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Educational Objectives

The goal of this program is to improve the management of ophthalmologic disorders. After hearing and assimilating this program, the participant will be better able to:

1.   Describe the appropriate use of the exophthalmometer and imaging for patients with proptosis.

2.   Diagnose and manage thyroid eye disease.

3.   Evaluate and treat proptosis due to primary and metastatic tumors or infection.

4.   Summarize the findings of the Tube vs Trabeculectomy study and choose the optimal approach for the treat­ment of refractory glaucoma.

5.   Explain possible causes of pterygia and the methods  used in their surgical removal.

Faculty Disclosure

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning com­mittee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, Drs. Kim, Budenz, and Perlman and the planning committee reported nothing to disclose. In his lecture, Dr. Perlman discusses the off-label or investigational use of a therapy, product, or device.

Acknowledgements

Lectures by Drs. Kim and Budenz were recorded at 8th Annual Downeast Ophthalmology Symposium, held October 2-4, 2009, in Bar Harbor, ME, and presented by the Maine Society of Eye Physicians and Surgeons. Dr. Perlman spoke at 726th Meeting of the New England Ophthalmological Society, held September 25, 2009, in Boston, MA, and presented by the New England Ophthalmological Society. The Audio-Digest Foundation thanks the speakers and the sponsors for their coop­eration in the production of this program.

Battle of the Bulge: Evaluation of the Proptotic Eye

Chang Hee Kim, MD, Assistant Professor of Ophthalmology, Moran Eye Center, University of Utah, Salt Lake City

Considerations: rate of onset, age of patient, laterality, presence of pain (indicates perineural or bony involvement), compression (check for afferent pupillary defect), systemic disease (eg, thyroid disease or lung, breast, or prostate cancer)

Evaluation: exophthalmometer  —  place on lateral orbital rims; focus on obtaining consistent relative measurements; direct observation  —  perform from above or below face; lid retraction or ptosis can make eye look larger or smaller; imaging  —computed tomography (CT) of orbits with or without contrast, with thin slices and coronal re­construction; CT especially useful for patients with thyroid or bony involvement; magnetic resonance imaging of orbits with or without gadolinium reveals cavernous hemangioma (most common orbital lesion); ultrasonography useful for assessing patients with orbital inflammation for scleral thickening or “T-sign” (due to inflammation of optic nerve at intersection with posterior sclera); also helps differentiate cystic from solid lesions

Thyroid Eye Disease (TED)

Background: also called thyroid-associated orbitopathy (TAO), or Graves-associated orbitopathy (occasionally, pa­tients have TAO without Graves disease); most common cause of unilateral and bilateral proptosis in adults

Presentation: nonspecific; includes dry eye, tearing, double vision (particularly when lying down), and chronic ach­ing; most frequent in middle-aged women who smoke (important to stop use of tobacco); 6% to 10% of patients eu­thyroid, but most develop abnormal thyroid over time; injection and chemosis of conjunctiva and retraction of lid common

Management: obtain CT of orbits to show affected muscles; use “I’M SLow” mnemonic for muscles affected by thy­roid disease (inferior rectus, medial rectus, superior rectus, and lateral rectus); autoimmune-associated myopathy produces influx of water, lipids, and glycosaminoglycans into muscles, production of fat in eye sockets, and even­tual fibrosis; active inflammation resolves after »18 mo; changes usually permanent, although early treatment may improve lid retraction; surgical interventions address decompression first, strabismus next, and lids last; allow in­flammation to resolve before surgery

Treatment Options

Symptomatic: mild  —  cool compresses in morning, chilled artificial tears, ointment at bedtime, and elevated head of bed; moderate  —  (with aching pain and diplopia) use same treatment as for mild form plus periocular steroids, ie, 40 mg triamcinolone (eg, Kenalog) in 1-mL syringe with short 27-gauge needle; external beam radiation (<4,000 cGy) also option; only 2 to 3 periocular injections of steroids needed (good tolerability and safety); severe  —  prepare for decompression and administer methylprednisolone (eg, Solu-Medrol) or high-dose prednisone (80 mg or 1 mg/kg); counsel patient about elevation of intraocular pressure if administering periocular injection

Systemic: critical to achieve euthyroidism with radioactive iodine, antimetabolites, or surgical removal of thyroid; evidence suggests radioactive iodine may trigger TED, but this concern should not deter medical treatment (treat­ment of thyroid condition takes precedence, as it poses greater threat to health); cessation of smoking important

