Ismail AM, Lee JS, Dyer DW, Seto D, Rajaiya J, Chodosh J. Selection Pressure in the Human Adenovirus Fiber Knob Drives Cell Specificity in Epidemic Keratoconjunctivitis. J Virol 2016;90(21):9598-9607.Abstract

Human adenoviruses (HAdVs) contain seven species (HAdV-A to -G), each associated with specific disease conditions. Among these, HAdV-D includes those viruses associated with epidemic keratoconjunctivitis (EKC), a severe ocular surface infection. The reasons for corneal tropism for some but not all HAdV-Ds are not known. The fiber protein is a major capsid protein; its C-terminal "knob" mediates binding with host cell receptors to facilitate subsequent viral entry. In a comprehensive phylogenetic analysis of HAdV-D capsid genes, fiber knob gene sequences of HAdV-D types associated with EKC formed a unique clade. By proteotyping analysis, EKC virus-associated fiber knobs were uniquely shared. Comparative structural modeling showed no distinct variations in fiber knobs of EKC types but did show variation among HAdV-Ds in a region overlapping with the known CD46 binding site in HAdV-B. We also found signature amino acid positions that distinguish EKC from non-EKC types, and by in vitro studies we showed that corneal epithelial cell tropism can be predicted by the presence of a lysine or alanine at residue 240. This same amino acid residue in EKC viruses shows evidence for positive selection, suggesting that evolutionary pressure enhances fitness in corneal infection, and may be a molecular determinant in EKC pathogenesis. IMPORTANCE: Viruses adapt various survival strategies to gain entry into target host cells. Human adenovirus (HAdV) types are associated with distinct disease conditions, yet evidence for connections between genotype and cellular tropism is generally lacking. Here, we provide a structural and evolutionary basis for the association between specific genotypes within HAdV species D and epidemic keratoconjunctivitis, a severe ocular surface infection. We find that HAdV-D fiber genes of major EKC pathogens, specifically the fiber knob gene region, share a distinct phylogenetic clade. Deeper analysis of the fiber gene revealed that evolutionary pressure at crucial amino acid sites has a significant impact on its structural conformation, which is likely important in host cell binding and entry. Specific amino acids in hot spot residues provide a link to ocular cell tropism and possibly to corneal pathogenesis.

Greenwald SH, Charette JR, Staniszewska M, Shi LY, Brown SDM, Stone L, Liu Q, Hicks WL, Collin GB, Bowl MR, Krebs MP, Nishina PM, Pierce EA. Mouse Models of NMNAT1-Leber Congenital Amaurosis (LCA9) Recapitulate Key Features of the Human Disease. Am J Pathol 2016;186(7):1925-38.Abstract

The nicotinamide nucleotide adenylyltransferase 1 (NMNAT1) enzyme is essential for regenerating the nuclear pool of NAD(+) in all nucleated cells in the body, and mounting evidence also suggests that it has a separate role in neuroprotection. Recently, mutations in the NMNAT1 gene were associated with Leber congenital amaurosis, a severe retinal degenerative disease that causes blindness during infancy. Availability of a reliable mammalian model of NMNAT1-Leber congenital amaurosis would assist in determining the mechanisms through which disruptions in NMNAT1 lead to retinal cell degeneration and would provide a resource for testing treatment options. To this end, we identified two separate N-ethyl-N-nitrosourea-generated mouse lines that harbor either a p.V9M or a p.D243G mutation. Both mouse models recapitulate key aspects of the human disease and confirm the pathogenicity of mutant NMNAT1. Homozygous Nmnat1 mutant mice develop a rapidly progressing chorioretinal disease that begins with photoreceptor degeneration and includes attenuation of the retinal vasculature, optic atrophy, and retinal pigment epithelium loss. Retinal function deteriorates in both mouse lines, and, in the more rapidly progressing homozygous Nmnat1(V9M) mutant mice, the electroretinogram becomes undetectable and the pupillary light response weakens. These mouse models offer an opportunity for investigating the cellular mechanisms underlying disease pathogenesis, evaluating potential therapies for NMNAT1-Leber congenital amaurosis, and conducting in situ studies on NMNAT1 function and NAD(+) metabolism.

