Minimally Invasive Lacrimal Surgery

3.1 Introduction

Stenoses of the lacrimal drainage system can lead to symptoms such as abnormal tearing or epiphora (which can be very troublesome for the patient), recurrent or chronic conjunctivitis, a more or less permanently increased Þlm of secretions or yellowish secretions in the conjunctival sac, and acute or chronic dacryocystitis.

performed in the context of rhinoplasty or maxillary fenestration [10])

¥Increased venous plexuses in the nasolacrimal duct (functional stenosis with passive patency of the lacrimal passages but inadequate active transport)

3.1.2Diagnosis of Stenoses

of the Lacrimal Drainage System

3.1.1Causes of Stenoses of the Lacrimal Drainage System

The causes include:

¥(Not yet perforated) membranous obstruction of the ostium of the nasolacrimal duct at the level of the valve of Hasner (neonates Ð children)

¥Post-inßammatory stenoses (usually in the nasolacrimal duct, less often in the canaliculi)

¥Dacryoliths in the lacrimal sac [97]

¥Tumours of the lower lacrimal drainage system [18, 80]

¥Nasal and paranasal sinus tumours

¥Extensive chronic polypoid sinusitis

¥Chronic inßammatory conditions such as sarcoidosis [1, 15]

¥Status post-midface fracture [2]

¥Status post surgery of the nose and paranasal sinuses (injury of the nasolacrimal duct during osteotomy

R. K. Weber

Department of ENT, Hospital Karlsruhe, Moltkestrasse 90, 76133 Karlsruhe, Germany

e-mail: rainer.weber@klinikum-karlsruhe.com

The diagnostic workup includes:

¥History.

¥External inspection and palpation (abnormalities in the region of the medial canthus, lids and lacrimal puncta Ð are these properly submerged in the lacrimal lake, lid margin, palpable mass). Tearing due to ectropion, for example, will of course not be improved by dacryocystorhinostomy (DCR).

¥Endoscopy of the nose: In addition to the exclusion of any endonasal causes (tumour, granulomatous inßammation, polyps, scars after surgery or trauma), it is important to evaluate the topography for surgical planning. Is septoplasty necessary to obtain sufÞcient space for the operation and post-operative care and to reduce the risk of formation of adhesions between the septum and the lateral nasal wall? Is reduction of the middle turbinate necessary? Does the endoscopic picture suggest that operative measures to enlarge the middle nasal meatus will be useful (resection of the uncinate process, opening of the ethmoid bulla)? Is there chronic sinusitis which indicates the need for a more extensive paranasal sinus procedure?

¥Probing to locate the site of the stenosis (stop in the region of the canaliculi already or in the lacrimal

sac) and irrigation to check for passive patency. Probing is not entirely uncontroversial as a lesion of the canaliculi and subsequent development of a presaccal stenosis cannot be entirely ruled out. It must therefore be performed particularly carefully. On the other hand, it is a very simple and valuable procedure which provides rapid and reliable information about the location of a lacrimal stenosis. The theoretical risk of a lesion of the canaliculi applies equally to the dacryocystography which would be necessary if probing and irrigation were not performed.

¥Dye disappearance test, e.g. with ßuorescein solution, to examine active tear transport. This is important because a number of lacrimal stenoses can be overcome by irrigation, thus falsely suggesting that the lacrimal ducts are sufÞciently patent. The functional relevance of partial obstruction through scars or thickened mucosa is only revealed by physiological testing. The test is performed by placing a drop of the yellow ßuid (caution: permanently stains clothing) in the conjunctival sac of both eyes and measuring the time to complete disappearance of the dye. With normal blinking the ßuid should have disappeared from the conjunctival sac within 2 min [12]. Differences between the two eyes, delayed disappearance and/or external overßow indicate stenosis. The successful transport into the nose can be objectiÞed endoscopically or by insertion of swabs which are then examined.

We consider the examination and diagnostic procedures described above to be indispensible. The following are useful in individual cases and should be employed as appropriate.

¥Dacryocystography [88], nowadays preferably performed using the subtraction technique, has proved valuable for documentation and precise topographic localisation of the stenosis. However, in our opinion, it is not necessary if the remaining Þndings obtained from the history, inspection and palpation, probing and irrigation and dye test are unambiguous, because in our experience, it provides no relevant gain in information which might inßuence the treatment. Unnecessary radiation exposure, expenditure and discomfort to the patient can be avoided. Dacryocystography carries the same inherent risk of inducing a pre-saccal stenosis through damage to the canaliculi.

¥A plain Þlm of the paranasal sinuses provides little useful information. It does not show the lacrimal

system. The information required for possible paranasal sinus surgery should be obtained by CT.

¥CT is necessary if there is a suspicion of paranasal sinuses which would require further operative measures, but not in the case of an uncomplicated stenosis.

¥Other procedures such as scintigraphy, magnetic resonance imaging or MR-dacryocystography [29] are not recommended for routine diagnostic evaluation.

¥Pre-operative endoscopy of the lacrimal drainage system may become relevant in the future. Through the development of suitably thin and powerful endoscopes, it appears to permit successful pre-operative evaluation increasingly often in the hands of experienced users [21, 39, 53, 59Ð61]. However, endoscopy should lead to a less invasive and at the same time equally effective treatment for it to become an established procedure, and should have at least the same informative value as dacryocystography. It cannot currently be said that this is the case. Nevertheless, the option of opening up a diagnosed stenosis by means of transcanalicular endoscopy appears interesting and the results must be observed.

3.1.3General Remarks Regarding Surgical Management

External DCR is considered the gold standard for surgical management of stenosis of the lacrimal system, at least in ophthalmological literature. It was Þrst described by Toti in 1904 and has been modiÞed several times, technical modiÞcations concerning mainly the creation and suture of mucosal ßaps. A standard component of external DCR is stenting of the lacrimal passages with silicone tubing for several weeks to several months. Success rates of 85Ð90% and more are reported [12, 18, 67, 77]. The main criterion used for deÞning success is freedom from clinical symptoms. Only some of the authors examined and documented additional outcome criteria such as probing, irrigation or the dye disappearance test. Methodological problems are the use of retrospective analysis in most cases and the heterogeneity of the procedures and patient populations studied.

In an editorial in 1999, Struck described success rates of transcutaneous external DCR of between 80 and 100%, and of 95% at specialised centres [77]. The most common reasons for failure are insufÞcient size