Mucoepidermoid carcinoma of the eyelid skin.

PURPOSE: Mucoepidermoid carcinoma involving the eye or its adnexa generally arises from the conjunctiva. We describe a nodular lesion of the lower eyelid skin with histologic features consistent with low-grade mucoepidermoid carcinoma. METHOD: Case report. RESULTS: By histology, the tumor demonstrated areas of squamous cell carcinoma and scattered islands of mucin-secreting cells. Histochemistry showed hyaluronidase-resistant mucin and intense immunoreactivity with an antibody against carcinoembryonic antigen suggesting that the tumor originated from acrosyringeal structures. CONCLUSIONS: To our knowledge, this is the first report of a mucoepidermoid carcinoma arising from sweat glands in the eyelid skin.

Complications of extraocular muscle surgery.

This article reviews the goals, complications, interventions, and potential outcomes of extraocular muscle surgery. The information will support nursing interventions in the operating room and ambulatory care arenas, as well as those in school or public health settings.

Retinopathy of prematurity.

Research studies have provided advancements in knowledge regarding retinopathy of prematurity. Examination identifies premature infants with threshold disease that indicates need for treatment. It is hoped that timely evaluation and treatment will reduce the incidence of ROP-related blindiness.

Bilateral diffuse iris nodular nevi. Clinical and histopathologic characterization.

BACKGROUND: Diffuse nodular nevus of the iris is an uncommon condition that presents with multiple verrucous excrescences distributed diffusely on the iris surface. METHODS: The authors describe 30 patients with bilateral diffuse iris nodular nevi and report associations with bilateral congenital cataract, neurofibromatosis, oculodermal melanocytosis, congenital ptosis, morning glory anomaly, Axenfeld anomaly, or Peters anomaly. RESULTS: Iris nodules were uniform in size and distribution and were brown, as was the surrounding iris. Light and electron microscopy of iridectomy specimens from one patient showed elevated plaques composed of aggregates of plump, lightly pigmented nevoid cells interwoven with mature, densely pigmented spindle-shaped uveal melanocytes. CONCLUSIONS: The authors report the largest clinical series and first ultrastructural description of bilateral diffuse iris nodular nevi, which represents a variant of neural crest development. No ocular complications could be attributed to the iris nodules, which should be differentiated from Lisch nodules and other pathologic iris lesions.

Intraocular dexamethasone penetration via subconjunctival or retrobulbar injections in rabbits.

Using high-performance liquid chromatography, we compared tissue levels of dexamethasone in the aqueous, vitreous, retina, and choroid of rabbits, 1 and 4 hours following subconjunctival or retrobulbar injection. One hour following injection, dexamethasone levels in all of these tissues were similar in both the subconjunctival and retrobulbar groups. Four hours following injection, the concentrations in the two groups also were similar, except in the choroid, in which the subconjunctival injection yielded significantly lower dexamethasone levels than the retrobulbar injection. Tissue steroid levels were comparable ipsilateral and contralateral to the injected eyes in both treatment groups after 4 hours, except in the retina, in which the levels were lower in the contralateral eye after subconjunctival injection. These data suggest that dexamethasone absorption and delivery is predominantly hematogenous following both subconjunctival and retrobulbar injection, especially in highly vascular tissues, such as the choroid. Hematogenous delivery of dexamethasone appears to peak earlier in the choroid and presumably in other intraocular tissues following subconjunctival injections, while retrobulbar injections provide more steady, long-term delivery.

Branch retinal vein occlusion and quadratic variation in arteriovenous crossings.

To explore further the origin and clinically observed regional variation of branch retinal vein occlusion, we studied fluorescein angiograms of 42 patients (42 eyes) with branch retinal vein occlusion and a control population of 126 consecutive patients. In a statistically significant percentage of crossings, the artery was anterior to the vein in those areas of the retina clinically predisposed to branch retinal vein occlusion. Thirty-nine of the 42 patients with branch retinal vein occlusion sites had artery-anterior-to-vein crossings (P = .002), whereas 183 of all 266 arteriovenous crossings in these same eyes were similarly positioned. The artery lay anterior to the vein in significantly more temporal retinal crossings (337 of 457) than nasal retinal crossings (89 of 149; P = .002). Similarly, significantly more superotemporal quadrant crossings (164 of 209) than inferotemporal quadrant crossings (173 of 248) had the artery anterior to the vein (P = .0045). These results suggested that variation in the pattern of arteriovenous crossings may have a role in the clinical distribution of branch retinal vein occlusion.

