Minimizing Post-Operative Scars in External Dacryocystorhinostomy: A Literature Review

Introduction

External dacryocystorhinostomy (Ext-DCR) remains the gold standard for treating nasolacrimal duct obstruction due to its high success rate and cost-effectiveness. However, visible post-operative scarring represents a significant drawback. Despite the availability of endonasal techniques that avoid cutaneous scars, Ext-DCR remains widely used because of its consistently high functional success rate, straightforward technique, and accessibility in low-resource settings.^1–4 However, visible scarring following Ext-DCR is a concern for many patients and surgeons. According to Huang et al, scarring after Ext-DCR was described as cosmetically unacceptable in 11% of cases.⁵

To minimize scarring, various alterations to the original Ext-DCR technique described in 1904 by Toti et al have been proposed.⁶ In the present review, we synthesize the existing scientific literature on strategies to reduce or minimize post-operative scarring in Ext-DCR. To the best of our knowledge, such a literature review has not been published during the last decade.

Methods

This systematic review analyzed the scientific literature focusing on surgical tools and techniques, postoperative care methods, and patient-related factors such as skin complexion, with the aim of reducing scar formation after external dacryocystorhinostomy (Ext-DCR). All surgical techniques and postoperative protocols were eligible for inclusion.

Eligibility Criteria

Outcomes of interest included the appearance and severity of postoperative scars, patient satisfaction with scar outcomes, and the incidence of complications such as hypertrophic scars or keloids. No restrictions were imposed on the definitions of scar assessment or the methods used to evaluate outcomes; each study’s definitions and methods were reported. Only studies published in English were eligible.

Search Strategy

A literature search was performed on July 25, 2024, using the databases PubMed, MEDLINE, Embase, Cochrane Central, and Cumulative Index to Nursing and Allied Health Literature (CINAHL). The search terms were “external dacryocystorhinostomy” AND “scar”.

Study Selection

One author (L.C.B.A.) screened titles and abstracts of all identified records and removed duplicates and irrelevant articles. Full texts were retrieved for potentially eligible studies. Two authors (L.C.B.A. and A.Z.K.) independently assessed the full texts, as well as additional relevant publications identified from reference lists. Disagreements were resolved by consensus.

Data Extraction

Two authors (L.C.B.A. and S.B.A.) extracted data independently using a predesigned form (Table 1). Extracted data included study characteristics, surgical technique, incision type, postoperative care, scar assessment method, patient satisfaction, and complications.

Table 1 Characteristics and Main Findings of Studies Evaluating Cosmetic Outcomes After External Dacryocystorhinostomy (Ext-DCR). Data Presented Include Study Design, Number of Cases, Surgical Technique (Incision Site, Design, and Length), Postoperative Care, Scar Grading Method, and Results (Including Scar Prevalence, Closure Method, and Patient-Related Factors)

Results

Study Selection and Characteristics

The initial search identified 270 records. After removal of duplicates (n=141) and exclusion of irrelevant articles, 73 studies underwent full-text screening. Following independent review, 40 studies met the eligibility criteria and were included in the final analysis (Figure 1). Together, these studies reported outcomes from 3750 Ext-DCR procedures, with scar assessments available for 3715 individuals.

Figure 1 Flow diagram of study identification, inclusion, and exclusion.

Main Findings

Across the included studies, reported rates of visible scarring ranged from 0% to 50%, though in most series cosmetically significant scars were observed in less than 10% of patients (Table 1).

Conjunctival approaches (retrocaruncular and transconjunctival) consistently avoided cutaneous scars and achieved high patient satisfaction. However, these techniques were technically more demanding and occasionally required conversion to a conventional Ext-DCR. Reported complications included conjunctival granuloma formation and minor eyelid lacerations.

For cutaneous approaches, the location of the incision played a central role in cosmetic outcomes. Incisions placed in natural creases such as the lower eyelid crease, subciliary margin, or periciliary line produced superior results compared with traditional vertical skin incisions.

Incision design also influenced scar outcomes. W-shaped and curvilinear incisions were generally associated with less visible scarring compared with straight vertical incisions. Curvilinear incisions along the tear trough line achieved particularly favorable results at follow-up.

Incision length was another factor, smaller skin incisions (5–10 mm) were associated with lower scar visibility and higher cosmetic satisfaction compared with traditional longer approaches.

Regarding closure techniques, sutureless methods using tissue adhesive or Steri-Strips frequently resulted in superior cosmetic outcomes and in some series completely avoided visible scarring. Suturing of the periosteum and lacrimal diaphragm reduced the incidence of hypertrophic scarring compared with unsutured wounds.

Patient-related factors influenced results. Darker skin types (Fitzpatrick IV–VI) were more prone to hypertrophic or pigmented scars, while younger patients were more likely to report cosmetic dissatisfaction compared with older individuals.

Discussion

Prevalence of Scarring

Conventional Ext-DCR is not a scarless procedure; scar assessment varies based on the grading scheme used, the patient’s subjective opinion, and the surgeon’s professional evaluation. Patient satisfaction is ultimately the most important outcome and is dependent on multiple factors, including the presence of complications and scar formation.

