ARTICLE

Scleral Lenses in the Management of Keratoconus

Muriel M. Schornack, O.D., and Sanjay V. Patel, M.D.

Management of patients with keratoconus consists primarily of Purpose: To describe the use of Jupiter scleral lenses (Medlens Innova- providing optical correction to maximize visual function. In very tions, Front Royal, VA; and Essilor Contact Lenses, Inc., Dallas, TX) in the management of keratoconus. mild or early disease, spectacle correction or standard hydrogel or Methods: We performed a single-center retrospective chart review of our silicone hydrogel lenses may provide adequate vision. However, initial 32 patients with keratoconus evaluated for scleral lens wear. All disease progression results in increasing ectasia, which gives rise patients were referred for scleral lens evaluation after exhausting other to complex optical aberrations. Rigid gas-permeable contact lenses nonsurgical options for visual correction. Diagnostic lenses were used in mask these aberrations by allowing a tear lens to form between the the initial fitting process. If adequate fit could not be achieved with contact lens and the irregular corneal surface. Zadnik et al. found standard lenses, custom lenses were designed in consultation with the that 65% of patients who enrolled in the Collaborative Longitudi- manufacturers’ specialists. The following measures were evaluated for nal Evaluation of Keratoconus study were wearing rigid gas- each patient: ability to tolerate and handle lenses, visual acuity with scleral permeable lenses in one or both eyes at the time of enrollment.4 lenses, number of lenses, and visits needed to complete the fitting process. Despite their optical benefit, corneal rigid gas-permeable lenses Results: Fifty-two eyes of 32 patients were evaluated for scleral lens may not be appropriate for all patients with keratoconus. In advanced wear. Of these, 12 patients (20 eyes) decided not to pursue scleral lens wear after initial evaluation. One patient (2 eyes) abandoned the fitting process cases, surface irregularity may increase the likelihood of significant after cataract surgery. The remaining 19 patients (30 eyes) were fit lens decentration or even dislocation, and some patients cannot adapt successfully. The average number of lenses ordered per eye was 1.5. The to the lens sensation induced by standard corneal lenses. Other fitting process required an average of 2.8 visits. Standard lenses were patients live or work in dry or dusty environments that are not prescribed for 23 eyes, and custom designs were needed for 7 eyes. Median conducive to corneal rigid gas-permeable lens wear. Piggyback lens best-corrected visual acuity improved from 20/40 (mean, 20/76) before systems or hybrid lenses may provide adequate comfort in some of scleral lens fitting to 20/20 (mean, 20/30) after fitting. Follow-up ranged these patients, but they also increase the complexity and cost of lens from 3 to 32 months. wear and storage. In addition to presenting fitting and adaptation Conclusions: Jupiter scleral lenses provide acceptable visual acuity and challenges, corneal rigid gas-permeable lenses may be associated with comfort in patients with keratoconus. The availability of diagnostic lenses an increased risk of corneal scarring in patients with keratoconus.5–7 facilitates the fitting process. The use of large-diameter “contact shells” in the management of Key Words: Keratoconus—Scleral contact lenses—Visual acuity—Ectasia. keratoconus was initially described by Kalt in 1888,8 at approxi- mately the same time as Mueller9 and Fick10 were describing their Ϫ (Eye & Contact Lens 2010;1: 39 44) experiments with blown glass shells. Manufacturing challenges and complete lack of oxygen permeability of these early lenses limited their use. The development of computer-assisted manufac- eratoconus is a noninflammatory, ectatic corneal disorder turing processes and the introduction of gas-permeable contact Kcharacterized by progressive thinning and distortion of the lens materials have led to a resurgence of interest in large-diameter apical cornea. The condition is bilateral but frequently asymmet- lens designs, and several authors have described the use of scleral ric.1 Visual acuity in patients with keratoconus may be compro- rigid gas-permeable lenses for the management of keratoconus.11–16 mised because of either irregular astigmatism or corneal scarring.2 At Mayo Clinic, we began using Jupiter (Medlens Innovations, Kennedy et al. reported that the prevalence of keratoconus was 55 Front Royal, VA; and Essilor Contact Lens, Inc., Dallas, TX) per 100,000 population; they also found that the probability of scleral lenses in June 2006. We fit lenses by using the 18.2-mm- survivorship without corneal transplantation for 20 years beyond diameter diagnostic lens series (manufactured by Medlens Inno- initial diagnosis was approximately 80%.3 vations), which includes standard and keratoconus designs. This study describes our initial experience with Jupiter scleral lenses in the management of keratoconus and highlights the relative ease, From the Department of Ophthalmology, Mayo Clinic, Rochester, MN. efficiency, and efficacy of fitting these large-diameter lenses. Supported by Research to Prevent Blindness Inc., New York, NY (an unrestricted grant to the Department of Ophthalmology, and SVP as Olga Keith Wiess Special Scholar), and Mayo Foundation, Rochester, MN. The authors have no financial interest in the products or manufacturers MATERIALS AND METHODS described. Address correspondence and reprint requests to Muriel M. Schornack, During the period of this study (June 2006 through November O.D., Department of Ophthalmology, Mayo Clinic, 200 First Street, SW, 2008), we evaluated 209 patients for possible scleral lens wear. Of Rochester, MN 55905; e-mail: [email protected] all patients evaluated for scleral lens wear, 32 (15%) had kerato- Accepted October 23, 2009. conus. All the patients with keratoconus referred to us reported DOI: 10.1097/ICL.0b013e3181c786a6 some level of dissatisfaction with vision or comfort with their current

