Refractive Surgery In the Military LTC Jeff Rabin, OD, PhD Center for Refractive Surgery Walter Reed...
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Transcript of Refractive Surgery In the Military LTC Jeff Rabin, OD, PhD Center for Refractive Surgery Walter Reed...
Refractive Surgery In the Military
LTC Jeff Rabin, OD, PhD
Center for Refractive SurgeryWalter Reed Health Care System
Washington, DC
In the past we had…
Radial Keratotomy (RK)
Deep spoke-like incisions
Central cornea flattens
For mild to moderate myopia
Good results Weakens cornea
Now we have…
Laser Procedures
• PRK
• LASIK
Photorefractive Keratectomy (PRK)
Excimer laser reshapes cornea
Very precise For myopia,
hyperopia, astigmatism
Good results & safety
LASIK Microkeratome flap Excimer laser
removes precise amount corneal tissue
For myopia, astigmatism and hyperopia
Rapid popularity worldwide
LASIK
PRK vs. LASIK
PRK• Day one: “Oowww!”• Less surgical risk• Slower recovery• 80% 20/20• Haze possible• No flap
LASIK• Day one: “Wow!”• Greater surgical risk• Quicker recovery• 80% 20/20• No haze• Flap
Center for Refractive Surgery
Do we need refractive surgery in the military…
OPERATIONAL VISION CORRECTIONOPERATIONAL VISION CORRECTION
Over 1/2 million soldiers, sailors and airmen
40% require optical correction
Annual cost of optical corrective devices…vast
OPERATIONAL VISION OPERATIONAL VISION CORRECTIONCORRECTION
Traditional way to correct all forms of refractive error
Relatively inexpensive Few complications Very precise
GLASSESGLASSES
• Disadvantages:Disadvantages:
GLASSESGLASSES
• Disadvantages:Disadvantages:
GLASSESGLASSES
Disadvantages:Disadvantages: Limit range of vision Fogging, scratched Broken or lost Compatibility problems--
with night vision goggles, protective mask inserts, etc.
GLASSESGLASSES
Advantages:Advantages: Cosmesis Increased FOV Less minification—
better vision in myopia
CONTACT LENSESCONTACT LENSES
Disadvantages:Disadvantages: Difficult to clean in field
environment May lead to infection Problematic in chemical
environments Dislodge with G-forces
CONTACT LENSESCONTACT LENSES
REFRACTIVE SURGERYREFRACTIVE SURGERY All-weather 24/7 correction Compatible with equipment Increased soldier confidence
(no broken or fogged glasses) Increased survivability
(lost glasses = casualty) Improved quality of life---
higher retention
ARMY POLICYARMY POLICY AR 40-501 prohibits entry with history
of refractive surgery, but… Waiver policy (OTSG May 2000)
allows for PRK or LASIK if--- At least 6 months since surgery Meet AR 40-501 vision standards
No visual side effects affecting daily activities
Refractive error stability Post-LASIK: excluded from HALO,
Flight, Diving and SF training Post-PRK: excluded from Aviation
ARMY POLICYARMY POLICY
Center for Refractive Surgery
WRESPWarfighter Refractive Eye Surgery Program
• WRESP -- limited resource available to commanders to enhance mission readiness
Center for Refractive Surgery
WRESPWarfighter Refractive Eye Surgery Program
• WRESP -- limited resource available to commanders to enhance mission readiness
• MEDCOM establishing WRESP Laser Eye Centers in MTFs designated by the DCSOPS
Center for Refractive Surgery
WRESPWarfighter Refractive Eye Surgery Program
• WRESP -- limited resource available to commanders to enhance mission readiness
• MEDCOM establishing WRESP Laser Eye Centers in MTFs designated by the DCSOPS
• WRESP Centers: Operational -- Ft. Bragg Planned -- Ft Campbell, Ft Hood, Tripler AMC, Landstuhl RMC
Center for Refractive Surgery
WRESPWarfighter Refractive Eye Surgery Program
• WRESP -- limited resource available to commanders to enhance mission readiness
