OCULAR POTPOURRI
| REFRACTIVE SURGERY UPDATE —David Rootman, MD, Associate Professor of Ophthalmology, University
Health Network, University of Toronto, ON
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| Definition: procedure that alters optical power of eye so that result as close as possible to emmetropia and normal accommodation
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| How results achieved: can alter corneal shape, replace or add to lens or ocular power, or (rarely) alter axial length (usually
through scleral buckle); altering corneal shape—incise cornea; make tissue contract; “sculpt” through tissue removal
or additive techniques; corneal procedures currently dominate field, due to safety, reliability, and range of
correctable values
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 | Incisional surgery: radial keratotomy—today “largely relegated to the history books” due to, eg, vision fluctuation,
unplanned under- or overcorrection, glare, infection, scarring, permanent corneal weakening
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| Corneal sculpting: usually performed with excimer laser; divided between surface and subsurface ablation; permanently
reshapes cornea by removing tissue; available since 1988; limited to +3.0 diopters (D) to -10.0 D, due to limits
on amount of corneal tissue that can be safely removed
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| Surface procedures: mostly variations on original photorefractive keratectomy (PRK; requires removal of epithelium,
then corneal reshaping)
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| Laser epithelial keratomileusis (LASEK) or epi-laser in situ keratomileusis (epi-LASIK): involves softening epithelium
chemically, followed by laser ablation and possible replacement of epithelium; sometimes called advanced
surface ablation (ASA), with epithelium removed by microkeratome; early comfort greater than with some other
surface ablation procedures, but may leave epithelium irregular; recovery may take several weeks; disadvantages include
long healing time, discomfort, glare, blurry vision, and risk for haze at higher corrections (rare today with
newer lasers; adjunctive treatment can reduce haze)
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| LASIK: associated with faster recovery of vision and greater patient comfort than seen with LASEK or epi-LASIK;
indicated for powers ranging from +3.0 D to -10.0 D (limited by available corneal tissue and optics created by altering
corneal curvature); no haze, but flap complications possible, as well as corneal ectasia (iatrogenic keratoconus);
leaving residual stromal bed of 250 µm advisable; correction <10.0 D; remaining K should be <49 for
hyperopic patient, >36 for myopic patient; residual stromal bed “bit of a moving target”; 250 µm usually considered
safe, but some surgeons recommend ≥300 µm; surface flaps currently measure ≈100 to 160 µm, leaving 100
to 150 µm available for correcting emmetropia; contraindications—exercise caution if corneal thickness <500
µm; anterior basement membrane dystrophy (if using microkeratome); complications—epithelial defects with
diffuse lamellar keratitis underneath; epithelial ingrowth; striae that compromise vision; most complications related
to flap creation
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| New technologies: femtosecond laser—creates thinner, more uniform flaps than microkeratome; also leaves “exquisitely
smooth” surface; can be modified to perform lamellar keratoplasty, arcuate cuts, and penetrating grafts; speaker
predicts femtosecond laser will be standard in corneal surgery within 5 yr; wavefront-guided procedures—employ
sophisticated optics to correct optical aberrations; may decrease aberrations induced by excimer lasers; may improve
vision (eg, gain in low-contrast acuity)
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| Intraocular lenses (IOLs): an option for very high myopes and hyperopes; 2 IOLs currently approved by Food and
Drug Administration; corneal ring implants (Intacs)—originally developed to treat low myopia; can also treat keratoconus
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| IN-OFFICE OCULOPLASTIC SURGERY —Gary L. Aguilar, MD, Associate Clinical Professor of Ophthalmology,
University of California, San Francisco, School of Medicine
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| Pearls: adding 1 mL bicarbonate or 10 mL xylocaine with epinephrine enhances patient comfort; avoid oral sedation
for frail elderly patients or those with history of cardiac disease (perform procedure in hospital); however, many elderly
patients can withstand short in-office procedures; younger patients can undergo procedures up to 2 to 3 hr; in
speaker’s office, patients given diazepam and alprazolam
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| Clonidine: now gaining favor as anesthetic; originally developed to control hypertension; good safety record (however,
