GP lens eye Rounds

KERATOCONUS: Adult Hybrid Keratoconus Case

Deepa Chandrasekaran MS, OD, FAAO, FIACLE

History

• HPI: 41-year-old African-American female with history of Keratoconus OU (OD > OS) since she was 28 years old was monitored by the Veterans Affairs with annual dilated eye examinations came to the Contact Lens (CL) clinic to be refitted in hybrid CLs. She was fit in hybrid CLs by an outside provider and her current hybrid contact lenses were more than one year old. The right hybrid CL tore and her left hybrid CL fell down the sink. She used preservative free (PF) 0.9% NaCl solution to fill the bowl of the hybrid lenses before she wore them. She does not sleep/shower/swim with her CLs in. She came in wearing her glasses to the appointment.
• CC: Needs new hybrid contact lenses for better vision as the vision with her glasses is not as good as with her contact lenses. With her previous hybrid CLs, she had to remove the lenses once mid-day and refill the lenses with PF saline for best comfort and vision. Her previous hybrid contact lenses were: OD: Ultrahealth 250 FLAT/-8.00D/14.5mm and OS: Ultrahealth 250 FLAT/-9.50D/14.5mm
• Modifying factors: She had symptoms of occasional eye dryness for which she used lubricating eye drops as needed.

Examination

• Entering visual acuities (VAs)(with current spectacle Rx):

OD: 20/30-2 w/PH 20/20-2
OS: 20/40 w/PH 20/25
Near VA: 0.50M binocularly

• Current spectacle Rx (2 years old; from an outside provider):

OD: -3.50 +1.00 X 110
OS: -2.00 +1.50 X 066

• Manifest Refraction:

OD: -3.50 +1.00 X 150 (20/20)
OS: -3.00 +0.75 X 065 (20/20)
No add in both eyes

• Slit Lamp Examination (OD & OS):

• Corneal Tomography (Oculus Pentacam Holladay Report)(Figure 1):

Keratometry:

OD: 46.01D @ 089/43.53D @179
OS: 44.20D @ 079/43.23D @ 169

Pachymetry:

OD: 459 um
OS: 505 um
HVID: 11.6 mm OD & OS

Decision-Making Process

• • Given the punctate epithelial erosions in both eyes, she was advised to use OTC PF eye drops four times a day until her contact lenses arrived, for better comfort.
  • She was advised to remake her glasses to give her the best vision possible.
  • The patient desired to continue wearing hybrid contact lenses and, as her comfort was good with them, it was decided to reorder her previous hybrid lenses, assess the fit of the lenses, and then make changes to the parameters of the lenses, instead of performing a new hybrid CL fitting in both eyes.

Fitting and Evaluation

• • The following hybrid CLs were ordered.

OD: Ultrahealth 250 FLAT (8.4)/-8.00D/14.5mm
OS: Ultrahealth 250 FLAT (8.4)/-9.50D/14.5mm

• • First dispense: Both hybrid lenses were applied with fluorescein in the bowl of the lenses and the fit and vision with them were assessed after five minutes of application. The lenses exhibited adequate apical clearance (cleared the apex of the cone; about 100 microns) with inner landing zone (ILZ) bearing (decreased corneal clearance in this area) in both eyes. Vision was OD: 20/25-2 and OS: 20/20. She was comfortable with the lenses but given the ILZ bearing, it was decided to try a steeper skirt in both eyes.
  • Hybrid refitting was performed on that day. Medium skirt hybrid lenses were inserted with fluorescein in the bowl of the lenses and the fit and vision with them were assessed after five minutes of application.
    OD: Ultrahealth 250 MED (8.1)/-9.00D/14.5mm; 20/30; SOR: +0.50 DS (20/25+); per the patient, this lens felt the same as the FLAT skirt CL
    OS: Ultrahealth 250 MED (8.1)/-9.00D/14.5mm; 20/20-; SOR: PL (20/20-); per the patient, this lens felt better than the FLAT skirt CL
    Both lenses exhibited adequate apical clearance (cleared the apex of the cone; about 100 microns) with a thin layer of fluorescein in the inner landing zone (ILZ) (adequate corneal clearance in this area) in both eyes.
  • New hybrid CLs were ordered.

OD: Ultrahealth 250 MED (8.1)/-8.50D/14.5mm
OS: Ultrahealth 250 MED (8.1)/-9.00D/14.5mm

• • The patient returned for the second hybrid CL dispense and evaluation appointment.
    Second dispense: Both hybrid lenses were inserted with fluorescein in the bowl of the lenses and the fit and vision with them were assessed after five minutes of application. Both lenses exhibited adequate apical clearance (cleared the apex of the cone; about 100 microns) with a thin layer of fluorescein in the inner landing zone (ILZ) (adequate corneal clearance in this area) in both eyes. VA at distance, OD: 20/25 (NI further with OR) and OS: 20/20. She was able to read 20/20 binocularly at near with these lenses without needing any add power. She was advised to replace the lenses every six months and use hydrogen peroxide solution to clean and store the lenses overnight. She was also advised to use PF 0.9% sodium chloride solution to fill the bowl of the hybrid lenses before she wore them. She was advised to not sleep/shower/swim with her CLs in.
  • One-month follow-up visit: She was very happy with the fit and the vision with the hybrid CLs. The hybrid lenses fit the same as before with the same level of vision as before. Plan: Lenses were finalized. She was advised to return in one year for a hybrid CL recheck. Figures 2a and b below show the fit of the hybrid CLs in the right and left eye respectively, after instilling fluorescein in the bowl of the lens and viewing with a diffuse illumination under a slit-lamp with a blue light filter.

Figure 2: a: OD hybrid fitting relationship; b: OS hybrid fitting relationship

Clinical Pearls

• • Hybrid contact lenses offer the optics of a GP lens and the comfort of a soft lens.
  • Hybrid contact lens fitting is made easier with fitting guides from manufacturers and the more experience a contact lens fitter gains in working with these lenses on patients with different eye conditions, the easier they are to fit and problem-solve and the less chair-time that is necessary with a patient.
  • Ultrahealth hybrid lenses are a great choice for patients with keratoconus, ectasias, post-surgical, post corneal cross-linking, intacs, and other corneal irregularities as they have a proprietary reverse geometry, aspheric GP center (hyper-Dk material) with a high-Dk silicone hydrogel soft skirt, often resulting in both good vision and initial comfort for the patient.