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PubMed1999

The relationship between contact lens oxygen permeability and binding of Pseudomonas aeruginosa to human corneal epithelial cells after overnight and extended wear.

PURPOSE: We designed a 3-year, prospective, randomized, masked clinical trial to evaluate the relationship of contact lens oxygen transmissibility and bacterial adherence to exfoliated surface epithelial cells in human overnight and extended lens wearers in a single center; corneal cell desquamation rate, surface epithelial cell size, and tear lactate dehydrogenase (LDH) levels were also determined concurrently. METHODS: One hundred nine human volunteers were successfully fit with test lenses prospectively and completed this study. Seven soft and three rigid gas permeable (RGP) lenses with stratified oxygen transmissibility were evaluated. After one week adaptation to daily wear, patients continually wore test lenses bilaterally for three months on a six nights wear, one night off basis. Before and after 24 hour, 1 month, and three months extended contact lens wear, exfoliated surface epithelial cells were collected using a modified corneal irrigation chamber. Bacterial binding was determined by measuring Pseudomonas aeruginosa (PA) adherence to exfoliated corneal epithelial cells. The number of exfoliated cells with adherent bacteria were counted using fluorescence microscopy. The effects of contact lens wear on the corneal surface were further assessed by alterations in tear LDH, and by surface epithelial cell size and epithelial thickness using in vivo tandem scanning confocal microscopy (TSCM). Baseline values of outcome measures served as controls for individual patients; a concurrent group of controls were also followed to monitor seasonal or possible individual fluctuations. RESULTS: Quantitative evidence demonstrated that lens physical oxygen transmissibility properties and not lens type significantly correlated inversely with binding of PA to human exfoliated corneal epithelial cells after overnight and extended wear (R=0.258, P=0.0084); there was a significant decrease in surface epithelial cell desquamation and a significant increase in surface cell size following wear for all test lenses (P<0.05). Epithelial thinning was also observed following lens wear (P<0.05). CONCLUSIONS: These results establish for the first time a significant correlation between contact lens-induced increases in epithelial PA binding and lens oxygen transmissibility in humans. New ultra-oxygen permeable test lenses did not appear to increase bacterial binding over individual control levels; all test lenses suppressed surface epithelial cell shedding. Taken together, these findings suggest that a new generation of contact lenses constructed from ultra-transmissible oxygen materials may offer a significant potential advance in safety for extended wear.

Adult↗

PubMed1992

A prospective multicenter clinical trial to assess safety and efficacy of Menicon SF-P RGP lenses for extended wear.

A prospective, multicenter, national clinical trial was undertaken to assess the safety and efficacy of Menicon SF-P (melafocon A) rigid gas permeable (RGP) contact lenses for extended wear in healthy human eyes. Ten investigators enrolled 167 patients (334 eyes), of which 143 (286 eyes) were initially fit with lenses for the 12-month study. Most subjects were reexamined at 18 months or more, with findings essentially unchanged from those noted at 1 year. Two hundred-two eyes (71%) completed the study. Seventy-two eyes (25%) discontinued, and 12 (4%) elected to continue extended wear. During the study, no significant adverse clinical reaction attributable to the lens was observed. Surface irritation, occasional punctate staining, and lens binding were very rare. The average wearing time was 6.2 days, mandated partially by FDA restrictions as well as patient response. As expected, keratometric shifts were principally vertical: less than 0.99 D (69%), 1.00-1.99 D (28%), and 2.00-2.99 D (4%). The majority of changes observed were toward sphericity. Two hundred lens replacements were required, 24% for adjustments in power/base curve. Only 16 lenses were replaced for warpage, and none for discoloration or crazing. Of those completing the study, 76% rated overall lens comfort and satisfaction to be very good. These results suggest that RGP lens extended wear can be safe and effective and offer patients an acceptable alternative to extended wear of disposable hydrogel lenses.

Adolescent↗

PubMed1991

Microbiological aspects of extended-wear soft contact lenses.

Corneal ulcers are the most devastating complication associated with extended-wear soft contact lenses. The increasing prevalence of microbial keratitis associated with the wear of these lenses is a major concern for the optometrist. Studies of extended-wear and daily-wear contact lens patients strongly suggest that extended-wear patients face a greater risk of ulcerative keratitis than other cosmetic contact lens wearers. This discussion addresses the potential risks of extended-wear, with emphasis on ulcerative keratitis, the likely causes for these increased risks, and what the optometrist can do to reduce the risk of a microbial infection.

