A multinational survey characterizing the use of surgical magnifying loupes in dermatological surgery

Abstract

Background

The use of surgical loupes has not been well‐documented in dermatological surgery.

Objectives

An online questionnaire was developed to characterize the use of loupes in dermatological surgery.

Methods

The questionnaire was circulated to the memberships of the British Society of Dermatological Surgery, the European Society of Micrographic Surgery, and the Australasian College of Dermatologists. Responses were analyzed with a mixed methods approach using quantitative data analysis and inductive content analysis.

Results

One‐hundred twenty‐five valid responses were received from 20 nations. Most respondents were from England (40%; 50/125), Australia (16%; 20/125), and the Netherlands (14.4%; 18/125). Overall, 71.2% (89/125) of respondents were consultants/Facharzt/attending. Furthermore, 55.2% (69/125) of respondents were Mohs surgeons. In dermatological surgery 38.4% (48/125) of respondents used surgical loupes routinely. The mode magnification level for loupes was 2.5× (67.5%; 27/40), with 3× second place (12.5%; 5/40). Exactly half (20/40) used through‐the‐lens style loupes and 40% (16/40) used flip‐up‐loupes. Inductive content analysis of the 51 free‐text responses from nonloupe users uncovered several deterring factor themes, including expense (18/51), can manage without/don't need (14/51), and narrow field of view a(11/51), and uncomfortable/too heavy (9/51).

Conclusions

This is the first time the use of surgical loupes in dermatological surgery has been internationally characterized.

1. INTRODUCTION

Surgical loupes are magnifying optical devices worn to improve visual acuity in surgery. Since the 1980s, the use of surgical loupes in dermatological surgery has become more popular. ¹ Despite the use of surgical loupes in dermatological surgery for over 40 years, to our knowledge, the practical utilization and uptake of surgical loupes has not been accurately evaluated in dermatological surgery—particularly internationally. Furthermore, for dermatologists surgeons considering surgical magnification, there is a diverse range of loupe and magnifying devices available, which are proffered in an assortment of configurations including full and partial customization. ²

This study was developed to characterize the use and configuration of loupes among dermatological surgeons. We hope this study provides a useful resource to our colleagues internationally. This information will better equip dermatological surgeons with the knowledge required to determine which loupes and/or devices to use in their practice and in what configuration.

2. METHOD

An online questionnaire was developed using an iterative process through several stages using SurveyMonkey™ (San Mateo, CA) (Appendix 1). The survey was distributed to the membership of British Society of Dermatological Surgery (BSDS), the European Society of Micrographic Surgery (ESMS), and the Australasian College of Dermatologists (ACD) in April 2021. The survey was a service evaluation and therefore ethical approval was confirmed to not to be required.

The questionnaire gathered brief background demographic information and questioned respondents on their use of surgical loupes (Appendix 1). Routine users of loupes were asked questions regarding magnification levels, loupe‐technology, loupe design, loupe‐mounted light use, the pros/cons of loupe‐use, and asked to rate the impact on surgical outcome from loupe use. Respondents not routinely using loupes were directed to follow‐up questions regarding other magnifying devices in dermatological surgery and asked if they had ever considered using loupes. Free‐text parts of the survey enabled respondents to substantiate their selections and provide context.

Prior to analysis, responses were scrutinized and nonclinician responses and duplicates were removed (8×). Analyses consisted of a mixed methods approach, using descriptive statistics with statistical analyses of the quantitative data and inductive content analysis for the qualitative data. Inductive content analysis was undertaken for the free‐text responses in a method described by Mayring. ³ Two authors (WH and IA) independently coded the full qualitative response data using the inductive process and then subsequently collaboratively compared and refined the coding to produce the final theme matrix with associated frequencies (Table 3). ³

TABLE 3.

Inductive content analysis categorization matrix according to frequency for two free‐text questions

Have you considered getting surgical loupes? (Y/N) If so, what factors deterred you? (51)
Themes	Order	Frequency	Indicative quotation
Expensive	1	18/51	“They are expensive so important to get to right”
Can manage without/don't need	2	14/51	“I haven't felt that I needed them.”
Narrow field of view	3	11/51	“Too zoomed in—can't see the bigger picture.”
Uncomfortable/too heavy	4	9/51	“Previous use of loupes was uncomfortable and cumbersome”
Accessibility to loupes	5	6/51	“Not sure how to get them, try them…”
Colleagues do not use	Other major	4/51	“Nobody else uses them”
Do you have any comments on using surgical loupes in dermatological surgery? (32)
Inability to work without loupes/ Essential		6/32	“Essential—I would rarely even do a punch biopsy without them…”
Praise for loupes		6/32	“Wonderful instrument…”
Not currently useful for themselves personally	3	5/32	“Have a role, but not for me now.”
Useful in certain situations		4/32	“Use them mainly for perioccular cases…”
Used by older professionals (presbyopia)		4/32	“As my presbyopia has kicked in and worsened over the last 8 years, I cannot operate without loops”
Reduced field of vision/blind spots	Other major	3/32	“A wider field of vision would be nice.”
Encourage registrars to use/try using loupes	Other major	2/32	“I recommend that all registrars and especially our Mohs trainees try loupes”

