Ophthal Plast Reconstr Surg, Vol. 30, No. 1, 2014

of the stent and did they observe the flow to be contributed by capillary action along the stent surface? The authors quoted studies from the otolaryngology literature about the long-term efficacy and safety of Rains stents for chronic frontal sinus disease. It is of concern that the criteria to define ‘long term’ is variable with it being as low as 3 months.5 There are also concerns about its long-term use and periodic stent replacements due to dislodgement or obstructions. Lin et al.5 showed retention rates of only 47.6% in a 6-year span. Although supportive, both the positives and negatives of the stent use in frontal sinus disease cannot be extrapolated to authors’ lacrimal surgery series in view of different anatomical boundaries, different high-risk etiology, difference in tissue behaviors, and the use of a modified stent. Canalicular intubation for 2 cases was performed to prevent internal punctal occlusion by the flange of the Rains stent. It would have been interesting to know why were they removed so late at 10 and 19 months, and how has this removal benefited in preventing the reocclusion of the internal punctal opening? It is very important to reiterate the very appropriate conclusions drawn by the authors that the results of this study must be tempered by the small cohort, shorter follow up, heterogenic etiopathogenesis and unknown long-term efficacy. I once again congratulate the authors for starting a newer approach in managing patients with a high-risk DCR and enriching the literature.

Mohammad Javed Ali, F.R.C.S. Correspondence: Mohammad Javed Ali, F.R.C.S., Dacryology Services, L. V. Prasad Eye Institute, Banjara Hills, Hyderabad 500034, India ([email protected]) The authors have no financial or conflicts of interest to disclose.

REFERENCES 1. De Castro DK, Santiago YM, Cunningham M, et al. A modified lacrimal sac implant for high-risk dacryocystorhinostomy. Ophthal Plast Reconstr Surg 2013;29:367–72. 2. Avisar I, McNab AA, Dolman PJ, et al. Endonasal dacryocystorhinostomy for nasolacrimal duct obstruction in patients with sarcoidosis. Orbit 2013;32:225–30. 3. Lee BJ, Nelson CC, Lewis CD, et al. External dacryocystorhinostomy surgery in patients with Wegener granulomatosis. Ophthal Plast Reconstr Surg 2012;28:389–92. 4. Mann BS, Wormald PJ. Endoscopic assessment of the dacryocystorhinostomy ostium after endoscopic surgery. Laryngoscope 2006;116:1172–4. 5. Lin D, Witterick IJ. Frontal sinus stents: how long can they be kept in? J Otolaryngol Head Neck Surg 2008;37:119–23.

Reply Re: “A Modified Lacrimal Sac Implant for High-Risk Dacryocystorhinostomy” To the Editor: We appreciate Dr. Ali’s interest in a surgical technique we recently described, and the opportunity to redress some apparent shortcomings in our original description. The adult patients to whom we offered this approach were phenotypically homogeneous, uniformly demonstrating severe, unrelenting nasal mucositis. We believed we could offer them 1 final attempt to salvage the lacrimal system before relegating them to complete lacrimal bypass with Jones tube. These patients were virtually indistinguishable on preoperative

