Scleral Lens Fit for Symptomatic Patient with Keratoconus
William J. Denton, OD, FAAO
Home:
822 Acacia Dr.
Sumter, SC 29150
(803)236-7589
Work:
6439 Garners Ferry Rd., Optometry Clinic – 2D153
WJB Dorn VAMC
Columbia, SC 29209
ABSTRACT:
Introduction: Keratoconus is a near central corneal thinning at the layer of the stroma, creating a physical out-pouching and optically irregular astigmatism and associated aberrations, which can lead to further complications causing decreased vision and most likely surgery. Case Report: DC is a 56 year-old Caucasian veteran came to the WJB Dorn VA medical center contact lens clinic with a long history in our program starting before 1998. Recently, he presented with keratoconus with substantial complaints related to allergic conjunctivitis and dry eye syndrome. Conclusion: Switching him from his present contact lens system to scleral lenses has dramatically improved his symptoms, proven with the Ocular Surface Disease Index (OSDI) questionnaire.
Key Words: Keratoconus, Piggyback Fitting Method, Dry Eye Syndrome, Scleral Lenses
INTRODUCTION:
Keratoconus is a near central corneal thinning at the layer of the stroma, creating a physical out-pouching and optically irregular astigmatism and associated aberrations. Clinically inferior keratometry readings can determine the extent of the disease. Less than 48D would be considered mild, 48-54D as moderate and greater than 54D as severe.1 The prevalence of keratoconus is 8.8 to 54.4 per 100,000 with no gender predilection. 2 There are too many disease associations with keratoconus to list in this case report. They include multisystem disorders, systemic disorders, ocular disorders and other corneal disorders. The offspring of patients with keratoconus are only affected in approximately 10% of cases. It is observed that keratoconus has an autosomal dominant inheritance with incomplete penetrance.1 This report will concentrate on clinically relevant information. A patient with unilateral keratoconus, would be more rare; however, it is more likely that it is bilateral with an asymmetric presentation.1 Asymmetry is more likely earlier in life as the disease begins at puberty and progresses until the third to fourth decade of life.1,3
CASE REPORT:
DC is a 56 year-old Caucasian veteran who came to the WJB Dorn VA medical center contact lens clinic with a long history in our program starting before 1998. He was diagnosed early on with keratoconus and was managed with many types of contact lenses including: Soper rigid gas-permeable (RGP), three different Boston material lenses, Rose K, Dyna Z large diameter, piggyback style, and Synergeyes prior to being considered for scleral contact lenses. Additionally, DC has quite a history of ocular allergies, dryness, and hordeola. Over the last ten or more years he was given carboxymethylcellulose ophthalmic solution, ketorolac ophthalmic solution, olopatadine ophthalmic solution, gentamicin ophthalmic solution (infection), lanolin ophthalmic ointment, Restasis® ophthalmic emulsion, tobramycin ophthalmic solution (infection/allergy), rimexolone ophthalmic suspension , cromolyn sodium ophthalmic solution, chlorphenamine tablet, and punctal plugs in no specific order. The patient also found that Similasan, an herbal eye drop preparation, also assists greatly. His son also had been diagnosed with keratoconus and was applying for disability, did not have a valid driver’s license and was without employment.
DC’s ocular health has been managed for over ten years in the optometry disease clinic. The posterior pole was unremarkable during the last examination.
DC was our first contact lens patient who was fit with scleral contact lenses in our clinic. After proper training and receiving trial sets, DC jumped at the opportunity to try anything that may allow for better comfort, improvement in his vision, or at least a decrease of his dryness symptomology. It is important to state that he was content with his previous contact lens situation, which consisted of SynergEyes Clear Kone hybrid contact lenses (SynergEyes, Inc, Carlsbad, CA). He routinely had to take his lenses out at least every two hours to clean them. He also had severe dryness symptoms and used Restasis® ophthalmic emulsion bid ou, Similasan (#2 Allergy) drops q30min OU, lanolin ophthalmic ointment and olopatadine ophthalmic solution bid ou. He was given the Ocular Surface Disease Index (OSDI) questionnaire and reported a 64.5 index prior to scleral lens fitting. He was asked to quantify his quality of life (scale: 1 worst, 10 best) before fitting with scleral lenses and he stated a 3, because of all the drops and cleaning he had to do. Despite his enthusiasm to try any other option, he did acknowledge it may not be any better than his current situation. He was encouraged to be fit with scleral contact lenses in order to improve his dryness and allergy symptoms, meanwhile keeping his present level of visual acuity.
