Prescription Habits of Scleral Lenses for the Management of Corneal Irregularity and Ocular Surface Disease Among Scleral Lens Practitioners

Abstract

Objectives:

To describe prescribing patterns of therapeutic scleral lenses (SLs) in the management of corneal irregularity and ocular surface disease among practitioners who prescribe SLs.

Methods:

Participants ranked treatment options for corneal irregularity and ocular surface disease in the order they would generally consider utilizing them in an electronic survey. Median rank score for each option are reported, along with the percentage of participants assigning first place ranking to each option. The percentage of participants assigning first, second, or third place ranking to each option is also reported.

Results:

778 practitioners participated. SLs are most frequently considered the as the first choice for the management of corneal irregularity based on overall median rank, followed by corneal rigid lenses (RGPS). SLs were the first choice of 42% of participants, followed by RGPs (20%). For ocular surface disease, lubricant drops are most frequently utilized first, followed by meibomian gland expression, topical cyclosporine or lifitegrast, topical steroids, punctal plugs, and SLs, respectively. Lubricant drops were the first therapeutic option considered for ocular surface disease by 63% of participants and 45% ranked SLs as their 6th, 7th or 8th treatment based on median overall rank.

Conclusions:

SLs were identified as the first option for management of corneal irregularity more frequently than RGPs. SLs are considered for management of ocular surface disease prior to surgical intervention but after meibomian gland expression, punctal occlusion, and topical medical therapy are attempted.

Scleral lenses (SL) are currently prescribed primarily for management of corneal irregularity and ocular surface disease. They have been shown to improve visual acuity for patients with corneal ectasias due to keratoconus^1–5, pellucid marginal degeneration⁶ and keratoglobus⁷ as well as patients with a history of prior ocular surgery^8–13 or trauma.^14,15 Additionally, SLs have been shown to improve patient comfort and maintain ocular surface integrity in patients with moderate to severe ocular surface disease^16–18, Chronic Graft-Versus-Host Disease^19–21, and Stevens Johnson Syndrome.²²

In a 2015 survey of SL practitioners, corneal rigid lenses (RGP) were considered the first management option for corneal irregularity, followed by SLs.²³ The survey included responses from 723 eye care providers who had fit five or more patients with SLs. The survey indicated that SLs tended to be considered for management of ocular surface disease following topical therapy but prior to surgical intervention such as tarsorrhaphy.²³ Considerable growth in the SL industry has been observed beginning in the early 2000’s and accelerating after 2007.²⁴ The purpose of the current study was to describe current therapeutic prescribing trends for management of patients with irregular corneal astigmatism and ocular surface disease among practitioners who prescribe SLs.

Methods

An electronic survey was developed and distributed to eye care providers between November 8, 2019 and March 31, 2020, utilizing REDCap (Research Electronic Data Capture).^25,26 Study design and materials were reviewed and approved by The Ohio State University Institutional Review Board as being in adherence to the tenets of the Declaration of Helsinki. Practitioners with SL prescribing experience were recruited for this study to evaluate the use of SLs in their practices. Participants of prior research studies, members of the Scleral Lens Education Lens Society and attendees of an international specialty contact lens meeting received e-mail invitations to participate in the survey. Additionally, a link to the survey was included in online eye care provider newsletters (I-Site and BCLA) and posted on the Scleral Lens Practitioners private Facebook group.

Potential respondents needed to verify that they had completed at least 5 SL fits in order to be eligible to participate in the survey. Participants were asked to identify their country of residence, primary mode of practice, and the year in which they first fit SLs. Additionally, they were asked to describe their general approach for the management of corneal irregularity by ranking the following treatments in the order in which they would generally consider the options: spectacles, standard hydrogel/silicone hydrogel lenses, custom hydrogel/silicone hydrogel lenses, RGPs, SLs, hybrid lenses and piggyback lens systems. Participants were then asked to elucidate their general approach for the management of ocular surface disease by ranking the following treatments in the order in which the options would be considered: over-the-counter lubricant drops, meibomian gland expression, moisture chamber glasses, topical cyclosporine or lifitegrast, topical steroids, topical antibiotics, systemic antibiotics, autologous serum tears, punctal plugs, SLs, conjunctival flap, amniotic membrane, limbal stem cell transplant and tarsorrhaphy.

