Dear Editor,

We want to congratulate Drs. S.L. Liao, et al., on their excellent paper entitled "Surgical coverage of exposed hydroxyapatite implant with retroauricular myoperiosteal graft". 1 In the paper they described "a newly developed technique with an autogenous retroauricular myoperiosteal graft" to repair defects with exposed hydroxyapatite implants.

However, they did not mention our retrospective, multicentered work published in 1999 in The American Journal of Ophthalmology. 2 In this paper we discussed a technique very similar to that of Dr. Liao and coworkers in which we covered exposed hydroxyapatite implants with a retroauricular muscle complex graft (complex refers to muscle, fascia, and vascular tissues). As with Dr. Liao's, et al., technique, we placed our retroauricular graft between the implant and the overlying Tenon's capsule and conjunctiva and the latter tissues migrated over the graft within several weeks.

We also used the thicker, stronger, retroauricular tissues anteriorly combined with the thinner tissues overlying the pinna for additional volume post-enucleation. This also facilitated the insertion of the spicular hydroxyapatite into the orbit post-enucleation. Additionally, we used only the thicker tissue between the mastoid and the overlying dermal flap anteriorly as a "cap graft" post-enucleation. Our techniques involved 83 patients with a mean follow-up of 36 months.

One difference in our technique and that of Dr. Liao and associates was that they used periosteum in their retroauricular complex graft for added strength and vascularity. We were reluctant to use periosteum in our grafts for fear of unduly compromising the vascularity of the underlying mastoid bone and the overlying dermal flap. The authors do not state that this occurred in their series of 9 patients in the duration of over one year. Accordingly, this may be a non-problem and it would appear that both techniques are efficacious. However, incorporation of the periosteum in the retroauricular myoperiosteal graft may not be necessary because of the strong, thick complex of muscle and fascia and vascular tissues between the underlying periosteum and overlying dermal flap.

Another difference in our technique is that we did not have to encounter active infections at the time of surgery and did not find it necessary to burr down the implant anteriorly. By undermining conjunctiva and Tenon's capsule the approximate distance of the equator of the globe, we have found that there is sufficient space for the graft to fit "flush tight" in the recipient bed.

The authors and readers might read with interest an article entitled "Variability of the postauricular muscle complex - analysis of 40 hemi-cadaver dissections" by Guerra, et al., including myself. 3 This article identifies and analyzes variations in the patterns of the posterior auricular muscle complex and the relations of the fascial contributions.

In our opinion, a signature thought would be to wrap a hydroxyapatite orbital implant with a strong autogenous graft of the surgeon's choice anteriorly to create a barrier between the implant and the overlying conjunctiva and Tenon's capsule to significantly decrease the chance of implant exposure.

Our technique has been discussed in a presentation of the 9th annual meeting of the European Society of Ophthalmic Plastic and Reconstructive Surgery in Dublin, Ireland, 1991, a presentation at the 23rd annual Scientific Symposium of the American Society of Ophthalmic, Plastic, and Reconstructive Surgery in Dallas, Texas, 1992, and discussed as a scientific video presentation at the annual meeting of the American Academy of Ophthalmology, 1994.

References

1. Liao S.L., Kao S.C.S, Tseng J.H.S., et al. Surgical coverage of exposed hydroxyapatite orbital implants with retroauricular myoperiosteal graft. Br J Ophthalmol 2005;89:92-95.

2. Naugle T.C., Lee A.M., Haik B.G., et al. Wrapping hydroxyapatite orbital implants with posterior auricular muscle complex grafts. Am J Ophthalmol 1999;128:495-501.

3. Guerra A.B., Metzinger S.E., Metzinger R.C., et al. Variability of the postauricular muscle complex - analysis of 40 hemicadaver dissections. Arch Facial Plast 2004;6:324-344.

Thomas C. Naugle Jr, M.D.
Department of Ophthalmology,
Tulane University School of Medicine,
New Orleans, LA, USA.