Systemic diseases/complications and treatments included:
Problem: / Medication/Device:Carpal Tunnel Syndrome / Naproxen
Degenerative Disc Disease
Gastroesophageal Reflux Disorder / Omeprazole
Gout / Allopurinol
Keratoconus / RGPs
Hyperlipidemia / Gemfibrozil
Simvastatin
Sleep apnea / CPAP machine
Dry Eye Syndrome / Lubricating ophthalmic ointment
Refresh artificial tears
Similasan eye drops #2 Allergy
Restasis® ophthalmic emulsion
Seasonal allergies / Loratadine
Fluticasone
Asthma / Albuterol
Initial Visit:
DC had a long history of contact lenses with varying results. His last contact lens parameters were:
Habitual Contact Lens Parameters:
OD: Clear Kone hybrid lens (SynergEyes, Inc, Carlsbad, CA)
Power: +4.50
Base Curve: 2.00 vault, medium skirt curve
Diameter 14.5
Assessment:
*Very little movement
*Centered
*Appropriate edge
*Good vision
OS: Piggyback Method
Intralimbal RGP (Lens Dynamics, Inc., Kansas City, MO)
Power: -3.00 D
Base Curve: 6.75 BC
Diameter: 11.2
Focus Night & Day (CIBA VISION Corporation, a Novartis AG Company)
Power: -0.50 D
Base Curve: 8.4
Diameter: 14.5
Assessment:
*Very little movement
*Centered
*Appropriate edge
*Good vision
Habitual glasses prescription: (from ten years ago)
OD: -9.00-5.00x135
OS: -4.00-3.50x135 +2.50 FT
*Patient does not wear his glasses.
The anterior segment examination showed the following signs: some corneal thinning (PACHs: 448 OD, 406 OS), quite obvious Munson’s sign OU, a trace amount of apical scarring OU with a Fleisher ring, Vogt’s striae OU, trace diffuse conjunctival injection, early pingueculae nasal and temperal OU, <1mm of neovascularization on the cornea 360o and 1+ central corneal staining OU. His puncta were open and without punctal plugs. His previous dilated examination showed no additional ocular health concerns.
Keratometry was not performed prior to this fitting. It is suspected that this was done prior to the implementation of computerized records and that each RGP fit was changed slightly from the prior habitual fit. DC was fit with scleral lenses without initial keratometry readings or corneal topography. It was solely performed through trial and error.
The initial few trial lenses were inserted OD without allowing for settling time due to an inadequate fit. The last/fourth lens was inserted with fluorescein strip coloring the fluid and allowed to settle for approximately thirty minutes. The patient was instantly impressed with both the comfort and the visual acuity once the over-refraction was determined. The same lens was started in the OS and a flatter base curve was initially ordered.
OD: Jupiter (Essilor Contact Lenses, Denver, CO)
Diameter: 15.6
Base Curve: 6.37
Power: -13.00 D
Over-refraction: +6.25 D 20/25
Assessment:
*No bubbles with adequate clearance central/peripheral
*Well centered
*No blanching
Subjective: Good vision; good comfort.
OS: Jupiter (Essilor Contact Lenses, Denver, CO)
Diameter: 15.6
Base Curve: 6.37
Power: -13.00 D
Over-refraction: +4.75 D 20/25
Assessment:
*No bubbles with adequate clearance central/peripheral
*Decentered 1mm nasally
*No blanching
Subjective: Good vision; good comfort.
Order #1:
Second Visit:
At the follow-up appointment, the lenses were inserted with fluorescein strips coloring the fluid and allowed to settle for approximately thirty minutes (Figures 1-6).
OD: Jupiter (Essilor Contact Lenses, Denver, CO)
Diameter: 15.60
Base Curve: 6.37
Power: -6.75 D
Over-refraction: +1.25 D 20/25
Assessment:
*No blanching
*Good central vault without touching peripherally.
*Well centered
Subjective: Patient extremely pleased with vision and comfort.
OS: Jupiter (Essilor Contact Lenses, Denver, CO)
Diameter: 15.6
Base Curve: 6.37
Power: -8.25 D
Over-refraction: +1.25 D 20/20
Assessment:
*No blanching
*Good central vault without touching peripherally
*Well centered
Subjective: Patient extremely pleased with vision and comfort.
Order #2:
The patient was instructed to use a peroxide-based cleaning system, which he was already using with great success. He also was instructed to pick up 0.9% sodium chloride inhalation solution (off label) at the VA pharmacy window for insertion of the lenses. Insertion and removal training was performed and the patient picked it up quite easily. The lenses were given to the patient so he could practice insertion and removal, but was warned that if he wore them that headaches and eye strain at near would occur. The change in the over-refraction was made and the patient was called for the next appointment when his next pair of lenses arrived.
Figures 1-3: OD fit
Figures 4-6: OS fit
Third Visit:
When DC arrived to this visit, he was given the newest lenses to insert himself to observe his technique. He was quite proficient and it was obvious he had been practicing insertion and removal of his lenses. No fluorescein strips were used prior to insertion.