dry mouth major drawback; make sure patients well hydrated); mild analgesic effect, as well as antiemetic qualities
and anxiolytic effect; cardioprotective (due to antihypertensive effect); diminishes bleeding and postoperative
bruising; stimulates brainstem α-adrenergic receptors and lowers sympathetic outflow; blood pressure (BP) drops
within 30 to 60 min after oral dose, reaching lowest point within 2 hr; slight risk for postural hypotension but benign;
plasma half-life 12 to 16 hr, but clinical effect ends within 4 to 6 hr; warn patients that clonidine may potentiate effects
of sedatives and sleeping medications; may also exacerbate bradycardia and atrioventricular (AV) nodal blockage
(warn patients who take β- or calcium channel blockers); administer ≈45 min before surgery (do not use if systolic BP
<105 mm Hg); if systolic BP 105 to 140 mm Hg—administer 0.1 mg clonidine; 140 to 160 mm Hg—0.2 mg clonidine;
avoid surgery if systolic BP >170 to 175 mm Hg; halve dose for thin elderly patients; contraindicated in patients with
porphyria or Raynaud’s disease
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| Oral sedation protocol: short procedures—alprazolam and diazepam 35 to 55 min before surgery; longer
procedures—alprazolam, diazepam, and clonidine
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| Oculoplastic surgery: distinguish between eyelid crease and fold (fold hangs over crease)
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| Anatomy: upper eyelid —orbital septum arises at arcus marginalis; blends with levator aponeurosis and fuses above
upper tarsal edge; levator aponeurosis inserts anteriorly into skin surface, posteriorly to anterior tarsal surface; anterior
skin projections form pretarsal plate; lower eyelid—anatomy similar, but orbital fat fuses with capsular palpebral fascia
and inferior tarsal muscle, with final 5 mm inserting into lower portion of tarsus; capsular palpebral fascia, sympathetic
tarsal muscle, and orbital septum tend to dehisce in patients with entropion, allowing tarsus to turn inward; in
upper eyelid, results in acquired ptosis
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| In-office biopsy: good reimbursement relative to time required; ellipsoid biopsy requires no closure and heals without
defect; do not perform incisional biopsy in patients with suspected melanoma (may spread tumor); wedge resections
possible if carried to lower portion of tarsus and slightly beyond; patients with verrucous lesions good candidates for
shave biopsy (use pressure to stop bleeding; do not cauterize [may destroy eyelashes])
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| Ectropion: congenital cases “different kettle of fish” from acquired ectropion; distinguish cicatricial from involutional
types (repairing cicatricial ectropion using standard techniques may lead to recurrence [repair failure]); during examination,
move eyelid to normal position; resistance suggests cicatricial component; repair during closure with
full-thickness skin graft
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| Tarsal strip procedure: cut inferiorly through lateral canthal tendon; clear away orbital septum, allowing eyelid to
swing freely (reduces risk for failure); excise anterior lamella to fashion tarsal strip; deepithelialize conjunctiva; extend
incision, using retractors to expose lateral orbital rim; sutures in tarsus should extend into inner surface of lateral
orbital rim, just above lateral orbital tubercle; cut away any fat that appears in wound; medial ectropion—
remove subpunctal pentagon; if ectropion due to paralysis, with significant medial component, deepithelialize lacrimal
portion of eyelid (protect canaliculi); can be done simultaneously with subpunctal excision; Y-V-plasty further
elevates medial tissue; Wies procedure—best way of repairing recurrent entropion; Bick procedure—apply curved
hemostat; cut lower lateral canthal tendon; overlap lid; place another curved hemostat at access point; suture closed;
ensure that sutures in lower capsular palpebral fascia; fix to orbital rim; lower suture should anchor lower border of
eyelid, preventing it from turning inward; also use for ectropion repair (fix tarsus as for tarsal strip procedure, but
without creating tarsal strip)
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| Acquired ptosis: several procedures available; as levator retracts into orbit, it pulls orbital septum and fat with it, creating
high hollowed-out eyelid fold on ptotic side; perform levator advancement procedure (physicians less experienced
with procedure should start dissection superiorly and open orbital septum widely to identify levator aponeurosis
below fat, then proceed downward); Mullerectomy—administer superorbital block, as well as small block in eyelid
margin; evert eyelid; before surgery, place one drop neosynephrin 2.5%; if eyelid returns to normal, “you know that a
Mullerectomy will work”
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| OCULAR ONCOLOGY FOR THE GENERAL OPHTHALMOLOGIST —Joan M. O’Brien, MD, Professor of Ophthalmology