Ying G-S, Vanderveen D, Daniel E, Quinn GE, Baumritter A, to of Group TAEA-PRPC. Risk Score for Predicting Treatment-Requiring Retinopathy of Prematurity (ROP) in the Telemedicine Approaches to Evaluating Acute-Phase ROP Study. Ophthalmology 2016;123(10):2176-82.Abstract

PURPOSE: To develop a risk score for predicting treatment-requiring retinopathy of prematurity (TR-ROP) in the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) study. DESIGN: Second analyses of an observational cohort study. PARTICIPANTS: Infants with birth weight (BW) <1251 g who had ≥1 imaging session by 34 weeks of postmenstrual age (PMA) and ≥1 subsequent retinopathy of prematurity (ROP) examination for determining TR-ROP by study-certified ophthalmologists. METHODS: Nonphysician trained readers evaluated wide-field retinal image sets for characteristics of ROP, pre-plus/plus disease, and retinal hemorrhage. Risk score points for predicting TR-ROP were derived from the regression coefficients of significant predictors in a multivariate logistic regression model. MAIN OUTCOME MEASURES: TR-ROP. RESULTS: Eighty-five of 771 infants (11.0%) developed TR-ROP. In a multivariate model, significant predictors for TR-ROP were gestational age (GA) (odds ratio [OR], 5.7; 95% confidence interval [CI], 1.7-18.9 for ≤25 vs. ≥28 weeks), need for respiratory support (OR, 7.0; 95% CI, 1.3-37.1 for high-frequency oscillatory ventilation vs. no respiratory support), slow weight gain (OR, 2.4; 95% CI, 1.2-4.6 for weight gain ≤12 g/day vs. >15 g/day), and image findings at the first image session including number of quadrants with pre-plus (OR, 3.8; 95% CI, 1.5-9.7 for 4 pre-plus quadrants vs. no pre-plus), stage and zone of ROP (OR, 4.7; 95% CI, 2.1-11.8 for stage 1-2 zone I, OR, 5.9; 95% CI, 2.1-16.6 for stage 3 zone I vs. no ROP), and presence of blot hemorrhage (OR, 3.1; 95% CI, 1.4-6.7). Image findings predicted TR-ROP better than GA (area under receiver operating characteristic curve [AUC] = 0.82 vs. 0.75, P = 0.03). The risk of TR-ROP steadily increased with higher risk score and predicted TR-ROP well (AUC = 0.88; 95% CI, 0.85-0.92). Risk score ≥3 points for predicting TR-ROP had a sensitivity of 98.8%, specificity of 40.1%, and positive and negative predictive values of 17.0% and 99.6%, respectively. CONCLUSIONS: Image characteristics at 34 PMA weeks or earlier independently predict TR-ROP. If externally validated in other infants, risk score, calculated from image findings, GA, weight gain, and respiratory support, enables early identification of infants in need of increased surveillance for TR-ROP.

Ebrahimiadib N, Abusamra K, Domina AM, Stiles ER, Ewer R, Bocian CP, Foster SC. A Novel NOD2-associated Mutation and Variant Blau Syndrome: Phenotype and Molecular Analysis. Ocul Immunol Inflamm 2016;:1-8.Abstract

PURPOSE: To describe the clinical and molecular implications of a novel mutation in the NOD2/CARD15 gene on a family and its seven affected members. METHODS: We reviewed the clinical presentations of family members who came to our center for refractory uveitis. Genetic testing and molecular testing was performed. RESULTS: All affected members had adult onset recurrent non-granulomatous panuveitis. The inheritance pattern suggested an autosomal dominant disease and genetic analysis identified a novel mutation in the NOD2 gene that converted amino acid 600 from glutamate to alanine (E600A). Transfection of the E600A NOD2 into human embryonic kidney-293 (HEK293) cells revealed constitutive activation and a reduced ability to respond to the NOD2 ligand, muramyl dipeptide (MDP) as compared with wild-type NOD2. CONCLUSIONS: The E600A mutation in the NOD2 gene may confer a higher penetrance of uveitis but a later onset of milder forms of non-ocular involvement.

