Ann P. Murchison and Jurij R. Bilyk

Abstract  Anophthalmic ptosis should never be considered as an entity in isolation, and in this regard it is unlike other forms of acquired ptosis. Surgical anophthalmia changes the relationship between the eyelids and the orbital contents. Furthermore, changes within the orbital soft tissue may secondarily manifest as ptosis. Conversely, lower lid laxity associated with anophthalmia may result in a downward displacement of the ocular prosthesis, resulting in masking of underlying ptosis. In all likelihood, the majority of anophthalmic ptosis is the result of multiple factors and must always be evaluated in relation to associated orbital and periocular soft tissues. Effective management of the ptotic lid in anophthalmia can be difficult and must take into account these orbital and periocular factors as well as prosthesis fitting.

Anophthalmic ptosis should never be considered as an entity in isolation, and in this regard it is unlike other forms of acquired ptosis. Surgical anophthalmia changes the relationship between the eyelids and the orbital contents. Furthermore, changes within the orbital soft tissue may secondarily manifest as ptosis. Conversely, lower lid laxity associated with anophthalmia may result in a downward displacement of the ocular

J.R. Bilyk (*)

Department of Ophthalmology, Jefferson University Hospitals and Thomas Jefferson University Medical College, Philadelphia, PA, USA

e-mail: jrbilyk@aol.com

prosthesis, resulting in masking of underlying ptosis. In all likelihood, the majority of anophthalmic ptosis is the result of multiple factors and must always be evaluated in relation to associated orbital and periocular soft tissues. Effective management of the ptotic lid in anophthalmia can be difficult and must take into account these orbital and periocular factors as well as prosthesis fitting.

Etiology

In most cases, anophthalmic ptosis occurs secondary to changes in deeper orbital soft tissue. In 1982, Tyers and Collin described a “postenucleation socket syndrome” manifesting as enophthalmos, ptosis with deepening of the superior sulcus, and laxity of the lower eyelid (Fig. 14.1) [1, 2].

The exact mechanism that leads to this constellation of findings remained obscure until Smit et al. provided CT data on the anophthalmic socket in two studies [3, 4]. By comparing parasagittal views of anophthalmic socket, either with or without an orbital implant, to the normal contralateral orbit in a series of 20 patients, the authors concluded that a rotation of orbital soft tissue occurs. Put simply, there is a migration of superior soft tissue posteriorly, and posterior soft tissue inferiorly (Fig. 14.2a). This results in a net rotation of orbital soft tissue inferiorly with a concomitant loss superiorly. Second, enucleation without orbital implant placement results in an anterior displacement of Tenon’s capsule with a

Fig. 14.1  Right anophthalmic ptosis secondary to postenucleation socket syndrome. Note the right enophthalmos and lower lid laxity, leading to prosthe-

Fig. 14.2  (a) In an anophthalmic socket, absence of an orbital implant can result in a rotation of the intraconal orbital fat (light yellow) inferiorly. The levator (dark gray) is also displaced away from the orbital roof while the inferior rectus (light brown) migrates superiorly (blue arrow), shallowing the inferior fornix. The result of this soft tissue movement is a posterior tilting of the superior edge of the prosthesis (orange), posterior slippage of the orbital septum and preaponeurotic fat (bright

sis dystopia. The orbital volume deficit and lower lid laxity must be addressed prior to attempted ptosis repair

yellow), poor support for the levator (dark gray), and Müller muscle (maroon) complex, manifesting clinically as ptosis with a deep superior sulcus. A similar mechanism occurs with an undersized orbital sphere (modified from [2]). (b) Placement of an appropriately sized orbital sphere (green) helps to maintain the orbital soft tissue relationships in a more normal configuration. Compare the anatomy in this figure with Fig. 14.2a (modified from [2])

simultaneous anterior migration of intraconal fat. Finally, the authors found evidence of a superior migration of the inferior rectus muscle from an unclear mechanism. Whether this inferior rectus muscle movement occurs because of the absence of the globe and further facilitates orbital soft tissue rotation inferiorly, or is a result

of that rotation, remains unclear. More recent MRI studies of extraocular muscle positions in anophthalmic sockets show the path and volume of the muscles is not significantly changed, though the length appears decreased [5].

Smit et al. [3, 4] also reported that the levator– superior rectus complex was displaced inferiorly

(away from the orbital roof), confirming earlier findings by Vistnes [6] and Soll [7]. This levator sag is postulated to result in a relative lengthening of the muscle, resulting in ptosis. However, CT studies of Smit et al. also noted that this perceived lengthening may be counterbalanced by retraction of the levator muscle. Tyers and Collin provide a different theory for anophthalmic ptosis: rotation of the intraconal soft tissue causes shallowing of the inferior fornix and a posterior tilting of the ocular prosthesis, with a resultant loss of support for the “fulcrum” of the levator muscle, which manifests clinically as ptosis.

In addition to volume loss and soft tissue rotation, other mechanisms for anophthalmic ptosis may also be present [8]. Iatrogenic injury to the levator muscle or to the superior division of the oculomotor nerve may occur during enucleation. Overzealous manipulation of orbital soft tissue or excessive bleeding may disrupt the normal orbital fascial matrix or cause fibrosis. Postoperatively, progressive orbital soft tissue contracture may lead to worsening enophthalmos and resultant ptosis. Of note, despite previous hypotheses that orbital fat atrophy plays a significant role in postenucleation socket syndrome [1], this has not been borne out in CT studies [3, 4]. However, undersizing of the orbital implant does play a role in enophthalmos and in all likelihood facilitates the previously described orbital soft tissue rotation. A volume loss of 6–7 cc was noted in the anophthalmic side by Smit et al., but the authors did not specifically study implant size in their series [3, 4].