Letters to the Editor

endonasal examination. Furthermore, they all suffered recurrent dacryocystitis, with 5 of the 6 patients having already undergone failed lacrimal and/or sinonasal surgery. They were severe, recalcitrant cases and, in our judgment, unlikely to respond to traditional dacryocystorhinostomy. We believed, therefore, a new approach was needed. There are, indeed, circumstances in which traditional dacryocystorhinostomy might succeed despite autoimmune rhinitis as reported by both Lee et al1 and Avisar et al.2 All the patients in Lee’s series were maintained on systemic immunosuppression, though none required increased perioperative dosing. Avisar’s patient population was more heterogeneous with a minority of subjects, requiring perioperative systemic corticosteroids. In contrast, only one of our patients was immunosuppressed at the time of surgery, and she did not require augmentation. An important advantage of the sinus stent approach is its independence from the immediate mucosal condition; systemic immunosuppression can be managed solely by the immunologist or rheumatologist based on systemic activity and without regard to the state of the nasal cavity. One of the many limitations of the sinus stent-lacrimal sac implant technique is the need for a patent lacrimal sac. That is why we obtained preoperative CT dacryocystography in all our patients. By revising the silicone head, we were able to implant the Rains stent in a partially stenosed sac. An implant designed expressly to fit the lacrimal sac would be smaller and could be accommodated by an even more severely scarred sac. Certainly, as with any lacrimal duct bypass technique, this method requires patent canaliculi and internal punctum. In the case of extensive lacrimal sac or canalicular scarring, other procedures such as conjunctivocystorhinostomy would be necessary. Regarding potential strangulation of the stent by encroaching bone, we could not identify a report documenting closure of the osteotomy after dacryocystorhinostomy. It is well known that the mucosal ostium contracts to 1.8 mm on average,3 but it seems unlikely that the Rains stent would succumb to a cicatrix of such friable mucosa; if anything, the tightening mucosa might stabilize the implant. To reiterate, the stent is made of medical grade silicone rubber. With an outer diameter of 0.4 cm and an inner diameter of 0.3 cm, the walls are approximately 0.5 mm thick. In any event, we have not observed this potential complication. With an inner diameter of 3 mm, the lumen is far too large to induce capillary flow of the tear fluid. As in a Jones tube, the tears drain by gravity and through volitional negative pressure generated by the patient. Perhaps, some fluid does flow around the stent into the nose—all the better! Frontal sinus stenting is currently considered an alternative to more standard approaches to frontal sinusitis. Typically, it is used by otolaryngologists for cases in which there is a high risk of recurrence—cases in which the frontal neo-ostium is small, or there is excessive denuded bone, osteitic bone in the frontal recess, or severe mucosal disease.4 Like ours, these are more severe cases. Studies on long-term endoscopic frontal sinus stent retention must be interpreted in this light. Furthermore, frontal sinus stents are frequently inserted temporarily, and thus, 6 months is considered relatively “long term.” The conclusion from the literature, however, is reasonably positive on both the safety and efficacy of these stents. While we obviously would not extrapolate those results to lacrimal sac placement, we can conclude that the material and form are reasonably well tolerated in the sinonasal environment, and the risks are acceptable. Table is meant to clarify any misunderstanding related to the frontal sinus stent literature. As for our own study, 8 of the 9 cases have continued to do well and remain symptom-free with no complications at an average of 32 months (range 12–59 months) of follow up. For the 2 with concurrent canalicular intubation, the silicone stents

© 2014 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.

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Letters to the Editor

Summary of otolaryngology literature on silicone frontal sinus stents # Patients, (# stents)

Study

Duration of stent placement

Weber et al. Freeman and Blom6

12 patients, (21 stents) All were removed at 6 mo 46 patients, (64 stents) Average 29 mo

Lin and Witterick7

11 patients, (21 stents) Average 16.3 mo

Orlandi and Knight8 Hunter et al.9

9 patients, (9 stents)

Average 32.6 mo

3 patients, (3 stents)

29–60 mo

5

Complications None 1 pt with pain relieved with stent removal 1 stent removed due to occlusion with dried serum 3 stents obscured by middle turbinate or polyps, 1 of these was removed 3 stents with spontaneous dislodgement (at 8.8 mo on average) 1 stent removed due to irreversible obstruction 1 stent removed due to migration into frontal sinus 2 stents (in 1 patient) removed due to recurrent sinusitis 1 stent removed at 61 mo due to infection 1 stent removed at 11 mo due to pain/edema 1 stent replaced at 29 mo due to pain, no recurrence of pain at 19 mo follow up

were left in place during the postoperative period until a window of mucosal quiescence was observed, and the heightened risk of canalicular scarring had elapsed (10 and 19 months).