3. RESULTS

One‐hundred and twenty‐five valid responses were analyzed from 20 nations (including United Kingdom nations) (Table 1). The highest number of respondents were from England (40%; 50/125), Australia (16%; 20/125), and the Netherlands (14.4%; 18/125). In total, 71.2% (89/125) of respondents were consultants/Facharzt/attending. Moreover, 55.2% (69/125) of all respondents were Mohs micrographic surgeons. In dermatological surgery 38.4% (48/125) of respondents used surgical loupes regularly. The most common magnification level for loupes was 2.5× (67.5%; 27/40), followed by 3× (12.5%; 5/40) (Table 2). Most respondents were unsure of the magnifying technology their loupes used (77.5%; 31/40). Exactly half (20/40) used through‐the‐lens style loupes and 40% (16/40) used flip‐up‐loupes. Nearly half (19/40) used a loupe‐mounted light source.

TABLE 1.

Baseline demographics of respondents

Domain	Response
Country of practice (top 5)	1. England ‐ 50/125 (40.0%) 2. Australia—20/125 (16.0%) 3. The Netherlands—18/125 (14.4%) 4. Wales—5/125 (4.0%) 5. Sweden and Switzerland—both 4/125 (3.2%)
Grade of specialist	Attending/consultant/Facharzt 89/125 (71.2%) Specialty doctor/associate specialist 21/125 (16.8%) Resident/registrar 10/125 (8.0%) Senior fellow 4/124 (3.2%) Other 1/125 (0.8%)
Mohs micrographic surgeon	Yes 69/125 (55.2%) No 56/125 (44.8%)
Routine use of surgical loupes	Yes 48/125 (38.4%) No 77/125 (61.6%)

TABLE 2.

Specification of surgical loupes utilized routinely by dermatologists

Loupe magnification level	2.5×—27/40 (67.5%) 3.0×—5/40 (12.5%) 3.5×—2/40 (5.0%) 4.0×—2/40 (5.0%) Other/not sure—4/40 (10%)
Loupe magnification technology	Galilean—7/40 (17.5%) Keplerian (prismatic)—2/40 (5.0%) Not sure—31/40 (77.5%)
Loupe style/type	Through‐the‐lens (TTL) loupe—20/40 (50.0%) Flip‐up loupe—16/40 (40.0%) Other—4/40 (10.0%)
Use of loupe‐mounted light	Yes—19/40 (47.5%) No—21/40 (52.5%)

The most frequently cited benefit of using loupes was improved acuity/vision (90%; 36/40) (Figure 1). Conversely, the most frequently cited limitation was expense (57.5%; 23/40). When rating surgical outcomes and the use of loupes on a 5‐point unipolar Likert scale (“not at all” to “a great deal”), most respondents felt that they improved their surgical outcomes by “a great deal” (40%; 16/40) (Figure 1). Converting the responses to interval data (1–5) demonstrated median improvement category was “a lot.” Of the 77 respondents that did not regularly use loupes, 17.9% (14/77) reported using other magnifying devices in dermatological surgery; 6 comments highlighted the use of dermoscopy and 2 comments cited magnifying glasses. Of the 77 respondents not routinely using loupes, 55.8% (43/77) had considered getting surgical loupes previously.

FIGURE 1.

(A) Responses to a question regarding the benefits of loupes. Of the 40 responses, 17.5% listed additional factors such as improved visualization of crevices, better lighting, and greater accuracy of tumor margins and tissue variation. (B) Responses to a question regarding the limitations of loupes. From the 40 responses, 22.5% listed additional limitations including musculoskeletal discomfort, blind spots with needle stick injury risk, easy to lose loupes, at times cumbersome, time constraints, and a reduction of field of depth. 1C. Unipolar Likert scale responses to the question regarding use of loupes and improvement of surgical outcomes

For respondents who did not use loupes, 51 comments were received when asked a follow up question on deterring factors for surgical loupe use. The top 5 themes are presented in Table 3 according to frequency following inductive content analysis. A final open question requesting for comments yielded 32 free‐text entries, which were analyzed in the aforementioned approach using content analysis (Table 3).