• MEDCOM establishing WRESP Laser Eye Centers in MTFs designated by the DCSOPS
• WRESP Centers: Operational -- Ft. Bragg Planned -- Ft Campbell, Ft Hood, Tripler AMC, Landstuhl RMC,
• DHS allocates appointments to supported units
Center for Refractive Surgery
WRESPWarfighter Refractive Eye Surgery Program
• WRESP -- limited resource available to commanders to enhance mission readiness
• MEDCOM establishing WRESP Laser Eye Centers in MTFs designated by the DCSOPS
• WRESP Centers: Operational -- Ft. Bragg Planned -- Ft Campbell, Ft Hood, Tripler AMC, Landstuhl RMC,
• DHS allocates appointments to supported units • Unit commands maintain by-name 3-month list
Center for Refractive Surgery WRESP Soldier Selection Criteria
Warfighter Refractive Eye Surgery Program• Assigned to unit with mission at line-of-battle or
behind hostile lines
Center for Refractive Surgery WRESP Soldier Selection Criteria
Warfighter Refractive Eye Surgery Program• Assigned to unit with mission at line-of-battle or
behind hostile lines• 1st priority -- SOC; Infantry, Armor, Field Artillery
Center for Refractive Surgery WRESP Soldier Selection Criteria
Warfighter Refractive Eye Surgery Program• Assigned to unit with mission at line-of-battle or
behind hostile lines• 1st priority -- SOC; Infantry, Armor, Field Artillery • 2nd priority-- CSS assigned to Division or Separate
Brigade
Center for Refractive Surgery WRESP Soldier Selection Criteria
Warfighter Refractive Eye Surgery Program• Assigned to unit with mission at line-of-battle or
behind hostile lines• 1st priority -- SOC; Infantry, Armor, Field Artillery • 2nd priority-- CSS assigned to Division or Separate
Brigade• Other service members -- space available
Center for Refractive Surgery WRESP Soldier Selection Criteria
Warfighter Refractive Eye Surgery Program• Assigned to unit with mission at line-of-battle or
behind hostile lines• 1st priority -- SOC; Infantry, Armor, Field Artillery • 2nd priority-- CSS assigned to Division or Separate
Brigade• Other service members -- space available• At least 18 mo remaining on AD or with reenlistment
Center for Refractive Surgery WRESP Soldier Selection Criteria
Warfighter Refractive Eye Surgery Program• Assigned to unit with mission at line-of-battle or
behind hostile lines• 1st priority -- SOC; Infantry, Armor, Field Artillery • 2nd priority-- CSS assigned to Division or Separate
Brigade• Other service members -- space available• At least 18 mo remaining on AD or with reenlistment• At least 12 mo remaining with same/similar unit
Center for Refractive Surgery WRESP Soldier Selection Criteria
Warfighter Refractive Eye Surgery Program• Assigned to unit with mission at line-of-battle or
behind hostile lines• 1st priority -- SOC; Infantry, Armor, Field Artillery • 2nd priority-- CSS assigned to Division or Separate
Brigade• Other service members -- space available• At least 18 mo remaining on AD or with reenlistment• At least 12 mo remaining with same/similar unit• Must return for follow-up as specified
Center for Refractive Surgery
• AD Army, Navy and Marines at Ft Bragg• To benefit Warfighter
(USASOC, 18th Airborne)
• 1500 pts/year (3000 procedures); 125/month • USASOC—PRK only• All others—LASIK or PRK• LASIK disqualifying for SOC schools
(HALO, scuba, SFQC, SERE)• Aviators—not eligible
Womack Army Medical CenterWarfighter Refractive Eye Surgery Program
NAVY POLICYNAVY POLICY
• Similar to ARMY for PRK• Excludes LASIK unless in
research protocol• WRESP Centers at San Diego,
Portsmouth, Bethesda• Four others planned
AIR FORCE POLICYAIR FORCE POLICY
• Waiver for PRK only• Aviation and special duty• Includes 200 rated aviators and
100 student aviators per year• WRESP Center at Wilford Hall;