The prevalence of visible scarring varied greatly across the reviewed studies, ranging from 0–50%. However, in most reports, the prevalence was under 10%, meaning most cases resulted in no or minimal visible scarring after Ext-DCR.^{2,3,10,13,21–25,27–34,36–40,42,43} Some study designs evaluated scarring at different post-surgery intervals, highlighting scar reduction over time.^2,8,36,40 For instance, Rizvi et al showed an initial assessment of 68% highly visible scars at post-operative week two, which decreased to 2% at 12 weeks after surgery.³⁶ Granuloma formation, keloids, and hypertrophic scarring ranged from 0–11%,^10,26 0–8%,^1,31 and 0–8%,^{13,29,32,33,38} respectively. Mckinley et al found one case of hypertrophic scarring, which resolved after eight weeks of daily massage of the scar.²⁹ Another study found that hypertrophic scarring could be resolved by steroid injection.³

Incision Site

The choice of incision site is a major determinant of postoperative cosmetic outcome in Ext-DCR. Different approaches have been described to either avoid visible skin scars or to conceal them within natural folds.

Conjunctival Approaches

To completely avoid cutaneous scarring, retrocaruncular and transconjunctival techniques have been proposed (Figure 2A and B).^7,19,26 These approaches place the incision through the conjunctiva, leaving no external scar. Most studies reported good functional results and high patient satisfaction, with only one case of lateral canthal scarring described.²⁶ Kaynak-Hekimhan et al highlighted the technical challenges: in 6 of 25 cases, conversion to a standard Ext-DCR was required. Reported complications included granuloma formation at the conjunctival incision site (10.6%) and minor eyelid margin laceration (5.3%).²⁶ Despite high patient satisfaction with the postoperative aesthetic outcome, the limited surgical field and relative unfamiliarity of these approaches among surgeons have restricted their widespread adoption.

Figure 2 Incisional designs and locations. (A) Retrocaruncular. (B) Transconjunctival. (C) Subciliary. (D) Periciliary V–incision. (E) W-shaped. (F) Traditional linear straight. (G) Curved linear/tear trough. (H) Minimal incision.

Alternative Cutaneous Incision Sites

Other modifications seek to hide the scar within natural skin creases or hair-bearing areas. Akaishi et al placed the incision in the medial relaxed skin tension line at the lower eyelid crease and reported significantly improved scar outcomes (Figure 2C).⁸

A subciliary incision has also been associated with good cosmetic results, with one study reporting no visible scarring based on patient self-assessment.¹⁴ Waly et al found only 5% of patients reported visible scarring in the subciliary group, compared with 50% in those receiving a traditional vertical incision.⁴¹

The periciliary “V–incision” (Figure 2D), involving incisions at both the upper and lower eyelid margins, was likewise associated with favorable cosmetic outcomes.⁴

Collectively, these approaches suggest that scar visibility can be reduced by strategic incision placement. However, moving further from the lacrimal sac increases technical difficulty, and subciliary/periciliary approaches may pose a risk of canalicular injury.

Cutting Instruments

The role of the incision instrument has also been studied. González-López et al conducted a comparative study analyzing periocular scars resulting from incisions made with a cold blade versus a microdissection needle.²⁰ The study found no significant differences in aesthetic outcomes between the two techniques, assessed by multiple validated scar assessment scales (Patient and Observer Scar Assessment Scale (POSAS), Vancouver Scar Scale (VSS), and Observer Scar Assessment Scale (OSAS)). Interestingly, the results indicated that DCR scars generally exhibited better cosmetic outcomes compared to other periocular surgical procedures, suggesting that incision instrument may play less of a role in post-operative scarring in Ext-DCR.

Incision Design

Alongside location, the design of skin incisions and modifications of techniques have also been investigated.

Ekinci et al conducted two studies in Turkey evaluating the impact of W-shaped (WS) versus traditional linear (LS) incisions on scar visibility after Ext-DCR (Figure 2E and F).^17,18 Results indicated that the WS incision significantly reduced visible scarring, particularly among younger patients. A similar study applied the WS incision to one side and the LS incision to the other during bilateral Ext-DCR. Postoperative scar assessments at six months showed that the WS incision had significantly lower scar visibility.¹⁸ The scars were assessed by both ophthalmologists and patients, with both reporting lower scores for the WS incision (p < 0.001). These findings collectively highlight the effectiveness of the WS incision in achieving better cosmetic outcomes and reducing visible scarring compared to the LS incision.

