT

focal laser

anti-VEGF is preferred today

How do we tx CNV?

emergent/urgent referral = ASAP bc scarring can cause significant damage to PR's quickly

f/u in 4 weeks after tx to ensure no recurrence, then continue to treat and extend with anti-VEGF

What is the referral and f/u timeline for treating CNV with anti-VEGF?

true = only treats CNV that may result from it, cannot treat drusen or GA

True or False: anti-VEGF does not treat AMD.

molecules that last longer in the eye so longer time between tx

What is the main feature being added to the future of anti-VEGF?

cure

Anti-VEGF is a treatment that requires routine f/u and monitoring, not a ___________.

Ozurdex = dexamethasone intravitreal implant

Iluvien = fluocinolone intravitreal implant

Retisert = fluocinolone intravitreal implant

YUTIQ = fluocinolone intravitreal implant

What are some examples of intraocular steroids?

macular edema = DME, RVO

CME (Irvine Gass) after CAT Sx

posterior uveitis after R/O infectious etiology

What are some indications for intraocular steroids?

CATs

glaucoma/increased IOP

immunosuppression = infection risk

Recall the main 3 S/E of intraocular steroids are?

Geographic Atrophy (GA) in AMD

New injectable meds Syfovre (pegcetacoplan) and Izervay (avacincaptad pegol) from 2023 are now available to treat which condition?

intravitreal C3 complement inhibitor = decreased GA growth by 25%

What is the MOA of Syfovre (pegcetacoplan) and Izervay (avacincaptad pegol)?

increased risk of CNV formation

What is the main S/E of Syfovre (pegcetacoplan) and Izervay (avacincaptad pegol)?

antibiotics (ceftiazidine, vancomycin, clindamycin) for endophthalmitis, toxoplasmosis

antivirals (foscarnet, ganciclovir) for CMV retinitis, ARN, PORN

antifungals (amphotericin B, voriconazole)

What are 3 classes of intravitreal anti-infective injections?