planned for AF Academy and Wright-Patterson
Center for Refractive Surgery
•80% -- 20/20 UCVA
•60% -- 20/16 UCVA
•>90% -- 20/20 on re-treatment
•Overall -- safe and effective
Completed Navy ResearchInitial Evaluation of PRK
Bottom line…
Center for Refractive Surgery
• How long before 20/20 uncorrected VA?- 40% at 1 week- 81% at 4 weeks- 81% at 12 weeks
• Prolonged recovery, transient CS loss
• Stable refraction in 6 weeks to 3 months
• Extended recovery period in PRK
Completed Navy ResearchVisual Recovery in PRK
Bottom Line…
Center for Refractive Surgery
• No correlation: pupil size & symptoms
• No correlation: pupil size & pre- / post-op visual performance differences
• Symptoms correlated with degree of myopia
Completed Navy ResearchPupil Size, Glare and Halos In PRK
Bottom line…
Center for Refractive Surgery
• Overall: 92% happy with outcome
• The greater the depression before PRK-- less happy and more regret after PRK
• Older patients: less happy, more regret
Completed Navy ResearchPsychiatric Factors and Patient
Satisfaction After PRKBottom line…
Center for Refractive Surgery
• Slight VA and CS decrease at 2 weeks
• Returned to normal at 4 weeks
• Transient loss of NVG performance
Completed Navy ResearchNVG Performance and PRK
Bottom line…
Center for Refractive Surgery
• RK, PRK, LASIK groups
• All: slight corneal swelling (12-34 microns)
• Hyperopic shift large in RK, slight in PRK/LASIK (0.2 – 0.3 D)
• Slight decrease in uncorrected and best corrected vision
Completed Navy ResearchQuality of Vision & Prolonged Exposure
to AltitudeBottom line…
Center for Refractive Surgery
• Distance for detection of road signs
• Detection distances decreased in symptomatic eyes & those with greater light scatter
• Promising functional approach
Completed Navy ResearchNight Driving Simulation After PRK
Bottom line…
Center for Refractive Surgery
• 20/20 UCVA in 73%
• Slight undercorrection of astigmatism common
• Induced cylinder—rare
Completed Navy ResearchVector Analysis Outcome of Astigmatic PRK
Bottom line…
Center for Refractive Surgery
• 92% -- 20/20 UCVA at 12 months
• 70% -- 20/16 UCVA
• Slight decrease in CS, resolved 3 months
• 1 displaced flap at I day post-op
• Rapid return to duty
Completed Navy ResearchInitial Evaluation of LASIK In Navy
Bottom line…
Center for Refractive SurgeryOngoing/Future Naval Research
• Visual performance after PRK and LASIK
• Initial evaluation of (INTACS)
• Hyperopic PRK
• Normative values for contrast sensitivity
• Wavefront sensing
• Cyclogyl vs tropicamide in refractive surgery
• NEI refractive surgery questionnaire
• PRK to retain ametropic Naval aviators
Center for Refractive Surgery
• 80 non-aviators, 20 controls; 30 months
• Comprehensive ophthalmological baseline
• Unique operational testing
• Contrast sensitivity, color vision, NVGs, glare disability, corneal haze detection
• Subsets: PRK at altitude PRK under high Gz loads PRK and cockpit visual simulation
USAF PRK Study
Center for Refractive Surgery
• Nearly 100 subjects; all myopic
• Safe and effective thus far
• Mean values at 6 months:UCVA 20/16BSCVA 20/14BSC SLCT 1.21
• Loss BSCVA and CS in some
Ongoing Air Force ResearchEvaluation of PRK In Air Force
Bottom line…
Center for Refractive Surgery
• Pre-op BSC vs post-op UC
• Decrease on each chart—high contrast VA – 2 letterslow contrast VA – 5 lettersSLCT – 11 letters
• 24% require Rx for 20/20 in one eye
Ongoing Air Force ResearchHigh & Low Contrast Vision In PRK
Bottom line…
Center for Refractive Surgery
• Post-op decrease for middle/low SFs
• More marked decrease with glare and dilation which persisted up to 1 year
• Likely due to refractive transition zone
