Custom Topographic Neutralizing Technique (TNT) with Topographically-Guided (TG) laser to correct complications David T.C Lin Simon Holland ASCRS 2010 Boston, MA *no financial interests

Aim  Evaluate custom Topographic Neutralizing Technique (TNT) using the Allegretto Wavelight laser  Aberrated eyes including enlargement of small optical zones (OZ) and decentered ablation

Methods  Retrospective consecutive case series  53 eyes: decentered ablations  62 eyes: symptomatic small optical zones, previously treated laser refractive surgery underwent topography-guided retreatment with Wavelight laser  Follow-up: 1, 3, and 6 months  Patient evaluation: symptom score, safety

Results  Results at six months and one year: UCVA, BSCVA, topography, and predictability of centration from pupil center ( mm)  24% of eyes ≥1 lines; 71% no change  53 eyes with small optical zones: increase central monodioptric optical zone, mm  All eyes improved astigmatism, range D  Symptoms improved or resolved in 82% (n=47, DA and OZ), 18% no change

TG LASIK Retreatment for OZ Enlargement  6 years post LASIK (-4 D)  Pre-op : mths post-op  BSCVA : 20/20UCVA : 20/30  TGL Tx: +0.76Rx : x90 20/20

TG LASIK Retreatment for OZ Enlargement  9 years post LASIK ( x2)  Pre-op : x756 month pos-top  BSCVA : 20/25UCVA : 20/25-  TGL Tx: -0.87Rx : x60 20/20

TG LASIK Retreatment for OZ Enlargement  5.5 years post LASIK ( x10)  Pre-op : x56 months post-op  BSCVA : 20/20UCVA : 20/20  TGL Tx: x180Rx : /20

TG LASIK Retreatment for Decentration  5 years post LASIK ( x75)  Pre-op : x703 months post-op  BSCVA : 20/20UCVA : 20/20  TGL Tx: x88Rx : /20

TG LASIK Retreatment for Decentration  3 years post LASIK ( x180)  Pre-op : months post-op  BSCVA : 20/20UCVA : 20/20  TGL Tx: x170Rx : /20

TG LASIK Retreatment for Decentration  11 years post LASIK (-3.75)  Pre-op : month pos-top  BSCVA : 20/250UCVA : 20/25  TGL Tx: +1.53Rx : x45 20/20

Discussion: Challenges in Treating Irregular Astigmatism  Treatment planning difficult  Induced refractive error - Topographic Neutralization method (TNT) can usually avoid need for 2 stage treatment  Patients need to have realistic expectations  Presently may be best surgical option for symptomatic patients with DA and small OZ (e.g. when poor wavefront capture )

Conclusions  Topographic-guided ablation using the Allegretto Wavelight laser is safe and effective in the management of highly aberrated corneas after laser refractive surgery  Treatment planning is challenging (predictability, Q factor correction), but can be improved by the Topographic Neutralization Technique