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Abstract
Aims To study the clinical and diagnostic profile of punctal dysgenesis with membranes, to classify and correlate the membranes clinicopathologically and study the outcomes of membranotomy.
Methods A prospective interventional study involving 55 dysgenetic puncta of 22 consecutive patients seen between July 2008 ansd December 2011. Data collected include demographics, clinical presentation, laterality, age at presentation, duration of symptoms, slit lamp examination, punctal profiles, types of membranes, associated lacrimal anomalies, management and outcomes. All the patients underwent membranotomy, after which the puncta were assessed for adequacy of the opening, the canaliculi were assessed with probes and irrigation was done to assess the patency of the lacrimal system. A minimal follow-up of 6 months was taken for final analysis. Primary outcome measures included were anatomical patency on irrigation and relief from epiphora assessed subjectively and also objectively by a dye disappearance test.
Results The patients included 11 males and 11 females, with a mean age of 82.4 months (range 5–264 months) at presentation. Bilateral punctal involvement was seen in 59% (13/22) and all the four puncta were affected in 31.8% (7/22) of the patients. Epiphora was the most common complaint noted in 95% (21/22), and the symptoms were noticed since birth in 68.1% (15/22). External membranes over the puncta were noted in 86.4% (19/22) and internal punctal membranes in 13.6% (3/22) of patients. All the patients underwent membranotomy, however additional procedures like probing was done in 13.6% (3/22), mini-monoka intubation in 9.1% (2/22), Crawford's bicanalicular intubation in 9.1% (2/22) and dacryocystorhinostomy in 4.5% (1/22). Uniformly, the punctal membranes on histopathological examination were fibrovascular membranes. The anatomical patency was 100% and relief from symptoms was seen in 91% (20/22) of the patients.
Conclusions This study presents the largest series to date (n=55 puncta) exclusively on punctal dysgenesis with membranes and, for the first time, has shown the clinicopathological correlation of these membranes. Incomplete punctal canalisation is probably a better term and this study could be the starting point for further exploration into the etiopathogenesis and genetics of this intriguing congenital disorder.
- Embryology and development
- Lacrimal drainage
- Pathology
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Introduction
Proximal lacrimal outflow dysgenesis involving the punctum and canaliculus is sparsely documented in the literature.1–9 The term ‘punctal atresia’ has been used interchangeably with punctal agenesis as well as being used for a spectrum of punctal disorders varying from a fine membrane in the punctum to absence of the punctum itself.1–11 Some authors have referred to mildest form of punctal dysgenesis with membranes simply as ‘punctal membranes’, whereas others have termed it ‘congenital imperforation of the puncta’ and yet others have classified it as a part of punctal stenosis.1 ,4 ,9 ,12 Deficiencies and lacunae in the current knowledge regarding punctal dysgenesis with membranes includes confusing terminologies, unknown etiopathogenesis, improper classification and non-standardised management protocols. The present study describe the largest series on punctal dysgenesis with membranes(n=55 puncta), attempts to introduce the term ‘incomplete punctal canalisation (IPC), to classify the condition further as those with external membranes and internal membranes, and to study its clinical and diagnostic profile along with the clinicopathological correlation of the membranes.