Ongoing Air Force ResearchContrast Sensitivity & Glare in PRK
Bottom line…
Refractive Surgery InMilitary Aviation
Center for Refractive SurgeryWalter Reed Health Care System
Washington, DC
Center for Refractive Surgery
• PRK and LASIK authorized without waiver, provided that…
• Post-operative condition has stabilized
• No significant adverse effects or complications
• Pilot meets FAA vision standards(Primary standard—corrected to 20/20 each eye)
FAA Policy onRefractive Surgery
Center for Refractive Surgery
• Ongoing study--PRK in rated aviators with promising results thus far
• Initiating study of pilots trainees at least three months post-op to PRK
Naval Aviation PRK Research
• 80 non-aviators, 20 controls; 30 months• Basic vision and operational testing• Altitude, high Gz loads, cockpit simulation• Promising results thus far
Air Force PRK Research
Center for Refractive Surgery
• Effective 2 Aug 00• Includes Aviation & Special Duty• Strict clinical criteria & follow-up• 200 rated aviators/year; 100 pilot candidates• Must have PRK done at approved DoD site• Myopia only: -1 to –5.5; up to 3D astigmatism
Air Force Waiver for PRK
No Current Navy or Army Aviation Waiver for PRK or LASIK Unless In Research Protocol
Center for Refractive Surgery
• Initiated Feb 01
• Visual & flight performance of flight school applicants who had laser surgery
• Enrollment criteria—3 months post-op, stable refraction, class 1 flight standards
• 100 LASIK, 100 PRK, 100 controls
• Goal—determine if PRK/LASIK waiverable
Refractive Surgery & Army AviationUSAARL Accession Study
Center for Refractive Surgery
• To begin Mar 02
• Prospective study of visual & flight performance of pilot trainees
• Refractive surgery at WRAMC Center • 40 PRK, 40 LASIK—matched for degree of pre-
operative refractive error
• Goals--determine if PRK/LASIK waiverable; expand applicant pool; identify factors to minimize risk and maximize performance
Refractive Surgery & Army AviationWRAMC/USAARL Accession Study
Center for Refractive Surgery
• Study approved Jan 02
• UH-60 Black Hawk rated aviators
• Refractive surgery at WRAMC Center • 40 PRK, 40 LASIK—matched for degree of pre-
operative refractive error
• Comparison between flight performance before surgery (with spectacle Rx) and performance after surgery (without Rx)
• LASIK vs. PRK
Refractive Surgery & Army AviationUSAARL/WRAMC Rated Aviator Study
Center for Refractive Surgery
Current Results
D V N Z RH N F V D
F U P V EP E R Z UF H P V E
Z R F N UP R Z E U
F V P Z DU P N H F
High Contrast Visual Acuity
Night Vision Performance and Visual Acuity After Photorefractive
KeratectomyBarbara O’Kane, PhD, Raymond Stefanik,
James Stevens, Prem Subramanian, MD, PhD,Jeff Rabin, OD, PhD, Robert Bauer, MD, PhD,
and Kraig Bower, MD
Center for Refractive SurgeryWalter Reed Army Medical Center
Washington, DCUS Army CECOM RDEC
Night Vision & Electronic Sensors Directorate Fort Belvoir, VA
•Vision often returns tonormal after refractive surgery(eg, PRK or LASIK).
•Despite reports of decreasednight vision…
•Tests of night vision are lacking.
Introduction
•Military operations--at night
•Evaluation of efficacy & safety of refractive surgery for combat…
•Must include night vision performance testing.
Introduction
Research Purpose
To evaluate visual acuity through
night vision gogglesand
detection of low contrast targets
before and after PRK.
• 19 Special Operations soldiers received PRK.
• All near-sighted before PRK (uncorrected VA: 20/40 to 20/400).
• VA evaluated through NVGs(before & 3 months after PRK).
• Detection of low contrast targets(before & 3 months after PRK).
Summary of Methods
•Before PRK— NVG VA was decreased when tested without glasses.