Two studies compared the scarring outcomes of different incision techniques.^16,40 One evaluated a curvilinear incision versus a W-shaped incision.¹⁶ Similar success rates were reported in lacrimal patency and comparable scar visibility scores, though the W-shaped incision group showed a modest reduction in visible scarring.¹⁶ The other altered both the location and the design of the traditional incision in Ext-DCR.⁴⁰ They compared a curvilinear incision (CLI) (Figure 2G), following the tear trough along the orbicularis muscle, to a W-shaped incision. The CLI group achieved superior cosmetic outcomes over time, suggesting that while both techniques are effective, the CLI along the natural tear trough line may offer an advantage in minimizing long-term scar visibility. A third study confirmed the tear trough to be among the best incisional methods.¹⁵ The authors reported that most patients (83%) rated their scars as invisible after three months. Surgeons also rated the scarring outcome favorably. A different study using CLI but not following the tear trough reported two cases of dehiscence and three cases of keloid scar formations from the total of 71 Ext-DCR cases.³¹

Incision Length

The length of skin incisions can also have an impact on the visibility of the scar. Two comparable studies support the efficacy of minimal incision techniques in Ext-DCR for enhancing cosmetic outcomes. One reported high patient satisfaction (97%) with reduced scarring using a small incision (10mm), while the other reported an even higher satisfaction rate with no visible scarring utilizing a modified 5mm incision without sutures (Figure 2H).^21,25 Both studies confirm that smaller incisions can minimize scar visibility, although the unsutured approach may offer superior aesthetic results while maintaining functional outcomes.^21,25

Sutureless Closure

The study by Kashkouli et al demonstrated that using a sutureless skin closure technique with Steri-Strips after Ext-DCR, which used the modified 5 mm incision, resulted in no visible scars after 6 months.²⁵ Similarly, a different study, which used a 10mm straight incision, compared subcuticular suturing to the sutureless skin closure technique and showed the cosmetic advantages of using Steri-Strips instead of sutures, with no visible scars observed after 12 weeks; compared to an 8% scar visibility rate in the subcuticular group.³⁶

Evaluating whether the skin incision should be left sutureless, the effects of suturing the lacrimal diaphragm and periosteum were evaluated.¹³ The results indicated that preservation of these structures contributed to a concave contour in the lacrimal region, effectively preventing webbing and thereby resulting in fewer visible scars and a significantly lower incidence of hypertrophic scarring compared to the unsutured control group.¹³ This approach also yielded better functional outcomes, as indicated by a higher success rate in the dye disappearance test. The results of these studies collectively underscore the importance of tailored incision and closure techniques in minimizing visible scarring, with both the preservation of underlying structures and sutureless closure showing promising results for optimal aesthetic outcomes after Ext-DCR.^13,25,35,36

Skin Complexion

Waly et al found that skin complexion influenced scar visibility and grading in Ext-DCR. While 50% of dark-skinned patients rated their scars as cosmetically significant, only 22% of fair-skinned patients reported the same.⁴¹ The mean scar grades also tended to be higher among dark-skinned patients compared to fair-skinned patients, but this difference did not reach statistical significance, possibly due to the small proportion of dark-skinned patients in the study. Nevertheless, this trend highlights the potential for increased scar hypertrophy and pigmentary changes in darker skin tones.

Individuals with darker skin types (Fitzpatrick IV–VI) are more prone to pathological scarring, such as keloids and hypertrophic scars, due to factors including increased fibroblast activity, excessive collagen deposition, and prolonged inflammatory phases during healing. Keloids and hypertrophic scars are significantly more common in individuals of African and Asian descent, potentially due to genetic predispositions relating to the regulation of collagen synthesis and growth factors. Moreover, the increased melanin content in darker skin contributes to hyperpigmentation, making scars more noticeable.⁴⁴

Limitations

A significant limitation of this systematic review is the lack of standardized scar assessment tools across studies. While some studies utilized validated grading scales, others relied on self-reported outcomes or non-validated scales, limiting the comparability of results.^4,20,25 Additionally, many studies did not describe their methodology for scar assessment in detail, further complicating comparisons. To minimize these limitations and allow for more successful comparisons of outcomes, future studies should aim for a more standardized means of assessment by using validated scales like the Visual Analogue Scale (VAS) or the Stony Brook Scar Evaluation Scale (SBSES).⁴³

Furthermore, greater heterogeneity in surgical techniques and patient populations would give a better understanding of which procedural initiatives make a clear difference in minimizing scarring. Several studies identified patient-related factors influencing scar visibility.^12,37,41 Moreover, studies have shown that children and younger females were more attentive and critical when rating the postoperative scar. This underscores the importance of considering patient demographics when planning surgical interventions and setting realistic expectations for postoperative outcomes. The use of professional and blinded graders could therefore optimize the accurate measurement of both scar occurrence and assessment, ensuring a consistent foundation for determining optimal surgical approaches for minimizing scarring after Ext-DCR. Additionally, this review highlights the lack of studies evaluating the impact on alternating post-operative care protocols, such as the use of antibiotics and steroid ointments. This could potentially have a significant effect on reducing scar formation.

Conclusion

Our review suggests that scar outcomes following Ext-DCR may be improved through careful selection of incision site and closure technique. However, current evidence is heterogeneous, and no single modification has achieved universal acceptance. Standardized scar assessment tools are needed to allow meaningful comparisons across studies.

Future research should aim to refine these approaches, with a focus on minimizing visible scarring while maintaining high rates of functional success.