4. DISCUSSION

Our findings demonstrate that over a third of international dermatological surgeons routinely use loupes in dermatological surgery (38.4%). To our knowledge, this is the first international characterization of surgical loupes use among dermatologists. In other disciplines, the implementation of loupes has been more extensively assessed. In dental and certain surgical specialties, the use of magnifying loupes is well‐embedded in practice by both senior colleagues and trainees. ⁴ , ⁵ , ⁶ , ⁷ , ⁸ , ⁹ Moreover, a recent survey of American Oculoplastic surgeons demonstrated 95% (228/239) owned loupes, and 78% used them regularly. ¹⁰ Similarly, in a survey of 255 hand surgeons, 100% owned at least one pair of loupes. ¹¹ In a survey of general dentists in teaching practices, 44.1% (30/68) reported using loupes, compared to 27.7% of 85 their dental trainees. ⁷ A study of trainee maxillofacial surgeons demonstrated that 70.6% (36/51) reported using loupes from 153 maxillofacial units across the United Kingdom. ⁶ In a smaller study focusing on trainee urological surgeons in Australia, over half (58%; 11/19) of trainees owned loupes and 37% (7/19) regularly used them. ⁹ In our study, 21.4% (3/14) of the registrars/residents and senior fellows routinely used surgical loupes. Furthermore, 43.8% (39/89) of consultant/attending/Facharzt respondents reported routinely using loupes in their dermatological surgery.

Regarding loupe‐magnification, the mode magnification level was 2.5× (67.5%), followed by 3× (12.5%). This is similar to other studies; a survey of oculoplastic surgeons showed that 69.7% use 2.5× magnification, followed by 3.5× (25.3%). ¹⁰ Various studies have consistently demonstrated that the loupe‐magnification level of 2.5× is the most frequently used in numerous specialists including maxillofacial surgeons (81%), ⁶ qualified dentists (56.7%), ⁷ and urologists. ⁹ Notably, however, the level of loupes magnification is commensurate with their purpose. Jarrett stratified surgical specialties according to their predilection to surgical loupes versus an operating microscope. ¹² For example, for nerve repairs, hand surgeons either use an operating microscope or loupes with magnification of 3.5× or greater. ¹¹ In dermatological surgery, our scope of practice overlaps with both maxillofacial surgeons and plastic surgeons, who are frequent users of loupes, but also unlike dermatological surgery in the main, utilize operating microscopes too. ¹²

Two broad loupe magnification technologies are available, namely the Galilean and prismatic (Keplerian) telescopic approaches. Galilean loupes employ two lenses for magnification—providing a cost‐effective, light, and straightforward telescopic technology for lower magnification levels. ¹³ Whereas prismatic lenses, tend to be proffered at higher magnification levels, and consist of a series of convex converging lenses with an additional intermediate prism (required to correct an inverted image and enhance the magnification). ¹³ In our study 77.5% (31/40) of the respondents using loupes, were not certain of their loupe technology. Of those that were able to specify, the most common technology was Galilean 7/40 (17.5%). These findings fit, given Galilean loupes tend to dominate the lower magnification loupe market. Other technical aspects regarding the loupe configuration include a through‐the‐lens (TTL) approach or flip‐up loupes. Flip‐up loupes offer convenience at a compromise of weight and field of view—the latter since the lenses tend to be further away from the users eye. In our study, 50% (20/40) of respondents used TTL loupes compared to 40% (16/40) with flip‐up loupes. Similarly a survey of 51 maxillofacial trainees, 65% of those using loupes employed the TTL variety. ⁶

Most respondents in this study, who routinely used loupes, rated that loupes improved their surgical outcomes (40% by “a great deal”; Figure 1C). Evidence suggests the use of loupes can improve surgical outcomes with tumor demarcation in facial BCCs. Sugrue et al. reported improved excision margins of a subgroup of BCCs with predetermined 4 mm margins—notably there was no significant difference of incomplete excisions. ¹⁴ Similar findings are found in the plastic surgery literature. ¹⁵ However, recent meta‐analysis determined that intraoperative use of loupes did not result in differences in incomplete excision rates for keratinocyte cancers compared to surgery without loupes (OR 1.6 [95% CI: 0·3–7·4], p = 0·537). ¹⁶ Moreover, there is minimal literature regarding scar cosmesis and loupe‐use; a recent small experimental in vivo study in rats which were randomized to have linear incisions repaired with subcuticular sutures under nil, 2.5× loupe, and microscopic magnification (assessments at 1,3, and 6 weeks), demonstrated no significant differences in dual observer‐blinded rated Vancouver scar scale ratings. ¹⁷ Fundamentally, the use of surgical loupes and dermatological surgery outcomes requires more research, in particular regarding scar cosmesis and surgical complication rates including postoperative bleeding (Figure 1A).