Vodopivec I, Cho TA, Rizzo JF, Frosch MP, Sims KB. Mitochondrial Encephalopathy and Optic Neuropathy Due to m.10158 MT-ND3 Complex I Mutation Presenting in an Adult Patient: Case Report and Review of the Literature. Neurologist 2016;21(4):61-5.Abstract

INTRODUCTION: Establishing a diagnosis of mitochondrial disease in adults remains a clinician's challenge. We report a case of syndrome reminiscent of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) in an adult patient who carries m.10158T>C mutation in complex I respiratory chain gene MT-ND3 (mitochondrially encoded NADH dehydrogenase 3). CASE REPORT: This 26-year-old man from Thailand presented with new-onset headaches, seizures, stroke-like episodes, and poor vision due to optic neuropathy and cortical blindness. Instead of expected mutations in the mitochondrial tRNA gene that are frequently associated with MELAS, the mutation in MT-ND3 with variable tissue heteroplasmy (blood 5.3%, muscle 89.5%) was demonstrated. The patient's clinical features, blood biomarkers, neuroimaging findings, muscle biopsy with histochemical and functional in vitro analysis, and genetic studies were analyzed and compared with all previously reported ND3 disease cases. CONCLUSIONS: ND3 disease due to m.10158T>C mutation was previously described only in patients with Leigh or Leigh-like syndrome. Our findings thus indicate that ND3 disease can manifest with atypical phenotype in adults. The diagnosis of mitochondrial disease caused by other than typical MELAS-associated mutations in adults with stroke-like episodes, headaches, and seizures should be considered. An analysis of tissue other than blood, which is more likely to harbor a tissue-specific mitochondrial DNA mutation at a measurable level, may be necessary for diagnosis.

da Cruz L, Dorn JD, Humayun MS, Dagnelie G, Handa J, Barale P-O, Sahel J-A, Stanga PE, Hafezi F, Safran AB, Salzmann J, Santos A, Birch D, Spencer R, Cideciyan AV, de Juan E, Duncan JL, Eliott D, Fawzi A, Olmos de Koo LC, Ho AC, Brown G, Haller J, Regillo C, Del Priore LV, Arditi A, Greenberg RJ, Greenberg RJ. Five-Year Safety and Performance Results from the Argus II Retinal Prosthesis System Clinical Trial. Ophthalmology 2016;123(10):2248-54.Abstract

PURPOSE: The Argus II Retinal Prosthesis System (Second Sight Medical Products, Inc, Sylmar, CA) was developed to restore some vision to patients blind as a result of retinitis pigmentosa (RP) or outer retinal degeneration. A clinical trial was initiated in 2006 to study the long-term safety and efficacy of the Argus II System in patients with bare or no light perception resulting from end-stage RP. DESIGN: Prospective, multicenter, single-arm clinical trial. Within-patient controls included the nonimplanted fellow eye and patients' native residual vision compared with their vision with the Argus II. PARTICIPANTS: Thirty participants in 10 centers in the United States and Europe. METHODS: The worse-seeing eye of blind patients was implanted with the Argus II. Patients wore glasses mounted with a small camera and a video processor that converted images into stimulation patterns sent to the electrode array on the retina. MAIN OUTCOME MEASURES: The primary outcome measures were safety (the number, seriousness, and relatedness of adverse events) and visual function, as measured by 3 computer-based, objective tests. Secondary measures included functional vision performance on objectively scored real-world tasks. RESULTS: Twenty-four of 30 patients remained implanted with functioning Argus II Systems at 5 years after implantation. Only 1 additional serious adverse event was experienced after the 3-year time point. Patients performed significantly better with the Argus II on than off on all visual function tests and functional vision tasks. CONCLUSIONS: The 5-year results of the Argus II trial support the long-term safety profile and benefit of the Argus II System for patients blind as a result of RP. The Argus II is the first and only retinal implant to have market approval in the European Economic Area, the United States, and Canada.