Responses from participants who ranked at least 50% of options for each condition (at least 4 of 7 options for corneal irregularity or at least 7 of 14 options for ocular surface disease) were included in this analysis. Not all respondents ranked every item. A minority of respondents did not rank most items, and were excluded from analysis. The goal of this analysis was to determine which treatments were selected most often, therefore a full ranking of options listed was preferred. Overall ranking by all participants and percentage of participants who ranked at least 50% of options are included in the Supplemental Digital Content.

Descriptive statistics were used to report overall survey results. Percentages of participants who identified each option as their treatment of first choice were calculated, as well as percentages of participants who identified each option as their first, second or third treatment of choice. Overall median rank scores were calculated for all options for each indication. A lower median ranking for a particular option indicates participants consider the option earlier in management.

Participants were classified into groups based upon country of residence, primary practice modality, and years of experience fitting SLs. Practitioners from the United States and those living outside of the United States are hereafter referred to as “U.S.” versus “non-U.S.” providers. University, hospital, or industry practices were categorized as “academic,” and private, group, or commercial practices were classified as “community”. Participants were considered “established” practitioners if they had fit their first SL in 2014 or earlier, while those who began to fit SLs in 2015 or later were considered “new” practitioners. Group medians were assessed. Non-parametric comparisons of median rank were performed using the Mann-Whitney test. The Mann-Whitney test compares the median ranks of two independent groups (as opposed to the t-test, which compares means). It can be used to evaluate all data sets, but must be used for non-parametric data which is data that does not follow a “normal” bell-shaped distribution. Interquartile range (IQR) is shown to demonstrate the statistical dispersion or spread of data. Quartiles segment data into four equal parts and the IQR includes the second and third quartiles or the middle half of the data.

Results

A total of 778 practitioners responded to at least one of the items identified above. Of these, 631 participants ranked at least 4 options for optical correction for corneal irregularity and 567 participants ranked at least 7 therapeutic options for management of ocular surface disease. The distribution of participants by indication and demographic groups (U.S./non-U.S., academic/community, established/new) is presented in Table 1.

Table 1:

Demographics of participants that responded to items regarding placement of scleral lens therapy for corneal irregularity and ocular surface disease categorized by country of residence (United States (U.S.) and outside of the United States (Non-U.S)), practice modality and practitioner experience.

Characteristics of Participants	Corneal Irregularity (n,%)	Ocular Surface Disease (n,%)
Country of Residence	628	565
U.S.	413 (66%)	400 (71%)
Non-U.S.	215 (34%)	165 (29%)
Practice Modality	626	565
Community	478 (76%)	432 (76%)
Academic	148 (24%)	133 (24%)
Experience	622	560
Established	416 (67%)	368 (66%)
New	206 (33%)	192 (34%)

Treatment Ranking: Corneal Irregularity

Overall, 42% of participants (262) indicated that SLs were their first choice for management of corneal irregularity. Spectacles were identified as the first choice by 26% (167) of participants, and 20% (132) of participants ranked RGPs as a first line therapy. The total number of participants who ranked each option as first, second, or third choice also suggests a preference for SLs; 74% (466) ranked SLs within their top three choices, followed by RGPs with 64% (401), hybrid lenses with 35% (219), and spectacles with 34% (215). Overall ranking of all therapeutic options for the management of corneal irregularity are available in supplemental digital content 1. Median rankings were calculated for each option; SLs and RGPs have the lowest (most favorable) ranking (Table 2).

Table 2:

Median [interquartile (IQR)] rank of therapeutic management options for corneal irregularity. Scleral lenses ranked as the most preferred choice (lowest ranking), with corneal rigid lenses the second most preferred choice.

