Surfing the COVID-19 Tsunami with Teleophthalmology: the Advent of New Models of Eye Care

Purpose of Review

In this article, we reviewed the impact resulting from the COVID-19 pandemic on the traditional model of care in ophthalmology.

Recent Findings

Though virtual eye care has been present for more than 20 years, the COVID-19 pandemic has established a precedent to seriously consider its role in the evolving paradigm of vision and eye care. New hybrid models of care have enhanced or replaced traditional synchronous and asynchronous visits. The increased use of smart phoneography and mobile applications enhanced the remote examination of patients. Use of e-learning became a mainstream tool to continue accessing education and training.

Summary

Teleophthalmology has demonstrated its value for screening, examining, diagnosing, monitoring treatment, and increasing access to education. However, much of the progress made following the COVID-19 pandemic is at risk of being lost as society pushes to reestablish normalcy. Further studies during the new norm are required to prove a more permanent role for virtual eye care.

Social media in ophthalmology: An analysis of use in the professional sphere

To characterize how ophthalmologists are using social media in their practice. A survey regarding ophthalmologists’ personal and professional use of social media was distributed online through a university alumni listserv. Data collection occurred over 4 weeks from January to February 2020. In total, 808 ophthalmologists opened the survey email, and 160 responded (19.8%). Of 160 respondents, 115 (71.9%) participated in social media for personal use. Professional use of social media was noted by 63 (39.4%) respondents. Age >40 years old correlated with less personal ( X2 = 5.06, p = 0.025) but not professional use ( p = 0.065). Private practice was associated with more use of social media professionally compared to those in an academic or Veteran’s Affairs hospital ( X2 = 6.58, p = 0.037). A majority of respondents (58.7%) were neutral regarding the effect of social media on their practice. The present survey showed that nearly 40% of respondents are involved in social media in a professional context. Private practice correlated with increased use of social media professionally, but providers were most commonly neutral regarding the impact of social media on their practice. This finding suggests further avenues of research including how providers using social media professionally are defining and assessing successful use.

P871Coronary artery aneurysms: clinical features, management and long-term outcomes, insights from the international coronary artery aneurysm registry (CAAR)

Background

Coronary Aneurysms are a focal dilatation of an artery segment of >1.5-fold the normal size of adjacent segments. Some limited series suggested an incidence of 0.3–12%. However, coronary aneurysms are not mentioned in practice guidelines and several questions remain unanswered.

Purpose

To investigate its clinical profile, prognostic predictors, and long term outcomes.

Methods

The coronary artery aneurysm registry (CAAR, NCT02563626) is a collaborative effort involving 32 hospitals across 9 countries (Canada, Cuba, Czech Republic, Germany, Italy, Netherlands, Spain, USA and Uruguay). When eligibility was uncertain, cases were reviewed by a core lab.

Results

We reviewed 436,467 consecutive angiographies between 2004–2016. 1,565 patients were ambispectively included. Global incidence was 0.35%. Most were male (78.5%) with a mean age of 65 years. Cardiovascular risk factors were frequent. An aortopathy history was present in 8.7% but a Kawasaki antecedent was unfrequent (0.3%).

The main indication for cath was an ACS in 966 cases. Most aneurysms were saccular and 82 giant. The number of aneurisms was low, mainly with 1–2 (95.8%) and only 3 patients with ≥6, proportionally with more coronary stenosis. The most affected artery was the LAD. Aortopathy was related with higher number of aneurysms. Most received any revascularization, commonly percutaneous (PCI). During a follow-up of 37.2 months, 485 suffered a MACE, (death/heart failure/unstable angina/reinfarction) and 240 died. Age, race, diabetes, renal failure, peripheral disease, acute cath, coronary stenosis, LVEF and anticoagulation remained as predictors of death/MACE after multivariate adjustments, without no major differences comparing CABG vs PCI. No restenosis was found in aneurysm with DES but those with BMS suffered 4 (p=0.002). MACE and death were more frequent in patients who received BMS.

Figure 1

Conclusions

Coronary aneurysmal disease is not uncommon. It is associated with severe coronary stenosis and a high cardiovascular risk burden, pointing out an aggressive atherosclerotic status. Antiplatelet therapy is a reasonable option and interventional procedures safe and effective, compared with surgery. Drug eluting stents should be preferred as the default strategy.

Acknowledgement/Funding

None

Molecular epidemiology and resistance profiles among healthcare- and community-associated Staphylococcus aureus keratitis isolates

PURPOSE

To characterize the molecular, epidemiological, and resistance profiles of methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) keratitis isolates.

PATIENTS AND METHODS

We used a combination of standard microbiological techniques and DNA microarray analysis to characterize the molecular and antibiotic resistance profiles of 75 Staphylococcus aureus keratitis isolates collected over an 11-year period (2006-2016).

RESULTS

Two major USA clonal complexes (CC), CC5 (n=30, 40%) and CC8 (n=28, 37.3%), accounted for 77.3% of the collected S. aureus isolates. USA100, traditionally healthcare associated (n=18/47, 38.3%), and USA300, traditionally community associated (n=12/47, 25.5%), were the dominant MRSA strains. Four (22.2%) of the USA100 MRSA isolates were recovered from patients with no prior healthcare exposure. Eleven (91.7%) of the USA300 isolates were recovered from patients with documented healthcare risk factors. MSSA isolates were polyclonal (n=13). Ninety-three percent of MSSA infections were of healthcare origin. Thirty-seven of 61 (60.6%) healthcare- and 11 of 14 (78.6%) community-associated strains were resistant to three or more antibiotic classes. Sixty-eight percent (n=51) of isolates harbored three of more resistance determinants (genes). The Panton-Valentine Leucocidin gene was detected in 11 (14.7%) of the study isolates. The majority (72.7%) of the strains were members of the USA300 MRSA clone.