Eye & Contact Lens • Volume 36, Number 1, January 2010 39 M.M. Schornack and S.V. Patel Eye & Contact Lens • Volume 36, Number 1, January 2010

FIG. 1. Scleral lens in situ on an eye with keratoconus. The lens rests on the sclera without conjunctival blanching and vaults the cornea from limbus to limbus. Because the lens extends into the fornices, minimal discomfort is generated from interaction with the eyelids. mode of correction. These patients represent the first patients with keratoconus evaluated in Mayo Clinic’s scleral lens practice. Because appropriate sagittal depth is more important than align- ment with the central cornea in scleral lens fitting, selection of the initial diagnostic scleral lens differs from initial lens selection for corneal lens fitting. As of yet, no specific fitting guidelines for scleral lenses have been validated or published. The fitting guide provided by Medlens Innovations for Jupiter lenses suggests that the base curve of the initial diagnostic lens should be approximately 1 diopter steeper than the steepest corneal curve. Consultants at Essilor suggest that the reference sphere from the elevation map generated by a corneal topographer may be the most appropriate starting point for diagnostic scleral lens fitting. Before fitting scleral lenses, we obtained topo- FIG. 2. Magnified view of scleral lens in situ. The scleral lens completely clears the cornea, reducing ocular surface discomfort, graphic images on all patients except one (2 eyes); simulated kera- and the tear lens formed between the scleral lens and the cornea tometry was recorded unless the corneal surface was too irregular to neutralizes much of the irregular astigmatism in keratoconus (black provide meaningful videokeratoscopic data (11 eyes). Reference arrow indicates the anterior surface of the lens, white arrow indicates sphere was also recorded for all eyes for which topographic images the posterior surface of the lens, and line segment indicates the depth of the post-lens fluid reservoir). were obtained. We based our initial diagnostic lens selection on the reference sphere and external observation of the profile of the anterior corneal surface. We used 18.2-mm-diameter diagnostic lenses for all dispensing the lenses. Revised lenses were ordered as needed to patients in this series. achieve optimal vision, comfort, and fit. Fitting goals for scleral lenses included scleral alignment with We assessed each patient’s ability to wear and handle the scleral little or no blanching of conjunctival vasculature, complete limbal lenses comfortably, visual acuity with scleral lens correction and with clearance, and complete corneal clearance (Figs. 1 and 2). If the spectacle overrefraction compared with acuity with habitual correc- initial diagnostic lens did not completely clear the cornea, lenses with successively greater sagittal depth were applied until corneal clearance was realized. If the depth of the post-lens fluid reservoir was excessive, successively shallower lenses were applied until a more appropriate clearance was realized. Post-lens fluid reservoir depth between 0.15 and 0.4 mm was considered acceptable. Depth was estimated by comparing its thickness to corneal thickness. Once a lens with appropriate sagittal depth was identified, a sphero- cylindrical overrefraction was performed. All lenses were ordered either from Medlens Innovations or Essilor Contact Lens, Inc. Patients who decided to proceed with scleral lens fitting after initial evaluation received individualized instruction in the care and handling of their lenses. Each patient returned for evaluation FIG. 3. Distribution of monocular visual acuity with habitual refrac- tive correction at the time of referral for scleral lens fitting (52 eyes of of vision and lens fit several hours after completing the training. 32 patients with keratoconus), comparing patients who proceeded with An additional follow-up visit was scheduled 2 to 4 weeks after scleral lens fitting to those who chose not to pursue scleral lens wear.

