Contact Lens and Anterior Eye xxx (xxxx) xxx–xxx Contents lists available at ScienceDirect Contact Lens and Anterior Eye journal homepage: www.elsevier.com/locate/clae Review article Potential contraindications to scleral lens wear ⁎ Daddi Fadela, , Elise Kramerb a DOptom, Private practice, Rome, Italy b OD, Private practice, Miami, USA ARTICLE INFO ABSTRACT Keywords: Research and reviews have resulted in clear indications for scleral lens (SL) wear. Those indications include Scleral lens visual rehabilitation; therapeutic use in managing ocular surface diseases, lid and orbit disorders; and refractive Indications correction to enhance visual quality, comfort and quality of life. In some cases, the use of SLs may be contra- Contraindications indicated: the presence of low endothelial cell density; Fuchs’ endothelial corneal dystrophy; glaucoma (because Endothelial cell density of the risk of an increase in intraocular pressure and the existence and location of draining devices and blebs); or Fuchs’ dystrophy overnight wear. Intraocular pressure Glaucoma While the literature provides an extensive description of the indications for scleral lens wear, the authors Drainage devices recognize that there is no paper reporting the contraindications to their use. The aim of this review is to illustrate Overnight wear the conditions for which SL wear is potentially contraindicated or requires caution. Improved knowledge of SL Patient expectations limits should reduce the risk of adverse events and increase the likelihood of fitting success. 1. Introduction 2. Method of literature search criteria The benefits of scleral lenses (SLs) have been well established inthe The literature reviewed was from PubMed on the 25th February literature since descriptions of glass-blown shells in the late 1800s 2018, using the following keywords, separately and in combination: [1–6]. SLs are fit for therapeutic use [1–3] and visual improvement scleral contact lens, irregular cornea, ocular surface diseases, indica- [3,2–6]. The first successful fitting of polymethyl methacrylate (PMMA) tions, management, contraindications, complications, endothelial cells, SLs was reported in 1939 [7]. However, complications related to hy- glaucoma, intraocular pressure, overnight wear. The search identified poxia, such as neovascularization and corneal edema, were important 112 papers on indications for SL use, 8 on intraocular pressure during limitations to SL use until the latter part of the 20th century [8,9]. SL lens wear, 4 on overnight wear of SLs. Articles were reviewed and High oxygen permeability (Dk) of rigid contact lens materials re- clinical indications and potential contraindications for SL wear are newed interest in the use of SLs. In 1983, Ezekiel first described the summarized respectively in Tables 1 and 2. successful use of gas-permeable SLs, which significantly reduced com- plications from corneal hypoxia [10]. Other pioneers reported the 3. Indications success of gas-permeable SLs for post-operative refractive correction and for keratoconus [9,11,12]. Since the 1990s, indications for SLs have A large number of publications summarize the indications for SLs. been improved and refined [9–124]. Yet the authors are not aware of As with early scleral shells, the main indication for modern SLs is current literature that clearly defines the contraindications to SL use. corneal irregularity [9–63,120,121,123,124]. Other reports describe The goal of this review is to describe the conditions for which SL use the benefits of SLs for managing ocular surface diseases is potentially contraindicated or requires caution. Awareness of po- [11,13,16,17,19,23,34,43,47,63–108]. Additionally, SLs are a viable tential contraindications can prevent unnecessarily high patient ex- therapeutic option for lid or orbital disorders and for refractive cor- pectations that would arise by initiating a SL fitting and having to rection in otherwise normal, healthy eyes, and as drug delivery devices discontinue their eventual use and can reduce the risk of adverse [9–11,13,34,39,40,42,58,64,105,109–122]. events. SLs are a good option to enhance visual quality and comfort [16,30,60,123], and hence quality of life [32,123,125,126]. In a ret- rospective review, 18.7% of all SL patients who presented between ⁎ Corresponding author. E-mail addresses: [email protected] (D. Fadel), [email protected] (E. Kramer). https://doi.org/10.1016/j.clae.2018.10.024 Received 21 May 2018; Received in revised form 28 October 2018; Accepted 30 October 2018 1367-0484/ © 2018 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved. Please cite this article as: Fadel, D., Contact Lens and Anterior Eye, https://doi.org/10.1016/j.clae.2018.10.024 D. Fadel, E. Kramer Contact Lens and Anterior Eye xxx (xxxx) xxx–xxx Table 1 Table 2 Indications for scleral lens use. Conditions for which SL wear is potentially contraindicated or needs caution. Irregular cornea Corneal endothelial