Contact Lenses, Extended-Wear↗

PubMed1991

Complications of extended wear.

Extended wear has been an attractive modality for many contact lens wearers. Despite the associated benefits of convenience and comfort, however, there have been many physiological complications reported for hydrogel extended-wear lenses, and a lesser number for rigid gas-permeable extended-wear lenses. This review describes the physiological as well as the mechanical complications of extended-wear lenses, for both soft lens and rigid lens materials, including etiology, clinical presentation, and management strategies.

Conjunctivitis, Allergic↗

PubMedDate not supplied

Disposable contact lenses vs. contact lens maintenance for extended wear.

We compared a disposable extended wear contact lens modality with conventional extended wear over a 6-week period. To do so, we refit 31 patients who had successfully worn conventional extended wear contact lenses for more than 1 year. One eye was fit with the AcuvueR disposable contact lens, and a new extended wear lens of the type the patient had been wearing was placed on the other eye. At weekly intervals the disposable lens was discarded and a new disposable lens inserted. At the same time, the conventional lens on the fellow eye was cleaned, disinfected, and reinserted. After 6 weeks the ocular response, subjective impressions, and condition of the lenses in the two eyes were compared. Both lenses were then cultured. Three subjects had to discontinue disposable lens wear because of adverse reactions to trapped cellular debris and corneal microcysts. Although the results were not statistically significant, the Acuvue lens appeared to perform better than or equal to the conventional lens in biomicroscopic observation, visual acuity measurement, and subjective patient preference. Eighty-seven percent of patients preferred to continue with the disposable system. There were no differences found in the type or degree of microbial contamination of the lenses.

Bacteria↗

PubMedDate not supplied

The disposable contact lens: a new concept in extended wear.

Due to reports of severe eye infections associated with the extended wear of soft contact lenses, this once-popular mode of contact lens wear has fallen into disrepute and been abandoned by many fitters and patients. Recently, an extended wear disposable contact lens was approved by the U.S. Food and Drug Administration. The lenses are designed to be worn continuously for one to two weeks and then discarded. A new pair is then inserted. This approach holds the potential to increase the safety, convenience, comfort, and quality of vision possible in extended wear. Clinical studies are presented in support of this position. I found this disposable contact lens to be a safe and convenient way to re-introduce extended wear.

Adolescent↗

PubMed1987

Results of the extended wear contact lens survey of the Contact Lens Section of the American Optometric Association.

Surveys of contact lens practice, comparing the use of daily wear and extended wear cosmetic soft contact lenses, were distributed to almost 3,000 members of the Contact Lens Section of the American Optometric Association. There were 759 responses received of which 440 were considered valid for analysis. The results of our analysis suggest that slightly more physiological complications are encountered with extended than with daily wear of contact lenses. Most optometrists (96%), however, are satisfied with this modality and continue prescribing extended wear lenses, although many have decreased the number of days over which patients are advised to use the lenses before removal and cleaning. Most of the respondees now favor medium water content, thin lens designs for extended wear use, with 70% of them suggesting weekly removal, cleaning and aseptization. Peroxide cleaning regimens are most popular for this function.

Contact Lenses, Extended-Wear↗

PubMed1985

Corneal infiltrates and extended-wear contact lenses.

Corneal infiltrates are a relatively rare but potentially serious complication of extended-wear contact lenses. Clinical experience with a large population of extended-wear patients suggested that these infiltrates have a characteristic location and appearance which may aid in diagnosis and management. The records of 51 patients (54 eyes) with extended-wear contact lenses and corneal infiltrates were reviewed. Nearly all the infiltrates were in the peripheral cornea and 67% were located superiorly, beneath the upper lid. No permanent visual loss resulted and all patients resumed extended-wear of contact lenses following a period of appropriate management. The clinical features, management, and possible etiologies are discussed. The sample reported herein is the largest, to date, of any reported in the ophthalmic literature.

Adolescent↗

PubMed1985

Extended-wear soft contact lenses for vision studies in monkeys.

The authors have designed and produced extended-wear contact lenses for rhesus monkeys. High-plus lenses to correct neonatal aphakia as well as lenses dyed black for use as occluders to treat amblyopia have been evaluated. Four infant monkeys fitted with soft lenses have successfully worn these extended-wear lenses almost continuously throughout their first year of life. These experiments demonstrate that rhesus monkeys tolerate extended-wear contact lenses well when these lenses are correctly designed, comfortably fitted, and their wear carefully monitored. Furthermore, the results demonstrate that usable levels of vision can be maintained in monocularly aphakic infant monkeys. Since similar methods are now used to treat children with monocular cataracts, our animal model using extended-wear contact lenses on young monkeys should facilitate new and clinically relevant amblyopia experiments.