•After PRK — NVG VA without glasses as good or better than pre-operative VA with glasses.
Results (next slide)
20
40
60
80
100
120
140
160
180
Night sky condition
Fullmoon
1/4moon
Starlight OvercastStarlight
Visual acuity(20/...)
NVG Acuity and PRK
mean + 1SEn = 19
binocular data
Pre-op: no correctionPre-op: with correctionPost-op: no correctionPost-op: with correction
worse
better
Results (next slide)Acuity at Low Contrast
• Decrease in VA with decreasing letter contrast.
• No difference between pre- and post-op VA.
• Relation between VA & contrast remained the same in all conditions.
.1 1 10 100
20
40
60
80
100
120
140
160RE/Pre-opRE/Post-opLE/Pre-opLE/Post-op
Contrast (%)
Acuity and Contrast In PRK
mean + 1SEn = 19
All valueswith best correction
Visual acuity(20/...)
worse
better
• After PRK, NVG performance(without glasses) as good or betterthan performance before surgery(with glasses).
• May translate to improved performance for soldiers unable to wear glasses in combat.
Conclusions
Visual Performance In Soldiers:One Year After PRKPreliminary Results
Center for Refractive SurgeryWalter Reed Health Care System
•VA tested across range of contrasts (1.25 - 100%)
•Small target CS•Spatial and temporal CS
(sine-wave; 2 alternative forced choice)
•Photopic and mesopic testing
•With/without glare
Methods
D V N Z RH N F V D
F U P V EP E R Z U
F H P V EZ R F N U
P R Z E U
F V P Z DU P N H F
High Contrast Visual Acuity
Logarithmic progression in
letter size
D V N Z RH N F V D
F U P V EP E R Z U
F H P V EZ R F N U
P R Z E U
F V P Z DU P N H F
Low Contrast Visual Acuity
Rendition of 10% contrast
D V N Z RH N F V D
F U P V EP E R Z U
F H P V EZ R F N U
P R Z E U
F V P Z DU P N H F
Low Contrast Visual Acuity
Rendition of 2.5% contrast
D V N Z RH N F V D
F U P V EP E R Z U
F H P V EZ R F N U
P R Z E U
F V P Z DU P N H F
Low Contrast Visual Acuity
Rendition of 1.25% contrast
Small Letter Contrast Sensitivity1 D R E Z U F V N H P
2 R P F D U N Z E V H
3 H R P E D V Z N F U
4 Z E D H P U V R N F
5 H P F D N V R E U Z
6 R Z F D P N U E V H
7 V D H P E N R H U Z
8 U R N E D Z H F V P
9 N V Z F H E P R D U
10 D V N Z R H F U P E
11 P H V D F U E Z N R
12 R V U N D P H Z E F
13 F R E U P Z H D V R
14 E R P D N Z F U V H
.1 1 10 100
-0.3
0.0
0.3
0.6
0.9
1.2MesopicPhotopicGlare
Visual Acuity and Contrast
Letter contrast (percent)
Visual acuity
(logMAR)
20/200
20/85
20/14
20/22
Photopic(daytime)
Mesopic(nighttime)
worse
better
Spatial Contrast Sensitivity:One Year After PRK
(minimum contrast to detect pattern as a function of pattern fineness)
1
10
100
1000
0.1 1 10 100Spatial frequency (cycles/deg)
Contrast sensitivity
(minimum contrastfor detection)
(coarse ---------- pattern fineness ------------------ fine)
Photopic(daytime)
Mesopic(nighttime)
1
10
100
0.1 1 10 100
Temporal frequency (cycles/sec)
Contrast sensitivity
Temporal Contrast Sensitivity:
Photopic(daytime)
Mesopic(nighttine)
One Year After PRK(minimum contrast to detect flicker as a function of flicker rate)
(minimum contrastfor detection)
(slow ---------- flicker frequency ------------------ fast)
Center for Refractive SurgeryWalter Reed Health Care System
Washington, DC
A New Test for Measuring Glare Disability in Refractive Surgery
•LASIK and PRK-- effective for correction of refractive error
•Despite efficacy of refractive surgery
•Many patients complain of glare…
•Particularly at night
Introduction
•Conventional glare testing--bright glare source under photopic conditions