Aaron Fay, M.D. Dawn K. De Castro, M.D. Correspondence: Aaron Fay, M.D., Ophthalmic Plastic and Reconstructive Surgery, Massachusetts Eye and Ear Infirmary, 243 Charles St., Boston, MA 02114 ([email protected]) The authors have no financial or conflicts of interest to disclose.

REFERENCES 1. Avisar I, McNab AA, Dolman PJ, et al. Endonasal dacryocystorhinostomy for nasolacrimal duct obstruction in patients with sarcoidosis. Orbit 2013;32:225–30. 2. Lee BJ, Nelson CC, Lewis CD, et al. External dacryocystorhinostomy surgery in patients with Wegener granulomatosis. Ophthal Plast Reconstr Surg 2012;28:389–92. 3. Linberg JV, Anderson RL, Bumsted RM, et al. Study of intranasal ostium external dacryocystorhinostomy. Arch Ophthalmol 1982;100:1758–62. 4. Rains BM, 3rd. Frontal sinus stenting. Otolaryngol Clin North Am 2001;34:101–10. 5. Weber R, Mai R, Hosemann W, et al. The success of 6-month stenting in endonasal frontal sinus surgery. Ear Nose Throat J 2000;79:930–2, 934, 937–8 passim. 6. Freeman SB, Blom ED. Frontal sinus stents. Laryngoscope 2000;110:1179–82. 7. Lin D, Witterick IJ. Frontal sinus stents: how long can they be kept in? J Otolaryngol Head Neck Surg 2008;37:119–23. 8. Orlandi RR, Knight J. Prolonged stenting of the frontal sinus. Laryngoscope 2009;119:190–2. 9. Hunter B, Silva S, Youngs R, et al. Long-term stenting for chronic frontal sinus disease: case series and literature review. J Laryngol Otol 2010;124:1216–22.

(Botox) and incobotulinumtoxinA (Xeomin) in the treatment of benign essential blepharospasm.” The authors compared the 2 formulations of botulinum toxin type A regarding patient preferences in the treatment of benign essential blepharospasm (BEB).1 While their results did not indicate a significant disparity in patients’ toxin preference (52% incobotulinumtoxinA vs. 48% onabotulinumtoxinA), patients who preferred incobotulinumtoxinA had significantly shorter treatment intervals. While previous studies have demonstrated that these 2 toxins have similar potencies,2 this recent report suggests that incobotulinumtoxinA may have a shorter duration of action.1 The authors postulate that perhaps there are differences in drug potency, diffusion, or uptake with the purified toxin of incobotulinumtoxinA compared with onabotulinumtoxinA. We propose that another potential cause of this discrepancy in results could be due to toxin reconstitution technique. Specifically, we wish to emphasize the importance of vial inversion in the reconstitution of incobotulinumtoxinA. Although both onabotulinumtoxinA and incobotulinumtoxinA are type A botulinum toxins, they are packaged differently and require unique reconstitution techniques. OnabotulinumtoxinA comes as a vacuum-dried powder that is positioned as a film at the bottom of the vial that becomes fully reconstituted when the normal saline fluid fills the bottom of the vial. In contrast, incobotulinumtoxinA comes as a lyophilized powder in the form of a tablet within the vial. During the course of normal shipping and handling, this tablet often breaks apart, and the power is distributed throughout the entire vial, including near the top of the vial, near the edges of the rubber stopper (Figs. A,B). To fully

Re: “Comparison of Preferences Between OnabotulinumtoxinA (Botox) and IncobotulinumtoxinA (Xeomin) in the Treatment of Benign Essential Blepharospasm” To the Editor: We read with interest the article by Chundury et al.,1 “Comparison of preferences between onabotulinumtoxinA

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Front (A) and side-view (B) photographs of a vial of ­incobotulinumtoxinA. The powder within the vial is distributed throughout, including the sidewall and the edges of the rubber stopper.

© 2014 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.

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