Amblyopia↗

PubMed1994

Extended-wear RGP contact lenses: a viable alternative to refractive surgery.

The rigid gas-permeable (RGP) extended-wear lens offers a unique alternative to the hydrogel extended-wear lens as well as to refractive surgery. In suitable patients it can provide almost maintenance-free visual correction for a wide variety of refractive errors. With prudent patient selection, use of high-permeability RGP materials, sound lens design and fitting principles, and conservative follow-up procedures, RGP extended-wear lenses can have success rates exceeding those of either hydrogel extended-wear lenses or refractive surgery, with fewer complications. The complications that do occur are often predictable after a short period of daily wear, and the remainder can often be managed with small changes to lens design.

Contact Lenses, Extended-Wear↗

PubMed1994

[Evaluation of parasternal (Ps) and supraclavicular (Sc) node dissection combined with targeting chemotherapy (activated carbon particle adsorbing aclarubicin) in breast cancer with Ps node involvement--usefulness of extended surgery for improvement of prognosis].

We treated breast cancer patients with Ps node involvement using an extended surgery (Ps+Sc, n = 17, group A) combined with targeting chemotherapy and compared the survival rate by this method with that by the dissection of the Ps node alone (n = 23, group B) to assess the prognosis of advanced breast cancer by extended surgery. 1) Overall patients: The disease-free survival rate was significantly higher in group A, while the overall survival rate was not significant. 2) Survival rate in relation to the number of metastatic Ps nodes or axillary (Ax) nodes: In patients with Ps = 1 or Ax < or = 3, the difference in the overall and disease-free rates were not significant. In patients with Ps > or = 2 or Ax > or = 4, both overall and disease-free rates were significantly higher in group A. It was therefore suggested that extended surgery should be performed if metastasis is found in 2 or more Ps nodes in the frozen section intraoperatively. The result of this study, although it is not a randomized trial, suggested a possibility that extended surgery may improve the prognosis of advanced breast cancer.

Aclarubicin↗

PubMed1994

Rigid gas permeable extended wear (RGPEW) for the postoperative patient: a review and clinical observations.

BACKGROUND: Contact lenses are often the indicated method of correction following cataract extraction without implantation of an intraocular lens and following penetrating keratoplasty. Unfortunately, many patients who stand to benefit from contact lens wear are unable or lack the motivation to perform proper lens hygiene. Thus, extended lens wearing schedules using soft and rigid lens designs are often utilized. METHODS: Following a review of the literature regarding extended wear rigid lenses (PMMA and oxygen permeable) for the aphakic patient, this paper presents results of fitting high DK (92 x 10-11) rigid contact lenses worn from 1-2 months prior to removal on 11 patients (six with aphakia, five following penetrating keratoplasty). All subjects with aphakia were considered to be unsuccessful with soft aphakic extended wear (SEW). Subjects in the penetrating keratoplasty group were new to contact lens wear. RESULTS: These data show that 60 percent of aphakic patients considered to be unsuccessful with SEW may be successful with rigid gas permeable extended wear (RGPEW). The predicted success with RGPEW following penetrating keratoplasty was lower at 20-40 percent. CONCLUSIONS: RGPEW should be considered for the postoperative patient who stands to benefit from the optical advantages of contact lenses but is unable or not motivated to perform the necessary lens hygiene. Patients who experience lens awareness or become intolerant to SEW due to corneal edema are potential candidates for RGPEW.

Aged↗

PubMed1983

Extended-wear aphakic soft contact lenses after penetrating keratoplasty.

Seven patients undergoing aphakic keratoplasty or combined keratoplasty and cataract extraction were fitted with a single type of high-water-content, extended-wear, aphakic soft contact lens (Permalens). Six patients were fitted early after keratoplasty, ie, before the removal of the sutures and while they were still receiving corticosteroid drops (1% prednisolone acetate). The patients were followed up at close intervals with high-magnification serial corneal photography. Complications of extended wear included superficial neovascularization, punctate epithelial keratitis, and variable visual acuity. Our results suggest that although extended-wear aphakic soft contact lenses may be an acceptance form of visual rehabilitation in selected patients who undergo transplantation, they are frequently problematic. In addition, fitting of these lenses should be withheld until after the removal of the sutures, and patients should be followed up at closer intervals than the patients with extended-wear aphakic soft contact lenses who have not undergone keratoplasty.

