congenital anophthalmia

Congenital Anophthalmia: Current concepts in managementCurrent Opinion in Ophthalmology 2011,22:380-384

IntroductionCongenital Anophthalmia – a rare

congenital eye anomaly due to deficiency in development of primary optic vesicle.

There is no detectable ocular tissue.

Associated with microblepharon,short conjunctival sac, absence of extraocular muscles.

Replaced completely by a cyst.

Purpose of review The introduction of hydrogel

socket & orbital expanders has modified approach towards rehabilitation of congenital anophthalmia.

Recent advancesHydrogel socket expander as an

outpatient procedure.Increased orbital volume

confirmed by CT ,MRI.Inflatable orbital tissue expander

new design

Clinical evaluationAssociate findings – Coloboma,dermoids,sclerocornea,glaucoma,lens

& optic nerve abnormalities. -Canalicular stenosis

Systemic abnormalities- Abnormalities of ears,palate,lower face Cardiac,renal & genital anomalies,brain

abnormalities - Anophthalmia-plus syndrome.

CT Ultrasonography MRI

Treatment Goals: -Simultaneous expansion of

lids,soft tissues,orbital bones /replace lost volume

-maintain structure of orbit -impart motility to prosthesis

1.Positioning of progressively enlarging static acrylic conformers asap after birth

- Orbital cyst –dynamic expander like conformer

Drainage or Excision – Rapid growth

- Uncomfortable

to wear MRI to exclude connection to

brain

Orbital implantSpherical implants: Inert material:

glass,silicone,methylmethacrylateBiointegrated: Hydroxyapatite, porous

polyethylene

Inert spherical implants Advantages Provide comfort and low rates of extrusion. Cost-effective choice in patients.Disadvantages decreased motility and implant migration. Buried motility implants anterior surface projections push the

overlying prosthesis with direct force and can

improve prosthetic motility. may pinch the conjunctiva between the

implant and the prosthesis - painful socket or implant erosion .

Hydroxyapatite and porous polyethylene implants allow for drilling and placement of a peg to integrate the prosthesis directly with the moving implant.

Pegging is usually carried out 6-12 months after enucleation. Pegged porous implants offer excellent motility,

Locations for implants -within the Tenon capsule /behind the posteri or Tenon capsule in the muscle cone.

Spheres may be covered with other materials such as

sclera (homologous or cadaveric) or autogenous fascia,

Secure closure of Tenon fasci a over the anterior surface of an anophthalmic implant is an important barrier to later extrusion.

TypesHard spherical implantInflatable soft tissue expanderHydrogel osmotic expander

Hard silicone spheres- Need of series of surgeries- Multiple general anaesthesias- Repeated trauma to soft tissues

Inflatable soft tissue expanders- Better orbital bone stimulation &

socket enlargement.- Difficult to control

direction ,maintain expansion pressure.

- Chance of displacing conformer,extrusion

Hydrogel expander implantTo stimulate growth of

conjunctival sac & eyelids followed by serial implantation for Orbital volume with temporary tarsorraphy.

Methylmethacrylate & N-vinylpyrrolidone

materials.Small Soft tissue incision – quick

surgery , recovery

Injectable pellet expanders through trocar tru skin at inferior orbital rim to deep orbit.

Safe & minimally invasive technique

Easy to insert , biocompatible.Migration & extrusion.

Positioning with cyanoacrylate glue

- No suture related complications - Avoids multiple general

anaesthesias - Outpatient procedure with

topical anaesthesia.

Dermis –fat graftsOutcomes: -Good orbital volume ,adequate

fornices -No excessive growth / need of

surgery -Allows lid & socket expansionProblems: -second surgical site,unpleasant

scar -delay in healing,chronic

discharge

A study on evaluation of an integrated orbital tissue expander in congenital anophthalmos . Am J Ophthalmol 2011

- An inflatable silicone globe sliding on titanium T- plate secured to lateral orbital rim with screws.

- Inflating with transconjunctival inj of normal saline ,30 G needle.

Outcomes: - ease of insertion - Absence of displacement - Uniform pressure - Reduced trauma

Guidelines for enucleation

A functionally and aesthetically acceptable anophthalmic socket must have following –

an orbital implant of sufficient volume centered within the orbit

a socket lined with conjunctiva or mucous membrane with fornices deep enough to hold a prosthesis.

eyelids with normal appearance and adequate tone to support a prosthesis

good transmission of motility from the implant to the overlying prosthesis

a comfortable ocular prosthesis that looks similar to the normal eye

Steps of Enucleation with orbital implant

Removal of contents

Advantages of Evisceration in orbital implantLess disruption of orbital

anatomy. Good motility of prosthesisLower rate of

migration,extrusion,reoperation.

Anophthalmic Socket Complications and Treatment Deep superior sulcusContracture of fornicesExposure & extrusion of implantContracted socketAnophthalmic ectropionAnophthalmic ptosisLash margin entropionCosmetic Optics