CONCLUSION

Clonal complexes CC5 and CC8 were the most frequent clones detected among both the MSSA and the MRSA keratitis isolates. USA100 and USA300 clones were the dominant MRSA genotypes. The USA300 MRSA clone has become a leading cause of healthcare-associated keratitis in South Florida. The USA100 MRSA clone has emerged as an increasing cause of community-associated corneal infections in our outpatient population. This shifting epidemiology coupled with the increasing prevalence of multidrug resistance among both MSSA and MRSA keratitis is a cause of concern.

Interventions and Outcomes in Patients with Infectious Pseudomonas scleritis: A 10-Year Perspective

Purpose: To identify interventional factors associated with improved visual results and faster time to resolution for patients with Pseudomonas scleritis. Methods: Retrospective study analyzing inciting factors, therapeutic modalities, and outcomes of patients with Pseudomonas scleritis. Results: A total of 24 patients were analyzed; 22 were treated as outpatients. All had resolution of infection and 58% (n = 14) maintained ≥20/200 vision. Medical therapy included topical and oral antibiotics; seven received additional subconjunctival injections; two were admitted for IV antibiotics. Patients presenting with ≥20/200 vision were more likely to maintain this level of vision (n = 8, 80%) compared to those presenting with severe vision loss (n = 5, 36%) (p = 0.04). A similar proportion of patients who received (n = 8, 61%) and did not receive (n = 5, 39%) oral steroids achieved 20/200 vision or better once infection resolved, p = 1.0. Conclusions: Pseudomonas scleritis can be successfully managed in the outpatient setting. Oral steroids do not appear harmful in the treatment of this disease.

Whole-exome sequencing links a variant in DHDDS to retinitis pigmentosa

Increasingly, mutations in genes causing Mendelian disease will be supported by individual and small families only; however, exome sequencing studies have thus far focused on syndromic phenotypes characterized by low locus heterogeneity. In contrast, retinitis pigmentosa (RP) is caused by >50 known genes, which still explain only half of the clinical cases. In a single, one-generation, nonsyndromic RP family, we have identified a gene, dehydrodolichol diphosphate synthase (DHDDS), demonstrating the power of combining whole-exome sequencing with rapid in vivo studies. DHDDS is a highly conserved essential enzyme for dolichol synthesis, permitting global N-linked glycosylation. Zebrafish studies showed virtually identical photoreceptor defects as observed with N-linked glycosylation-interfering mutations in the light-sensing protein rhodopsin. The identified Lys42Glu variant likely arose from an ancestral founder, because eight of the nine identified alleles in 27,174 control chromosomes were of confirmed Ashkenazi Jewish ethnicity. These findings demonstrate the power of exome sequencing linked to functional studies when faced with challenging study designs and, importantly, link RP to the pathways of N-linked glycosylation, which promise new avenues for therapeutic interventions.

Oral and maxillofacial surgeons' role in the first successful modified osteo-odonto-keratoprosthesis performed in the United States

Corneal disease constitutes the second most common cause of blindness and often leads to corneal damage or scarring. Several corneal scarring is a complex and difficult condition for ophthalmologists to manage. In the most severe cases, the scarring is accompanied by excessive dryness and keratinization of the ocular surface. Certain etiologies, including Stevens-Johnson syndrome, cicatricial pemphigoid, Lyell's syndrome, and chemical trauma to the surface of the eye, are responsible for the most severe cases. Traditional allogeneic corneal transplantation is not effective because of the significant scarring and dryness of the eye. To allow light and images to be focused on the retina, a keratoprosthesis is required to position a lens on the surface of the eye. One of the oldest and most effective types of keratoprosthesis, the osteo-odonto-keratoprosthesis (OOKP), was first described and documented in 1963 by Strampelli and subsequently modified by Falcinelli et al. The modified OOKP (MOOKP) is a unique prosthesis consisting of a lens fabricated from a polymethylmethacrylate (PMMA) cylinder and cemented to an autogenous graft composed of tooth and bone, traditionally termed the osteo-odonto lamina. In this context, lamina refers to a thin rectangular plate of tooth and bone (Fig 1). The MOOKP involves 4 procedures performed in 3 surgical stages.

Laboratory results in ocular viral diseases: implications in clinical-laboratory correlation

PURPOSE

To document etiology and predictive value of clinical diagnosis in laboratory confirmed viral diseases.

METHODS

Reports of culture-positive cases of samples collected from patients presenting from January 1987 - December 2001 were evaluated.

RESULTS

One thousand nine hundred and sixty-four (1964) cultures were submitted during 1987-2001. Twenty-six percent were positive (514). Human herpesvirus 1 was the most frequent agent isolated from all positive culture (56%). Adenovirus was the most common virus isolated from conjunctiva (66%), human herpesvirus 1 from lid and cornea (76%, 88%) and cytomegalovirus from vitreous (27%). Some unusual pathogens were recovered from conjunctiva as cytomegalovirus and from cornea as adenovirus, enterovirus and cytomegalovirus. Recognition of common viral syndromes was human herpesvirus 1 (88%), epidemic keratoconjunctivitis (88%), acute hemorrhagic conjunctivitis (70%) and varicella zoster virus (100%). However, some misdiagnosed cases were observed. Thirteen percent of conjunctivitis thought to be caused by herpes were due to adenovirus, 3.2% to Enterovirus, 3.2% to varicella zoster virus and 3.2% to human cytomegalovirus. Also, 5% of cases with a clinical diagnosis of herpes keratitis were caused by adenovirus and 2.7% by enterovirus. Finally, 4.8% of cases thought to be adenovirus conjunctivitis were herpes conjunctivitis.

CONCLUSIONS

Human herpesvirus 1 remains the most frequently isolated virus from ocular sites in general (56%). Nonherpetic corneal isolates were in decreasing order: adenovirus, enterovirus and cytomegalovirus. Clinical and laboratory correlation was less than 90%. The most misdiagnosed cases were herpes conjunctivitis and keratitis, some cases of adenovirus conjunctivitis some cases of acute hemorrhagic conjunctivitis. It is essential that a rapid and specific diagnosis is offered under atypical viral presentation for the institution of specific antiviral therapy and to avoid complications that can be a result of misdiagnosis and inappropriate treatment. Also it is important to do viral testing in order to confirm clinical diagnosis, report emerging infections, resistance and change in the epidemiology.

