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Patient history
His spectacle vision was inadequate and he was originally fitted with corneal rigid gas-permeable (RGP) contact lenses approximately 10 years ago to give him the best correctable vision.
The right eye had significant apical scarring and the visual acuity (VA) was only correctable to 6/24 Snellen. He ceased lens wear in this eye as he found the inferior image quality compared to that seen by the left created more of a binocular vision conflict than a benefit. He was awaiting a corneal graft in the right eye. He needed to continue lens wear in the left eye in spite of his CLAPC, as this was his only useful seeing eye.
His general health was good, he was on no medication and he was not aware of any allergies. There was no family history of any general health problems or any family ocular history of note.
Contact lens fitting history
Prior to his referral, the strategy had been to reduce the diameter of the corneal RGP lens in an attempt to alleviate the symptoms by reducing the surface area of the lens, therefore reducing the surface deposits and lessening the hypersensitivity reaction. This was successful for six months but unfortunately his symptoms recurred. Further reduction of the corneal RGP lens diameter was unsuccessful since this aggravated the CLAPC, perhaps due to the mechanical effect of the lens edge.
Drug history
His referring consultant ophthalmologist then prescribed the following treatment to enable him to continue lens wear:
gtts Predsol 0.5 per cent (preservative-free) qds left eye
gtts. Opatanol bd left eye
Presenting complaint
Although he was happy with the left corneal RGP contact lens VA, he was aware that the contact lens was attributable to the CLAPC. He was also concerned about the risks of long-term use of topical steroids.
Aim
To refit the left contact lens to try to reduce the CLAPC to an asymptomatic level, without the use of topical steroids.
Clinical examination
Unaided Vision: R 1/60 L 3/60
VA with RGP contact lens: L 6/6
Wearing time (average): 15 hours, seven days a week.
The left contact lens was a satisfactory keratoconic fit. The lens centred well and movement was adequate. There was good edge clearance 360º but was slightly reduced superiorly, and there was light central touch with good tear exchange (Figure 2).
Keratometry (K) readings: L 6.60 @ 10 6.15 @ 100
The corneal topography, taken with the Orbscan, showed central corneal elevation (Figure 3, top left), a steep asymmetric 'bow tie' with greater steepening inferiorly (Figure 3, bottom left) and a thin cornea centrally (Figure 3, bottom right).
Contact lens fitting
The intention of the referring consultant was to fit a non-ventilated RGP scleral contact lens, with the aim of reducing mechanical irritation to the superior tarsal conjunctiva attributing to the CLAPC.
However, this was aborted following a trial of a full diameter (23mm), and a reduced diameter (18mm) mini scleral, neither of which sealed sufficiently to prevent admission of air bubbles into the tear reservoir, created between the cornea and scleral lens.
The full diameter scleral leaked air bubbles due to the irregular topography of the sclera and the mini scleral snagged on the lower lid (Figure 4). Often mini sclerals can help to seal the lens on the eye, since the lens fits closer to the limbus.
An eye impression was taken in an attempt to improve the scleral zone sealing, but in view of the cumbersome and protracted prospects involved with this course of action, a trial of an extra limbal design was initiated. The same theory as for scleral lens fitting was applied here, since reduction of lens diameter had already been tried from the referring hospital.
Initially, a 14.00mm diameter S-lim lens (Jack Allen) with a sag of 3.32 {lens code SM21 (7.10/ 14.00/ -4.00DS)} was tried. This lens gave just compressive apical contact with a slightly tight mid-periphery. However, the edge clearance was good and a VA of 6/6 was attained with a -1.00DS over refraction. Figure 5 shows the lens on the eye at the fitting appointment.
The fitting of these lenses is based on the sag of the lens. One should note that the back optic zone radius of the lens in this case is significantly flatter than the K readings, and flatter than what the base curve would be for a corneal lens this is because of the greater sag associated with the larger diameter of these lenses.
A lens with an increased sag was then tried. The SM22 {sag 3.37 (7.00/ 14.00/-4.00DS)} alleviated the central contact but the best attainable VA was not as good, obtaining 6/9-1.
The SM21 {sag 3.32 (7.10/ 14.00/-5.00DS)} S-lim was therefore ordered with the following modifications:
? All peripheral curves flattened by 0.2
? 2 x fenestrations at 4mm in from edge (corresponding to mid-peripheral pool).