Diplopia: apply patch or provide Fresnel prisms if deviation mild; avoid permanent prisms during active phase be­cause of variability of disease course

Surgical: decompression not always necessary for bilateral symmetric proptosis; orbital decompression performed on only 7% of patients; eyelid surgery more common; small fraction of patients need all 3 surgeries (ie, decompres­sion, strabismus, and eyelid)

Disease course: TED and systemic disease can run separate courses

Tumors

Primary orbital: include cavernous hemangioma (most common), lymphoma, lacrimal gland, eg, pleomorphic ade­noma (important to resect en bloc), adenoid cystic (poor prognosis), meningioma, and glioma

Metastatic: from cancers of lung, breast (creates more enophthalmos than exophthalmos), prostate, and liver

Evaluation: obtain complete blood count and CT of chest, abdomen, and pelvis; surgery mainly diagnostic if lesion metastatic; use systemic treatment (chemotherapy and radiation); primary neoplasm unknown in »25% of patients with ophthalmic findings (prognosis usually poor)

Infection: cellulitis  —  preseptal (periorbital) or septal (orbital), which causes painful ophthalmoplegia and injection of conjunctiva; sinusitis  —  most common cause of orbital cellulitis; trauma; dacryocystitis (commonly viral infec­tion of lacrimal gland) and dacryoadenitis

Orbital pseudotumor: nonspecific orbital inflammation; diagnosis of exclusion; rapid onset; called orbital myositis if muscles themselves involved, rather than orbit; severe injection; responds rapidly to corticosteroids (prednisone at 60 mg/day for 2 days)

Surgery: incisional biopsy helpful for diagnosis; excisional biopsy to remove tumor; palliative debulking appropriate for advanced disease

Proptosis vs enophthalmos: relative proptosis may appear to result from enophthalmos in fellow eye caused by or­bital fractures or breast cancer; proptosis may result from increased axial length (eg, after surgery for retinal de­tachment); ptosis and lid retraction may cause pseudoproptosis

Management of Refractory Glaucoma:
Tube Shunt vs Trabeculectomy

Donald L. Budenz, MD, MPH, Professor of Ophthalmology, Epidemiology, and Public Health, Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL

Refractory glaucoma: failure of medical therapy or trabeculectomy (gold standard); newer procedures (internal tra­beculectomy [eg, Trabectome] or canaloplasty) have not replaced trabeculectomy; failures common in patients with conjunctival scarring from previous cataract surgery, uveitic glaucoma, neovascular glaucoma, or iridocorneal en­dothelial (ICE) syndrome

Tube vs Trabeculectomy Study

Background: randomized trial comparing safety and efficacy of tube shunt surgery with that of trabeculectomy with mitomycin C (MMC) in patients with previous cataract surgery or failed trabeculectomy; inclusion criteria  —  18 to 85 yr of age; intraocular pressure (IOP) ³18 and <40 mm Hg with maximally tolerated medical therapy; previous cataract extraction with implantation of intraocular lens (IOL), trabeculectomy, or both; exclusion criteria  —  secondary glaucoma (eg, neovascular, uveitic), patients unwilling to discontinue use of contact lenses (contraindi­cated in patients with filtering blebs because of risk for infection), patients with severe posterior blepharitis (be­cause of risk for infection), aphakia, vitreous in anterior chamber, previous cyclodestructive surgery, scleral buckling procedures, silicone oil, severe conjunctival scarring, or need to combine surgery with other procedures, eg, penetrating keratoplasty or vitrectomy

Study groups: tube group  —  received 350-mm² Baerveldt implant in superotemporal quadrant with flow restriction; trabeculectomy group  —  superior site with 0.4 mg/mL of MMC for 4 min (rather than standard dose of 0.2 mg/mL for 2 min)

Outcome measures: IOP and need for IOP-lowering medications; complications; failure  —  defined as IOP >21 mm Hg, and/or IOP reduced by <20%, or by £5 mm Hg on 2 consecutive visits after 3 mo; need for additional glaucoma surgery; loss of light perception vision; qualified success  —supplemental IOP medication required; com­plete success  —  no supplemental IOP medication required

