Complications of orbital endoimplantation in the Eye Clinic of the Lithuanian University of Health Sciences.

The aim of the study was to analyse the rate of complications of orbital endoimplantation in patients operated from 2002 to 2014 at the Eye Clinic of the Lithuanian University of Health Sciences and to compare it with the results in the literature. Enucleation must be performed very carefully in order to prevent any additional trauma, infection, deformation, and to create an optimal conjunctival socket. However, complications occur despite efforts and qualified surgeons. The most common complications described in the literature are thinning and cysts of the conjunctiva, a foreign body reaction, secretion, symblepharons, fornix deficiency, ptosis, permanent pain, dislocation, migration and protrusion of the implant, a primary or secondary infection, and implant extrusion. From 2002 to 2014, 128 patients underwent orbital endoimplantation surgery at the Eye Clinic. The most common complications were conjunctival erosion (five patients, or 2.9%), cysts (nine patients, or 7%), and implant extrusion (five patients, or 2.9%). The type and rate of complications were very similar to the data in the literature.

INTRODUCTION

An implant is a medical device, which is grown into the human body to replace a malfunctioning or missing part of the body or tissue, or to make their function more adequate. Since the surface of the implant is in contact with human tissue it should be produced from materials that are hypoallergenic, non-toxic, and indestructible chemically or mechanically as loose parts can disturb the activity of other organs (1).

This paper is about endoimplantation of the anophthalmic orbit. The purpose of this procedure is to restore the orbital volume, to save the function of extra-ocular muscles, to improve the motility of the artificial eye, and to minimize the symptoms of the post-enucleation socket syndrome (PESS).

The removal of the eyeball must be performed very carefully in order to avoid any unnecessary trauma, infection, deformation, or other complications and to create the optimal conjunctival sac. Despite the mo-st favourable conditions and qualified surgeons, the possibility of complications still remains (2–8, 11, 24).

The most frequent complications of orbital endoimplantation found in the literature are the following: thinning of the conjunctiva (3.2–8.3%), conjunctival cysts (3.2–6.0%), a foreign body reaction (5.4%), secretion (6.0–21.0%), symblepharons (3.0%), deficiency of conjunctival fornices (10.0%), ptosis (10.5–23.5%), permanent pain (2.0–6.0%), implant dislocation and/or migration (11.0%), erosion (0.8–36.8%), primary or secondary infection (0.4–5.8%), and implant extrusion (1.9–50.0%) (9–21, 37).

The reasons for complications of orbital endoimplantation are very different. The early postoperative period can be complicated by incorrect implantation, poor wound closure, haemorrhage, oedema, an over-sized implant, or infection. Complications of the late postoperative period are caused by the erosion of the tissue above the implant that can be caused by irregularity of the anterior surface of the implant, improper artificial eye or improper wearing of the artificial eye, or secondary infection of a protruded orbital implant.

A good surgical technique, a proper-sized and good-quality orbital implant (36, 38), appropriate and qualified care of the artificial eye and the ophthalmic socket are necessary for prevention of complications. If a complication occurs, adequate treatment is needed (39).

AIM OF THE STUDY

To evaluate complications of orbital endoimplantation during the period of 2002 to 2014 in the Eye Clinic of the Lithuanian University of Health Sciences and to compare them with the data in the literature.

MATERIALS AND METHODS

The work was performed at the Eye Clinic of the Lithuanian University of Health Sciences and was based on a retrospective analysis of the data of 128 patients who underwent orbital endoimplantation surgery at the clinic from 2002 to 2014. Primary and secondary orbital endoimplantation was performed on 111 patients (86.7%) and 17 patients (13.2%), respectively.

RESULTS

For primary and secondary endoimplantation silicone spheres (68–53.1%), hydroxyapatite (9–7.0%), bioceramic (8–6.3%), porous polyethylene (39–30.5%) implants, and autogenous dermofat graft (4–3.1%) were used (Fig. 1).

Fig. 1.

