The Protective Advantage of Scleral Contact Lenses
Maria K. Walker OD MS, Patrick Caroline, Beth Kinoshita OD, Matt Lampa OD, Frank Zheng OD, Mark André, Randy Kojima
Pacific University College of Optometry, Forest Grove, Oregon
Impact-resistant safety glasses provide the maximum protection from potential foreign body injury. Rigid corneal contact lenses also provide an environmental barrier; however, their protective benefits remain controversial.1-5
The re-emergence of scleral contact lenses has broadened the spectrum of contact lens protective functions. These large-diameter (14-22mm), thick (0.30-0.45mm) lenses provide a formidable barrier to both the cornea and the adjacent sclera (Figure 1). Additionally, they feature a deep underlying tear reservoir that acts as a cushion, further shielding the cornea from foreign body penetration.
Here we present the case of a woman who was spared serious ocular injury by virtue of her scleral contact lenses.
Figure 1. These large-diameter (14-22mm), thick (0.30-0.45mm) lenses provide a formidable barrier to both the cornea and the adjacent sclera
Our patient, a 64-year-old elementary school teacher with bilateral keratoconus, has been wearing scleral contact lenses since 2010. She presented to the clinic reporting that one week prior, while fixing a jam in her electric stapler, a staple sprang from the device and hit her left eye with a “force that put a hole through the hard contact” (Figure 2). The patient recalled that immediately after the incident, she experienced moderate pain (3/10) and conjunctival redness. She removed her left lens, and the eye remained mildly irritated for 1-2 days.
Figure 2. Examination of the contact lens revealed a 1x2mm full-thickness hole with relatively clean edges and minimal adjacent lens cracking.
When the patient presented to the clinic one week after the incident, her left eye was white and quiet (Figure 3). She was wearing a backup lens, and entering acuities were 20/25 OD, 20/20- OS. We speculate that the staple hit the lens and ricocheted away from the eye, with some of the broken lens fragments entering the scleral lens tear chamber and surrounding ocular environment. The minor abrasive injuries, created by these fragments, manifested as the slight irritation experienced by the patient in the days following the incident.
Figure 3. When BZ presented to the clinic 1 week after the incident, her left eye was white and quiet with no abrasive injuries.
Discussion & Conclusion
The rigidity of a scleral contact lens, as well as the deep tear reservoir beneath, provide a strong protective barrier to the cornea and anterior segment. If this patient had not been wearing scleral lenses, the result would likely have been traumatic.
This example does not imply that rigid contact lenses are a replacement for safety spectacle eyewear, but this is a remarkable example of the unique protective benefit of wearing scleral contact lenses.
Poster presented at the Global Specialty Lens Symposium 2015
Mandell, RB. Contact Lens Practice. 3rd ed. Charles C. Thomas Publisher. 1981.
Dohlman CH, Dudenhoefer EJ, Khan BF, Morneault S. Protection of the ocular surface after keratoprosthesis surgery: the role of soft contact lenses. CLAO. (2002): 28(2);72-74.
Romero-Rangel T, Stavrou P, Cotter J, Rosenthal P, Baltatzis S. Foster CS. Gas-permeable scleral contact lens therapy in ocular surface disease. Am J of Ophthalmology (2000). 130(1); 25-32.
O’rourke PJ. Traumatic fracture of contact lens with corneal injury. Brit J Ophthal. (1971) 55:125-127.
Dixon JM, Lawaczeck E. Some disadvantages of contact lenses. Eye, Ear, Nose and Throat Mon., (1964); 43(9):62-63.
Maria K. Walker is currently an Assistant Clinical Professor at The University of Houston College of Optometry. She completed a Cornea & Contact Lens Residency at Pacific University College of Optometry in Forest Grove, Oregon, and received her Doctorate of Optometry and Master’s in Vision Science from The New England College of Optometry in 2013. Her main interests include contact lens optics, corneal physiology, and multifocal lens performance in presbyopia and myopia control.