Baseline characteristics: 212 patients with average age of »70 yr and IOP of »25 mm Hg while taking »3 medica­tions; included patients with range of ethnicities; tube group had slightly more patients with pseudoexfoliation (groups otherwise diagnostically similar)

Results: IOP decreased immediately in trabeculectomy group; IOP dropped more slowly in tube group because tubes temporarily closed with suture; IOPs equivalent at 6 mo through 36 mo; number of medications reduced to 1 in both groups at 3 yr; IOPs averaged 13 to 14 mm Hg in both groups; found rates of failure of 18% in tube group vs 34% in trabeculectomy at 3 yr (statistically significant); if failure defined as IOP >17 mm Hg, tube group still had higher rate of success (not statistically significant); rates of failure equivalent at IOP >14 mm Hg

Reasons for failure: inadequate reduction of IOP (most common); persistent hypotony more common in trabeculec­tomy group; one patient lost light perception vision

Reoperations for glaucoma: included Baerveldt implant (most common in patients who failed trabeculectomy and small number in whom Baerveldt implants failed initially); trans-scleral cyclophotocoagulation; endoscopic cyclo­photocoagulation and cataract extraction, and others

Complications: early  —  (eg, wound leaks) more common in trabeculectomy group; late  —  more bleb dysesthesia and bleb leaks in trabeculectomy group; little difference in total number of late complications; no significant differ­ence in rates of endophthalmitis; persistent diplopia seen in 3% to 5% of patients with Baerveldt implants (difficult to correct; patients should be warned of risk); serious  —  rates of reoperation or loss of vision ³2 Snellen lines simi­lar between groups; similar rates of PKP in both groups, despite concerns about corneal edema with tubes; pars plana vitrectomies and tube shunt revision with patch graft performed in tube group; bleb revision performed in tra­beculectomy group; rates of surgery for drainage of choroidal effusion similar; one suprachoroidal hemorrhage drained in trabeculectomy group

Visual results: found 36% and 37% rates of loss of 2 Snellen lines of vision in both groups; losses related to underly­ing glaucoma, macular disease (eg, cystoid macular edema), central retinal vein occlusion, vascular occlusive events, cataracts, and other factors unrelated to surgery (eg, ischemic ocular neuropathy, posterior capsular opacifi­cation, diabetic retinopathy, suprachoroidal hemorrhage, and retinal detachment)

Cataract progression: common; similar rates in both groups

Comparison of tube shunts: randomized prospective trials of Ahmed FP-7 vs 350-mm² Baerveldt under way

Questions and answers: prevalence of leaks  —  speaker believes high prevalence of leaks seen because of require­ment for Seidel testing at every visit; choice of flap type left to investigators, and leaks possibly more common with fornix-based than limbus-based flaps; significance of target IOP <18 mm Hg  — Advanced Glaucoma Intervention Study (AGIS) had average baseline IOP of 26 mm Hg, and post hoc analysis found no net progression in patients with IOP <18 mm Hg at every postoperative visit; however, study not designed to determine target IOP; evidence from clinical trials suggests 30% reduction in IOP as treatment goal (good stability of visual fields observed using this goal in Normal Tension Glaucoma Study)

Pterygium: Pathogenesis and Treatment

Elliot M. Perlman, MD, Associate Professor of Ophthalmology, Warren Alpert School of Medicine, Brown Uni­versity, Providence, RI

Background: prevalence higher in populations living close to equator; surgery performed earlier and as cosmetic rather than vision-salvaging procedure; difficult to predict cosmetic outcome of surgery

Definition: triangular, wing-shaped, degenerative, fibrovascular, hyperplastic, proliferative tissue growing from con­junctival limbal area onto cornea (actually describes only head of pterygium); usually nasal and bilateral; head ad­heres to cornea, neck adheres to limbus, and body loosely adherent, at times extending to caruncle

Proposed causes: proliferative growth disorder; mutation of tumor suppressor gene; exposure to UV light and living in proximity to equator; hereditary and environmental factors; focal limbal stem cells  —  limbal stem cells produce corneal epithelial cells and form junctional barrier between cornea and conjunctival cells; located deep in limbus; signs of deficiency include conjunctival ingrowth and vascularization; most UV light that reaches ocular surface composed of scattered (albedo) rather than direct light; most albedo light reaches temple aspect of eye, becomes re­fracted by cornea, and produces 20-fold more UV light at nasal limbus than temporally; good protection provided by UV-blocking contact lenses (but not by ordinary sunglasses); refracted light can strike focal limbal stem cells di­rectly and cause loss of barrier function, with conjunctivalization of peripheral cornea

