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“Refractive PRK for Corneal Scars
to 20/20 vision”
Financial Disclaimer: Dr. Gulani has no financial interest in this presentation
Gulani AC
Goal: VISION not Surgery
• Using Corneoplastique ™ principles and applying the “5S” system, practically any Corneal scar no matter how complex can be visually rehabilitated.
• Corneal scar affects vision by direct disturbance in optical pathway as well as indirect impact on refractive error.
• All principles of Corneoplastique™ surgery maintained:
Topical, Brief, Aesthetically pleasing & Visually promising.
Gulani AC
Why Laser PRK ?
• Shape of Cornea decides refractive status so why not use that principle with the law of Optics (Anterior lens surface shape is more significant than posterior irregularities in shape and or clarity).
• Myopic Laser PRK shapes the cornea (based on refraction) and while shaping the cornea (photoablation), it automatically moves the scar more posterior or removes it significantly.
** Many patients despite a residual corneal scar see 20/20
• Unlike Laser PTK which addresses the scar but may distort shape (which is the prime vision driver), PRK is aiming for vision despite the scar.
• No change in PRK protocol with 0.02% Mitomycin-C. Short Learning Curve.
• All interventional surgeries including lamellar and penetrating corneal transplants can still be a back up if the Laser PRK does not get the desired results.
Gulani AC
Gulani 5S Refractive Algorithm
Gulani “5S” Classification System
Sight Scar Shape Strength Site
Improv No Impro Clear Scar Irreg Reg Thin Thick Central Periph
superficial DeepMyopia
CL over RX Hyperopia
Astigmatism
Using this 5S system, we see that the Sight( vision), Scar, Shape (Irregular)& Site (central) are affected. This algorithm makes any complex case scenarioSimple to understand and effectively treat.
So in this case, since strength is normal, we need to peel off the scar with simultaneous Laser refractive ablation (not PTK) so we can measure the actual refractive error. The present ref error is a play of the corneal scar.Once we have the true ref error then we can accurately correct it.
Gulani Co Scar Laser Algorithm
Gulani “Corneal Scar” Laser PRK Algorithm
Depth Refraction Pach Topography Pattern
InCornea
OnCornea
>20/30 <20/40 >400 <250 Reg Irreg Diffuse Focal
>20/30
NI
LK
Laser PRK
DLK
PKP
Hard CL RxLaser PRK
2 Staged Laser PRK
LK +AMT
Laser PRK
Reversing Multifocal Nightmare
Patient referred with corneal scar following Excimer Laser x 2 to correct Multifocal lens surprise. Best corrected Vision: 20/200.
Using Corneoplastique ™ principles, I peeled off her corneal scar under the Laser and simultaneously ablated her cornea in a PRK mode.Upon healing, this resulted in a Clear Cornea with a measurable, true refractive error of +6.00 D -0.50 x 170 and best corrected vision
of 20/25.
Corneal Scar Pre-Laser Clear Cornea Post-Laser
Algorithm in Action : 20/200 to 20/20
Corneal Scar Pre-Laser: Vsc 20/200
Post Laser + Piggy-back IOL: Vsc 20/20
Laser Scar Peel + PRK
Piggy-back lens on ReStor
Gulani AC
Conclusion
Refractive Laser PRK Surgery when
Practiced as an ART can not only address virgin eyes with all levels ofammetropia but also reverse and correctcomplex as well as complicated cases with corneal scars back to 20/20 vision
Refractive surgery truly then can come to its own Rescue !
References:
Gulani AC. Corneoplastique™. Techniques in Ophthalmology 5(1):11-20, 2007Gulani AC. Irregular Astigmatism: Management in Unstable Cornea. Textbook of Irregular Astigmatism. Slack Inc. 2007; Slack Inc Gulani AC, John T. Combined corneal scar excision, Laser PRK surgery seeks unaided emmetropia. Ocular Surgery News. Cornea & External
disease section, June. 2008. Gulani AC. " Corneoplastique system repairs cornea before or after Laser refractive surgery” Ocular Surgery News, Nov 2007; 25 (21). 124-125