Risk factors for corneal infiltrates with continuous wear of contact lenses

PURPOSE

To describe the factors associated with symptomatic corneal infiltrates in a postmarket surveillance study of continuous wear contact lenses.

METHODS

Patients intending to wear lotrafilcon A lenses continuously for 30 days and nights were registered in a 1-year study at 131 clinical sites. A self-administered questionnaire was used to gather demographic and other data at baseline. The severity of the incidence of corneal infiltrative events during the year-long study was graded by an independent adjudication committee.

RESULTS

Of 6245 lens wearers, 163 were reported to have symptomatic corneal infiltrative events (2.6%). In 159 wearers, the infiltrates were judged to be lens-related (2.5%). Age < or =25 years and >50 years was significantly associated with the development of corneal infiltrates (< or =25 years OR = 1.75, 95% CI = 1.24-2.48 and >50 years OR = 2.04, 95% CI = 1.40-2.98). Ametropia of > or =5.00 D was significantly associated with corneal infiltrates (OR = 1.60, 95% CI = 1.08-2.37). Study participants who typically wore lenses for >21 consecutive days and nights were significantly less likely to have infiltrates than those who wore lenses for fewer consecutive days and nights (OR = 0.43, 95% CI = 0.24-0.75). Smoking concurrent with contact lens wear was weakly associated with corneal infiltrates (OR = 1.47, CI = 0.99-2.18).

CONCLUSIONS

Patient age, degree of refractive error, and failure to achieve the intended wearing schedule were associated with development of symptomatic corneal infiltrative events.

Corneal stroma regeneration in felines after supradescemetic keratoprosthesis implantation

PURPOSE

To show corneal regeneration in 3 cats that underwent lamellar keratectomy (90%) depth during supradescemetic keratoprosthetic implantation.

METHODS

Three 2-year-old cats that underwent spontaneous keratoprosthesis extrusion between 15 and 150 days after implanting a supradescemetic prosthesis into their right eyes were studied. Corneal structures and stroma thickness were evaluated by slit-lamp photographs, pachymetry, and confocal microscopy. Regenerated corneal epithelial cells, stroma matrix, and keratocyte morphology were studied with histology and transmission electron microscopy. Epithelial and stromal cell immunocharacterization was performed.

RESULTS

Corneas progressively regained normal thickness and improved clarity within 40 to 60 days. Slit-lamp photographs and pachymetry showed gains in stromal thickness until 600 microm or more. In vivo confocal microscopy showed the restoration of normal epithelium and stroma in all cats. Corneal nerves were seen in the regenerated stroma of 2 cats. Immunostaining showed absent alpha-smooth muscle actin (SMA) expression and a keratin K3-expressing epithelium. Electron microscopy showed regeneration of normal epithelium with a well-formed basement membrane, organized corneal lamellae, and the presence of normal keratocytes.

CONCLUSION

Felines are capable of regenerating corneal structures including epithelium and reinnervated stroma matrix after deep lamellar keratectomy. The use of feline models in corneal keratoprosthesis is therefore questionable.

The Incidence of Microbial Keratitis among Wearers of a 30-Day Silicone Hydrogel Extended-Wear Contact Lens

PURPOSE

To estimate the incidence of presumed microbial keratitis with and without loss of visual acuity among wearers of a silicone hydrogel contact lens (Lotrafilcon A, Night & Day, CIBA Vision, Inc., Duluth, GA), recently approved for up to 30 days of continuous wear.

DESIGN

Prospective cohort postmarket surveillance study.

PARTICIPANTS

Contact lens wearers (recruited from 131 practices) who had been prescribed the lens for intended continuous wear of as many as 30 nights.

METHODS

The occurrence of a corneal infiltrate was ascertained through a combination of center report and direct contact with participants at 3 and 12 months. Whenever a corneal infiltrate was suspected, study and treatment medical records were systematically reviewed by an Endpoints Committee using a predetermined classification scheme for corneal infiltration. Cases of presumed microbial keratitis were determined based on the constellation of presenting signs and symptoms and clinical course.

MAIN OUTCOME MEASURES

The incidence of presumed microbial keratitis with and without loss of visual acuity.

RESULTS

A total of 6245 participants were recruited between August 13, 2002 and July 2, 2003. Of these, 4999 subjects (80%) completed 12 months of follow-up, and these participants contributed a total of 5561 person years of lens wearing experience. Approximately 80% of participants routinely wore their lenses continuously for 3 or more weeks. The overall annual rate of presumed microbial keratitis was 18 per 10,000 (95% confidence interval (CI): 8.5-33.1). There were 2 cases of presumed microbial keratitis with loss of visual acuity, an annual rate of 3.6 per 10,000 (95% CI: 0.4-12.9), and an additional 8 cases without loss of visual acuity, an annual rate of 14.4 per 10000 (95% CI: 6.1-28.4). The rate of presumed microbial keratitis was lower for users reporting typical wear of 3 or more weeks than for those wearing the lens for less than a 3-week continuous period (P = 0.02).

CONCLUSIONS

The incidence of loss of visual acuity due to microbial keratitis among users of the silicone hydrogel contact lens was low. The overall rate of presumed microbial keratitis with the wearing schedule of as many as 30 nights was similar to that previously reported for conventional extended-wear soft lenses worn for fewer consecutive nights.

