5/9/17 Overview Laser Learning Lecture and Lab: • Why we use lasers YAG caps, LPI, and SLT • YAG capsulotomy • Laser Peripheral Iridotomy (LPI or PI) Aaron McNulty, O.D., F.A.A.O. • Argon Laser Peripheral Iridoplasty (ALPI) Nate Lighthizer, O.D., F.A.A.O. • Argon Laser Trabeculoplasty (ALT) • Selective Laser Trabeculoplasty (SLT) • Other Laser Trabeculoplasty Why do we use lasers? Posterior Capsular Opacification (PCO) • Vision is decreased from PCO following cataract surgery • Lens capsular bag has an anterior and • Narrow angles/angle closure posterior surface • Glaucoma is progressing in a pt on max meds – Anterior surface usually removed w/ capsulorhexis – Something else needs to be done – Surgery not wanted yet • PCO is the formation of a cloudy membrane • Compliance issues on the posterior surface of the capsular bag • Cost issues following ECCE • Convenience issues – AKA: Secondary cataract • Doctor preference PCO YAG Laser • Incidence: • Nd: YAG laser – Most common complication of post ECCE – Neodymium: Yttrium aluminum garnet laser – 10-80% of eyes following cataract surgery – Can form anywhere from a few days to years post surgery • Tissue interaction: Photodisruptive laser – Younger patients higher risk of PCO – High light energy levels cause the tissues to be reduced – IOL’s to plasma, disintegrating the tissue • Silicone > acrylic – A large amount of energy is delivered into very small focal spots in a very brief duration of time • Prevention: • 4 nsec – – Capsulotomy during surgery No thermal reaction/No coagulation when bv’s are hit – Posterior capsular polishing – Pigment independent* 1 5/9/17 YAG Cap Risks, Complications, YAG Cap Pre-op Exam Contraindications • Visual acuity, glare testing, PAM/Heine lambda Contraindications Risks/complications – Vision 20/30 or worse 1. Corneal problems 1. IOP spike/elevation • Slit Lamp Exam 2. Intraocular inflammation • Most often transient • IOP’s 3. Macular problems 2. Inflammation • Dilate – will be able to visualize • Pred Forte QID X 1 week 4. Patient unable to hold steady • Use appropriate laser energy the PCO much better or fixate • Posterior segment exam – Macula 3. Floaters – Periphery 4. Retinal detachment • Educate Pt 5. Permanent vision loss • Informed Consent Signed YAG Cap Procedure YAG Cap Procedure • Patient Pre-op Drops • Focus HeNe beams on the PCO – dilating drops • Perform the procedure – 1 drop Alphagan or Iopidine 15-30 minutes prior to – No pain for patients • Laser Settings – May feel popping/snap/clap in ears – Energy 1.3 – 2.5 mJ • Usually done in a cruciate pattern – Spot Size fixed – Duration fixed • Other patterns: – Pulses 1 – Horseshoe – Offset 250 microns – Circular YAG Cap Procedure 1 week post-operative exam • Post-op Care • VA’s – Remove laser lens – Rinse Eye/Clean eye • Anterior segment exam – 1 drop of Alphagan or Iopidine post-laser – Check for cell/flare – IOP measurement 15-30 minutes post-laser • Check IOP • Post-op drops • Dilate – Pred Forte QID to surgical eye X 1 week – Check for holes/tears/RD’s – Pt ed – S/S of RD • D/C Pred Forte • RTC 1 week for f/u • Release back to referring doc 2 5/9/17 Anatomically Narrow Angles / Angle YAG Cap Closure • Reimbursement codes • Anatomic disorder characterized by peripheral – 66821 $243.98 iris & TM apposition • 90 day global period • 4 basic forms: – Pupillary block – Plateau iris – Phacomorphic glaucoma – Malignant glaucoma Anatomically Narrow Angles / Angle Anatomically Narrow Angles / Angle Closure Closure • Anatomic disorder characterized by peripheral • Anatomic disorder characterized by peripheral iris & TM apposition iris & TM apposition • 4 basic forms: • 4 basic forms: – Pupillary block – Pupillary block – Plateau iris – Plateau iris – Phacomorphic glaucoma – Phacomorphic glaucoma – Malignant glaucoma – Malignant glaucoma PI Indications PI Indications • Primary angle closure • Primary angle closure • Plateau iris syndrome/configuration • Plateau iris syndrome/configuration • Secondary pupillary block • Secondary pupillary block – Phacomorphic, malignant glaucomas – Phacomorphic, malignant glaucomas • Pigmentary glaucoma • Pigmentary glaucoma • Prophylaxis* • Prophylaxis* – Narrow angles on gonioscopy – Narrow angles on gonioscopy – Most often reason why PI is done – Most often reason why PI is done 3 5/9/17 PI Alternatives PI Pre-op Exam • • Surgical Iridectomy Visual acuity • Slit Lamp Exam OU – Equal results to laser PI – Note lid position – Much more invasive – Note AC depth • • More trauma to iris Gonio OU – Pigment in the TM? • Infection – Neovascularization? – Peripheral anterior synechiae? – If concurrent surgery not occurring, laser PI is the • IOP’s OU way to go • Educate Pt • Informed Consent Signed PI Risks, Complications, PI Procedure Contraindications