Therapeutic Option	Median [IQR]
Scleral lenses	2 [3]
Corneal rigid lenses	3 [2]
Custom hydrogel/silicone hydrogel lenses	4 [2]
Hybrid lenses	4 [3]
Piggyback lens systems	5 [3]
Standard hydrogel/silicone hydrogel lenses	5 [4]
Spectacles	5 [6]

Median ranking [interquartile range] were calculated for each option as reported by U.S. versus non-U.S., community versus academic, and established versus new practitioners; lower median ranking for a particular option indicates participants consider the option earlier in the management of corneal irregularity (Table 3). SLs were considered earlier compared to all other options for all groups of respondents, but non-parametric comparison of median rank suggests that U.S. practitioners are more likely to consider SLs earlier in treatment than their non-U.S.-based counterparts (p<0.001). In contrast, non-U.S. practitioners are more likely to consider custom hydrogel/silicone hydrogel lenses (p=0.01) or piggyback lens systems (p=0.001) earlier than U.S. practitioners. Academic practitioners were more likely to use SL (p-0.006) or hybrid lenses (p=0.001) than community practitioners. Additional ranked preferences are provided in Table 3.

Table 3:

Comparison of median [interquartile (IQR)] rank of interventions for the management of corneal irregularity between United States (U.S.) versus non-United States (Non-U.S.), community versus academic, and established versus new practitioners.

	U.S. (n=413)	Non-U.S. (n=215)	U.S. vs. Non-US	Community (n=478)	Academic (n=148)	Comm vs. Acad	Established (n=416)	New (n=206)	Est. vs. New
Intervention	Median [IQR]	Median [IQR]	P-value	Median [IQR]	Median [IQR]	P-value*	Median [IQR]	Median [IQR]	P-value*
Scleral lenses	2 [2]	2 [3]	<0.001	2 [2]	2 [3]	0.006	2 [2]	2 [3]	0.045
Corneal rigid lenses	3 [2]	2 [3]	0.18	3 [2]	2 [3]	0.01	3 [2]	3 [2]	0.02
Custom hydrogel/silicone hydrogel lenses	4 [2]	4 [2]	0.01	4 [2]	4 [2]	0.99	4 [2]	4 [2]	0.55
Hybrid lenses	4 [3]	4 [3]	0.36	4 [3]	5 [3]	0.001	4 [3]	4 [3]	0.38
Standard hydrogel/silicone hydrogel lenses	5 [4]	5 [4]	0.18	5 [3]	4 [4]	0.094	5 [3]	4 [4]	0.06
Piggyback lens systems	5 [3]	5 [3]	0.001	5 [2]	5 [3]	0.36	5 [3]	5 [3]	0.003
Spectacles	6 [6]	5 [6]	0.66	5 [6]	6 [6]	0.79	6 [6]	5 [6]	0.02

Treatment Ranking: Ocular Surface Disease

There were 567 participants who ranked at least 7 of 14 management options for ocular surface disease. Over-the-counter lubricant drops were ranked as first choice of treatment by 358 (63%) participants. SLs were ranked as initial treatment option by just 17 (<1%) participants; 253 (45%) ranked SLs either 6th, 7th, or 8th. Median [IQR] rankings for all management options are shown in Table 4. Over-the-counter lubricant drops had the lowest median rankings, while SLs ranked 6th after lubricant drops, meibomian gland expression, topical cyclosporine or lifitegrast, topical steroids, and punctal occlusion. Overall ranking of all therapeutic options for the management of ocular surface disease are available in supplemental digital content 2.

Table 4:

Median [interquartile (IQR)] rank of therapeutic options for the management of ocular surface disease. Over-the-counter lubricant drops are the first choice of treatment. Scleral lenses are a mid-ranked treatment option.

