Lecture 5 - Degenerative Disorders of the Orbit and Adnexa

What are the two degenerative disorders of the orbit/adnexa discussed in this lecture?

Enophthalmos and Myotonic Dystrophy

What is another term for exophthalmos?

Proptosis

What can cause exophthalmos (proptosis)?

Neoplastic, inflammatory, infectious, traumatic conditions, or congenitally small orbits

What is enophthalmos?

Posterior displacement of the globe within the orbit

What is hypoglobus?

Inferior displacement of the globe

What are the three main mechanisms of enophthalmos?

Structural abnormality, retrobulbar/orbital fat atrophy, and traction

What is the structural abnormality mechanism of enophthalmos?

Changes in the bony orbit that result in posterior displacement of the globe

What is the most common cause of structural abnormality-related enophthalmos?

Trauma (orbital blowout)

What is orbital fat atrophy?

A decrease in the number of cells through apoptosis and a decrease in cell size

How does orbital fat atrophy cause enophthalmos?

It reduces the volume of orbital contents, allowing the globe to sink backward

What is senile enophthalmos?

Age-related enophthalmos caused by orbital fat atrophy

What is an example of lipodystrophy that can cause orbital fat atrophy?

Prostaglandin-induced lipodystrophy

What is the traction mechanism of enophthalmos?

Posterior traction secondary to fibrosis of the extraocular muscles or connective tissues

What is traction-related enophthalmos usually associated with?

Ocular motility problems

What conditions can cause traction-related enophthalmos?

Orbital metastatic fibrosis from breast carcinoma, trauma, idiopathic orbital inflammatory syndrome (IOIS), and thyroid eye disease in the inactive fibrotic stage

What characteristic eyelid appearance can occur with enophthalmos?

Deep superior sulcus and narrowed palpebral fissure (pseudoptosis)

What may be present in cases with a very deep superior sulcus?

Lagophthalmos

How is age-related enophthalmos usually distributed?

Usually bilateral but may be asymmetrical depending on the rate of fat atrophy

What age group is generally affected by age-related enophthalmos?

Patients older than 70 years, although age is variable

What eyelid disorders may be associated with age-related enophthalmos?

Blepharoptosis, dermatochalasis, entropion, and ectropion

What non-age-related factors can contribute to enophthalmos?

Cancer therapy, dehydration, and anorexia

How can age-related enophthalmos be verified?

Exophthalmometry or worm's-eye-view examination (looking from the bottom upward)

What is prostaglandin-associated periorbitopathy (PAP)?

Periocular fat atrophy associated with prostaglandin analogue use

What happens to adipocytes in prostaglandin-associated periorbitopathy?

Individual adipocytes shrink with loss of lipid content

When do prostaglandin-associated periorbitopathy changes tend to occur?

Late in the course of treatment

Are prostaglandin-associated periorbitopathy changes permanent?

No, they are somewhat reversible

In which population is prostaglandin-associated periorbitopathy often more noticeable?

The Asian population

Which topical ocular medications are responsible for prostaglandin-associated enophthalmos?

Prostaglandin analogues (medications ending in -prost)

What is the first management consideration in prostaglandin-associated enophthalmos?

Address prostaglandin use if applicable

What causes should be ruled out when enophthalmos is asymmetrical?

Trauma and chronic sinusitis

What imaging study may be ordered when evaluating asymmetrical enophthalmos?

Orbital/facial high-resolution CT scan

Who should patients with true senescent orbital fat atrophy be referred to?

An oculoplastics specialist

What donor tissue graft may be used for volume replacement in senescent orbital fat atrophy?

AlloDerm grafts (acellular donor tissue)

What autologous procedure may be used for volume replacement in senescent orbital fat atrophy?

Autologous fat injection (fat grafting)

What reconstructive procedure may be needed in some cases of enophthalmos?

Socket reconstruction

What is another name for myotonic dystrophy?

Steinert disease

What is another medical name for myotonic dystrophy?

Myotonic muscular dystrophy (MMD)

How is myotonic dystrophy classified?

A chronic, slowly progressive, inherited, degenerative, multisystemic disease

Where does muscle weakness usually begin in myotonic dystrophy?

The hands, feet, neck, or face

How does muscle involvement progress in myotonic dystrophy?

It slowly progresses to other muscle groups, including the heart

How does the prevalence of myotonic dystrophy compare between males and females?

It affects males and females equally

What are the two forms of myotonic dystrophy?

Adult-onset and congenital

When does adult-onset myotonic dystrophy usually present?

During the fourth through seventh decades of life

When can congenital myotonic dystrophy manifest?

Any time after birth

What facial appearance is characteristic of myotonic dystrophy?

A mournful or stupefied facial expression ("droopy dog")

What hair finding is commonly associated with myotonic dystrophy?

Frontal balding

What speech abnormality may occur in myotonic dystrophy?

Slurred speech

What cardiac disease may occur in myotonic dystrophy?

Cardiomyopathy

What pulmonary manifestation may occur in myotonic dystrophy?

Pulmonary disease

What sleep-related breathing disorder is associated with myotonic dystrophy?

Obstructive sleep apnea

What neurologic sleep disorder is associated with myotonic dystrophy?

Narcolepsy

What laboratory abnormality may be present in myotonic dystrophy?

Increased serum creatine kinase levels

What eyelid abnormality is a common ocular sign of myotonic dystrophy?

Ptosis

What extraocular muscle abnormality is a common ocular sign of myotonic dystrophy?

Ophthalmoplegia

What type of cataract is characteristic of myotonic dystrophy?

Early-onset Christmas tree cataracts

What pupillary abnormality may occur in myotonic dystrophy?

Bilateral light-near dissociated pupils

What does light-near dissociation mean?

The pupils accommodate but do not react to light

What intraocular pressure finding may occur in myotonic dystrophy?

Low intraocular pressure (hypotony)

What optic nerve abnormality may occur in myotonic dystrophy?

Bilateral optic neuropathy

Is there a cure for myotonic dystrophy?

No cure or disease-specific treatment currently exists

What is the primary management approach for myotonic dystrophy?

Management of systemic and ocular complications

How are cardiac conduction abnormalities managed in myotonic dystrophy?

Pacemaker implantation

How is obstructive sleep apnea managed in myotonic dystrophy?

Continuous positive airway pressure (CPAP)

What may be used for exposure keratopathy in patients with myotonic dystrophy?

Night goggles

What medication may be used to promote wakefulness in myotonic dystrophy?

Modafinil (Provigil)

What type of medication is modafinil?

Central nervous system stimulant

What is the effect of modafinil?

Promotes wakefulness

Which medications have shown potential benefit for treatment of myotonia in small studies?

Imipramine, clomipramine, and taurine

What supportive therapies may benefit patients with myotonic dystrophy?

Physical therapy and mobility aids