Traction induced by pterygia: equivalent to that induced by extraocular muscles in primary gaze; where pterygium head covers cornea, traction induces astigmatism and (with abduction of eye) corneal striations; also, traction at medial canthus pulls semilunar fold and caruncle temporally

Surgical removal: minimalist approach involves bare-sclera excision with MMC (has high rate of recurrence); inter­mediate approach involves conjunctival grafts (sealed with suture) or amniotic membrane grafts; full approach in­volves extended removal of pterygium and extended conjunctival transplant; requires 1 hr of surgery in full operating room, with extensive dissection and isolation of medial rectus muscle; produces excellent cosmetic re­sults, with 1 recurrence seen in 250 patients; speaker stays close to semilunar fold and creates thin conjunctival graft, using thrombin on bare sclera and several drops of fibrinogen on undersurface of conjunctival graft; then lays graft onto bare sclera and allows it to adhere for 1 to 2 min

Postoperative issues: recurrences (regrowth onto cornea) can look worse than primary pterygium; greater visibility of tissue near semilunar fold; vascularized appearance of conjunctiva (“conjunctival recurrence”); pyogenic gran­ulomas can occur, even in absence of sutures

“Natural approach”: conjunctival tissue used to replace excised conjunctival tissue, without MMC; safer and cheaper method, but requires longer time for surgery

“Artificial approach”: amniotic membrane replaces excised conjunctival tissue; better results obtained with MMC; produces shorter operating times, but has potential for more serious complications because of MMC; amniotic membrane more expensive

Optimal extent of removal of pterygia: remains unclear

Suggested Reading

Alpay A et al: Comparing techniques for pterygium surgery. Clin Ophthalmol 3:69, 2009; Costa RM et al: Orbital myositis: diagno­sis and management. Curr Allergy Asthma Rep 9:316, 2009; Detorakis ET, Spandidos DA: Pathogenetic mechanisms and treatment options for ophthalmic pterygium: trends and perspectives (Review) Int J Mol Med 23:439, 2009; Dickinson J, Perros P: Thyroid-associated orbitopathy: who and how to treat. Endocrinol Metab Clin North Am 38:378, 2009; Gedde SJ et al: Review of results from the Tube Versus Trabeculectomy Study. Curr Opin Ophthalmol Dec 19, 2009 [Epub ahead of print]; Lowery AF, Kerin MJ: Graves’ ophthalmopathy: the case for thyroid surgery. Surgeon 7:290, 2009; Kandavel R et al: Comparison of pterygium recurrence rates in Hispanic and white patients after primary excision and conjunctival autograft. Cornea Nov 11, 2009 [Epub ahead of print]; Mauro J, Foster CS: Pterygia: pathogenesis and the role of subconjunctival bevacizumab in treatment. Semin Ophthalmol 24:130, 2009; Nguyen QH: Primary surgical management refractory glaucoma: tubes as initial surgery. Curr Opin Ophthalmol 20:122, 2009; Peker E et al: Periorbital cellulitis caused by Bacillus thuringiensis. Eur J Ophthalmol 20:243, 2010; Perros P, Krassas GE: Graves orbitopathy: a perspective. Nat Rev Endocrinol 5:312, 2009; Perry JD, Feldon SE: Rationale for radiotherapy in thyroid eye disease. Am J Ophthalmol 148:818, 2009; Por YM, Tan DT: Assessment of fibrin glue in pterygium surgery. Cornea 29:1, 2010; Razeghinejad MR et al: Preliminary results of subconjunctival Bevacizumab in primary pterygium excision. Ophthalmic Res 43:134, 20096; Sarkisian SR Jr: Tube shunt complications and their prevention. Curr Opin Ophthalmol 20:126, 2009; Soliman Mahdy MA, Bhatia J: Treatment of primary pterygium: role of limbal stem cells and conjunctival autograft transplantation. Eur J Ophthalmol 19:729, 2009; Todani A, Melki SA: Pterygium: current concepts in pathogenesis and treatment. Int Ophthalmol Clin 49:21, 2009; Wishart PK et al: Ahmed glaucoma valves in refractory glaucoma – a seven year audit. Br J Ophthalmol Dec 3, 2009, [Epub ahead of print].