Direct imbrication of the levator muscle, either during extraocular muscle fixation to the implant or during closure of Tenon’s capsule, may injure or restrict the levator mechanism. A poorly fitted ocular prosthesis may either change the function of the levator mechanism or directly injure it. Chronic papillary conjunctivitis secondary to the prosthesis may result in chronic eyelid edema and eventual stretching of soft tissues. Excessive manipulation of the prosthesis could also result in eyelid laxity and ptosis.

Of note, the same mechanisms that result in anophthalmic ptosis may simultaneously act to mask its presence. Kaltreider et al. noted that

ectropion and lower lid laxity often resulted in a downward displacement of the ocular prosthesis, resulting in a relative elevation of the upper lid [8]. Manual tightening of the lower eyelid with temporary repositioning of the prosthesis would unmask the ptosis.

Forniceal shortening or more severe contraction of the socket (“malignant socket contracture”) [9] may also occur and lead to eyelid malposition and difficulty in retaining a prosthesis. This challenging presentation often requires a staged approach; as with all anopthalmic ptosis, patients with any orbital volume insufficiency should have this addressed before final evaluation and possible ptosis repair.

Evaluation

Anopthalmic patients presenting with eyelid abnormalities require a full examination of the orbit, upper and lower eyelids (including fornices), and the ocular prosthesis. Evaluation of the ptosis alone is inadequate and frequently leads to unsatisfactory results. With the prosthesis in place, the patient should first be evaluated for any significant enophthalmos. If this is present, there is little to be gained from ptosis repair; the enophthalmic socket should be reconstructed first. The superior sulcus should be examined for deepening and symmetry when compared to the opposite side. The presence of a significant conjunctival papillary reaction should be recorded. The size of the prosthesis and the amount of superior prosthetic buildup should also be evaluated. In general, a large prosthesis typically connotes an orbital soft tissue volume deficit and results in a higher incidence of lower lid laxity, both of which may need to be addressed before ptosis repair.

The upper eyelid position should be noted and levator function evaluated. Significant rotation of the prosthesis may occur after initial fitting. This may result in a migration of the pupil in relation to the contralateral side and ptosis evaluation may become inaccurate. When evaluating the upper eyelid, it is important to assure that the

lower eyelid is in correct position. If laxity is present, the lower lid should be manually tightened by gently pulling it toward the lateral canthus. This may result in significant upward movement of the prosthesis and a relative worsening of the ptosis.

The movement of the prosthesis should be evaluated as compared to the contralateral eye. Poor movement can be due to fornix abnormalities, enophthalmos or poor prosthesis fit. The prosthetic should then be removed and evaluated for size and integrity. The socket should be evaluated for inflammation, excessive mucous, giant papillary conjunctivitis under the upper eyelid, and pyogenic granulomas. The forniceal depth should be noted, specifically noting if the superior fornix is excessively deep or if the fornices are not well defined. The tissue over the implant should be examined for thinning, fistula, or exposure. Lastly, palpation of the socket can determine the presence or absence of an implant and the position of the implant within the orbit.

In all monocular patients, the remaining eye must also be evaluated in a serial fashion, with the frequency determined by the patient’s age, history, and health of the eye. The patient should always be reminded about monocular precautions and the use of polycarbonate safety glasses, and this conversation should be documented in the medical record.

built-up superior ledge may help raise the upper lid. In cases with minimal ptosis, this may be a good option, although motility is generally reduced. With greater ptosis, care must be taken not to create a large, heavy prosthetic to avoid subsequent problems.

There are several surgical techniques to address residual ptosis after orbital volume and lower eyelid laxity have been addressed. Levator surgery, including external levator resection, or posterior procedures work well in patients with good levator function. However, the latter must be performed with care to avoid shortening the superior fornix. If there is complete ptosis with little to no levator function, a frontalis sling may correct the ptosis. In such cases, patients must be counseled that a conventional unilateral frontalis sling may fail to correct the ptosis to any significant degree because there is no visual advantage to frontalis contracture in a nonseeing (or prosthetic) eye. In cases of poor levator function, a maximal levator resection or a tethering of the upper eyelid via a frontalis sling may be options, but the patient must be warned about the need for possible postoperative lubrication of the prosthesis and the potential cosmetic outcome of a static lid and decreased prosthetic motility. Details on each of the surgical techniques may be found in subsequent chapters.

Solutions

The solutions to anophthalmic ptosis vary in invasiveness. Care should first be taken to rule out ptosis which is secondary to orbital volume deficiency or lower eyelid laxity; these issues should be addressed before addressing the ptosis (Fig. 14.2b).

One minimally invasive option is a ptosis crutch on the patient’s glasses. The crutch must be fit individually and for patients unable or unwilling to have surgery, it can clear the ptosis from the patient’s “visual axis.” Proper prosthesis fitting, sometimes with a “sulcus crutch” or

Conclusion

Upper eyelid ptosis in the anophthalmic socket typically has multiple etiologies and the evaluation and management can be complex. While true, isolated ptosis may occur, upper eyelid dystopia due to poor support from the prosthesis, decreased orbital volume from an undersized implant, orbital soft tissue rotation, abnormal implant location, and lower eyelid malposition are usually present in various degrees. A systematic approach taking into account orbital, periocular, and prosthetic dynamics should be used in the evaluation and treatment of the anophthalmic patient presenting with apparent ptosis.