Successful removal of a congenital fibrovascular pupillary membrane in 2 cases with variable age at presentation and sparing of the crystalline lens

Abstract

Introduction and importance

Congenital fibrovascular pupillary membranes (CFPMs) represent a rare poorly understood condition that has been sporadically reported in the literature. The presence of such a membrane can cause pupillary block and further complications, therefore must be properly diagnosed and managed.

Case presentation

We are presenting the successful treatment of 2 cases with CFPM. The first patient presented 2-days after birth with an absent red reflex and had a less complicated clinical course. The second presented at a later age of 5-months and was referred as a case of congenital cataract. This baby had associated pupillary block glaucoma. Each of these cases was managed surgically by membrane peeling with sparing of the lens, which was found to be clear in the second case.

Discussion

Even though CFPM has been rarely reported, it should be correctly identified since it can progress with the development of glaucoma and lens changes. The etiology of CFPM is not well understood but might be related to the presence of ectopic iris tissue, which was suspected as an etiology in our second case. Several techniques have been described to remove the membrane, and occasionally this might necessitate removal of the lens. We described successful removal of CFPM in 2 cases without affecting the crystalline lens.

Conclusion

General Ophthalmologists and Pediatricians should be aware of CFPM, especially when dealing with an absent or dull red reflex in a newborn. Referral for definitive diagnosis and treatment is essential to preserve vision.

Highlights

• •Congenital fibrovascular pupillary membranes (CFPMs) are rare.
• •Histopathologically, CFPMs have vascular, fibrous, and smooth muscle components.
• •Clinical presentation depends on the age at presentation and surgical removal is advisable to avoid visual complications.
• •We report 2 infants with CFPM successfully treated by membrane peeling with sparing of the lens.

1. Introduction

Fibrovascular pupillary membrane is described in the literature as a rare unilateral anterior segment disorder. It was first reported by Cibis et al. in 1986, and since then, different names were used to describe such a membrane, which is thought to arise from ectopic iris tissue [[1], [2], [3]]. These include “congenital pupillary-iris-lens membrane with “goniodysgenesis,” “congenital idiopathic microcoria,” and “fibrous congenital iris membrane with pupillary distortion”. [4]

The Pupillary membrane may or may not be adhered to the crystalline lens. [5]

Histopathological examination typically reveals fibrovascular tissue, containing arterioles and venules, fibrocytes, extracellular collagen, and immunoreactive elongated cells that show reactivity for smooth muscle antibodies. [6]

It is advisable to remove this membrane since it has tendency to progress and can cause obstruction of the pupil leading to angle closure glaucoma. [4]

We report the clinical findings of congenital fibrovascular pupillary membrane (CFPM) in 2 cases presenting at different age with histopathological confirmation of the diagnosis. The first was a 2-days-old infant successfully treated by surgical removal of the membrane with sparing of the crystalline lens. Our infant was unique since he presented with unilateral fibrovascular pupillary membrane at birth and underwent successful surgical excision of the membrane with sparing of the crystalline lens. The second case presented at a later stage at the age of 5 months and was misdiagnosed and referred as a case of congenital cataract. The difference of the age at presentation and the fact that the second case presented later after birth support the theoretical origin of CFPM from ectopic iris tissue possibly being hidden in the anterior chamber angle at birth. Our cases demonstrate the ability to spare a clear lens following the removal of the CFPM if surgery is done carefully. Finally, we had no recurrence of the CFPM -even though this is common- in any of our cases. This case report of the 2 patients has been prepared according to the guidelines of SCARE. [7]

2. Presentation of cases

2.1. Case 1

A 2-days-old baby boy was referred to our service because of absent red reflex in his left eye. He was delivered at the age of 36 weeks due to fetal growth retardation. The maternal history was negative for intrauterine infections. The child's birth and medical history were otherwise unremarkable. The baby was the parents' first-born child of non-consanguineous marriage. There was no similar family history of developmental anomalies and no history of trauma.

During examination the infant was blinking to light in both eyes. Red reflex was absent in the left eye. A fibrovascular membrane was noted over the left pupil (Fig. 1A). The pupil was not dilating with routine cycloplegic drops (Cyclopentolate 0.5 %). There was no fundus view, therefore ultrasound (B-scan) was performed and showed normal flat retina and normal axial length ruling out microphthalmic globe.

Fig. 1.

A: the pre-operative photo of left eye in case 1 showing the congenital pupillary fibro-vascular membrane (CFPM). B: The post-operative photo of the same treated eye showing clear lens and visual axis.

The case was discussed with the parents and the decision was to surgically remove that membrane to avoid further complications. The informed consent was obtained, and the surgery was performed at the age of 27 days by the treating experienced pediatric surgeon in the same institution under general anesthesia. Corneal incision was made, and the anterior chamber was filled using ophthalmic viscosurgical device. Posterior synechiolysis was done 360 degrees around the pupil edge using the same ophthalmic viscosurgical device and intraocular scissors. The pupillary membrane was carefully and slowly peeled to prevent inadvertent violation of the anterior lens capsule. The peeling was carried out using intraocular forceps. The whole membrane was removed as a single intact piece and was sent in formalin for routine histopathology. The patient was examined 1 day after the surgery. Red reflex was good, with deep and quite anterior chamber and clear lens (Fig. 1B).