and Pediatrics, and Director, Ocular Oncology Unit, University of California, San Francisco, School of Medicine
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| Conjunctival melanosis and malignant melanoma: conjunctival nevi—most common conjunctival tumor;
classified as hamartomas or benign neoplasms; often noticed first during adolescence, as they become darker (may
resemble primary acquired melanosis [PAM] or melanoma); distinguished from PAM by presence of epithelial
cysts; cysts present in compound and stromal nevi; risk for transformation <1%; nevi appear most commonly on
bulbar conjunctiva; forniceal involvement suggests PAM or premalignant state (requires biopsy)
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| Differential diagnosis: racial melanosis—do not automatically assign this diagnosis; histopathologically benign; periodic
observation needed only if atypical features present; ocular melanocytosis—congenital scleral pigmentation;
slate gray; if eyelid skin involved, designated oculodermal melanocytosis; may also involve orbit, soft
palate, and meninges; pigmentation of uvea increased (risk for uveal melanoma 1 in 400); PAM—develops at age
40 to 50 yr; moves with conjunctiva (similar to conjunctival nevi); presentation ranges from flat golden-brown to
dark (muddy) brown; may have contiguous brown areas, or multiple small scattered spots; no associated epithelial
cysts; most common in fair-skinned people, but seen rarely in darker-skinned individuals; usually occurs at
limbus, but may be epibulbar or interpalpebral; may extend onto corneal epithelium and eyelid epidermis; pigment
may wax and wane over time (nonpigmented nodules not uncommon; suspect melanoma if nodules present)
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| Management of PAM: photograph and closely watch flat nonprogressing lesions (do not resect); if lesion thick, progressive,
and at <3 o’clock, excise to base and margins with cryotherapy; if simple resection not possible, perform
map biopsy
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| Malignant melanoma of conjunctiva: occurs, on average, ≈20 yr later than PAM; median age at diagnosis 62 yr; however,
occurs rarely in children and individuals with racial melanosis; clinical presentation—varies; tan to brown in
color; may be elevated; pigment may be light or nonexistent
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| Conjunctival nodules: all require aggressive management; may be limbal, bulbar, forniceal, palpebral; may involve
eyelid margins or cornea; typically have prominent feeder vessels; associated flat PAM common; 50% of conjunctival
nodules arise from PAM (remainder arise de novo); multiple recurrences possible, even with meticulous resection;
recurrence rate 26% at 5 yr and 65% at 15 yr; management—complete excision with wide margins (biopsy-
proven negativity necessary at every margin); magnetic resonance imaging if orbital extension suspected; if disease
unresectable, offer patient proton-beam radiation if available (still investigational); some centers perform sentinel
lymph node biopsies
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| Other differential diagnoses: conjunctival intraepithelial neoplasia (may resemble squamous cell carcinoma); oncocytoma
(benign); must observe pathology before proceeding to surgery
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| Posterior uveal melanoma: diagnosis—A-scan ultrasonography (US) shows low internal reflectivity; provides apical
tumor height for planning radiation therapy; vertical spike oscillations represent tumor vasculature; B-scan US delineates
tumor shape; transillumination allows estimation of tumor diameter but cannot distinguish among different types
of lesions; differential diagnosis—melanocytoma of optic nerve (converts rarely to malignant melanoma); choroidal
nevi (difficult to distinguish from melanoma); treatment—diode laser may break down scleral barrier, allowing cancer
to extend to orbit; small-tumor trial proposed
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| Other differential diagnoses: age-related macular degeneration (ARMD) with eccentric disciform scar—hemorrhage
from neovascularization may present as dark elevated subretinal mass; include in differential diagnosis; presence of
blood and fibrin suggest ARMD; watch for shrinkage on US over time; choroidal metastases—most often involve
posterior pole; may be multiple; usually associated with extensive exudative detachment; patient may have history
of systemic cancer; echography reveals medium to high reflectivity and slight heterogeneity; von Hippel-Lindau
disease—characterized by hemangioblastomas of retinal capillaries; combined hamartomas of retina and retinal
pigment epithelium (RPE)—may involve retinal vasculature, adjacent vitreous, as well as retina (all layers); congenital
hypertrophy of RPE—flat, jet-black, and well-delineated; margins often scalloped, with intrinsic lacunae