Sivaraman KR, Jivrajka RV, Soin K, Bouchard CS, Movahedan A, Shorter E, Jain S, Jacobs DS, Djalilian AR. Superior Limbic Keratoconjunctivitis-like Inflammation in Patients with Chronic Graft-Versus-Host Disease. Ocul Surf 2016;14(3):393-400.Abstract

PURPOSE: Describe the presentation and management of superior limbic keratoconjunctivitis (SLK)-like inflammation and secondary limbal stem cell dysfunction in the setting of ocular chronic graft-versus-host disease (cGVHD). METHODS: Retrospective observational case series in a multicenter clinical practice. Participants were 13 patients (26 eyes) with ocular cGVHD and SLK-like inflammation presenting to the University of Illinois at Chicago and BostonSight® between January 1, 2009 and July 1, 2013. MAIN OUTCOME MEASURES: 1) Reversal or worsening of SLK, and 2) development of limbal stem cell dysfunction. RESULTS: All eyes showed evidence of SLK-like inflammation and superior limbal stem cell dysfunction manifested by conjunctival injection and superior conjunctival and corneal staining. In addition to aggressive lubrication, management strategies for SLK included topical steroids (20/26), punctal occlusion (18/26), topical cyclosporine (24/26), autologous serum tears (12/26), therapeutic soft contact lens (13/26 eyes) and scleral lenses (4/26 eyes). SLK and limbal stem cell dysfunction were reversed in 23/26 eyes. Three eyes of two patients with long-standing disease demonstrated frank limbal stem cell deficiency (LSCD) and corneal pannus, with one patient requiring multiple reconstructive surgical procedures. CONCLUSIONS: SLK-like inflammation is an under-recognized condition in patients with severe dry eyes secondary to ocular cGVHD. Untreated SLK can potentially lead to permanent LSCD over time. Early recognition and management of SLK in ocular cGVHD can improve vision, reverse signs, and may prevent these long-term consequences.

Payal AR, Sola-Del Valle D, Gonzalez-Gonzalez LA, Cakiner-Egilmez T, Chomsky AS, Vollman DE, Baze EF, Lawrence M, Daly MK. American Society of Anesthesiologists classification in cataract surgery: Results from the Ophthalmic Surgery Outcomes Data Project. J Cataract Refract Surg 2016;42(7):972-82.Abstract

PURPOSE: To explore the association of American Society of Anesthesiologists (ASA) classification with cataract surgery outcomes. SETTING: Five Veterans Affairs Medical Centers, United States. DESIGN: Retrospective observational cohort study. METHODS: The study analyzed the outcomes of cataract surgery cases. Corrected distance visual acuity (CDVA), unanticipated events, and vision-related quality of life (VRQL) were assessed using the National Eye Institute Visual Function Questionnaire (NEI-VFQ), comparing ASA classes I through IV. For some analyses, ASA classes I and II were designated as Group A and ASA classes III and IV were designated Group B. RESULTS: Of the 4923 cases, 875 (17.8%) were in Group A, 4032 (81.9%) were in Group B, and 16 (0.3%) had missing data. The mean CDVA and mean composite NEI-VFQ score improved after cataract surgery in both groups (P < .0001); however, Group A had a better mean postoperative CDVA and postoperative VFQ composite scores than Group B (P < .0001, both outcomes). A higher ASA class was associated with an increased risk for 2 unanticipated events; that is, clinically significant macular edema (CSME) (Group A: 4 [0.47%] versus Group B: 50 [1.28%]; adjusted odds ratio [OR], 3.02; 95% confidence interval [CI], 1.02-13.05; P = 0.04) and readmission to the hospital within 30 days (2 [0.23%] versus 56 [1.41%]; OR, 8.26; 95% CI, 1.71-148.62; P = .004) CONCLUSIONS: Among United States veterans, the ASA classification could be an important predictor of VRQL and visual outcomes. In this cohort, it was associated with an increased risk for 2 serious unanticipated events-CSME and readmission to the hospital-both costly, unwanted outcomes. FINANCIAL DISCLOSURE: Dr. Vollman is a consultant to Forsight Vision5. None of the authors has a financial or proprietary interest in any material or method mentioned.