Overview of the Potency of Moxifloxacin Ophthalmic Solution 0.5% (VIGAMOX®)

Antibiotics have been the mainstay of therapy for infectious diseases since their origins in the 1940s. As microorganisms changed and resistance developed, more advanced antibiotics were ultimately needed to provide adequate coverage and spectrum. By selecting optimal antibiotics and dosing regimens, clinicians can avoid treatment failures and adverse events and can help prevent the emergence of further antibiotic resistance. The fourth-generation ophthalmic fluoroquinolones include moxifloxacin (VIGAMOX, Alcon Laboratories, Inc., Fort Worth, TX) and gatifloxacin (Zymar, Allergan, Irvine, CA), and they are now approved for the treatment of bacterial conjunctivitis. This review highlights four scientific methods that compare and rank antibiotic potencies and predict their clinical efficacy and their propensity to develop resistance: 1) in vitro assay for minimum inhibitory concentrations, 2) in vivo models for pharmacokinetic and pharamacodynamic properties, 3) therapeutic index or inhibitory quotient, and 4) in vitro assay for mutant prevention concentration. The fourth-generation ophthalmic fluoroquinolones perform well in these assays. Both antibiotics have better in vitro activity against gram-positive bacteria than ciprofloxacin or ofloxacin. Moxifloxacin penetrates better into ocular tissues than gatifloxacin and older fluoroquinolones; in vitro activity of moxifloxacin and gatifloxacin against gram-negative bacteria is similar to that of older fluoroquinolones. Moxifloxacin also has better mutant prevention characteristics than other fluoroquinolones. These findings support the use of the newer fluoroquinolones for the prevention and treatment of serious ophthalmic infections (e.g., keratitis, endophthalmitis) caused by susceptible bacteria.

Ophthalmic Infections and Their Anti-infective Challenges

This introduction provides an overview of the succeeding articles contained within this supplement on the new fourth-generation fluoroquinolone antibiotic product, moxifloxacin ophthalmic solution 0.5% (VIGAMOX, Alcon Laboratories, Inc., Fort Worth, TX). Moxifloxacin was developed specifically to address the increasing incidence of resistance to earlier-generation antibiotic molecules. Structural modifications to the moxifloxacin molecule have decreased the likelihood of the development of resistant organisms. This antibiotic has been shown to possess greater activity than previous-generation molecules against gram-positive bacteria while maintaining excellent potency against gram-negative organisms and nontuberculous (atypical) mycobacteria. Moxifloxacin ophthalmic solution 0.5% exhibits enhanced bioavailability due to a unique molecular structure that combines high lipophilicity for enhanced corneal penetration with high aqueous solubility at physiological pH. Numerous studies have shown that moxifloxacin ophthalmic solution 0.5% has high potency against a broad range of microbial species and a favorable profile in terms of safety and tolerability. The results presented in this supplement provide additional evidence for the potential benefits of moxifloxacin ophthalmic solution 0.5% in surgical prophylaxis and treatment of sight-threatening infections, such as bacterial conjunctivitis, endophthalmitis and keratitis.

Biocompatibility of a Nonpenetrating Synthetic Cornea in Vascularized Rabbit Corneas

PURPOSE

This study was designed to assess feasibility and biocompatibility of a lamellar, nonperforating supraDescemetic Synthetic Cornea (sDSC) implanted in rabbit eyes after a corneal injury.

METHODS

Corneal vascularization and scarring was induced in the right eye of 15 rabbits by application of 1-heptanol and complete surgical removal of the limbus. An sDSC (7-mm diameter, 450-microm-thick optical zone, 100-microm-thick outer flange) was implanted after 45 +/- 5 days. The keratoprostheses were implanted with their central optic part positioned on a completely exposed Descemet's membrane (DM) while the outer flange was located in deep stroma. Three different materials were tested: hydrophobic PMMA (n = 5) and hydrophilic HEMA-MMA (n = 5) and HEMA-NVP (n = 5) with a water content of 34% and 75%, respectively. The corneal surface was covered with a conjunctiva-Tenon flap. Central flap trephination was performed after 63 +/- 7 days. DM vascularization and scarring was assessed and graded after flap opening and weekly thereafter.

RESULTS

In all 15 consecutive cases implantation could be completed successfully without perforation of DM. Repair of the conjunctival flap had to be performed in five rabbits. Four months postoperatively, the flaps were opened. Four of five corneas (80%) with a PMMA implant and three of five (60%) with a HEMA-NVP75 implant had retained their original transparency. The others had developed significant neovascularization in the Descemet-sDSC optic interface. All corneas (100%) that received an sDSC made of HEMA-MMA34 displayed a completely clear DM without any vessels or scarring. DM was found firmly attached to the posterior surface of the optic.

CONCLUSION

Implantation of a nonperforating synthetic cornea on top of an exposed DM is feasible. HEMA-MMA34 showed the most promising results. Because opening of the anterior chamber is not required, a lamellar supraDescemetic Synthetic Cornea would theoretically reduce some of the risks attributed to penetrating keratoprostheses.

Biological Response to a SupraDescemetic Synthetic Cornea in Rabbits

OBJECTIVE

To evaluate the biocompatibility of a novel nonpenetrating keratoprosthesis (supraDescemetic synthetic cornea) in a rabbit model.

METHODS

Seven rabbits received a supraDescemetic synthetic cornea (7-mm diameter, 350-microm-thick optical zone, 100-microm-thick peripheral flange) in their healthy right eyes. A surgical technique was developed that allowed implantation of the device on top of the bare Descemet membrane. Three rabbits received a supraDescemetic synthetic cornea made of hydroxyethyl methacrylate-methyl methacrylate(26), 1 received a hydroxyethyl methacrylate-N-vinyl pyrrolidone(75) mesoplant, and 3 were implanted with devices made of polymethyl methacrylate. All rabbits were euthanized after 8 weeks; the eyes were enucleated and examined by conventional histological and immunohistochemical evaluations.

RESULTS

All eyes became quiet within several days. The Descemet membrane remained transparent during the observation period. Indirect ophthalmoscopy performed through the prosthesis allowed accurate examination of the posterior pole. Histological evaluation of the implanted corneas displayed no signs of an acute or chronic inflammatory reaction to the supraDescemetic synthetic cornea in 5 eyes; a few inflammatory cells were detected in the corneas of 2 rabbits. The interface between the Descemet membrane and the mesoplant displayed ingrowth of very thin (<10-microm) tissues colonized by keratocytes in 3 of the 7 corneas.