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| Retinoblastoma: examine patient, siblings, and offspring under anesthesia; otherwise, tumor might be missed, as appearance
often subtle; early lesions small, round, and intraretinal; over time, they become spherical and develop excrescences;
treatment leads to calcification, atrophy, and scleral baring; differential diagnoses—endophthalmitis;
uveitic syndrome; juvenile rheumatoid arthritis; sarcoidosis; toxoplasmosis; hypopyon (scan posterior pole before
performing any intraocular procedure); medulloepithelioma hardest to distinguish
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| Treatment: based on disease stage; of patients in children’s oncology unit enrolled in National Cancer Institute clinical
trial, those with earliest stage (Group A) receive local therapy (laser); Group B—local therapy plus 2-agent chemotherapy;
Group C—local therapy plus 3-agent chemotherapy; can preserve some macular function; Group D—
treat over time with high-dose carboplatin and close monitoring; Group E—accounts for ≈95% of patients with
unilateral disease; enucleation necessary
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Suggested Reading
Barnes JA et al: Simple effective surgery for involutional entropion suitable for the general ophthalmologist. Ophthalmology
113:92, 2006; Chalasani R et al: Role of topical chemotherapy for primary acquired melanosis and malignant
melanoma of the conjunctiva and cornea: review of the evidence and recommendations for treatment. Clin Experiment
Ophthalmol 34:708, 2006; Della Rocca DA: The lateral tarsal strip: illustrated pearls. Facial Plastic Surg 23:200, 2007;
Katsanevaki VJ et al: One-year clinical results after epi-LASIK for myopia. Ophthalmology 114:1111, 2007; Kim
TW et al: Contrast sensitivity after LASIK, LASEK, and wavefront-guided LASEK with the VISX S4 laser. J Refract
Surg 23: 355, 2007; Leibovitch I et al: Non-cicatricial upper eyelid ectropion. Br J Ophthalmol 89:1226, 2005; Lin
SM, Ferrucci S: Primary acquired melanosis of the conjunctiva. Optometry 77:223, 2006; McAllum PJ et al: Deep
anterior lamellar keratoplasty for post-LASIK ectasia. Cornea 26:507, 2007; Nishi Y et al: Pain reduction after epi-
LASIK with a simple surgical procedure. J Cataract Refract Surg 33:555, 2007; O’Brart DP et al: Laser epithelial
keratomileusis for the correction of hyperopia using a 7.0-mm optical zone with the Schwind ESIRIS laser. J Refract Surg
23:343, 2007; Piskiniene R: Eyelid malposition: lower lid entropion and ectropion. Medicina (Kaunas)42:881, 2006;
Shields JA et al: Primary acquired melanosis of the conjunctiva: risks for progression to melanoma in 311 eyes: the
2006 Lorenz E. Zimmerman Lecture. Ophthalmology Sept 18, 2007 [Epub ahead of print]; Smith DS, Wax MK: The
lower-eyelid tarsal-strip procedure. Ear Nose Throat J 84:698, 2005; Tanioka H et al: Assessment of epithelial integrity
and cell viability in epithelial flaps prepared with the epi-LASIK procedure. J Cataract Refract Surg 33:1195, 2007; Teus
MA et al: LASEK versus LASIK for the correction of moderate myopia. Optom Vis Sci 84:605, 2007.
Educational Objectives
| The goal of this program is to improve refractive surgery, oculoplastic surgery, and management of ocular malignancies.
After hearing and assimilating this program, the listener will be better able to:
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| 1. List the ways in which refractive surgery can alter ocular power.
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| 2. State why radial keratotomy is rarely performed.
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| 3. Explain why it is important to differentiate between involutional and cicatricial ectropion.
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| 4. Recognize the difference between conjunctival nevi and primary acquired melanosis.
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| 5. Provide the rationale for why examination for retinoblastoma should be performed while patient anesthetized.
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Faculty Disclosure
In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty members 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, the faculty reported nothing to disclose.
Acknowledgements
Dr. Rootman spoke at Update in Medicine and Ophthalmology, presented December 8-9, 2006, in Toronto, ON, and sponsored
by the University of Toronto, Faculty of Medicine, Department of Ophthalmology and Vision Sciences, and Office
of Continuing Education. Drs. Aguilar and O’Brien was recorded at Ophthalmology 2007: Takes and Outtakes, presented
December 1-2, 2006, in San Francisco, and sponsored by the University of California, San Francisco, School of Medicine,
Department of Ophthalmology, Beckman Vision Center. The Audio-Digest Foundation thanks the speakers and the sponsors
for their cooperation in the production of this program.
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