Lowry EA, Hou J, Hennein L, Chang RT, Lin S, Keenan J, Wang SK, Ianchulev S, Pasquale LR, Han Y. Comparison of Peristat Online Perimetry with the Humphrey Perimetry in a Clinic-Based Setting. Transl Vis Sci Technol 2016;5(4):4.Abstract

PURPOSE: We determined the receiver operating characteristic (ROC) curves for Peristat online perimetry at detecting varying degrees of glaucoma and the correlation between Peristat online perimetry and Humphrey visual field. METHODS: A prospective, comparative study of Peristat online perimetry (an achromatic static computer threshold testing program) and Humphrey visual field (HVF) 24-2 SITA standard testing was performed by 63 glaucoma patients and 30 healthy controls in random order. The number of total adjacent abnormal test points were identified for each test, and compared with Spearman correlation. Receive operating characteristic curves were generated for Peristat online perimetry detection of mild and moderate-severe glaucoma patients using contrast sensitivity thresholds of -16.7, -21.7, and -26.7 dB. RESULTS: The area under the ROC curve for glaucoma detection ranged from 0.77 to 0.81 for mild disease (mean deviation [MD], >-6 dB on HVF) and 0.85 to 0.87 for moderate to severe disease (MD, <-6 dB on HVF) depending on contrast threshold. Peristat online perimetry and Humphrey visual field abnormal points were highly correlated with Spearman rank correlations ranging from 0.55 to 0.77 (all P < 0.001). CONCLUSIONS: Peristat online perimetry exhibits a reasonable ROC curve without specialized equipment and exhibited significant correlation with the conventional 24° Humphrey visual field test. TRANSLATIONAL RELEVANCE: Low cost widely available internet-based visual fields may complement traditional office-based visual field testing.

Jakobiec FA, Stagner AM, Lee NG. Clear-Cell (Reticulated) Transformation of Eyelid Eccrine Sweat Glands. Ophthal Plast Reconstr Surg 2016;Abstract

A 24-year-old man with a painful, recurrent left upper eyelid nodule underwent an excision. Histopathologic evaluation disclosed a granulomatous process, most likely in response to a ruptured epidermoid cyst. In the vicinity of the nodule were multiple eccrine sweat glands displaying a curious clear-cell appearance in the adlumenal cells, the first example of such a phenomenon in the eyelids. Alcian blue, periodic acid Schiff, and documented staining failed to disclose, respectively, any cytoplasmic mucosubstances, glycogen accumulation, or lipid in the adlumenal secretory cells. Cytokeratin 7 immunostained the adlumenal cells of the eccrine secretory coil, while cytokeratin 5/6 stained the ablumenal myoepithelial and ductular cells. Gross cystic disease fluid protein 15, normally demonstrable in the eccrine secretory cells, was not detectable. Clear-cell transformation should not be confused with syringoma of the lower eyelids, in which glycogen is responsible for the ablumenal clear-cell change.