CONCLUSIONS

This study validates the biocompatibility of this new type of nonpenetrating keratoprosthesis. Because opening of the anterior chamber is not required with the supraDescemetic synthetic cornea, the risk for intraocular infection is minimal, and the implantation procedure is less traumatic compared with a penetrating device.

Percutaneous treatment of superior vena cava syndrome using metallic stents

The purpose of this study was to evaluate the results of treatment of superior vena cava syndrome (SVCS) in patients with benign and malignant disease using expandable metallic stent. From January 1995 to April 2000, 87 expandable stents were implanted in 82 patients (59 men, 23 women; mean age 57.8 years, age range 39-79 years) for the treatment of SVCS. The SVCS was defined as symptomatic bilateral obstruction of venous drainage from head, neck and upper extremities. In 68 patients SVCS was due to malignant neoplasia, and in 14 cases it was due to benign aetiology. All patients were treated with expandable stent. We implanted 81 Wallstent prostheses and 6 Palmaz stents. Adjuvant thrombolysis was applied in 12 patients who required fibrinolysis. After recanalization, the stent was implanted in all cases in SVC (infra- or supra-azygos vein). All patients were treated with heparin of low molecular weight (HBPM) during 6 months. Patency was analyzed according to clinical symptoms and Doppler US or venograms exploration. Technical success was observed in all cases. Clinical success was reached in 78 of 82 patients (95.1%) (absence of symptoms in 2 or 3 days). Four patients suffered immediate thrombosis which required fibrinolitic treatment with a new prosthesis placement in 1 case. The follow-up for the malignant process was of 7.1 months (range 1-39 months) and in benign cases was 31.2 months (range 11-61 months). Sixty-two (91.1%) patients with malignancy died without SVCS symptomatology. All the patients with benign pathology are alive. Clinical primary patency in malignant cases was 87% with assisted patency of 96.2%. Endovascular therapy using metallic stent and thrombolysis is a successful method to treat SVCS due to benign or malignant aetiology.

Amniotic membrane transplantation for bullous keratopathy in eyes with poor visual potential

PURPOSE

To evaluate the long-term outcomes of epithelial debridement and amniotic membrane transplantation (AMT) for pain and discomfort relief in patients with symptomatic bullous keratopathy and poor visual potential.

SETTING

Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA.

METHODS

This retrospective study included 18 eyes (18 patients) with bullous keratopathy presenting with intractable pain or discomfort and poor visual potential. After epithelial debridement, all eyes had AMT with the basement membrane side up. During a mean follow-up of 25.1 months +/- 9.6 (SD) (range 12 to 45 months), pain relief, epithelial healing, and visual changes were analyzed.

RESULTS

Pain relief was obtained in 88% of patients. Sixty-six percent of eyes had complete resolution of ocular discomfort starting soon after the first postoperative day. One eye had evisceration for persistent pain 10 months postoperatively. Corneal epithelial healing was complete in all except 1 eye. Remaining complaints included foreign-body sensation (5%), tearing (11%), and photophobia (5%).

CONCLUSIONS

Amniotic membrane transplantation was a safe, effective, and long-lasting treatment modality for intractable pain associated with chronic bullous keratopathy in eyes with poor visual potential. It can be an alternative to conjunctival flaps for the long-term management of patients with bullous keratopathy in whom corneal transplantation is not indicated. A comparison of the efficacy of AMT with that of other surgical procedures must be performed.

Use of an introducer sheath for colonic stent placement

We describe a technical modification of Wallstent implantation for the treatment of malignant rectosigmoid and descending colonic obstructions. The modification is the routine placement of an introducer sheath via the rectum before stent implantation in order to straighten the rectosigmoid region. This device facilitates catheter and guide wire manipulations and obtaining specimen biopsies for histopathological studies. The introducer sheath has been used without complications in 21 consecutive patients.

[13C]linoleic acid oxidation and transfer into milk in stunted lactating women with contrasting body mass indexes

BACKGROUND

The fat concentration of human milk is associated with maternal adiposity, but there is no clear understanding of the mechanisms controlling milk fat concentration.

OBJECTIVE

We evaluated the effect of postpartum body mass index (BMI; in kg/m(2)) on the metabolic distribution of an oral dose of [13C]linoleic acid in lactating women.

DESIGN

Ten lactating women stratified by BMI (either <22.5 or >23.5) at 5 mo postpartum received orally 2.5 mg [13C]linoleic acid/kg body wt. Exhaled air, milk, and plasma samples were collected in relation to tracer administration. Linoleic acid was determined by gas chromatography. Dietary intake, serum, milk composition, [13C]linoleic acid enrichment in milk and plasma, and exhaled 13CO2 (by isotope ratio mass spectrometry) were assessed.

RESULTS

Women with a higher BMI exhaled more 13CO2 than did women with a lower BMI (22.8 +/- 9.4% compared with 8.6 +/- 3.5% of dose, P < 0.03). Cumulated 72-h transfer of [13C]linoleic acid to milk was not significantly different between groups (14.8 +/- 6.5% compared with 17.7 +/- 6.7% of dose). Within the first 9 h after dose administration, 51.6 +/- 4.9% of the total isotope transfer into milk had passed in women with a higher BMI, but only 24.0 +/- 15.3% had passed in those with a lower BMI (P = 0.02).

CONCLUSIONS

Women with a lower BMI, who were reputed as having less body fat, oxidized and secreted into milk less dietary linoleic acid within 12 h after tracer administration than did women with a higher BMI. In both groups, a large proportion of [13C]linoleic was retained in the maternal compartment, most likely fat tissue, in a slow turnover pool, and released slowly in later hours.

Amniotic membrane transplantation after the primary surgical management of band keratopathy

PURPOSE

To determine the safety and efficacy of amniotic membrane transplantation to restore and maintain a stable corneal epithelium and reduce ocular surface pain after surgical removal of band keratopathy arising from ocular causes.

