Effects of IOP Lowering Agents on Myopic Regression after Refractive Surgery

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Effects of IOP Lowering Agents on Myopic
Regression after Refractive Surgery

• Lim, Taehyung M.D., Hong, So Jin M.D., Cho, Beom
  Jin M.D., Ph.D.
• Chung Kyu-Hyung M.D, Ph.D, Choi Kee-Yong M.D,
  Ph.D.
• HanGil Eye Hospital

All authors have no financial interest in the
subject matter of this poster.
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Background
Evidences of correlation between IOP and
refractive error after LASIK
Factors affecting the forward shift of posterior
corneal surface after laser in situ
keratomileusis. Baek T, et al,
108(2)317-20, 2001, Ophthalmology
The higher IOP, the more anterior shifting of the
cornea
Differences between regressive eyes and
non-regressive eyes after LASIK for myopia in
the time course of corneal changes assessed with
the Orbscan. Pan, et al,
218(2)96-101, 2004, Ophthalmologica
Regressive eye vs. Non-regressive eye differed
in the corneal shifting movements after LASIK
Regression-related factors before and after laser
in situ keratomileusis. Qi H.
et al, 220(4)272-6,2006 Ophthalmologica
IOP lowering may prevent myopic regression.
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Background
Evidences of correlation between IOP and
refractive error after LASIK
Effects of antiglaucoma drugs on refractive
outcomes in eyes with myopic regression after
laser in situ keratomileusis. Kamiya K, et al,
145(2)233-238, Am J Ophthalmol, 2008
27 eyes with myopic regression after LASIK Mean
regression 1.260.48D(-0.5 -2.25D) 2.5
Nipradilol bid for 3months
Pretreatment 3 Months
Spherical -1.020.52D -0.440.39D
Astigmatism -0.550.30D -0.490.22D
IOP 11.42.4mmHg 9.18.2mmHg
CCT 505.239.3um 505.638.7um
15 of patients did not respond to the treatment.
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Background
Evidences of correlation between IOP and
refractive error after LASIK
Effects of antiglaucoma drugs on refractive
outcomes in eyes with myopic regression after
laser in situ keratomileusis. Kamiya K, et al,
145(2)233-238, Am J Ophthalmol, 2008
It is suggested that backward movement of the
cornea may occur, possibly flattening the corneal
curvature by lowering the IOP
Pretreatment 3 Months
Mean refractive power of the total cornea (3mm) 38.42.0D 37.72.0D
Posterior corneal surface shifted posteriorly by 9.18.2um (mean) Posterior corneal surface shifted posteriorly by 9.18.2um (mean) Posterior corneal surface shifted posteriorly by 9.18.2um (mean)
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Purpose
To evaluate effects of IOP lowering agents on
patients who have myopic regression after laser
vision correction(LVC)
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Methods
94 eyes in 47 patients (Male 11 , Female
36) Mean age 33.7 years (2253) Patients
who have myopic regression after LVC Occurrence
of Myopic regression after LVC
postoperative 4y5m 3y11m (1month 12 years)
Op PRK LASIK LASEK
Number 9 65 20
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Methods
At the time of diagnosis, treatment was started
with topical 0.5 timolol 5 dorsolamide
combination (Cosopt, MSD, USA), twice daily for
3 months. Outcome parameters UCVA, BCVA, IOP,
CCT, MR, Topography and ACD f/u period 1
week, 1 month, 3 months
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Results
Pre-treatment Post-treatment 1 month Post-treatment 3 months
Spherical error (D) -1.021.55 -0.501.27 -0.410.92
Astigmatism (D) -0.230.78 -0.180.77 -0.180.67
IOP(mmHg) 10.555.75 9.173.69 9.643.78
CCT(um) 486.995.1 486.995.1 481.6109.1
ACD(um) 3.230.50 3.290.61 3.270.58
Keratometry(D) Anterior Posterior 39.613.77 -6.430.64 38.363.94 -6.360.51 39.433.36 -6.410.55
p lt 0.05, paired T test for pre-treatment
Post-treatment 3 months p lt 0.05, paired T
test for pre-treatment Post-treatment 1 month
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Results
Pre-treatment Post-treatment 1 month Post-treatment 3 month
UCVA(logMAR) 0.380.51 0.170.41 0.150.39
BCVA(logMAR) 0.010.06 0.010.07 0.010.08
p lt 0.05, paired T test for pre-treatment
Post-treatment 3 months
Refractive error and UCVA changes through 3
months treatment
Refractive Improvement UCVA improvement
73.3 87.5
Refractive improvement manifest refraction
error (spherical or cylindrical) improvement of
more than 0.5D
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Change of UCVA(LogMAR)
UCVA (LogMAR) improved significantly through 3
months treatment.(plt0.05)
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Conclusion

• UCVA improved in 87.5 of patients much more
  than that of refractive error improvement(73.3).
• It is suggested that IOP lowering may induce the
  change of corneal curvature, according to 1-month
  result.
• IOP lowering agents may be helpful to reduce
  myopic regression.

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Discussion

• Although 3-month result showed no statistically
  significant change in corneal curvature, it is
  still though to be important mechanism that IOP
  lowering may induce the change of corneal
  curvature.
• Long term follow-up should be needed.
• We stopped the medication at 3 months and are
  evaluating patients to confirm the effect and
  mechanism.