abnormalities Endothelial cell density Primary corneal Keratoconus [9–43,52,58,60,120,127] Fuch’s endothelial corneal dystrophy ectasias Pellucid-marginal degeneration Glaucoma Intraocular pressure [13,34,35,43–46,63,66,120] Location of drainage devices Keratoglobus [13,33,43,47,120] Blebs Post-keratoplasty Penetrating keratoplasty (PK) Overnight wear [9,11,16–20,25,34,39–41,48–52,58–60,66,120,124] Anterior lamellar keratoplasty (ALK) [13,17,18,34,51,60,120] 1999 and 2003 had undergone corneal transplants and achieved 20/20 Post-refractive Post LASIK [13,34,53–57,97,120] surgery Post LASEK [120] or 20/25 vision with their SLs [16]. DeLoss et al. showed that even eyes Post PRK [11,63,120] with advanced keratoconus may benefit from SLs and that the visual Post RK [61,63,120] outcome for stage four ectasia was better and more rapid with SL cor- Post-other surgeries Pterygium surgery [120] rection than with keratoplasty [124]. A recent study demonstrated the Corneal scarring Herpes simplex keratitis [13,120] successful long-term treatment with SLs in severe keratoconus that Other keratitis [13,34,120] Trauma [10,13,34,67,120,121,125] otherwise would have led to transplant surgery [127]. The authors of that study concluded that SLs reduce the need for corneal transplan- Ocular surface diseases Keratitis sicca Sjögren's syndrome tation in severe keratoconus [127]. [13,16,17,34,64,66,70,75,83,93,97,118,120] Neurotrophic keratopathy [34,63,64,82,83,90,93,109,118,120] 4. Potential contraindications to the use of scleral lenses Following irradiation [13,64,84,120] Acne rosacea [64] 4.1. Corneal endothelial abnormalities Chemical burns [64] Undifferentiated dry eye [64,69,93] Cicatrizing Stevens-Johnson syndrome 4.1.1. Endothelial cell density conjunctivitis [13,34,40,63,64,71–74,84,93,97,106,120] The major concern with SLs is their use in cases with reduced or low Ocular cicatricial pemphigoid endothelial cell density (ECD). Reduction of ECD may be related to age [13,34,64,83,84,88,93,100,120] [128–137], diabetes [138–142], contact lens wear [143–154], oph- Corneal dystrophies Salzmann’s nodular degeneration [43,102–104,120] and Terrien’s marginal degeneration [43,47,120] thalmic surgeries [155–160], or dry eye [161]. degenerations Recurrent corneal erosion [17,70,91,93,101] At birth, the endothelial layer is regular and uniform. It comprises 2 Lattice corneal dystrophy [64] about 500,000 cells, with a density of about 4500 cells/mm [128,129], Granular dystrophy [64] although variation is large (2987 to 5632 cells/mm2)[130,131]. The Exposure Exophthalmos (Grave’s disease) endothelium undergoes quantitative and qualitative changes related to keratopathy [64,83,90,92,93,109,120] Nerve palsies [11,13,34,63,84,99,118,120] aging [131–146]. Those changes include a decrease in cell density to 2 Post eyelid surgery [84,117,120] 1000–2000 cells/mm [131–137](Table 3). Acoustic neuroma resection [11,13,84,120] It is controversial whether ECD is altered in diabetes. Some studies Graft versus host disease [13,17,34,70,75–80,88,93,94,96,97,110,120] that investigated central corneal thickness and morphologic char- Atopic keratoconjunctivitis [13,107,120] acteristics of the corneal endothelium in diabetic patients have reported Congenital corneal hypoanesthesia [120] Symblepharon [120] lower ECD than in non-diabetic controls [138–142]. However, others Limbal stem cell deficiency [11,13,34,63,71,72,77,86,88,106] studies have observed ECD similar to that in non-diabetics [162–170]. Vernal keratopathy [81,119] Leem et al. found lower ECD in diabetic contact lens wearers than in Persistent epithelial defects [23,64–66,84,91,93,104,105,108,120,144,269–271] diabetic non-wearers [138]. In contrast, O’Donnell and Efron found that Lid/orbit disorders endothelial cell characteristics among diabetic soft lens wearers were Lid surgery [110] similar to age-matched non-diabetic subjects wearing soft contact Facial trauma [112] Dermatochalasis [120] lenses [170]. Crouzon syndrome [13,120] Studies results vary on the effects of contact lens use onen- Goldenhar syndrome [13] dothelium cell density [143–155]. Studies have reported that both rigid Bulbous atrophy [120] and soft contact lenses can contribute to a decline in cell density above Ptosis [9,13,120,122] and beyond the expected age-related decline [147–151]. Hollingsworth Trichiasis [13,84,120] Ectropion [120] and Efron reported that ECD was unaffected by rigid gas-permeable Entropion [120] (RGP) lens wear [152]. Other studies observed that reduced ECD in the Eyelid coloboma [120] central cornea is a consequence of a small redistribution of endothelial Refractive correction and normal cornea cells from the central to the peripheral cornea, rather than a true loss of Myopia [9,10,13,34,120] Hyperopia [10,13,34,39,120] Astigmatism [11,13,34,39,120] Table 3 Anisometropia [13,120] Relation between endothelial cell density and age (source: Presbyopia [13,34,120] Edelhauser, 2006; Niederer, 2007).