Material and methods
This research included a prospective interventional study involving 55 dysgenetic puncta with membranes in 22 consecutive patients seen at a tertiary referral centre between July 2008 and December 2011. Data collected include demographics, clinical presentation, laterality, age at presentation, duration of symptoms, slit lamp examination, punctal profiles, types of membranes, associated lacrimal anomalies, management and outcomes. The clinical examination revealed two typical locations of the membranes. The external membrane variety, which the authors prefer to call IPC-EM, typically covers the external surface of the puncta and hides it beneath, giving a false impression of punctal agenesis (figures 1A and 2A). The internal membrane variety, which the authors prefer calling IPC-IM, typically demonstrates blurred punctal margins but, just at the entry into the puncta, covers it entirely with a membrane (figure 1B,C). The membranes usually appear translucent (figure 1A,C). Clinical diagnosis is based on a high degree of suspicion, slight avascular dimpling at the site of puncta (figure 1A) and/or at the medial aspect of meibomian gland orifices. In the authors’ experience, the membrane tends to stand out as a translucent structure from the surroundings if indirect illumination is used with the help of a slit lamp and a thin slit beam is placed perpendicularly and adjacent to the punctum (figure 1C). All the patients underwent membranotomy using a simple punctum dilator (figure 2B), after which the puncta were assessed for adequacy of the opening (figure 2C), the canaliculi were assessed with probes and irrigation was done to assess the patency of the lacrimal system. The membranes were sent for pathological examination. A minimal follow-up of 6 months was taken for final analysis. Primary outcome measures included were anatomical patency on irrigation and relief from epiphora, assessed subjectively and also objectively by a dye disappearance test.
(A) External photograph of the left lower lid showing a translucent membrane covering the puncta. (B) External photograph of the right lower lid showing blurred punctal margins with a membrane just at the entrance. (C) Slit lamp photograph of the same patient as in figure 1B in a higher magnification, clearly showing the translucent internal membrane.
External photograph of the right lower lid showing incomplete punctal canalisation-external membranes. Note the classical dimple in the area of the puncta (A). The same patient undergoing a membranotomy (B). Note the puncta following a simple membranotomy (C).
Results
The patients included 11 males and 11 females, with a mean age of 82.4 months (range 5–264) or 6.8 years at presentation. Bilateral punctal involvement was seen in 59% (13/22) and 41% (9/22) had unilateral involvement. Among those with unilateral involvement, 77% (7/9) affected the left eye. All the four puncta were affected in 31.8% (7/22) of the patients, the bilateral lower puncta alone in 18.2% (4/22), the bilateral upper puncta alone in 9.1% (2/22), unilateral upper and lower puncta in 27.3% (3/22), a single lower punctum in 9.1% (2/22) and a single upper punctum in 4.5% (1/22) of the patients. Epiphora was the most common complaint, noted in 95% (21/22), and the symptoms had been noticed since birth in 68.1% (15/22). There was no family history of any such symptoms and the ocular surface was healthy in all patients. External membranes over the puncta were noted in 86.4% (19/22) and internal punctal membranes in 13.6% (3/22) of patients. Canaliculi were found to be stenotic following membranotomy in 13.6% (3/22) and associated congenital nasolacrimal duct obstruction (CNLDO) was noted in 13/6% (3/22) patients. All the patients underwent membranotomy; however, additional procedures like probing was done in the three cases of associated CNLDO, of which one responded well to a simple probing only and one required an additional Crawford silicone intubation; the case that did not respond favourably to probing underwent a dacryocystorhinostomy with mitomycin-c (0.4 mg/ml) and bicanalicular Crawford intubation (4.5%, 1/22). Among the canalicular stenosis group, both cases underwent a mini-monoka intubation (9.1%, 2/22). The punctal membranes on histopathological examination uniformly showed fibro-collagenous tissue with few vascular channels without any evidence of inflammation that was suggestive of fibrovascular membranes (figure 3A–C). The anatomical patency was 100% on irrigation and relief from symptoms was seen in 91% (20/22) of the patients.
(A) Microphotograph showing a membrane at low magnification (H&E×40). (B, C) Membrane at higher magnifications uniformly showing fibro-collagenous tissue with few vascular channels without any evidence of inflammation suggestive of fibrovascular membranes (B: H&E×100), (C: H&E×400). H&E, Hematoxylin and eosin stain.