Therapeutic Option	Median [IQR]
Over-the-counter lubricant drops	1 [1]
Meibomian gland expression	3 [5]
Topical cyclosporine or lifitegrast	4 [3]
Topical steroids	4 [3]
Punctal occlusion	6 [4]
Scleral lenses	7 [4]
Systemic antibiotics	7 [4]
Topical antibiotics	7 [5]
Autologous serum tears	8 [4]
Moisture chamber glasses	8 [5]
Amniotic membrane	10 [3]
Conjunctival flap	12 [3]
Limbal stem cell transplant	13 [2]
Tarsorrhaphy	13 [3]

Median [IQR] were calculated for each option as reported by U.S. versus non-U.S., community versus academic, and established versus new practitioners; median values are compared between groups (Table 5). U.S. practitioners considered over-the-counter lubricant drops (p=0.001), topical cyclosporine or lifitegrast (p<0.001), topical steroids (p<0.001), punctal occlusion (p=0.002) and amniotic membrane (p<0.001) sooner than non-U.S. practitioners, while those residing outside of the U.S. ranked moisture chamber glasses (p=0.05), topical antibiotics (p<0.001), autologous serum tears (p=0.006), SLs (p<0.001) and conjunctival flap (p<0.001) earlier than practitioners in the U.S.. Community practitioners considered placement of a conjunctival flap earlier than academic practitioners (p=0.03), but no other differences between median values for any other therapeutic options were noted between community and academic practitioners. Established practitioners consider SL earlier compared to new practitioners (p=0.005).

Table 5:

Comparison of median [IQR] rank of therapeutic options for the management of ocular surface disease between United States (U.S.) versus non-United States (Non-U.S.), community versus academic, and established versus new practitioners. Artificial tears rank as the top choice for all groups. Scleral lenses are considered after topical therapies but sooner than surgical intervention for all groups.

	U.S. (n=400) Median [IQR]	Non-U.S. (n=165) Median [IQR]	U.S. vs. Non-U.S. P-value*	Community (n=432) Median [IQR]	Academic (n=133) Median [IQR]	Comm vs. Acad P-value*	Established (n=368) Median [IQR]	New (n=192) Median [IQR]	Est. vs. New P-value*
Intervention									P-value*
OTC artificial tears	1 [1]	1 [2]	0.001	1 [1]	1 [3]	0.1	1 [1]	1 [2]	0.2
MG expression	3 [5]	3 [5]	0.3	3 [4]	3 [5]	0.4	3 [5]	3 [5]	0.8
Moisture chamber glasses	8 [4]	7 [6]	0.05	8 [5]	8 [5]	0.09	8 [5]	8 [5]	0.3
Topical cyclosporine or lifitegrast	4 [2]	6 [4]	<0.001	4 [4]	4 [3]	0.2	4 [3]	4 [4]	0.2
Topical steroids	4 [2]	5 [5]	<0.001	4 [3]	5 [4]	0.3	4 [3]	4 [4]	0.2
Topical antibiotics	8 [4]	6 [4]	<0.001	7 [5]	7 [5]	0.6	7 [5]	8 [4]	0.4
Systemic antibiotics	7 [4]	8 [4.75]	0.1	7 [4]	6 [4]	0.2	7 [4]	7 [5]	0.2
Autologous serum tears	9 [3]	8 [4]	0.006	8 [3[	8 [4]	0.9	8 [4]	8 [3]	0.3
Punctal occlusion	6 [4]	7 [4]	0.002	6 [4]	6 [4]	0.9	6 [3]	6 [4]	0.5
Scleral Lenses	7 [3]	6 [5]	<0.001	7 [4]	7 [4]	0.7	7 [3]	7 [3]	0.005
Conjunctival flap	12 [s]	11 [3]	<0.001	12 [3]	12 [2]	0.03	12 [3]	12 [2]	0.2
Amniotic membrane	9 [3]	11 [3]	<0.001	10 [3]	10 [3]	0.1	10 [3]	9.5 [4]	0.03
Limbal stem cell transplant	13 [2]	12 [3]	0.2	12 [2]	13 [1]	0.2	12 [2]	13 [2]	1.00
Tarsorrhaphy	13 [3]	13 [4]	0.5	13 [3]	13 [3]	0.8	13 [3]	13 [2]	0.8