Nondetectable electroretinogram in combined methylmalonic aciduria and homocystinuria.

We present the case of a patient with congenital methylmalonic aciduria with homocystinuria and a nondetectable electroretinogram. To our knowledge, this is a new entity to be considered in the differential diagnosis of nondetectable electroretinography in infancy.

Orbital and sinus inflammation with secondary optic neuropathy.

Optic neuropathy with simultaneous orbital and sinus inflammation is a diagnostic dilemma. Although sinus inflammation was described previously as causative in some cases of optic neuritis, the relatively high rate of asymptomatic sinus opacification in radiologic studies of the general population (as high as 13%) makes this a diagnosis of exclusion. We describe a patient who had optic neuropathy associated with simultaneous orbital and sinus inflammation. Although definitive determination of etiology may not be made without tissue biopsy, cases suspected of having a bacterial etiology may benefit from an initial 48-hour trial of intravenous antibiotics before initiation of systemic corticosteroids.

Penetrating ocular injury from contaminated eating utensils.

Although the rate of infectious endophthalmitis following penetrating ocular injury is generally less than 10%, certain settings may carry a greater risk of infection. One such setting is penetrating injury resulting from eating utensils contaminated with oral flora. We reviewed six of these injuries. Culture-positive bacterial endophthalmitis developed in four of the six eyes; only one of the eyes retained reading visual acuity (greater than 20/50) and two eyes lost light perception. The potential for infection and limited visual outcome in this series warrants aggressive prophylaxis and treatment. The unexpected isolation of Haemophilus influenzae in two of the four infections suggests that broad-spectrum antibiotic treatment should be considered in all such injuries since less common organisms may be encountered.

Vitrectomy in asteroid hyalosis.

Asteroid hyalosis (AH), a condition in which calcium-lipid complexes form in the collagen meshwork of the vitreous, affects from 0.5% to 0.9% of the general population. In patients with dense AH and visual loss, obscuration of fundus detail on ophthalmoscopy and even on fluorescein angiography may complicate the diagnosis and treatment of underlying posterior segment disease. To evaluate the usefulness of vitrectomy in AH, we reviewed 7 cases of dense AH in 6 patients who underwent vitrectomy in the setting of decreased visual acuity of uncertain cause. Additional diagnoses made following surgery included age-related macular degeneration (ARMD) in 2 eyes, ARMD with associated epiretinal membrane in one eye, and the staging of diabetic retinopathy as proliferative in one eye. Although no major surgical complications occurred in this series, the potential for serious complications exists, and pars plana vitrectomy (PPV) should be considered only after less invasive diagnostic evaluations and therapeutic approaches have been exhausted.

Diffuse iris nevus in oculodermal melanocytosis: a light and electron microscopic study.

We studied by light and electron microscopy the diffuse iris nevus of an eye in a 16-year-old patient with oculodermal melanocytosis and choroidal malignant melanoma. The nevus cells in the anterior border layer of the iris appeared to be poorly differentiated, showing moderate infolding of the nuclear membrane with heterochromatin clumping, watery cytoplasm, abundant mitochondria, fine filaments, rough endoplasmic reticulum, and numerous pinocytotic vesicles. Small scattered immature melanosomes and occasional giant melanosomes were observed in these cells. Deep in the iris stroma, however, nevus cells were found singly or in small groups, and were associated with an increasing number of melanized melanosomes and cytoplasmic filaments and reduced numbers of other cytoplasmic organelles, such as mitochondria and free ribosomes. Differentiation of the iris nevus cells appeared to progress from the anterior border layer toward the iris stroma. This observation suggests that intrastromal nevi may be more benign than nevi with surface plaque. The ultrastructural characteristics of the diffuse nevi of oculodermal melanocytosis were compared with those of other iris nevi.

Primary carcinoma of the distal male urethra: a case treated with lymphadenectomy and interstitial radiation therapy.

We report a case of primary squamous cell carcinoma of the distal male urethra with a single inguinal node metastasis. Treatment consisted of unilateral pelvic and inguinal lymphadenectomy, and a combined course of external beam and interstitial radiation therapy to the distal urethra and penis by the Henschke modification of the Paris technique.