•Paradoxical improvement in vision
•Due to constriction of the pupil
•Which decreases effects of peripheral aberrations
Introduction
•New approach to quantify glare disability
•Which overcomes problems of conventional tests
•By using contrast-modulated stimulus
•Under reduced luminance to encourage pupil dilation
New Test of Glare Disability
•Small letter contrast test(20/25 letters varied in contrast)
•Viewed at low luminance (3 cd/m2)
•With and without diffuse surrounding glare
•Chart luminance remains constant with/without glare
•Minimal (<1mm) change in pupil size
New Test of Glare Disability
1 D R E Z U F V N H P
2 R P F D U N Z E V H
3 H R P E D V Z N F U
4 Z E D H P U V R N F
5 H P F D N V R E U Z
6 R Z F D P N U E V H
7 V D H P E N R H U Z
8 U R N E D Z H F V P
9 N V Z F H E P R D U
10 D V N Z R H F U P E
11 P H V D F U E Z N R
12 R V U N D P H Z E F
13 F R E U P Z H D V R
14 E R P D N Z F U V H
Viewed at low luminance
Without glare
1 D R E Z U F V N H P
2 R P F D U N Z E V H
3 H R P E D V Z N F U
4 Z E D H P U V R N F
5 H P F D N V R E U Z
6 R Z F D P N U E V H
7 V D H P E N R H U Z
8 U R N E D Z H F V P
9 N V Z F H E P R D U
10 D V N Z R H F U P E
11 P H V D F U E Z N R
12 R V U N D P H Z E F
13 F R E U P Z H D V R
14 E R P D N Z F U V H
1 D R E Z U F V N H P
2 R P F D U N Z E V H
3 H R P E D V Z N F U
4 Z E D H P U V R N F
5 H P F D N V R E U Z
6 R Z F D P N U E V H
7 V D H P E N R H U Z
8 U R N E D Z H F V P
9 N V Z F H E P R D U
10 D V N Z R H F U P E
11 P H V D F U E Z N R
12 R V U N D P H Z E F
13 F R E U P Z H D V R
14 E R P D N Z F U V H
Viewed at low luminance
With glare
•Shift from photopic to mesopic...8-line decrease in CS
•Addition of glare...further decrease 3-lines
ResultsGlare Disability & Mesopic CS
1-Year After PRK
Photopic Mesopic Mes+Glare
0.0
0.3
0.6
0.9
1.2
1.5Glare Disability 1-Year After PRK
Test condition
Log small letter
contrast sensitivity
8 lines
3 lines
mean+2SE, n=18 eyes
• Infrared pupillometry under mesopic conditions...
•Larger pupils--lower CS,both with/without glare
•Suggests adverse effect of peripheral aberrations
ResultsGlare Disability & Mesopic CS
1-Year After PRK
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Mesopic CS, Glare & Pupil Size:1-Year After PRK
Mesopic pupil size (mm)
Log small letter
contrast sensitivity
MesopicMes+Glare
Center for Refractive Surgery
Future Research
Video C am era
F ixation Target(adjustable focus)
W avefront Sensor
Probe Laser
Eye
Center for Refractive Surgery
• Performance with night vision devices
Future research will assess the impact of refractive surgery on…
Center for Refractive Surgery
• Performance with night vision devices• Night firing
Future research will assess the impact of refractive surgery on…
Center for Refractive Surgery
• Performance with night vision devices• Night firing• Land navigation
Future research will assess the impact of refractive surgery on…
Center for Refractive Surgery
• Performance with night vision devices• Night firing• Land navigation• Helmet-mounted displays
Future research will assess the impact of refractive surgery on…
Center for Refractive Surgery
• Performance with night vision devices• Night firing• Land navigation• Helmet-mounted displays• Flight training
Future research will assess the impact of refractive surgery on…
Center for Refractive Surgery
• Performance with night vision devices• Night firing• Land navigation• Helmet-mounted displays• Flight training• Night flight