40 Eye & Contact Lens • Volume 36, Number 1, 2010 Eye & Contact Lens • Volume 36, Number 1, January 2010 Scleral Lenses in the Management of Keratoconus

TABLE 1. Characteristics of Patients Who Did Not Complete the Scleral Lens Fitting Process

Habitual Reason for scleral lens Entering visual Simulated Reference Outcome; reason for Patient Age Sex correction evaluation Eye acuity keratometry sphere outcome 1 28 F Spectacles Contact lens intolerance OS 20/60 52.12/47.62 @ 148 47.3 Initial evaluation only; good spectacle- corrected VA OD (20/20) 2 63 F Spectacles Blurred vision OD 20/40 Ϫ 2 Not available 40.3 Initial evaluation only; no improvement in OS 20/50 ϩ 1 54.37/48.87 @ 122 48.6 visual acuity due to lens opacity 3 71 F Corneal RGP Contact lens intolerance OD 20/50 Ϫ 1 54.37/45.87 @ 086 50.8 Initial evaluation only; handling concerns, no improvement in OS 20/40 Ϫ 1 45.87/45.12 @ 034 45.2 vision due to lens opacity 4 17 M No correction Contact lens intolerance OS 20/50 49.12/45/12 @ 034 47.5 Initial evaluation only; good uncorrected VA OD (20/20) and handling concerns 5 18 M Spectacles Blurred vision OD 20/400 Not available 56.0 Initial evaluation only; central corneal scar limited visual potential to 20/80, proceeded to transplant 6 26 M Corneal RGP Contact lens intolerance OD 20/30 Ϫ 1 46.75/44.75 @ 034 44.8 Initial evaluation only; lack of insurance OS 20/30 Ϫ 1 55.12/48/87 @ 148 48.7 coverage 7 28 M Spectacles Contact lens intolerance; OD 20/25 Ϫ 1 48.12/44.87 @ 056 45.3 Initial evaluation only; blurred vision minimal visual OS 20/20 47.37/44.87 @ 120 45.0 benefit demonstrated 8 33 M Spectacles Contact lens intolerance; OD 20/20 43.75/41.00 @ 002 41.6 Initial evaluation only; blurred vision minimal visual OS 20/20 43.50/40.50 @ 180 41.2 benefit demonstrated 9 33 M Piggyback Interest in scleral lenses OD 20/50 ϩ 1 48.25/46.00 @ 002 46.5 Initial evaluation only; contact (vision and comfort good comfort and lenses adequate in current OS 20/25 Ϫ 1 Not available 51.6 visual function with correction) current correction 10 37 M No correction Interest in scleral lenses OD 2’/400 Not available 61.7 Initial evaluation only; good uncorrected vision OS (20/20) 11 42 M Spectacles Contact lens intolerance OD 20/25 48.00/46.12 @ 082 46.8 Initial evaluation only; good spectacle- OS 20/20 Ϫ 1 47.87/46.62 @ 108 46.7 corrected vision, handling concerns 12 49 M Toric hydrogel Contact lens intolerance; OD 20/30 ϩ 1 45.37/39.75 @ 088 42.9 Initial evaluation only; lenses fluctuating vision minimal visual OS 20/20 Ϫ 1 44.37/36.87 @ 084 42.1 benefit demonstrated 13 66 F Spectacles Contact lens intolerance OD 20/40 47.86/46.62 @ 068 46.6 Fit abandoned; had OS 10/400 62.37/57.87 @ 108 53.5 cataract surgery RGP indicates rigid gas permeable; VA, visual acuity. tion at the time of referral, the number of lenses ordered per eye, and After initial consultation, 12 patients (20 eyes) chose not to proceed the number of visits necessary to complete the fitting process. with the fitting process. The most common reason was a lack of visual benefit with scleral lenses compared with the habitual correction; 9 of the 12 patients were able to resolve 20/20 or 20/25 binocularly with RESULTS their habitual correction. Patients 2, 3, and 5 (five eyes) had either lens A total of 32 patients (52 eyes) were evaluated for scleral lens or corneal opacities that precluded improvement in visual acuity with wear during the course of the study. At the time of presentation, 16 scleral lenses. One patient cited handling concerns as the determin- patients were primarily wearing spectacle correction, 8 were wear- ing factor in his decision not to pursue scleral lens wear. One ing corneal rigid gas-permeable lenses, 1 was wearing hydrogel patient (two eyes) had cataract surgery during the fitting process toric lenses, 3 were wearing piggyback systems, and 4 were and found that her vision was adequate with spectacles after wearing no correction. Mean patient age was 39 years (range, surgery. Characteristics of patients who were not successfully fit 17–71 years) and 12 patients were women. Monocular visual with scleral lenses are summarized in Table 1. Median entrance acuity with habitual correction at the time of referral ranged from visual acuity of eyes considered for scleral lens wear in patients 20/20 to 20/400 (Fig. 3). Average follow-up was 22.5 months who chose not to pursue scleral lens fitting was 20/30. Median (range, 5–34 months). binocular acuity in these patients was 20/20.

