GP lens eye Rounds

OCULAR SURFACE DISEASE: Dry Eye Case

Julie Song OD, FAAO, FSLS

History

• 70-year-old female is a long time monovision GP lens wearer who had been struggling with her dry eye symptoms. She reported the lenses felt “stuck on” and had difficulty with lens removal. She also experienced itching with her lenses.
• The patient had previously tried preservative-free artificial tears, warm compresses, olopatadine 0.2%, doxycycline 50 mg capsule, nighttime ointment, punctal plugs, and Tobradex, but was still very symptomatic. She did not have any remarkable medical history or systemic conditions.

Examination

• Entering Visual Acuites (VAs): OD 20/20, OS 20/40, OU 20/20
• Manifest Refraction: OD -4.25 -1.75 X 045; OS -2.25 -0.75 X 135; near Add +2.25D; BCVA 20/20 OD/OS/OU
• Slit Lamp Examination:

• Dilated Fundus Examination: Mild peripheral reticular degeneration in the form of pigment migration in far periphery, otherwise unremarkable.

Decision-Making Process

• It is important to determine the root cause of what is inducing dry eye symptoms. For example, this particular patient’s differential diagnoses can include keratoconjunctivitis sicca, rosacea conjunctivitis, meibomian gland dysfunction, demodex blepharitis, staphylococcal blepharitis, and seborrheic blepharitis. Diagnosing the patient with the appropriate condition is necessary to prescribing the appropriate treatment modality.
• For dry eye patients who have already exhausted multiple dry eye treatment modalities, scleral lenses can be a tertiary or quaternary treatment option.
• As the patient was already wearing gas permeable contact lenses and appreciated the visual clarity that it affords, we discussed proceeding with scleral lens fitting so that she could achieve additional relief without giving up her visual clarity.

Fitting and Evaluation

• Diagnostic scleral lens fitting typically begins with selecting an initial starting diameter. This is typically determined by the patient’s horizontal visible iris diameter. However, for ocular surface disease patients, this diameter might be larger to cover more surface area. For this patient, although we were prescribing scleral lenses partially for dry eye disease purposes, we chose a 15.4mm overall diameter lens to start with because she had small vertical apertures and was not able to get her eyelids open large enough for a larger diameter lens.
• To choose a starting sagittal depth, review the patient’s K values on the corneal topography scan and follow the contact lens manufacturer’s fitting guide to select a starting lens.
• c) According to the Scleral Shape Study Group, only 5.7% of scleral shapes are spherical1, so it is best practice to start with a diagnostic scleral lens that has a toric periphery.
• d) Despite the ideal recommendations, sometimes diagnostic fitting can be limited based on the trial lenses available in office. For example, due to the limited availability of trial lenses
• e) Initial Diagnostic Scleral Lens:
  • OD: Power: -2.00D; Overall Diameter (OAD): 15.4mm; Base Curve (BCR): 7.5mm; 4400 SAG; standard edge; material: Hyper Dk F-S/A; center thickness (CT): .25mm
    • Centered
    • No movement
    • Central: 1:1/2 vault
    • Paracentral: 1:1/2 vault
    • Midperipheral: 1:1/2 vault
    • Limbal: 1:1/4 vault
    • Edges: alignment
  • OS: Power: -2.00D; Overall Diameter (OAD): 15.4mm; Base Curve (BCR): 7.42mm; 4500 SAG; standard edge; material: Hyper Dk F-S/A; center thickness (CT): .25mm
    • Centered
    • No movement
    • Central: 1:1 vault
    • Paracentral: 1:1/2 vault
    • Midperipheral: 1:1/3 vault
    • Limbal: 1:1/3 vault
    • Edges: alignment
  • BCVA with over-refraction is 20/20 OD/OS; however, OS was to be maintained as the near eye in a monovision modality so it was 2D under-corrected to achieve adequate near visual acuity and match the habitual gas permeable lenses.
• First Trial Order
  • OD: Power: -6.00D; OAD: 15.4mm; BCR: 7.5mm; 4400 SAG; standard edge; material: Hyper Dk F-S/A; CT: .25mm
    • Centered
    • No movement
    • Central: 1:1 vault
    • Paracentral: 1:1 vault
    • Midperipheral: 1:1/2 vault
      Limbal: 1:1/4 vault
    • Edges: alignment
  • OS: Power: -2.00D; OAD: 15.4mm; BCR: 7.42mm; 4500 SAG; standard edge; material: Hyper Dk F-S/A; CT: .26mm
    • Centered
    • No movement
    • Central: 1:3/4 vault
    • Paracentral: 1:1/2 vault
    • Midperipheral: 1:1/3 vault
    • Limbal: 1:1/4 vault
    • Edges: alignment
  • After over refracting and binocular balancing the patient, a power change of +0.50D OU was determined.
• Final Scleral Lens Prescription with post-lens tear film settling after four hours
  • OD: Power: -5.50D; OAD: 15.4mm; BCR: 7.5mm; 4400 SAG; standard edge; material: Hyper Dk F-S/A; CT: .25mm
    • Centered
    • No movement
    • Central: 1:3/4 vault
    • Paracentral: 1:1/2 vault
    • Midperipheral: 1:1/3 vault
    • Limbal: 1:1/4 vault
    • Edges: alignment
  • OS: Power: -1.50D; OAD: 15.4mm; BCR: 7.42mm; 4500 SAG; standard edge; material: Hyper Dk F-S/A; CT: .26mm
• Slit lamp examination findings after discontinuing gas permeable lens wear and switching to scleral lenses:

• • The patient appreciated significant improvement in visual comfort and dry eye symptoms after continuous scleral lens wear.

Clinical Pearls

• Consider moving symptomatic dry eye patients who are already contact lens wearers into scleral lenses if they have tried many different dry eye treatment modalities without significant improvement in clinical signs and/or symptoms.
• Make sure you are using the appropriate vital dyes to examine the patient’s anterior segment: sodium fluorescein for tear film and cornea, lissamine green for corneal and conjunctiva.
• If the patient has meibomian gland dysfunction, prescribe dry eye treatment to manage it alongside scleral lens wear.

Beneficial Resources

1. Craig JP, Nelson JD, Azar DT, et al. TFOS DEWS II Report Executive Summary. The Ocular Surface 2017;1-11.
2. DeNaeyer G, Sanders D, van der Worp E, Jedlicka J, Michaud L, Morrison S. Qualitative Assessment of Scleral Shape Patterns Using a New Wide Field Ocular Surface Elevation Topographer: The SSSG Study. Journal of Contact Lens Research and Science 2007;1(1):12-22.