GP lens eye Rounds

POST-SURGICAL: Post-LASIK Corneal GP Case (left eye only)

Maria Walker OD, PhD, FAAO, FSLS

History

• CC: Blur and distortion at distance and near; s/p monovision LASIK procedure several years ago.
• HPI: Currently wears OTC +1.25 readers and reports trouble at all distances. Been trying to be fitted by another doctor for >1 year in soft MF lenses and having failures with every brand. Reports doubling of images (ghosting) with the left eye.

Examination

• Entering visual acuities:
  • With spectacles: OD 20/60- OS 20/20
• Entrance testing: normal
• Refraction (reporting distortion OU)

OD: +1.50 -1.00 x 001, 20/20-
OS: +0.25 -0.50 x 105, 20/20-

• Slit Lamp Examination

• Corneal topography (Figure 1)
• Other auxiliary testing:
  • Tear osmolarity:
    • OD: 302mOsm
    • OS: 319mOsm
  • InflammaDry: (+) result OU
• DFE: normal OU
• Lens fitting (Figure 2)
• Assessment:
  • Hypermetropia, irregular astigmatism, and presbyopia OU – good vision, fit and comfort with corneal GP lenses.
  • Dry eye syndrome OU – able to tolerate corneal GP lenses
• Plan:
  • 1 & 2. Finalized corneal GP lens wear OU. Pt educated to use artificial tears as needed. Clean with GP multipurpose solution and periodic enzymatic cleaning.

 Figure 1: Corneal topography. Ks OD: 40.82 / 43.96. Ks OS: 43.45 / 45.10. The elevation maps OU show an elevation difference from “peak” to “valley” of 100-125 um.

Lens Fitting Process

 Figure 2: Contact lens fitting assessment. Two trials were ordered per eye. First trials were too flat OU, steepened and incorporated over-refraction to improve the fit.

Decision-Making Process

• Patient has intra-pupil corneal irregularities and a flat cornea, which make it difficult to achieve suitable vision with spectacles or soft contact lenses.
• Rigid lenses will provide most stable vision – pt has MGD, dry eye with an inflammatory component, and excess debris in the tear film, as well as small apertures and a history of difficulty with soft contact lens application, so the enthusiasm for a scleral is limited.
• Reverse geometry lenses should be considered in post-refractive surgery cases but only if the cornea is oblate in shape. In this case, patient is still prolate in shape.

Clinical Pearls

• Inflammatory dry eye and MGD can be a challenge for soft lens fitting and can exacerbate symptoms like MDF and lens comfort
• Post-LASIK patients often have challenges being fitted with SCL after the procedure due a flat cornea (subsequent poor fit). In this case, the patient was still >40D so not extremely flat but experienced some discomfort due to instability of lenses on her irregular cornea and likely due to MGD.

Beneficial Resources

1. https://www.reviewofcontactlenses.com/article/fitting-rigid-lenses-after-refractive-surgery
2. Steele C, Davidson J. Contact lens fitting post-laser-in situ keratomileusis (LASIK). Cont Lens Anterior Eye. 2007 May;30(2):84-93. https://pubmed.ncbi.nlm.nih.gov/17329148/
3. Tan G, Yang J, Chen X, He H, Zhong X. Changes in wave-front aberrations after rigid gas permeable contact lens fitting in post-laser in situ keratomileusis patients with visual complaints. Can J Ophthalmol. 2010 Jun;45(3):264-8. https://pubmed.ncbi.nlm.nih.gov/20436548/
4. Tan G, Chen X, Xie RZ, He H, Liu Q, Guo Y, Liao A, Zhong X. Reverse geometry rigid gas permeable contact lens wear reduces high-order aberrations and the associated symptoms in post-LASIK patients. Curr Eye Res. 2010Jan;35(1):9-16. https://pubmed.ncbi.nlm.nih.gov/20021249/