Hodges RR, Dartt DA. Signaling Pathways of Purinergic Receptors and Their Interactions with Cholinergic and Adrenergic Pathways in the Lacrimal Gland. J Ocul Pharmacol Ther 2016;32(8):490-497.Abstract

PURPOSE: Purinergic receptors play a key role in the function of the lacrimal gland (LG) as P1 purinergic receptors A1, A2A, and A2B, P2X1-7 receptors, and many of the P2Y receptors are expressed. METHODS: This review examines the current knowledge of purinergic receptors in the LG as well as the signaling pathways activated by these receptors. RESULTS: These receptors are expressed on the acinar, ductal, and myoepithelial cells. Considerable crosstalk exists between the pathways activated by P2X7 receptors with those activated by M3 muscarinic or α1D adrenergic receptors. The mechanism of the crosstalk between P2X7 and M3 muscarinic receptors differs from that of the crosstalk between P2X7 and α1D adrenergic receptors. CONCLUSIONS: Understanding purinergic receptors and how they modulate protein secretion could play a key role in normal and pathological responses of the LG.

García-Solache M, Lebreton F, McLaughlin RE, Whiteaker JD, Gilmore MS, Rice LB. Homologous Recombination within Large Chromosomal Regions Facilitates Acquisition of β-Lactam and Vancomycin Resistance in Enterococcus faecium. Antimicrob Agents Chemother 2016;60(10):5777-86.Abstract

The transfer of DNA between Enterococcus faecium strains has been characterized both by the movement of well-defined genetic elements and by the large-scale transfer of genomic DNA fragments. In this work, we report on the whole-genome analysis of transconjugants resulting from mating events between the vancomycin-resistant E. faecium C68 strain and the vancomycin-susceptible D344RRF strain to discern the mechanism by which the transferred regions enter the recipient chromosome. Vancomycin-resistant transconjugants from five independent matings were analyzed by whole-genome sequencing. In all cases but one, the penicillin binding protein 5 (pbp5) gene and the Tn5382 vancomycin resistance transposon were transferred together and replaced the corresponding pbp5 region of D344RRF. In one instance, Tn5382 inserted independently downstream of the D344RRF pbp5 gene. Single nucleotide variant (SNV) analysis suggested that entry of donor DNA into the recipient chromosome occurred by recombination across regions of homology between donor and recipient chromosomes, rather than through insertion sequence-mediated transposition. The transfer of genomic DNA was also associated with the transfer of C68 plasmid pLRM23 and another putative plasmid. Our data are consistent with the initiation of transfer by cointegration of a transferable plasmid with the donor chromosome, with subsequent circularization of the plasmid-chromosome cointegrant in the donor prior to transfer. Entry into the recipient chromosome most commonly occurred across regions of homology between donor and recipient chromosomes.

Wladis EJ, Shinder R, Lefebvre DR, Sokol JA, Boyce M. Clinical and microbiologic features of dacryocystitis-related orbital cellulitis. Orbit 2016;35(5):258-61.Abstract

Dacryocystitis-related orbital cellulitis is a relatively rare condition, and large case series of this clinical entity have been reported. This study was undertaken to identify a larger cohort of patients with this ailment, with the intent of defining its clinical and microbiologic features. Case logs from four institutions were reviewed to identify patients that suffered from dacryocystitis-related orbital cellulitis. A retrospective chart review was then performed to identify clinical features, management strategies, microbiologic features, and outcomes. A dedicated statistical software package was utilized to identify correlations between these variables. 13 patients (7 females, 6 males; mean age = 57.2 years, range = 7-89 years) were identified. One patient carried a diagnosis of immunosuppressive disease. All patients underwent emergent surgical drainage and received intravenous antibiotics. Primary acquired nasolacrimal duct obstruction was found to be the underlying etiology in nine cases (69.2%), whereas four patients suffered from specific causes of their obstructions. An average of 1.07 organisms/patient (standard deviation = 0.49 organisms/patient) were recovered from microbiologic cultures, and Gram-positive bacteria represented the majority of cultured organisms. All patients experienced either stable or improved vision upon discharge. The relationships between a specific etiology and the possibility of vision loss or the number of organisms cultured, between the number of organisms cultured and vision loss, and immunosuppression and vision loss or the number of organisms cultured were all not statistically significant (p > 0.05). Dacryocystitis-related orbital cellulitis most commonly occurs in adult patients who do not carry immunosuppressive diagnoses and suffer from primary obstructions. Multiple microbiologic species may cause this problem, although Gram-positive organisms are most common. With appropriate management, stable or improved vision can be achieved.