OD: Jupiter (Essilor Contact Lenses, Denver, CO)
Diameter: 15.60
Base Curve: 6.37
Power: -5.50 D
Over-refraction: plano 20/20
Assessment:
*No blanching
*Good central vault without touching peripherally
*Good centration
Subjective: Patient extremely pleased with vision and comfort.
OS: Jupiter (Essilor Contact Lenses, Denver, CO)
Diameter: 15.6
Base Curve: 6.37
Power: -7.00 D
Over-refraction: Plano 20/20
Assessment:
*No blanching
*Good central vault without touching peripherally
*Well centered
Subjective: Patient extremely pleased with vision and comfort.
After his vision was checked and over-refraction was performed, fluorescein strips were wet and smeared on his superior conjunctiva and sent out to the waiting room for thirty minutes. Upon return, DC showed fluorescein dye in his tear lens behind the scleral lens. He was asked to return in 3 months for a follow-up visit.
Fourth Visit:
DC was seen three months later to assess his scleral lenses. He bragged at length how comfortable his lenses were and that he even noticed better vision than before. Additionally, he mentioned he only had to take the lenses out once a day to clean, instead of every two hours. His eye drops now consisted of Similasan qd-bid OU, patanol prn ou, lanolin ophthalmic ointment qhs ou, restasis qam ou. The post-fitting OSDI questionnaire was filled out also, recording a 0.00 index score. He was asked to quantify this quality of life (scale: 1 worst, 10 best) after being fit with scleral lenses and reported a 9 due to the fact that “he still had to wear lenses for maximum vision”. Table 1 shows the pre- and post-scleral lens fitting results. He left our clinic stating he will be getting his son fit with scleral lenses. Since then his son has been successfully fit, has a restricted driver’s license and is employed.
Table 1: Pre- and post-scleral fitting comparisons
Pre-Fitting / Post-FittingOSDI: / 64.6 / 0
Quality of Life (1-10): / 3 / 9
Symptoms: / Dryness / None
Itching
Blurred vision
Medications: / Similasan (#2 Allergy) q30min OU / Similasan (#2 Allergy) qd-bid OU
Olopatadine ophthalmic solution bid ou / Olopatadine ophthalmic solution prn ou
Lanolin ung qhs ou / Lanolin ung qhs ou
Restasis® ophthalmic emulsion bid ou / Restasis® ophthalmic emulsion qam ou
*Max # of med instillations per day: / 29 / 5
*Mechanical Rub Cleaning: / q2h / q6h
*Assuming 12 hr wearing
DISCUSSION:
Symptoms that are common for patients with keratoconus include, frequent changes in spectacle prescription, decreased tolerance to contact lens wear, glare.1 The author has noticed a tendency of many patients with moderate to severe keratoconus prefer additional minus in their glasses that can be explained by the expected contrast sensitivity reduction. Caution and awareness of this is important not to cause near vision symptoms or headaches. Some theorize that keratoconus is the result of mechanical rubbing.4 Research has suggested that inflammatory mediators, proteins and enzymes may be in the tears.3,5 Additionally, patients with concomitant autoimmune and allergic immune diseases may point to an immune component in the pathogenesis of keratoconus.6 With all pubescent patients who rub their eyes or are on anti-allergic ophthalmic drops, it wouldn’t take much to scan the cornea and perform keratometry readings. It is important to compare central keratometry readings with readings with the patient looking up slightly. On a typical keratometer this can be the “+” sign about an inch above the usual target.
Many times, keratoconus is not found as a reason for decreased vision due being an early stage and not routinely recording keratometry readings on all patients. There are some signs that are possible, but not necessarily rules, for patients with keratoconus.1 An “oil droplet” reflex may be seen with the direct ophthalmoscope at a distance. “Scissor” reflex with retinoscopy due to irregular astigmastism. During the slit lamp examination, fine vertical and deep stromal striae can be seen, known as “Vogt lines or striae”, which disappear with external pressure on the globe. A brownish or olive green “Fleisher ring” can be seen surrounding the base of the cone indicating epithelial iron deposits.1,5 Progressive corneal thinning up to one-third of normal thickness centrally or inferocentrally can occur resulting in both reduction in vision and steep keratometry. “Munson sign” can be appreciated when the patient looks down and the bulge of the cornea is outlined by the lower lid.
Most patients who are diagnosed with keratoconus will have plenty of questions regarding the disease. It is important to instruct them what to look for and to keep in touch with you regarding their eyes. The clinician must also know what to check during each contact lens or annual ocular examination. Complications include acute hydrops, thinning and even spontaneous perforation. 7 Acute hydrops are caused by a rupture in Descemet’s membrane allowing an influx of aqueous into the cornea and a drop in visual acuity and significant discomfort and watering. Healing takes about a couple months for the breaks to close and edema to clear. Stromal scarring may develop. Acute episodes are treated with hyperosmotics and a soft bandage contact lens when possible. An ironic outcome may result in better vision due to a flattening of the cornea from scarring.1