Implants used for primary and secondary implantation

As can be seen from the data in the chart above, the most common complication was the conjunctival cyst (nine patients, 7%). Five implants (2.9%) were protruded, five (2.9%) extruded, and two (1.6%) dislocated. One (0.8%) patient had a lacrimal gland cyst formation, and three patients (2.3%) developed upper lid ptosis.

Protruded and dislocated implants were integrated, extruded were silicone implants. One implant (0.78%) extruded in the early postoperative period, during the first month after surgery. Other complications – five protrusions (2.9%), four extrusions (3.12%), and two dislocations (1.56%) – occurred during the late postoperative period, several years after surgery.

Types of complications

The type of implant was not statistically significant for cysts and formation of the upper lid ptosis (Table).

Table

Types of complications, by type of implant

Complication/Types of implant	Protrusion		Dislocation		Extrusion		Cysts		Ptosis
	Early period	Late period	Early period	Late period	Early period	Late period	Early period	Late period	Early period	Late period
Silicone					1	4		3		1
HA (hydroxyapatite)		3		1				3		1
Bioceramic				1				2
Porous polyethylene		2						2		1
Dermofat graft

One conjunctival cyst, which disturbed the artificial eye fitting and one cyst connected to the lacrimal gland, in the upper lateral quadrant of conjunctival sac, which dislocated implant down, were removed surgically, other cysts – left for observation. All three patients with an upper lid ptosis underwent surgical treatment. One backward and downward dislocation of the orbital implant was repaired with a dermofat graft. Four protruded implants were covered with conjunctiva, two of them protruded again; one silicone sphere was extruded; another, integrated, caught infection was removed and replaced with a new one. One conjunctival erosion above the implant epithelised under conservative treatment.

For one patient extruded implant was reimplanted in the late postoperative period, the others were left for following up.

DISCUSSION

The downward dislocation of the implant blocs the inferior fornix, the artificial eye becomes unstable and starts to fall out of the sac. The backward and downward dislocation leads to the loss of the orbital volume and to a more obvious post-enucleation socket syndrome (22). This was confirmed by the results of our examination. In the early postoperative period the reasons of implant extrusion are improper implantation, inadequate wound closure, haemorrhage, oedema that leads to tissue dissecation, or an oversized implant (23–28).

We are of the view that the early extrusion of implant in our patients was caused by the latter reason.

Late postoperative complications are caused by damage to the integrity of the tissue above the implant – erosion. In its turn, erosion is the outcome of an irregular anterior surface of the implant, bad quality of the artificial eye, or not proper wearing of it. The artificial eye, which presses the implant, causes ischemia, the implant protrudes and can be extruded. Treatment of this complication is difficult because of scarring and tissue contraction (23–28).

For one of our patients the implant extruded after he started wearing a new individual prosthesis, which, in to our opinion, was too large.

Infection is another well-known reason of implant protrusion and extrusion (29–31). Primary infection is the outcome of surgical intervention, and secondary infection is caused by partially protruded implant. There exist several opinions on the treatment of protruded implant. Some surgeons recommend conservative treatment (6, 11), others give preference to surgical treatment (27, 32–35) leaving the implant in place. The third group of surgeons hold the view that the protruded implant should be removed because it is the cause of infection (6).

We treated successfully one case of conjunctival erosion above the implant, two patients underwent surgical treatment leaving implant in place, one infected implant was removed after unsuccessful surgery, and one was extruded.

There is an opinion that non-integrated implants migrate and are extruded more often than integrated implants, but conjunctival erosion is more frequent above the latter (17, 19).

According to our data, five (2.9%) non-integrated silicone implants extruded, four (3.12%) integrated implants and one (0.78%) silicone implant protruded. Thus the above-mentioned results observed at the Eye Clinic of the Lithuanian University of Health Sciences confirm the data found in the literature.

The most common complications of orbital endoimplantation at the Eye Clinic during the analysed period were conjunctival erosion, cysts, and implant extrusion.

The types and the rate of complications observed in our study are consistent with the data found in the literature.

CONCLUSIONS

Raimonda Piškinienė, Mantas Banevičius