Contraindications Risks/complications 1. Corneal problems 1. Non-perforation • Patient Pre-op Drops 2. Intraocular inflammation 2. IOP spike/elevation – 1 drop Pilocarpine 1% or 2% OU 3. Iris in contact with endo • Most often transient – 1 drop Alphagan or Iopidine OU 3. Inflammation 4. Angle closure from NVG or • Laser Settings inflammatory glaucoma • Pred Forte QID X 1 week • Use appropriate laser energy 5. Patient unable to hold steady – Depends on which laser you use • Others: hyphema, or fixate synechiae, peaked pupil, 6. Macular problems? floaters, blur, monocular diplopia, RD, permanent vision loss PI Laser Options PI Procedure Argon laser Yag laser • Sit patient comfortably • Adjust laser for your comfort • Less commonly used • More commonly used – Armrest, oculars, controls • Advantages: • Advantages: • Instill proparacaine in both eyes – Less bleeding – Very good penetration rate • Select PI location – Less debris • Disadvantages: – Usually superiorly under lid • Disadvantages: – More likely to bleed – Crypt – Less successful compared to YAG laser in penetration – Much more debris – 11:00 or 1:00 • Requires more shots • Settings: • Place Abraham Iridotomy laser lens on eye with • Settings: – Spot size = fixed goniosol or celluvisc – Spot size = 50 microns – Duration = fixed – Orientation of lens matters – Duration = 0.1 sec – Energy = 2.0 – 5.0 mJ – Button @ 11 or 1 o’clock (for a superior PI) – Power = 300-1200 mW – Offset = 0 – 250 microns 4 5/9/17 PI Procedure PI Procedure • Focus HeNe beams on the iris • Perform the procedure OU • Often times it takes 2 visits to finish PI – Argon first for pre-treatment – YAG to finish PI – 70-80% through the first visit – No pain for patients - usually – 150-250 mJ maximum energy for me on 1 visit – May feel popping/snap/clap in ears • Goals: – Takes longer than a YAG Cap – patent PI ≈ 1mm in size • Occasional bleeding – Deepening of the AC • Debris/pigment – “pigment plume” – IOP control PI Procedure 1 week post-operative exam • Post-op Care • VA’s – Remove laser lens • Anterior segment exam – Rinse Eye/Clean eye – Check for cell/flare – 1 drop of Alphagan or Iopidine post-laser – Note AC depth – IOP measurement 30 minutes post-laser – Is the PI patent? • • Post-op drops Gonio – did angle deepen? – Pred Forte QID to surgical eye X 1 week • Check IOP • Pt ed • D/C Pred Forte • RTC 1 week for f/u • Release back to referring doc Peripheral Iridotomy (PI) Why do we need lasers? • Glaucoma is progressing in a pt on max meds • Reimbursement codes – Something else needs to be done – 66761 $222.05 – Surgery not wanted yet • 10 day global period • Compliance issues • Cost issues • Convenience/quality of life issues • Systemic side effect issues of drops • Doctor preference 5 5/9/17 Laser Trabeculoplasty (LTP) Laser Trabeculoplasty (LTP) • Use of laser light to burn areas of the TM to • Most common laser procedure for OAG increase aqueous outflow – ALT in the 90’s and early 2000’s – SLT has largely taken over • Two types • Usually a Secondary Line of Treatment – – Argon laser trabeculoplasty (ALT) After meds fail to control IOP – Selective laser trabeculoplasty (SLT) • Some use as Primary Treatment • Both increase aqueous outflow • Universally Accepted Laser Trabeculoplasty (LTP) LTP Indications • Glaucoma Laser Trial (1990) • POAG – Compared ALT to topical meds in the control of IOP • Normo-tensive glaucoma and VF and ONH status – Results: • Pigmentary dispersion glaucoma • Pts who underwent ALT as first-line therapy achieved better • Pseudoexfoliative glaucoma control of IOP and better VF and ONH status than those treated initially with topical meds • 44% proper IOP control in the ALT group • 30% proper IOP control in the meds group • Fewer eyes that underwent ALT as first-line therapy ultimately required 2 or more meds postoperatively to control IOP LTP Contraindications Argon Laser Trabeculoplasty (ALT) • Advanced POAG • • Narrow Angle Glaucoma Traditional form of laser therapy for patients • Angle Closure (Emergency IOP decrease) with glaucoma • Inflammatory Glaucoma • Presented as an alternative to filtering surgery • Angle Recession Glaucoma for patients whose open angle glaucoma was • Neovascular Glaucoma not controlled by meds • Congenital Glaucoma • Exact mechanism of effect is unknown but: • Prior LTP that failed – Mechanical effects from laser burns scarring tissue • Under 40 years of age and causing contracting of tissue and opening of • Hazy media adjacent areas of the TM – Biologic effects with increased inflammatory cells with “clean up” the TM 6 5/9/17 Argon Laser Trabeculoplasty (ALT) ALT Procedure • ALT complications/risks • Patient Pre-op Drops 1. IOP spike/elevation – 1 drop Alphagan or Iopidine 15-30 minutes prior • Most often transient to • High risk