Di Zazzo A, Tahvildari M, Florakis GJ, Dana R. Ocular Manifestations of Inherited Phospholipase-Cγ2-Associated Antibody Deficiency and Immune Dysregulation. Cornea 2016;Abstract

PURPOSE: To report the ocular manifestations of phospholipase-Cγ2-associated antibody deficiency and immune dysregulation (PLAID). METHODS: Case report and literature review. RESULTS: A 21-year-old woman diagnosed with PLAID was referred for evaluation of repeated episodes of ocular inflammation resulting in bilateral peripheral corneal pannus with episcleritis and corneal scarring accompanied by systemic manifestations including epidermolysis bullosa and interstitial lung disease. Systemic immunosuppression with corticosteroids and interleukin-1 (IL-1) receptor antagonist (anakinra) was supplemented with topical anakinra to avoid systemic side effects, which resulted in partial improvement of the ocular symptoms. Oral prednisone was restarted to treat active lesions during bouts of inflammation. CONCLUSIONS: Ocular PLAID is a bilateral chronic or recurrent inflammatory disease of the ocular surface leading to severe and early cicatricial ocular surface and corneal involvement because of high IL-1 production. Management of PLAID may require both topical and systemic immunomodulatory treatments, potentially including targeted local anti-IL-1 therapy.

Stagner AM, Afrogheh AH, Jakobiec FA, Iacob CE, Grossniklaus HE, Deshpande V, Maske C, Hiss DC, Faquin WC. p16 Expression Is Not a Surrogate Marker for High-Risk Human Papillomavirus Infection in Periocular Sebaceous Carcinoma. Am J Ophthalmol 2016;170:168-175.Abstract

PURPOSE: To evaluate the role of high-risk human papillomavirus (HR-HPV) infection in periocular sebaceous carcinoma (SC) using multiple methods of detection, and to determine whether p16 overexpression is present and can be used as a surrogate marker for HR-HPV. DESIGN: Retrospective observational case series with laboratory investigations. METHODS: Unstained paraffin sections of 35 cases of periocular SC were analyzed with immunohistochemistry for p16 and subjected to polymerase chain reaction (PCR) for HR-HPV. A subset of 18 lesions that were p16-positive was further studied with a novel method of mRNA in situ hybridization (ISH) for the detection of transcriptionally active HR-HPV, an advanced technique with an enhanced sensitivity and specificity. RESULTS: The clinical findings were in keeping with those of comparable earlier studies. Strong immunohistochemical p16 positivity (meeting the criterion of >70% nuclear and cytoplasmic staining) was present in 29 of 35 cases of periocular SC (82.9%). The selected 18 p16-positive cases tested were negative for HR-HPV using mRNA ISH. PCR yielded unequivocal results with adequate DNA isolated in 24 cases, 23 of which were negative for HR-HPV. One case was positive for HPV type 16, which was found to be a false positive as collaterally determined by mRNA ISH negativity. CONCLUSION: No evidence was found for HR-HPV as an etiologic agent in the development of periocular SC using multiple modalities to maximize sensitivity and specificity and reduce the limitations of any single test. p16 overexpression is common in periocular SC but unrelated to HR-HPV status. Although p16 may be used as a surrogate marker for HR-HPV status in other tissue sites, this interpretation of p16 positivity is not applicable to periocular SC.