METHODS

Fifteen patients (16 eyes) from two centers with band keratopathy secondary to ocular causes underwent amniotic membrane transplantation as a graft after surgical removal of calcific deposits with or without the use of ethylenediaminetetraacetic acid. In a prospective, consecutive, uncontrolled case series, the rate of corneal epithelialization and resultant surface stability were recorded over a mean follow-up period of 14.6 months.

RESULTS

Pain from ocular surface instability was the presenting complaint in 14 of 15 (93.3%) patients and resolved in all cases after the procedure even for those who experienced a recurrence of the calcific deposit. Fifteen of 16 eyes (93.7%) achieved epithelialization with a mean time to epithelial healing of 15.2 days. The only eye that failed to heal was subsequently diagnosed with total limbal stem cell deficiency. Visual acuity improved in five of nine (44%) sighted eyes and remained unchanged in four of nine (56%). No patient experienced any major surgical or medical complication after the procedure.

CONCLUSION

Amniotic membrane transplantation represents a safe and effective method to restore a stable corneal epithelium in eyes after primary surgical removal of band keratopathy arising from ocular causes.

Combined penetrating keratoplasty and trabeculectomy with mitomycin C

OBJECTIVE

To evaluate corneal graft survival and intraocular pressure control in eyes that have undergone combined penetrating keratoplasty and trabeculectomy with mitomycin C (MMC).

DESIGN

Retrospective noncomparative case series.

INTERVENTION

Penetrating keratoplasty combined with trabeculectomy with MMC and other surgical procedures.

PARTICIPANTS

Twenty-four eyes of 22 patients undergoing combined penetrating keratoplasty and trabeculectomy with mitomycin C.

MAIN OUTCOME MEASURES

Corneal graft clarity and intraocular pressure control.

RESULTS

The cumulative probability of corneal graft survival was 85% at 1 year and 60% at 2 years. The cumulative probability of adequate pressure control was 67% at 3 months, 55% at 12 months, and 50% at 24 months. The incidence of bleb failure was higher in cases involving additional concomitant procedures, such as anterior vitrectomy, lens implantation or exchange, and drainage tube implantation.

CONCLUSIONS

Combined penetrating keratoplasty and trabeculectomy with mitomycin C is associated with good corneal graft survival but also a risk of early failure of intraocular pressure control. Other concomitant procedures during the combined penetrating keratoplasty/trabeculectomy may increase the risk of early bleb failure.

Acute colorectal obstruction: treatment with self-expandable metallic stents before scheduled surgery--results of a multicenter study

PURPOSE

To evaluate the efficacy of treatment with self-expandable metallic stents for acute colonic obstruction before elective surgical resection.

MATERIALS AND METHODS

In 71 patients with malignant obstruction seen from October 1993 through December 1996, lesions were located in the transverse colon in one patient, in the descending colon in 22 patients, and in the rectosigmoid region in 48. A total of 72 self-expandable metallic stents were implanted within 24 hours of diagnosis.

RESULTS

Technical success was obtained in 64 patients (90%). In two cases (3%), it was not possible to advance across the obstructing mass. In five cases (7%), the prostheses were poorly positioned at the site of obstruction, requiring placement of a new stent in three cases. Clinical improvement and resolution of the obstruction were confirmed in 66 patients (93%) within 96 hours. Minor complications developed in nine cases (13%). One patient (1%) underwent surgery to resolve a colonic perforation caused by wires at the ends of the stent. The mean time between stent placement and surgery was 8.6 days (range, 6-16 days).

CONCLUSION

Implantation of colorectal stents is a safe treatment of acute malignant colonic obstruction before resection.

Acute colorectal obstruction: stent placement for palliative treatment--results of a multicenter study

PURPOSE

To evaluate the usefulness of stent implantation as a palliative treatment in patients with acute colonic obstruction who are not surgical candidates.

MATERIALS AND METHODS

Twenty-four patients (eight women, 16 men; age range, 60-98 years) with acute colonic obstruction underwent colonic stent placement. In nine patients, the procedure was considered a primary palliative treatment; seven patients had a previous diagnosis of disseminated neoplastic disease, and two were not surgical candidates because of their poor general condition. In the remaining 15 patients, stent placement was considered the definitive palliative treatment after tumor staging. The mean time of follow-up was 8.4 months (range, 1-24 months) for patients who lived and 6.3 months (range, 1-12 months) for those who died.

RESULTS

Stent placement was successful in all patients. Clinical and radiographic findings of bowel obstruction resolved within 24 hours after stent placement in 23 (96%) patients. None of the patients required colostomy for bowel decompression after immediate stent placement. Complications developed in 10 (42%) patients: Two (8%) patients had mild rectal bleeding; three (12%), abdominal pain; two (8%), malpositioning of the stent; two (8%), pseudo-obstructive episodes due to fecal impaction; and one (4%), occlusive tumor ingrowth into the stent lumen. One (4%) patient underwent surgery to resolve stent malfunction due to poor positioning. Two (8.3%) patients--one with malpositioning of the prosthesis and the other with stent occlusion--required a new stent. The remaining complications required no further treatment. The mortality rate at 6 months was 24%. Eight patients were alive at the time this article was written.

CONCLUSION

Colorectal stent placement resulted in successful palliation of acute colonic obstruction in patients with disseminated neoplastic disease.

Efficacy of ofloxacin vs cefazolin and tobramycin in the therapy for bacterial keratitis. Report from the Bacterial Keratitis Study Research Group

PURPOSE

To compare ofloxacin solution with a combination of fortified antibiotic cefazolin sodium and tobramycin sulfate solutions in the treatment of bacterial keratitis.

METHODS

Patients under care at any one of 28 participating clinical centers who had an eye with suspected bacterial keratitis were randomly allocated in a double-masked manner to treatment with 0.3% ofloxacin solution or a combination of the fortified antibiotics (1.5% tobramycin and 10.0% cefazolin solutions).

MAIN OUTCOME MEASURES

Time to healing defined as complete re-epithelization, accompanied by a nonprogressive stromal infiltrate for two consecutive visits. Secondary outcome measures included patient symptoms and signs of infection and adverse reactions to study medications. Only patients with a positive bacterial corneal culture were included in most analyses.