Collection appointment
Figure 6 shows the lens in situ on collection. The lens was sitting slightly superiorly, the movement minimal (because of the size of the lens), the edge clearance was optimal nasally and temporally, slightly excessive inferiorly and minimal superiorly.
However, when the lens dropped down the opposite was true, giving a dynamic variation in the edge clearance. There was light central touch with tear exchange, and light annular contact in the mid-periphery. The fenestrations aided the tear exchange and somewhat alleviated the mid-peripheral pool, but intermittent bubbles were still present underneath the lens.
These bubbles were mobile and therefore unlikely to cause any dimpling. The contact lens VA was 6/6.
Three-month follow-up
The patient wore the lens on average 15 hours a day on a daily basis and attained a VA of 6/6 with no over refraction. He was complaining of the left lower lid 'not blinking over the lens' and of inferior tarsal conjunctival hyperaemia.
He had seen his referring ophthalmologist five weeks prior to this appointment who had stopped his topical medication.
Slit lamp examination did reveal the lens resting on his left lower lid, (Figure 6) so the lens diameter was reduced by 1mm, and re-edged. After modification, slit-lamp examination revealed the lens only resting on the left lower lid intermittently, and it immediately felt more comfortable to the patient after insertion the fit was otherwise in the status quo (Figure 7).
Six month follow-up
There were no problems to report at six months. His wearing time, VA and contact lens fit (Figure 7) were stable. He decided to defer his right graft since he is keen on contact sports and was now managing well with a contact lens in the left eye without the use of topical steroids. He was seen two months previously by his referring ophthalmologist and his next follow up is in 10 months.
Conclusion
This demonstrates a case where increasing the diameter of the lens suitably, successfully reduced the symptoms of his CLAPC, and the patient did not require additional topical medication.
Discussion
The aetiology of CLAPC is multifactorial. The immunological response seen on the superior tarsus could be secondary to lens surface deposits1 and mechanical irritation from the lens.2
Soft lenses often cause CLAPC more than RGP corneal lenses.3 Often simply modifying the cleaning regime,4 including used of a protein remover,5 or frequent replacement of the lens4 can reduce symptoms. Furthermore, CLAPC can be managed by reducing the lens diameter, using a lens which is less likely to attract protein deposits (such as a non-ionic lens), minimising irritation from the edge of the lens, or changing the material to one which has less lid-lens friction. However, it may be necessary to add topical treatment,4 and mast cell inhibitors have been shown to be effective.6 Long-term use of a mast cell stabiliser or an antihistamine may be required to manage CLAPC successfully. Topical steroids are not often prescribed due to the potential threat to vision, but are sometimes used under medical supervision to effectively reduce symptoms.7
In this case, an alternative lens which could have been tried is a keratoconic soft lens such as the Kerasoft (Ultravision) or Soft K (Acuity Contact Lenses) lens, of course taking into consideration the factors discussed here.
References
1 Richard NR et al. Evaluation of tear protein deposits on contact lenses from patients with and without giant papillary conjunctivitis. CLAO J, 1992 18 (3): 143-7.
2 Richmond PP. Giant papillary conjunctivitis - a closer look. J Am Optom Assoc, 1980 51(3): 252-4.
3 Douglas JP et al. Giant papillary conjunctivitis associated with rigid gas permeable contact lenses. CLAO J, 1988 14 (3):143-7.
4 Katelaris CH. Giant papillary conjunctivitis - a review. Acta Ophthalmol Scand Suppl, 1999 (228): 17-20.
5 Korb DR et al. Treatment of contact lenses with papain. Increase in wearing time in keratoconic patients with papillary conjunctivitis. Arch Ophthalmol, 1983 101 (1): 48-50.
6 Bailey CS et al. Nedocromil sodium in contact-lens-associated papillary conjunctivitis. Eye, 1993 7 (3): 29-33.
7 Friedlaender MH et al. A double-masked, placebo-controlled evaluation of the efficacy and safety of loteprednol etabonate in the treatment of giant papillary conjunctivitis. The Loteprednol Etabonate Giant Papillary Conjunctivitis Study Group I. Am J Ophthalmol, 1997 123 (4): 455-64.
Acknowledgements
The author would like to thank Scott Hau, Ken Pullum and Dan Ehrlich for their help and support. She would also like to thank the medical illustration department at Moorfields Eye Hospital for the photographs.
Shreeti Lakhani is principal optometrist of the Contact Lens Service at Moorfields Eye Hospital in London. The author has no affiliation with any company mentioned