© 2010 Lippincott Williams & Wilkins 41 M.M. Schornack and S.V. Patel Eye & Contact Lens • Volume 36, Number 1, January 2010

TABLE 2. Summary of Fitting Process and Scleral Lens Design

Visual acuity Base curve With scleral Patient Habitual Reason for scleral Simulated Reference of final No. No. Lens (plus spectacle ID Age Sex correction lens evaluation Eye keratometry sphere lens lenses visits design Entrance overrefraction)

1 34 F Piggyback Fluctuating vision, OD 48.12/46.25 44.8 48.12 1 3 Standard 20/30 20/40 contact dryness @ 144 lenses OS 56.12/53.62 48.4 51.87 2 Standard 20/60 20/70 @ 088 2 43 F Corneal Blurred and OD 49.37/44.50 46.6 46.00 1 2 Standard 20/40 20/20 RGP fluctuating @ 076 vision 3 44 F Spectacles Contact lens OD Not available 57.7 52.25 1 2 Standard 20/80 20/30 (20/20) intolerance; OS 54.37/48.12 47.7 48.12 1 Standard 20/25 20/25 (20/20) blurred vision @ 146 4 44 F Spectacles Contact lens OS Not available 45.7 54.00 2 3 Custom 20/400 20/400a (20/20) intolerance; blurred vision 5 46 F Spectacles Poor vision OD Not available 44.3 65.92 1 3 Standard Unable to 20/40 (Lea symbols) testb 6 47 F Piggyback Contact lens OD Not available 46.9 52.25 2 4 Standard 20/200 20/40 contact intolerance OS Not available 50.9 50.50 2 Standard 20/25 20/25 lenses 7 52 F Spectacles Blurred vision OD 45.00/41.87 43.4 42.12 2 3 Standard 20/50 20/40 (20/20) with spectacles @ 004 and RGPs OS 45.50/43.50 43.6 43.25 2 Standard 20/30 20/25 (20/20) @ 014 861FNo Contact lens OD Not available Not 52.25 1 3 Custom 20/200 20/70 correction intolerance; available blurred vision OS Not available Not 49.00 1 Custom 20/60 20/25 Ϫ 2 available 920MNo Contact lens OS 66.5/48.12 54.8 51.37 1 3 Custom 20/400 20/60 ϩ 2 correction intolerance @ 160 10 22 M Spectacles Contact lens OD Not available 45.6 40.00 2 3 Standard 20/50 20/25 Ϫ 1 intolerance 11 23 M Corneal Contact lens OS 49.25/48.25 49.8 46.00 1 2 Standard 20/50 20/20 RGP intolerance @ 044 12 27 M Corneal Recurrent apical OS Not available 55.7 50.50 1 3 Standard 20/30 20/30 RGP erosions; contact lens intolerance 13 30 M Spectacles Contact lens OD 50.62/44.37 44.9 45.12 1 3 Standard 20/25 20/20 intolerance @ 046 OS 54.37/48.87 47.8 48.12 1 Standard 20/50 20/20 @ 144 14 31 M Corneal Contact lens OD Not available 48.2 46.87 2 3 Standard 20/40 20/20 RGP intolerance OS 44.87/41.00 43.2 46.87 2 Standard 20/20 20/20 @ 120 15 31 M Spectacles Contact lens OD 46.87/44.87 45.3 46.87 1 2 Standard 20/20 20/20 intolerance @ 176 OS 47.25/47.25 47.0 48.12 1 Standard 20/20 20/20 @ 180 16 39 M Spectacles Work-related RGP OD 53.00/45.37 50.8 48.12 2 4 Standard 20/50 20/20 intolerance; @ 104 blurred vision OS 62.12/50.12 56.1 61.00 3 Custom 20/150 20/70 with spectacles @ 164 17 39 M Corneal Work-related RGP OD 49.25/42.87 46.2 49.87 1 3 Standard 20/20 20/20 RGP intolerance; @ 038 blurred vision OS 48.75/45.25 46.6 49.12 1 Standard 20/20 20/25 with spectacles @ 132 18 57 M Spectacles Contact lens OD 54.50/49.25 48.2 49.00 1 2 Standard 20/30 20/25 (20/20) intolerance; @ 060 fluctuating vision 19 44 M Corneal Contact lens OD 61.87/51.12 57.7 49.00 2 3 Custom 20/50 20/40 RGP intolerance; @ 050 fluctuating OS 52.00/46.37 49.2 43.50 2 Custom 20/40 20/30 vision @ 148 aUnilateral scleral lens fit, high myopia in the right eye, intentional undercorrection in the scleral lens reduced the risk of spectacle-induced aniseikonia. bDown syndrome, unable to measure visual acuity with Snellen chart, Lea chart not available at initial examination. RGP indicates rigid gas permeable.

42 Eye & Contact Lens • Volume 36, Number 1, 2010 Eye & Contact Lens • Volume 36, Number 1, January 2010 Scleral Lenses in the Management of Keratoconus