Discussion
The embryonic origin of lacrimal passages are along the line of the cleft between the lateral nasal process and the maxillary process of the embryonic face.6 After the cleft obliterates, a solid epithelial rod appears in the embryo of 9.5 mm length and then completely separates from the surface in an embryo of 15 mm. The canaliculi are formed by budding of the upper end of this solid cord in an embryo of 18–24 mm.9 The process of canalisation begins in a 35-mm embryo by the disintegration or apoptosis of the central cells. The entire canaliculus is canalised except near the puncta; this portion, which is of significance in the current study, opens onto the lid surface when the embryo is 130 mm, before the separation of the eyelids at the 7th month of intrauterine life.3 ,4 ,6 ,9
The pathogenesis of punctal membranes is unknown but is believed to either represent failed dehiscence of the epithelium overlying the normally formed canaliculi or a failure of canalisation of the most proximal part of the lacrimal apparatus.1 ,3 ,9 The latter seem to make more sense after the current study looked at the membranes histopathologically, although further studies would be required for a detailed embryo–pathogenic correlation. The membranes were fibrovascular with few blood vessels and no inflammation. It appears that the entire canaliculus was canalised and the last portion of the punctum failed to do so, resulting in the remnant non-canalised segment.
Katowitz et al8 discussed congenital aetiologies of the upper nasolacrimal system and noted that the membrane may be present within the punctal orifice or may overlie it like a veil, and may only be represented as a small dimple in the lid margin. Apart from the three features that are helpful in the diagnosis of IPC—which have already been elucidated earlier—the normal architecture and conformation of the pars lacrimalis of the eyelid is intact in contrast to punctal agenesis, where it is lost.1 ,4 ,6
Kashkouli et al12 classified punctal membranes as Grade 1 punctal stenosis and advocated the use of 25-gage needle perforation followed by punctum dilatation. The authors of the present study do not agree with this, as they did not find any punctal stenosis following membranotomy (figure 2C) and the use of the 25-gage needle has the potential to harm the mucosa in inexperienced hands.
Ahn Yuen et al1 studied lacrimal outflow dysgenesis comprehensively and found that 66% of their cases were bilateral and 89% of them had some form of proximal lacrimal system dysgenesis. They believed (and rightly so) that the presence of punctal membrane represents the mildest form of proximal lacrimal outflow dysgenesis. They found a strong familial pattern for the patients with punctal membranes. The present study looked exclusively at one form of punctal dysgenesis and found that bilateral punctal involvement was seen in 59% (13/22) of the patients and 86.4% (19/22) had external membranes over the punctum. The current study did not find any familial patterns in the large number of patients that were studied.
Unlike punctal agenesis, which is associated with systemic syndromes like ectodermal dysplasia,1 ,6 Hay–Wells1 and Levy–Hollister syndromes,8 the authors did not find any systemic associations with IPC in the present study, although associated lacrimal system anomalies like canalicular stenosis and CNLDO were noted.
Management modalities that have been elucidated in the literature include a punctoplasty with membrane lysis, and intubation or retrograde marsupialisation during dacryocystrhinostomy.1 ,4 We do not advocate any retrograde approach, since it is technically challenging and because that membranotomy using a simple punctum dilator is almost always helpful. Intubation is helpful for associated canalicular stenosis; however, the authors do not advocate the use of routine intubation following membranotomy, since the diameter of the punctum is fairly large following the procedure and does not tend towards restenosis later on (figure 2C).
In conclusion, this study presents the largest series till date (n=55 puncta) on punctal membranes and, for the first time, has shown the clinicopathological correlation of these membranes. IPC is probably a better terminology than punctal atresia or punctal membranes, and this study could be the starting point for further exploration into the etiopathogenesis and genetics of this intriguing congenital disorder.
Footnotes
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Contributors MJA: concepts and manuscript writing. SM: data collection. KM: pathological examination and correlation. MNN: concepts. SGH: concepts.
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Competing interests None.
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Patient consent Obtained.
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Ethics approval This study has been reviewed by the ethics committee and has been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki. Informed consent was obtained from the parents/guardians of the patients.
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Provenance and peer review Not commissioned; externally peer reviewed.