Adult↗

PubMed2002

Prognostic factors after pancreatoduodenectomy with extended lymphadenectomy for distal bile duct cancer.

BACKGROUND: Since 1995, we have been performing pancreatoduodenectomy with regional and para-aortic lymph node dissection for patients with distal bile duct cancer. Prognostic indicators after extended lymphadenectomy have not been fully understood. HYPOTHESIS: Pancreatoduodenectomy with extended lymphadenectomy and adjuvant chemotherapy is the treatment of choice for patients with distal bile duct cancer. DESIGN: In a retrospective study, univariate and multivariate models were used to analyze the effect of patient demographics, tumor characteristics, and treatment factors on long-term survival. SETTING: Oita Medical University and its affiliated hospitals in Japan. PATIENTS: From 1995 to 1999, 27 patients with distal bile duct cancer underwent pancreatoduodenectomy with extended lymphadenectomy. In 9 patients fluorouracil (500 mg/d) was infused continuously for 14 days after surgery as adjuvant chemotherapy. MAIN OUTCOME MEASURES: Clinicopathologic characteristics and long-term results. RESULTS: In 6 patients (22%) major surgical complications occurred including 1 in-hospital death (3.7%). For 26 patients, the survival rates were 65% for 1 year and 37% for 3 and 5 years. Univariate analysis found that the absence of lymph node metastasis, no more than 2 involved nodes, and negative resection margins were predictors of survival. Multivariate analysis with a Cox proportional hazards regression model revealed that favorable factors for survival included up to 2 positive nodes, negative resection margins, and the use of postoperative adjuvant chemotherapy. CONCLUSIONS: Patients with up to 2 positive lymph nodes had a more favorable prognosis than that of other patients. We recommend pancreatoduodenectomy with extended lymphadenectomy and adjuvant chemotherapy for the treatment of patients with distal bile duct cancer.

Antimetabolites, Antineoplastic↗

PubMed1995

Outcome of extended right hepatectomy after biliary drainage in hilar bile duct cancer.

OBJECTIVE: Evaluation of extended right hepatectomy (ERH) after biliary drainage in patients with hilar bile duct cancer. DESIGN: Case series. SETTING: University hospital. PATIENTS: Extended right hepatectomy was performed in 25 patients, and 12 underwent other surgical procedures. INTERVENTIONS: Among the 25 patients, 16 had obstructive jaundice. After biliary drainage, 11 had no biliary stasis in both lobes and five had undrained biliary trees in the right lobe. MAIN OUTCOME MEASURES: Long-term disease-free survival, presence or absence of undrained biliary trees in each lobe, rate of decrease in serum total bilirubin levels, and future remnant liver (left lobe) volume. RESULTS: Patients who underwent ERH had significantly longer disease-free survival than patients who underwent other procedures. There were no hospital deaths and no significant differences in morbidity between patients with and without prior jaundice. Patients with an undrained biliary tree in the right lobe had a larger future remnant liver volume, a slower rate of decrease in serum total bilirubin levels after biliary drainage, and a more rapid return of the postoperative serum total bilirubin level to the normal range than patients without biliary stasis in both lobes. CONCLUSIONS: Extended right hepatectomy can be performed safely even in patients showing a very slow decrease in the serum total bilirubin level after biliary drainage, caused by the presence of an undrained biliary tree in the right lobe with no biliary stasis in the left lobe, which induces compensatory hypertrophy of the left lobe. Extended right hepatectomy is a suitable surgical choice for achieving long-term survival in patients with hilar bile duct cancer.

Adult↗

PubMed2002

Risk of injury to child passengers in compact extended-cab pickup trucks.