nus. In severe keratoconus, the irregularity of the anterior corneal surface can make it difficult to achieve reasonable lens centration and stability with corneal lenses. A retrospective study by Salam et al.20 indicated that scleral contact lenses provide visual acuity that was comparable with that attained with corneal lenses in patients with moderate to severe keratoconus. Significant improvement in visual acuity was reported with scleral lenses in patients with keratoconus in the study by Visser et al.,21 and Segal et al.18 reported that 91% of patients with keratoconus achieved 20/40 or better acuity with scleral lenses. Similarly, 87% of our patients FIG. 4. Comparison of visual acuity with habitual correction at the achieved 20/40 or better Snellen acuity with scleral lenses. time of presentation to visual acuity with scleral lenses in patients The perception that fitting large-diameter lenses is time consum- who were successfully fit. ing, costly, and complex may be limiting their widespread use at present. Our experience suggests that fitting scleral lenses with the The remaining 19 patients (30 eyes) were successfully fit with use of standard diagnostic trial sets may be similar to, or even Jupiter scleral lenses. Demographic characteristics, information on easier than, fitting corneal or corneoscleral rigid lenses. Although habitual refractive correction at the time of referral, topographic keratoconus can cause considerable corneal irregularity, our ability indices, and a summary of the fitting process for these patients are to successfully fit scleral lenses with regular peripheral parameters summarized in Table 2. Acceptable scleral lens fit was achieved in suggests that the contour of scleral tissue may be less affected by an average of 2.8 visits (range, 2–4 visits). Fitting was completed the disease. Fitting scleral lenses avoids the challenges associated in 2 visits for 5 patients, in 3 visits for 12 patients, and in 4 visits with attempting to balance lenses on highly irregular tissue and to for 2 patients. On average, 1.5 lenses (range, 1–3) were ordered for instead align the lenses with relatively normal scleral tissue. each eye during the fitting process. The first lens ordered was the Advanced imaging technology can certainly be used to design lens prescribed for 17 eyes (57%), the second lens ordered was the scleral lenses,22 but we were able to successfully fit Jupiter lenses lens prescribed for 12 eyes (40%), and the third lens ordered was by standard diagnostic lenses. We habitually collect topographic the lens prescribed for 1 eye. Standard lens designs were pre- data on patients with keratoconus before any contact lens fitting; scribed for 23 eyes (77%) whereas 7 eyes required custom designs therefore, we did obtain topography on patients in this study. to optimize the scleral lens fit. Median monocular entrance visual However, we did not observe a close association between any acuity of eyes of patients who were successfully fit with scleral single topographic index and the base curve of the final scleral lens lenses was 20/40. Median binocular acuity at initial examination prescribed. It is likely that we could have successfully fit Jupiter was 20/25. After scleral lens fitting, visual acuity improved by an scleral lenses with diagnostic lenses in the absence of any topo- average of 2.9 lines, and median visual