RESULTS

A positive bacterial corneal culture was obtained in 140 (56%) of the 248 enrolled patients. The time to healing was similar among the 73 patients receiving ofloxacin and the 67 patients receiving fortified antibiotics (P = .70). By 7 days after study entry, the keratitis in 37% of the ofloxacin group and 38% of the fortified antibiotics group had healed. By 28 days, keratitis in 89% of the ofloxacin group and 86% of the fortified antibiotics group had healed. Two patients receiving ofloxacin and one receiving fortified antibiotics discontinued study medication because of lack of efficacy. Patients receiving ofloxacin reported substantially less burning and stinging on instillation than the patients receiving fortified antibiotics (P < .001). Five of six patients among the 140 with positive bacterial cultures who had study medications discontinued because of ocular side effects were in the fortified antibiotics group; an additional three patients, all in the fortified antibiotics group, among the remaining 108 receiving study medications had ocular side effects.

CONCLUSIONS

The efficacy of ofloxacin solution in treating bacterial keratitis is equivalent to that of the fortified cefazolin and tobramycin solutions. The reduced frequency of ocular toxic effects and the relative ease of preparation of ofloxacin are additional considerations.

Surgical management of dislocated intraocular lenses

Intraocular lens (IOL) malpositions range from simple IOL decentration to luxation into the posterior segment. Many surgical techniques and approaches have been devised to treat visually significant IOL dislocation. In this series, 78 eyes with IOL dislocation were managed by anterior segment and vitreous surgeons with a variety of surgical techniques using a limbal, pars plana, or combined limbal-pars plana approach. Most of the dislocated lenses were posterior chamber IOLs. In 39 of 78 eyes (50%), final visual acuity was 20/50 or better. Neither surgical approach nor management technique appeared to be related to outcome. The timing of surgery did not appear to affect visual outcome but was not examined in a randomized fashion. Guidelines for determining optimal management are presented.

Treatment of infectious scleritis and keratoscleritis

We reviewed 28 cases of culture-proven infectious scleritis and keratoscleritis to clarify the role of an operation in this disorder. Surgical management in 11 patients with keratoscleritis included cryotherapy, five; penetrating corneal-scleral graft, two; lamellar corneoscleral graft, two; and tectonic penetrating keratoplasty, two; in addition to intensive fortified antibiotic eyedrops. Eight patients with keratoscleritis were treated medically only with intensive fortified frequent antibiotic eyedrops, one; intensive instilled plus intravenous antibiotics, three; and instilled, intravenous, and subconjunctival antibiotics, four. Seven of eight patients treated with antibiotics alone and two of 11 patients who received surgical intervention in addition to antibiotics eventually required evisceration or enucleation of the eye. These results suggest that cryotherapy, lamellar or penetrating corneoscleral graft, in addition to intensive antibiotic therapy, may improve the outcome of patients with infectious keratoscleritis. Five eyes with isolated scleritis without corneal involvement were treated with conjunctival recession and cryotherapy in addition to aggressive antibiotics, and four were treated with antibiotics alone. The infections of these nine patients resolved.

Biofilm and scleral buckle-associated infections. A mechanism for persistence

Scleral buckle infections tend to be persistent as well as resistant to antimicrobial treatment. Often, scleral buckle infections require removal of the buckling elements for resolution. To determine if bacteria are able to persist on scleral buckles by elaborating a glycocalyx matrix or biofilm that offers protection against host defenses and antimicrobial treatment, the authors cultured 28 scleral buckle elements removed for infection and extrusion. Bacteria were isolated from 18 elements (64%). The most frequently isolated bacteria were Staphylococcus epidermidis and other coagulase-negative staphylococci (8), Staphylococcus aureus (3), corynebacteria (3), Mycobacterium chelonei (3), and Proteus mirabilis (3). Eleven (65%) of 17 buckles evaluated with scanning electron microscopy demonstrated the presence of bacteria encased in biofilm. Biofilm was demonstrated on the surfaces and ends of solid silicon elements. In the silicon sponges, biofilm also extended into the matrix of the sponges. The authors believe that bacterial production of biofilm offers an explanation for the persistence of scleral buckle infections and their ability to withstand antimicrobial treatment.

Antibiotic therapy for Bacillus species infections

We reviewed 36 cases of culture-proven Bacillus species ocular infections occurring between September 1974 and December 1989. Kirby-Bauer disk sensitivities were available in 34 of the 36 cases (95%). All Bacillus species isolates were sensitive to the aminoglycoside antibiotics (N = 34) and to vancomycin hydrochloride (N = 32); resistance to clindamycin was found in four of 18 (22%) of tested isolates. Although B. cereus was uniformly sensitive to these antibiotics, resistance to clindamycin occurred in four cases in the non-B. cereus group. The microbroth dilution technique confirmed the Kirby-Bauer data. The aminoglycosides were uniformly effective, but the cephalosporins (first, second, and third generation drugs) were consistently ineffective against B. cereus and varied from sensitive to moderately sensitive for the non-B. cereus isolates. Our microbiologic laboratory findings suggest that vancomycin hydrochloride in combination with an aminoglycoside ensures more consistent antibiotic coverage of Bacillus species ocular infections.

Microbiology of contact lens-related keratitis

We reviewed 397 cases of microbial keratitis examined at the Massachusetts Eye and Ear Infirmary, Boston, MA, U.S.A., from January 1982 through December 1985. Of these, 136 cases (34%) were related to contact lens use. Extended-wear contact lenses were used by 107 (79%) of these patients. Cosmetic contact lenses accounted for 59 (44%) of lens-related cases, aphakic contact lenses 44 (32%), and therapeutic (bandage) contact lenses 33 (24%). Fifty-three microbial keratitis cases associated with contact lens wear were culture-positive: 28 (52%) were gram-positive, and 19 (36%) were gram-negative. Mixed cultures, fungi, and Acanthamoeba accounted for two cases (4%) each. Pseudomonas aeruginosa was specifically associated with cosmetic soft contact lens use.