The patient was doing well 2 weeks post operatively. The visual axis was still clear allowing for cycloplegic refraction and fundus examination of the operated eye. Last follow up was 3 months post-operatively and the clear visual axis was maintained with no evidence of regrowth of the membrane.

The histological sections of the specimen in the first patient showed an irregular fibrovascular membrane that consists of spindle-shaped cells and numerous venous and capillary like blood vessels. In one focal area, few uveal pigment deposits were observed. The membrane was similar in appearance to the tissue described in cases of posterior persistent hyperplastic primary vitreous (PHPV), however, no glial component was seen. No Periodic Acid Schiff (PAS)-positive lens capsule was observed in the sections provided (Fig. 2). The overall histopathological appearance was consistent with a fibro-vascular membrane, which supported the clinical diagnosis of a congenital fibro-vascular pupillary membrane.

Fig. 2.

A: The histopathological appearance of the pupillary vascular membrane in case (Original magnification ×200, Hematoxylin and eosin). B: The delicate vascular network highlighted by endothelial cell marker (Original magnification ×400, CD34). C: Higher power of the membrane (Original magnification ×400, Hematoxylin and eosin).

2.2. Case 2

A 5-month-old baby girl was referred to the service as a case of congenital cataract in the right eye. The baby was a product of full-term uneventful pregnancy and was born without any complications and had normal milestones after birth. There was no history of maternal infection. She was the first child in the family, with no siblings and no family history of congenital cataract. The parents recalled normally appearing right eye at birth and absent membrane with clear red reflex soon after birth. They also denied any history of trauma. Examination under sedation revealed quite conjunctiva, clear cornea with a diameter of 13 mm, a dim red reflex in the right eye, and a fibrovascular membrane covering the whole pupil and extending over most of the iris surface (Fig. 3A). Intraocular pressure (IOP) was 33 mmHg in the right eye using Tono-pen. Biological microscope (UBM) showed 360 degrees iris bowing causing pupillary block, shallow anterior chamber, and a normal lens position and zonules. B-scan showed no retinal detachment but large cupping. Axial length was 25.00 mm in the right eye and 20.50 mm in the left eye. The examination of the left eye was within normal limit.

Fig. 3.

A: Pre-operative photo of the second case right eye showing large cornea diameter with more extensive fibro-vascular membrane covering the iris and pupil. B: The histopathological appearance of the thick highly vascular pigmented pupillary membrane in the same case (Original magnification ×200, Hematoxylin and eosin). C: The larger numerous blood vessels highlighted by endothelial cell marker (Original magnification ×400, CD31). D: The bleached histological sections of the pupillary membrane (Original magnification ×200, Hematoxylin and eosin-bleached).

The patient was started on anti-glaucoma medication and the case differential diagnosis, status, and management options were discussed with the parents. The final decision with the treating pediatric ophthalmologist was to go for surgical intervention taking into consideration the visual access obscuration by the membrane and the dim light reflex. The patient underwent surgery, which involved removing the pupillary membrane, performing a sphincterotomy and surgical peripheral iridectomy.

After filling the anterior chamber with ophthalmic visco-surgical device (OVD), the pupillary membrane was carefully removed using intraocular forceps and simcoe, then the membrane was sent for histopathology. The excised tissue showed numerous similar proliferating blood vessels of variable calibre within hypocellular fibrous network (Fig. 3B). The vascular component was highlighted using CD31 stain for endothelial cells and the smooth muscle component was expressed using the corresponding smooth muscle actin (SMA) stain (Fig. 3C). The membrane in this case was relatively thicker, more vascular with larger capillaries and more pigmented stroma with adherent iris like tissue -for which bleached sections were prepared- (Fig. 3D).

Postoperative care included prednisone acetate 1 %, anti-glaucoma, antibiotics, and atropine 1 % drops. On day 1 post-op, the IOP was normal, and the eye showed mild corneal edema and small clotted blood in the anterior chamber. After 7 days, the IOP was 9 mmHg in the right eye, the corneal edema improved, the anterior chamber was deep and quiet, and there was no blood or residual fibrous membrane. The lens was further confirmed to be clear. One-month follow-up after surgery, the patient had normal IOP, clear cornea, deep and quite anterior chamber, pharmacologically dilated pupil, clear lens, clear vitreous, flat retina, and optic disc cupping around 0.8.

3. Discussion

Congenital fibrovascular pupillary membranes (CFPM) have been described as a rare developmental anomaly in the literature that might be complicated by adherence to the lens and the development of glaucoma. [4,5] Clinical findings of CFPMs include miosis, pupillary membrane, anterior capsular cataract, corectopia, posterior embryotoxon, microphthalmos and persistent iris vessels [6]. Our first patient had miosis, pupillary membrane and persistent iris vessels while the second presented 5 months after birth with pupillary block glaucoma.