acuity was 20/20 (Fig. 4). graphic data. Diagnostic lens fitting carries the added advantage of allowing the patient to experience the sensation and vision that can be expected with scleral lenses before committing to the complete DISCUSSION fitting process. The majority (77%) of the lenses that we prescribed Awareness of the potential benefits of large-diameter rigid were standard designs, although we used consultative services gas-permeable lenses for patients with a wide range of ocular provided by the lens manufacturers to assist us in designing conditions has been steadily increasing during the past several custom lenses when necessary. Base curve radius and diameter can years. Management of corneal ectasia with scleral contact lenses be adjusted, as can radius of curvature and diameter of any of the has been described in several studies.11,12,15,17,18 Pullum and Buckley17 four peripheral curves, to create appropriate sagittal depth across reported a 60% overall success rate in a group of 530 patients fit the entire cornea and limbus. with scleral lenses for a variety of diagnoses, more than half of The wide variety of corneal lens options (rigid gas-permeable which had keratoconus. Segal et al.18 fitted 48 patients (66 eyes), lenses, hybrid lenses, custom hydrogels, and piggyback systems) of whom 75% had keratoconus, with an overall success rate of allow for adequate management of most cases of keratoconus, and 90%. Visser et al.19 described the use of the ProCornea lens and these options may certainly be explored before considering scleral reported that 50% of patients fitted with that particular scleral lenses. However, some patients with keratoconus do not achieve design had keratoconus. As noted earlier, 15% of patients referred adequate vision or comfort with corneal contact lenses. Further- to us for scleral lens evaluation had keratoconus. We successfully more, one patient in our series experienced recurrent apical ero- fitted 59% of all patients with keratoconus referred to us for scleral sions with corneal lenses. In situations such as this, scleral lenses lens evaluation. All but one of our patients who ultimately chose may be advantageous because they vault the cornea and allow the not to pursue scleral lens wear decided to continue with their entire corneal epithelium to be bathed with fluid. Scleral lenses can habitual correction immediately after initial scleral lens evaluation; be used to manage ocular surface diseases such as neurotrophic the majority (9 of 12, 75%) of these patients were able to resolve keratitis12 or graft versus host disease.23 The stability of scleral 20/25 (Snellen) or better binocularly with their habitual correction. lenses along with their generous optical zone diameter (8.2–8.6 We were able to provide acceptable vision and comfort with scleral mm) allow them to provide consistent vision; lens awareness is lenses in 95% (19 of 20) patients who chose to proceed with the fitting minimized because the conjunctival tissue on which scleral lenses process after initial evaluation. rest is less sensitive compared with corneal tissue, and lid inter- Corneal rigid gas-permeable lenses have long been assumed to action is minimized because the lenses extend well into the provide the best possible visual acuity in patients with keratoco- fornices. The Collaborative Longitudinal Evaluation of Keratoco-