Gentamicin-resistant pseudomonal infection. Rationale for a redefinition of ophthalmic antimicrobial sensitivities

Eight pseudomonal species were involved in 106 invasive infections of the eye; all were community acquired. Eighteen percent of the total and 9% of the Pseudomonas aeruginosa strains were gentamicin resistant, as defined using conventional criteria. All 10 cases of "resistant" pseudomonal (nine P. aeruginosa) keratitis responded satisfactorily to treatment with gentamicin. The resistance breakpoint (defined by safe serum levels in parenteral therapy) for most P. aeruginosa is much lower than ocular gentamicin levels achievable by optimal local application. We argue for a specific ophthalmologic definition of antibiotic resistance in infections of the cornea and external eye. MIC quantitative determinations of ocular isolates would provide more useful information to ophthalmologists than conventional qualitative disc sensitivity testing.

Ulcerative keratitis associated with contact lens wear

From October 1982 through June 1986, 658 patients developed ulcerative keratitis. In 196 of these patients it was contact lens-related. Fifty-nine patients wore extended-wear contact lenses for cosmetic purposes. On culture, Pseudomonas species was the organism most frequently isolated from the ulcers associated with contact lens wear. No cases of fungal keratitis were found in the contact lens group as compared to 40 cases (17%) in the noncontact lens group. Compared to results of a similar study covering January 1977 through September 1982, current results showed a larger number of patients using extended-wear lenses for cosmetic reasons (59 vs one) and overall younger age.

Topical retinoid therapy for squamous metaplasia of various ocular surface disorders. A multicenter, placebo-controlled double-masked study

In a prospective, double-masked clinical study, the authors evaluated the efficacy and safety of topically applied tretinoin ophthalmic ointment (0.01%) versus placebo in the treatment of squamous metaplasia associated with various ocular surface disorders involving dry eyes. Study parameters consisted of graded symptoms and signs, and serial impression cytologies. A total of 161 patients were enrolled in the study. Of these patients, 116 who had a minimum of 4 to 8 months of follow-up qualified for final statistical analysis. These patients were classified into two major groups: (1) keratoconjunctivitis sicca (KCS) and (2) conjunctival cicatricial diseases (Stevens-Johnson syndrome, inactive pemphigoid, radiation-induced dry eye, drug-induced pseudopemphigoid, and toxic epidermal necrolysis). An analysis of adjusted mean changes for KCS patients showed no statistically significant differences between active drug and placebo. A similar analysis of patients with conjunctival cicatricial diseases indicated a statistically significant (P less than 0.05) reversal of conjunctival keratinization in the temporal bulbar site after treatment with active drug, however, clinical symptoms and signs showed no significant improvement with active drug relative to placebo. Side effects were limited to blepharoconjunctivitis and were reversible upon tapering or stopping the drug.

Idiopathic bilateral lipid keratopathy

A 52-year-old Mexican man presented with asymptomatic, bilaterally symmetrical lipid infiltrates of the cornea and adjacent limbus. No evidence of previous ocular disease or systemic disorder of lipid metabolism could be detected. Penetrating keratoplasty of the right eye was required. The cornea was rigid and thick, with posterior bulging into the anterior chamber. Light microscopy revealed deep corneal lipid granules, foamy histiocytes, vascularisation, and chronic non-granulomatous inflammation. Transmission electron microscopy showed extracellular lipid spaces and numerous intracytoplasmic lipid vacuoles in histiocytes, keratocytes, conjunctival epithelium, and the endothelium of blood vessels in the corneal stroma and adjacent limbal conjunctiva. Histochemical analysis revealed the presence of neutral fats, free fatty acids, cholesterol, and phospholipids.

Effects of gentamicin on healing of transdifferentiating conjunctival epithelium in rabbit eyes

We examined the effects of commercially prepared gentamicin, a wide-spectrum topical antibiotic, on the healing of epithelial defects of the rabbit cornea. Abrasions were created by: (1) removing the corneal epithelium and 3 mm of the conjunctival epithelium (Group 1); and (2) producing the same initial trauma and subsequently removing the central 8 mm of epithelium 28 days after initial healing (Group 2). The complete healing of the large corneal and conjunctival epithelial defects was not delayed when gentamicin solution was used four times a day (Group 1). When the healed epithelium was reinjured while transdifferentiating from conjunctival to corneal epithelium (day 28, Group 2), treatment with the gentamicin solution and its vehicle, both containing benzalkonium chloride, delayed epithelial healing significantly compared with treatment with saline (P less than .01).

Clinically atypical granular corneal dystrophy with pathologic features of lattice-like amyloid deposits. A study of these families

Four patients from families in Pennsylvania, Massachusetts, and Argentina were diagnosed clinically as having granular dystrophy. Results of pathologic examination of the corneal buttons from each patient after penetrating keratoplasty confirmed granular deposits in the anterior third of the stroma. Amyloid was demonstrated within some of these granular deposits by Congo red staining with birefringence and dichroism and by electron microscopy. In addition to the morphologically granular deposits, numerous fusiform deposits identified as amyloid by histochemistry and electron microscopy and morphologically identical to those seen in lattice corneal dystrophy were detected deep to the granular deposits. It was further shown that the histochemical pattern of staining of the granular material by a series of lectins was similar to that present in corneas with lattice dystrophy. Although a relationship between these patients cannot be definitively proven, each family traces its origins to the Italian province of Avellino.

Pharmacologic pupillary modulation in the perioperative period

The perioperative management of the pupil is essential to the success of anterior segment surgery. A new dilating regimen was tested in 65 cases of cataract extraction and intraocular lens implantation. The alpha-adrenergic agonist, phenylephrine 2.5%, was used after pretreatment with the adrenergic beta-blocker, timolol 0.5%. This treatment successfully dilated the pupil in all but three cases, was maintained by intraoperative epinephrine infusion, and was readily reversed with intraocular acetylcholine. We conclude that this pharmacologic regimen provided a successful and easily reversible mydriasis during surgery.