Future research will assess the impact of refractive surgery on…
Center for Refractive Surgery
• Performance with night vision devices• Night firing• Land navigation• Helmet-mounted displays• Flight training• Night flight• Performance of experienced aviators
Future research will assess the impact of refractive surgery on…
Center for Refractive Surgery
Beyond 20/20
In Pursuit ofSuper-Normal Vision
Small Letter Contrast Sensitivity
1 D R E Z U F V N H P
2 R P F D U N Z E V H
3 H R P E D V Z N F U
4 Z E D H P U V R N F
5 H P F D N V R E U Z
6 R Z F D P N U E V H
7 V D H P E N R H U Z
8 U R N E D Z H F V P
9 N V Z F H E P R D U
10 D V N Z R H F U P E
11 P H V D F U E Z N R
12 R V U N D P H Z E F
13 F R E U P Z H D V R
14 E R P D N Z F U V H
D V N Z RH N F V D
F U P V EP E R Z UF H P V E
Z R F N UP R Z E U
F V P Z DU P N H F
High Contrast Visual Acuity
Center for Refractive Surgery
• In standard eye exam, we test for--near-sightedness, far-sightedness, astigmatism
• Additional optical aberrations(e.g., coma, spherical aberration)
• Also have a significant impact on vision.
Beyond 20/20In Pursuit of Super-Normal Vision
Center for Refractive Surgery
• Objective technique now exists for comprehensive measurement of the optics of the eye…
• Shack-Hartmann wavefront aberrometry
• Based on the shape of the wavefront of light reflected from the eye.
Beyond 20/20In Pursuit of Super-Normal Vision
Center for Refractive Surgery
• Beam of light is reflected from the eye
• Through a micro-lens array producing a spot image array of reflected light.
• Computer analysis determines relative displacement of each spot image
• Used to compute local slope & character of the wavefront of light.
Beyond 20/20In Pursuit of Super-Normal Vision
Center for Refractive Surgery
• The analyzed wavefront is used to derive a correction profile
• Which can be used to—guide laser eye surgery.
• FDA studies nearly complete verifying the efficacy & safety of this approach.
Beyond 20/20In Pursuit of Super-Normal Vision
Center for Refractive Surgery
• Our research & development includes…
• State-of-the-art laser with eye tracking
• Coupled with wavefront technology
• Unique measures of visual performance
• To achieve optimal vision for soldier & civilian alike.
Beyond 20/20In Pursuit of Super-Normal Vision
Center for Refractive Surgery
• A correction which minimizes optical aberrations will improve….
• Visual acuity—as much as 2x.
• Small target contrast sensitivity(as much as 7x).
• And performance at night when pupil becomes large.
Beyond 20/20In Pursuit of Super-Normal Vision
Center for Refractive Surgery
Beyond 20/20In Pursuit of Super-Normal Vision
What will Super-Normal Vision look like??
Small Letter Contrast Sensitivity1 D R E Z U F V N H P
2 R P F D U N Z E V H
3 H R P E D V Z N F U
4 Z E D H P U V R N F
5 H P F D N V R E U Z
6 R Z F D P N U E V H
7 V D H P E N R H U Z
8 U R N E D Z H F V P
9 N V Z F H E P R D U
10 D V N Z R H F U P E
11 P H V D F U E Z N R
12 R V U N D P H Z E F
13 F R E U P Z H D V R
14 E R P D N Z F U V H
Before correctionof aberrations
Small Letter Contrast Sensitivity1 D R E Z U F V N H P
2 R P F D U N Z E V H
3 H R P E D V Z N F U
4 Z E D H P U V R N F
5 H P F D N V R E U Z
6 R Z F D P N U E V H
7 V D H P E N R H U Z
8 U R N E D Z H F V P
9 N V Z F H E P R D U
10 D V N Z R H F U P E
11 P H V D F U E Z N R
12 R V U N D P H Z E F
13 F R E U P Z H D V R
14 E R P D N Z F U V H
After correctionof aberrations