© 2010 Lippincott Williams & Wilkins 43 M.M. Schornack and S.V. Patel Eye & Contact Lens • Volume 36, Number 1, January 2010 nus study found that contact lens wear was associated with an 2. Negishi K, Kumanomido T, Utsumi Y, et al. Effect of higher-order increased risk of corneal scarring in patients with keratoconus aberrations on visual function in keratoconic eyes with a rigid gas perme- able contact lens. Am J Ophthalmol 2007;144:924–929. 6 (odds ratio, 2.50). Because scleral lenses do not touch the cornea, 3. Kennedy RH, Bourne WM, Dyer JA. A 48-year clinical and epidemiologic the risk of apical scarring could potentially be less with scleral study of keratoconus. Am J Ophthalmol 1986;101:267–273. lenses than with traditional corneal lenses. This intriguing possi- 4. Zadnik K, Barr JT, Edrington TB, et al. Baseline findings in the Collabo- bility has not been formally studied but may warrant further rative Longitudinal Evaluation of Keratoconus (CLEK) Study. Invest Oph- thalmol Vis Sci 1998;39:2537–2546. investigation. 5. Barr JT, Schechtman KB, Fink BA, et al. Corneal scarring in the Collab- Corneal contact lens intolerance is one of the primary indica- orative Longitudinal Evaluation of Keratoconus (CLEK) Study: Baseline tions for keratoplasty in patients with keratoconus.24 The option of prevalence and repeatability of detection. Cornea 1999;18:34–46. fitting scleral lenses may defer the need for keratoplasty in patients 6. Barr JT, Wilson BS, Gordon MO, et al. Estimation of the incidence and factors predictive of corneal scarring in the Collaborative Longitudinal who are intolerant to traditional contact lens designs and who do Evaluation of Keratoconus (CLEK) Study. Cornea 2006;25:16–25. not have visually significant corneal scarring. Although penetrat- 7. Barr JT, Zadnik K, Wilson BS, et al. Factors associated with corneal ing keratoplasty has a 93% to 96% initial success rate,24 many scarring in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study. Cornea 2000;19:501–507. patients still require rigid contact lenses for their best vision, and 8. Pearson RM. Kalt, keratoconus, and the contact lens. Optom Vis Sci complications can occur including graft rejection and graft failure 1989;66:643–646. in approximately 20% and 10% of eyes, respectively, over 15 years.25 9. Pearson RM, Efron N. Hundredth anniversary of August Muller’s inaugural Furthermore, ectasia can recur in 6% to 11% of eyes receiving a dissertation on contact lenses. Surv Ophthalmol 1989;34:133–141. 10. Efron N, Pearson RM. Centenary celebration of Fick’s Eine Contactbrille. 26,27 penetrating keratoplasty for keratoconus, frequently requiring Arch Ophthalmol 1988;106:1370–1377. repeat keratoplasty in this young group of patients.28 Scleral lenses 11. Schein OD, Rosenthal P, Ducharme C. A gas-permeable scleral contact lens can provide good vision and comfort in many contact lens-intolerant for visual rehabilitation. Am J Ophthalmol 1990;109:318–322. patients and may delay the need for primary or repeat surgical 12. Rosenthal P, Croteau A. Fluid-ventilated, gas-permeable scleral contact lens is an effective option for managing severe ocular surface disease and intervention in this relatively young group of patients. many corneal disorders that would otherwise require penetrating kerato- At present, there is considerable confusion regarding the termi- plasty. Eye Contact Lens 2005;31:130–134. nology used to describe large-diameter lenses. We have suggested 13. Pullum