Our study highlighted some perceived benefits of using loupes. These included improved vision/acuity, improved blade and suturing precision, identification of bleeding points, and improved posture (Figure 1A). Similar findings are replicated in other studies. ¹⁰ , ¹⁸ , ¹⁹ Improved posture is a major consideration; a survey of Mohs surgeons and workplace ergonomics demonstrated that 90% of respondents reported a degree of musculoskeletal symptoms. ²⁰ Another benefit of loupe‐use, not represented in this study, but highlighted elsewhere, is the advantage of eye‐protection. ¹⁰ , ¹⁸ There were also several limitations identified by respondents of loupe‐use (Figure 1B). Namely, expense, reduction in visual fields, and being cumbersome and heavy. These limitations were echoed by qualitative content analysis themes identified from an open question on deterring factors to loupe‐use (Table 3). Other themes emerging were that loupes are unnecessary/not required (14/51), uncertainty on accessing loupes (6/51), and that their colleagues do not use loupes (4/51) (Table 3). It was also evident there were proponents of loupes and those who were less enthusiastic (Table 3). Another potential negative factor is that recent study has demonstrated that loupes can act as a surface for microbes—however there is insufficient evidence to suggest that this could be linked to increased surgical site infections. ²¹ , ²² Nevertheless, routine cleaning of loupes should be recommended.

For the 77/125 respondents that did not use surgical loupes routinely, 6/77 (7.8%) reported dermoscopy as a magnifying device perioperatively for margin assessment. The evidence partially supports this approach. In a small retrospective study of slows Mohs, the number of positive lateral margins were significantly lower using dermatoscopic margin assessments compared to the naked eye (5/26 [19.3%] vs. 15/28 [53.6%]; p = 0.012). ²³ Additionally, they identified that the mean number of stages was significantly less in the dermoscopy group (1.3 vs. 1.7; p = 0.01). ²³ However, an included literature review demonstrated that in case series the results are divided as to whether dermoscopy reduces the overall number of stages in Mohs surgery. ²³ The reasons for incongruent outcomes from various studies are likely multifactorial, including sample size differences, differences in methodological approaches, and presence or absence of loupe‐enhanced margin assessment in the control arm. ²⁴ , ²⁵

Our study had some limitations. The precise response rate is difficult to assess across the organizations that kindly circulated the survey. This is since the ESMS membership roster includes laboratory technicians who would have been ineligible for the survey and likewise some members of the BSDS are honorary and associate members may not be in a position to reply. Furthermore 4/125 of respondents (3.2%) did not provide country details and were not calculated in the overall response data but were included in the study otherwise. In light of this, the response rates should be interpreted with caution, but provide a rough estimate. For the BSDS, the response rate was 14.9% and 60/404. For the ESMS member responses, if all responses compared certified surgeon members roster, the response rate is over a quarter at 27.3% (41 of ∼150). Finally, the responses from the Australasian College of Dermatologists (ACD) were low at 3.8% (21 of ∼550); however, this figure represents the entire ACD fellows of which a reasonable number may not be undertaking significant dermatological surgery. Another component of consideration with responses is the risk of response bias with dermatological surgeons holding strong views on the subject (either way) perhaps more likely to respond. The final notable limitation is that certain countries are underrepresented despite dermatological surgery being prevalent across the United Kingdom, Europe, and Australia. This disproportionate response demographic may mean that clinicians’ experience with loupes in certain countries is not fully delineated.

5. CONCLUSION

To our knowledge, this is the first international characterization of loupe‐use among dermatological surgeons. Our survey findings demonstrate that surgical loupes are routinely used by a large group of dermatological surgeons (38.4%), but the proportion may vary significantly by country of practice. We define the specifications of loupes used, the perceived benefits, limitations, and overall assessment on surgical outcomes associated with loupe‐use. Using qualitative content analysis, we determined the barriers to loupe‐use among respondents that do not use loupes routinely. We anticipate the findings presented are helpful to colleagues across the world in determining if they wish to use loupes and if so, in what set‐up. Specifically, most dermatological surgeons use 2.5× magnification through‐the‐lens loupes, which are likely to be Galilean.

CONFLICT OF INTEREST

The authors report no conflict of interest

APPENDIX 1.

SUMMARY OF QUESTIONNAIRE QUESTIONS

In which country do you undertake dermatological surgery?

What grade of specialist are you?

Are you a Mohs micrographic surgeon?

Do you use surgical loupes routinely in your dermatological surgery?

If Yes

What magnification are your loupes?

What type of magnification technology does your loupe use?

What type of loupes do you use ?

Do you use a loupe‐mounted light?

What are the benefits of using loupes?

What are the limitations of using loupes?

Do you think the use of loupes improves your surgical outcomes?

If No

Do you use any magnification devices routinely for your dermatological surgery?

Have you considered getting surgical loupes?

Final question for both

Do you have any comments on using surgical loupes in dermatological surgery?

Hunt WTN, Ashraf I, Nelson TG. A multinational survey characterizing the use of surgical magnifying loupes in dermatological surgery. Skin Res Technol. 2022;28:439–444. 10.1111/srt.13144