Discussion

This study shows that SLs are now considered first-choice therapy for patients with corneal irregularity compared to a similar study of SL practitioners from 2015. At that time, 44% of participants reported that corneal rigid lenses were the option of first choice for this indication.²³ Across all groups, SLs were often selected before RGP’s, a trend which persisted across most subgroups of practitioners. Despite evidence that SLs are increasingly being utilized in patients with irregular corneas, this study detected variations in practice patterns between types of practitioners. Reasons for practitioner preferences were not specifically queried, therefore reasons for this variation are not clear. International availability of different lens designs could contribute to the differences in preferences observed between U.S. and non-U.S. practitioners. Academic practices and experienced prescribers are likely to care for patients with more severe ectasia, where SL fitting can represent the penultimate step prior to transplantation. Patient demographics, financial burden of lenses, lack of access to advanced SL designs or technology devices such as tomography and profilometry may also contribute to some of the variations in practice patterns seen between various groups of practitioners.

In terms of ocular surface disease management, this study found that SLs are typically considered after lubricant drops, meibomian gland expression, topical cyclosporine or lifitegrast, topical steroids, and punctal occlusion. This is consistent with the DEWS II study which recommends SLs be considered in step 3 out of 4 steps after ocular lubricants, meibomian gland expression, prescription eye medications and punctal occlusion.²⁷ The placement of SLs in the management of ocular surface disease has remained relatively stable. In both the present and the 2015 study, SLs were prescribed after topical therapy but before surgical intervention.²³ Over-the-counter lubricant drops continue to represent the first therapeutic option by a large majority of participants, as they did in 2015. Many of the available therapies for ocular surface disease are effective, particularly for mild and moderate disease. Non US-based practitioners may consider SLs earlier due to cost or access to amniotic membranes, punctal occlusion, topical steroids, and topical cyclosporine or lifitegrast which are ranked as generally being utilized later. A possible reason for the stability of SLs in the treatment algorithm is the increased availability of treatments for meibiomian gland dysfunction. For some patients, restoration of meibomian gland function with or without the use of medication, may alleviates symptoms making SL use unnecessary. However, once the severity of the condition increases and/or maximal medical therapy fails, practitioners employ SLs. SLs have been shown in multiple studies to be effective therapy for even severe ocular surface disease.^28–34

Conclusions that can be drawn from this study are limited both by constraints of survey research in general and by specific aspects of this survey design including potential order bias. With all survey research, the sample of individuals who respond may not accurately represent the views of the entire population surveyed. Data presented here may be biased towards SLs because the population surveyed had demonstrated at least some level of interest in SLs; had the survey been distributed to a wider population of eye care providers, results may have been different. A strength of this study is that both the 2015 and current surveys were distributed to similar groups of practitioners. It therefore provides a broad overview of emerging overall trends in SL prescription practices within the community of practitioners who fit SLs. The large number of non-academic respondents is a unique way of accessing practice patterns in this cohort, who are less likely to publish in the peer-reviewed literature. This survey does not, however, represent the general community of eye care providers in all specialties. Furthermore, this study did not attempt to differentiate between various levels of disease severity or to the etiology of corneal irregularity including prior corneal transplantation. SL providers would certainly consider disease severity and prior surgical history in order to determine their first therapeutic option in individual patients, and the survey was not designed to ascertain information on specific cases. Future prospective, multicenter, longitudinal studies could provide a more detailed understanding of sequential use of various therapeutic options to achieve optimal visual and physiological outcomes and could utilize more systematic treatment options for dry eye disease.^27,35. Such studies could facilitate the development of evidence-based algorithms for management of corneal irregularity and ocular surface disease.

In the absence of funding for such studies, periodic surveys of large numbers of SL practitioners can provide information on current prescribing patterns. In this study, SL emerge as the first-choice option for the management of corneal irregularity among practitioners that prescribe SLs. SLs remain a lower-tier therapeutic option for ocular surface disease, and are placed after use of lubricants, meibomian gland expression, punctal occlusion, and topical medical therapy, but prior to surgical intervention. This information allows individual practitioners to compare their practice patterns with those within the international SL community. Future evaluation of trends in SL utilization may be affected by introduction of new therapeutic options and lens designs as well as increasing knowledge of the risks and benefits of SL wear.