KW, Whiting MA, Buckley RJ. Scleral contact lenses: The expand- ing role. Cornea 2005;24:269–277. that lenses be described based on their fitting characteristics rather 14. Cotter JM, Rosenthal P. Scleral contact lenses. J Am Optom Assoc 1998; than their overall diameter. Lenses that do not extend beyond the 69:33–40. limbus are generally considered to be “corneal” lenses. Lenses that 15. Pullum KW. The unique role of scleral lenses in contact lens practice. Cont extend past the limbus but rest on the cornea could be referred to Lens Anterior Eye 1999;22(suppl 1):S26–S34. 16. Tan DT, Pullum KW, Buckley RJ. Medical applications of scleral contact as “corneoscleral” lenses. Lenses that are supported entirely by the lenses. I. A retrospective analysis of 343 cases. Cornea 1995;14:121–129. sclera, completely clear the limbus, and measurably vault the cornea 17. Pullum KW, Buckley RJ. A study of 530 patients referred for rigid gas could be defined as “scleral” lenses.23 By these definitions, the lenses permeable scleral contact lens assessment. Cornea 1997;16:612–622. described in this study would be defined as scleral lenses. 18. Segal O, Barkana Y, Hourovitz D, et al. Scleral contact lenses may help where other modalities fail. Cornea 2003;22:308–310. 19. Visser ES, Visser R, van Lier HJ, et al. Modern scleral lenses. I. Clinical features. Eye Contact Lens 2007;33:13–20. CONCLUSIONS 20. Salam A, Melia B, Singh AJ. Scleral contact lenses are not optically inferior Scleral lenses can provide good vision and comfort for patients to corneal lenses. Br J Ophthalmol 2005;89:1662–1663. 21. Visser ES, Visser R, van Lier HJ, et al. Modern scleral lenses. II. Patient with keratoconus. Our early experience with the Jupiter lenses satisfaction. Eye Contact Lens 2007;33:21–25. suggests that a diagnostic fitting process is reasonably efficient. 22. Gemoules G. A novel method of fitting scleral lenses using high resolution The lenses may delay the need for keratoplasty in patients who optical coherence tomography. Eye Contact Lens 2008;34:80–83. have exhausted other options for visual correction. Therefore, we 23. Schornack MM, Baratz KH, Patel SV, et al. Jupiter scleral lenses in the management of chronic graft versus host disease. Eye Contact Lens 2008; consider Jupiter scleral lenses an excellent option for patients with 34:302–305. keratoconus who achieve inadequate outcomes with spectacles or 24. Rabinowitz YS. Keratoconus. Surv Ophthalmol 1998;42:297–319. corneal contact lenses. 25. Patel SV, Hodge DO, Bourne WM. Corneal endothelium and postoperative outcomes 15 years after penetrating keratoplasty. Trans Am Ophthalmol Soc 2004;102:57–65; discussion 65–66. ACKNOWLEDGMENTS 26. Pramanik S, Musch DC, Sutphin JE, et al. Extended long-term outcomes of The authors thank Dr. Keith Baratz for his assistance in the penetrating keratoplasty for keratoconus. Ophthalmology 2006;113:1633– 1638. preparation of this manuscript. 27. Raecker ME, Erie JC, Patel SV, et al. Long-term keratometric changes after penetrating keratoplasty for keratoconus and Fuchs endothelial dystrophy. Am J Ophthalmol 2009;147:227–233. REFERENCES 28. Patel SV, Malta JB, Banitt MR, et al. Recurrent ectasia in corneal grafts and 1. Krachmer JH, Feder RS, Belin MW. Keratoconus and related noninflam- outcomes of repeat keratoplasty for keratoconus. Br J Ophthalmol 2009; matory corneal thinning disorders. Surv Ophthalmol 1984;28:293–322. 93:191–197.

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