CONTEXT: An increasing number of compact pickup trucks can accommodate restrained rear occupants. Rear seats in these pickup trucks are exempt from regulatory safety testing though their relative safety has not been determined. OBJECTIVES: To evaluate the risk of injury to children in compact extended-cab pickup trucks compared with children in other vehicles and to determine if any unique hazards exist. DESIGN: Cross-sectional study of children aged 15 years or younger in crashes of insured vehicles, with data collected via insurance claim records and a telephone survey. SETTING AND PARTICIPANTS: Probability sample of 7192 multirow vehicles involved in crashes, with 11 335 child occupants, in 3 large US regions from December 1, 1998, to November 30, 2000. MAIN OUTCOME MEASURE: Relative risk of injury, defined as concussions and more serious brain injuries, spinal cord injuries, internal organ injuries, extremity fractures, and facial lacerations, estimated by odds ratios (ORs) adjusting for age, restraint use, point of impact, vehicle weight, and crash severity. RESULTS: Injuries were reported for 1356 children, representing 1.6% of the population. Children in compact extended-cab pickup trucks were at greater risk of injury than children in other vehicles (adjusted OR, 2.96; 95% confidence interval [CI], 1.68-5.21). Children in the rear seats of compact pickup trucks were at substantially greater risk of injury than rear-seated children in other vehicles (adjusted OR, 4.75; 95% CI, 2.39-9.43). Children seated in the front seat of compact extended-cab pickup trucks were at greater risk of injury than children in the front seats of other vehicles, but this risk was not statistically significant (adjusted OR, 1.70; 95% CI, 0.78-3.69). CONCLUSIONS: Children in compact extended-cab pickup trucks are not as safe as children in other vehicles, primarily due to the increased relative risk of injury in the back seat. For families with another choice of vehicle, clinicians should advise parents against transporting children in compact pickup trucks. The current exemption for regulatory testing for occupant protection in the rear seats of compact pickup trucks should be reconsidered.

Accidents, Traffic↗

PubMed1997

Extended lymph node dissection in gastrointestinal cancer.

We reviewed the literature concerning the effect of extended lymph node dissection on survival in patients with gastrointestinal cancer. Most retrospective and/or prospective nonrandomized comparative studies have claimed that extended lymph node dissection significantly improves survival rate in patients with esophageal cancer, gastric cancer, and colorectal cancer. However, it is difficult to interpret these results since specialized care provided in trials may itself improve survival. In gastric cancer, several prospective randomized trials have failed to demonstrate a survival advantage of extended dissection, while there are few well-done prospective randomized trials in esophageal or colorectal cancer. Therefore, the therapeutic value of extended lymph node dissection remains to be determined in gastrointestinal cancer. Randomized prospective studies within the bounds of the ethical treatment of patients can and should be done.

Clinical Trials as Topic↗

PubMed1999

Prognostic factors after extended esophagectomy for squamous cell carcinoma of the thoracic esophagus.

BACKGROUNDS AND OBJECTIVES: In Japan, extended esophagectomy with extensive lymphadenectomy has become the standard surgical procedure for carcinoma of the thoracic esophagus. Although mortality and morbidity rates after such extensive esophagectomy have been acceptable, the long-term outcomes are not necessarily satisfactory. METHODS: Among 235 patients with primary squamous cell carcinoma of the thoracic esophagus between June 1981 and March 1998, 143 patients (60.9%) underwent extended esophagectomy with extensive lymphadenectomy. To exclude the effects of surgery-related postoperative complications, 14 patients who died within 90 days after operation were excluded. Thus, clinicopathological characteristics and prognostic factors of 129 patients were retrospectively investigated. RESULTS: Sixty-three patients were alive and free of cancer. Sixty-six patients died: 37 of recurrence of the esophageal cancer and 29 of other causes. The 1-, 3-, 5-, and 10-year overall survival rates in the 129 patients were 78.8%, 53.5%, 45.8%, and 30.9%, respectively, and the disease-specific survival rates were 85.7%, 69.1%, 67.9%, and 56.2%, respectively. The factors influencing the disease-specific survival rate were tumor location (upper third vs. non-upper third), Borrmann classification (0, 1 vs. 2, 3), size of tumor (</=3.0 vs. >3.0 cm), depth of invasion (T1, 2 vs. T3, 4), number of lymph node metastases (0 or 1 vs. >/=2), time of operation (</=420 vs. >420 min), amount of blood transfused (</=2 vs. >/=3 U), lymph vessel invasion (marked vs. not marked), and blood vessel invasion (marked vs. not marked). Among those significant variables, independent prognostic factors for survival determined by multivariate analysis were number of lymph node metastases (P < 0.001), amount of blood transfusions (P = 0.0016), and tumor location (P = 0.0382). CONCLUSIONS: Patients with a single metastatic node after extended esophagectomy should be considered to have excellent prognosis, like patients with pN0 tumors. Patients with multiple involved nodes should receive aggressive postoperative adjuvant treatments. Reduced blood loss during extended esophagectomy and minimal blood transfusions might improve the outcome of curative esophageal resections.

Aged↗