Histopathology evaluation revealed many types of cells in different case reports that suggested CFPM is a variant of persistent fetal vasculature [[4], [5], [6]]. Our first case was very similar in the histopathological constituents and appearance to that described by Kesarwani et.al with elongated spindle-shaped cells and adherent pigmented tissue [9]. The presence of more developed adherent iris tissue in the second case with a delayed presentation and longer history that indicated the absence of this membrane at birth, may support the theory of CFPM being related to the presence of an ectopic iris tissue at birth. In addition, a mesenchymal origin marker, CD31 used to stain the endothelial cell and blood vessel wall of the second case similar to the histopathological finding of Lambert et al. [6]

Few instruments and techniques have been suggested to surgically remove such a membrane like vitrector, bipolar radiofrequency diathermy, small gauge needle and forceps [6,8]. However, because of the high risk of membrane recurrence and lens damage, surgical removal is challenging and occasionally, it is not possible to remove the whole membrane without lensectomy. Lensectomy is indicated if the visual axis clarity is affected by the presence of lens cataractous changes. Our 2 patients didn't undergo lensectomy since the lens was observed to be clear by the end of manual membranectomy of the CFPM. In case of secondary glaucoma coexists, the child will need more invasive surgery for controlling IOP and the surgical outcome will depend on the severity of iris adhesion and proliferation of fibrovascular membrane.

Liang et al. published 9 cases of the CFPM with secondary glaucoma. All cases had membranectomy, peripheral iridectomy, pupilloplasty, and goniosynechialysis as initial surgery. Following primary surgery, 4 patients had an intractably elevated IOP [9]. Additional surgeries including membranectomy, pupilloplasty, goniosynechialysis, cyclocryotherapy, ciliary photocoagulation, Ahmed valve implantation, and lensectomy were performed. IOP was controlled in 8 patients and at the last follow up none of the patients could fix and follow at targets. Anterior iris root insertion was noticed in 4 eyes with uncontrolled IOP [9].

Zhu Y, et al. reported 25 cases of congenital fibrovascular membrane with secondary glaucoma [10]. All cases had anterior segment reconstruction surgery, by performing peripheral iridotomy and blunt dissecting the membrane from the anterior lens capsule. This was done by injecting viscoelastic through the peripheral iridectomy. In this study, they used UBM to classify the membrane severity. They found that class I had (72.7 %) success rate and additional surgery was needed in most of classes II and III [10].

The most known complication after surgical removal of CFPM is recurrence. It has been reported in all patients in a case series by Lamber et.al, where primary iris sphincterotomy was not done along with membranectomy. The recurrence appeared within 1 week to 6 months. [6]

On the other hand, other single case reports did not report any recurrence up to one year of follow up [11,12] No recurrence was noted in any of our patients after a period of 3 months.

4. Conclusion

In conclusion, this is an interesting and rare occurrence of a CFPM that was diagnosed and managed effectively by surgical membranectomy with sparing of a clear lens and successful outcome. CFPM share the presence of vascular component as well as fibrous and smooth muscle-like component, which has been demonstrated histopathologically in our cases. When indicated, the surgery management needs to be conducted early to prevent visual deprivation and amblyopia. Every attempt should be made to spare the crystalline lens while removing the pupillary membrane, which has been achieved in both our cases with no recurrence. The aim is to preserve accommodation and eliminate the need for future surgeries (cataract removal) and visual rehabilitation.

Provenance and peer review

Not commissioned, externally peer reviewed.

Source of funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Ethical approval

IRB is not required for case reports in our institution. However, information was obtained and reported in a manner that was compliant with the standards set forth by the Health Insurance Portability and Accountability Act, and the Declaration of Helsinki as amended in 2013.

Consent

General informed written consent was obtained from the 2 patients' guardians including permission for anonymous use of photos and for reporting. Copies of the written consents are available for review by the Editor-in-Chief of this journal upon request.

CRediT authorship contribution statement

Abdullah Al Otaibi & Mohammed AlShamrani: Case report design, the clinical and surgical care of the patient.

Ghufran Alarfaj, Budoor Alsalman & Hanan A Neyaz: Review of chart for data collection, literature review and first manuscript draft.

Hind M Alkatan: Histopathological review of slides and images. Critical revision of the manuscript for submission and Corresponding author.

Research registration

Not applicable.

Guarantor

The Corresponding author.

Hind M. Alkatan, MD, Professor, College of Medicine, Departments of Ophthalmology & Pathology, King Saud University, Riyadh, Saudi Arabia.

Email: hindkatan@yahoo.com; hkatan@ksu.edu.sa.

Tel. No: +966-504492399, Fax No: +966-11-2052740.

Declaration of competing interest

None.