Penetrating Keratoplasty for Corneal Ectasia after Laser in Situ Keratomileusis

Purpose

To improve the visual acuity of patients with progressive keratectasia following laser in situ keratomileusis (LASIK).

Methods

Five eyes of four patients underwent penetrating keratoplasty for ectasia after LASIK. In one patient the second eye was operated on 10 months after the first keratoplasty. The pre- and postoperative refraction, best spectacle-corrected visual acuity, and topographic data were evaluated.

Results

The preoperative refraction was −20.0 diopters (D) with high cylindrical values in all eyes at the time of surgery. After penetrating keratoplasty, mean spherical equivalent was −13.08±3.62 (SD) and mean refractive cylinder was −3.87±1.12 (SD). In one eye Urrets-Zavalia syndrome was noted as an early postoperative complication. In the second operated eye of another patient, there had been graft rejection several times. In this patient, frequent steroid use led to secondary glaucoma and he required filtering surgery.

Conclusions

Penetrating keratoplasty is effective and successful in treating iatrogenic keratectasia after LASIK, but these patients need a close and lifelong follow-up to treat late-term complications such as graft rejection and secondary glaucoma.

Evaluation of Platelet Indices in Lung Cancer Patients

BACKGROUND

In this study, we aimed to determine platelet indices such as platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), Plateletcrit (PCT) platelet count (PLT) in lung cancer cases, and evaluate any relationships between these parameters and stage or histologic types.

MATERIALS AND METHODS

This retrospective study covered 44 lung cancer patients and 47 healthy subjects. Platelet indices including PLT, PCT, MPV, PDW were estimated and compared with normal subjects. The results were evaluated statistically.

RESULTS

The PDW value was significantly higher in the cancer group compared to the control group; however, the values for PCT and MPV were lower.

CONCLUSIONS

We suggest potential use of platelet indices in diagnosis of lung cancer.

Cytokines, adipocytokines and inflammatory markers in patients on continuous ambulatory peritoneal dialysis and hemodialysis

BACKGROUND

Cytokines are essential mediators of immune response. Chronic renal failure patients suffer from chronic inflammation that results from factors such as impaired renal function, accumulation of uremic toxins and bio incompatibility of dialyzer membranes. These patients are also at increased risk of cardiovascular diseases. We have evaluated cytokines, adipocytokines and inflammatory markers in patients with chronic renal failure undergoing hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD).

MATERIAL AND METHODS

We have determined serum tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), leptin and ghrelin levels of chronic renal failure patients treated with either HD (n = 20) or CAPD (n = 20). TNF-α, IL-6, ghrelin and leptin measurements were performed by commercially available kits based on enzyme-linked immunosorbent assay (ELISA) method. hsCRP levels were determined by turbidimetric methods.

RESULTS

Serum TNF-α and IL-6 levels of patients on HD were significantly higher than those of the ones on CAPD (p < 0.05). Ghrelin, leptin and hsCRP concentrations were similar in both groups.

CONCLUSIONS

We can conclude that cytokine production is more obvious in HD process.

8-Isoprostane and Coenzyme Q10 Levels in Patients with Metabolic Syndrome

BACKGROUND

Metabolic syndrome has become an important health problem, which involves obesity, hyperlipidemia, insulin resistance, and high blood pressure values. The components of metabolic syndrome are all suggested as independent cardiovascular disease risk factors along with high mortality and morbidity rates accompanied by many organ and system complications.

OBJECTIVE

We aimed to determine 8-isoprostane (8-IsoP) and coenzyme Q10 (CoQ10) levels in patients with metabolic syndrome and healthy individuals and demonstrate whether there was any relation between these parameters and metabolic syndrome criteria.

MATERIALS AND METHODS

A total of 30 patients (10 male, 20 female) with metabolic syndrome and 20 age-matched healthy individuals (9 male, 11 female) were involved in the study. Body mass index, waist and hip circumferences, systolic and diastolic blood pressures and serum glucose, triglyceride, total cholesterol, high-density lipoprotein cholesterol, insulin, HbA1c, 8-IsoP and CoQ10 levels, and homeostasis model assessment of insulin resistance indexes of all participants were determined.

RESULTS

8-IsoP levels were significantly increased in metabolic syndrome compared to healthy individuals (P = 0.003), however, there was no significant difference between groups for CoQ10 levels. 8-IsoP levels were positively correlated with waist circumference (r = 0.303, P = 0.032), diastolic blood pressure (r = 0.337, P = 0.017), systolic blood pressure (r = 0.329, P = 0.020) values and total cholesterol levels (r = 0.354, P = 0.012).

CONCLUSION

We can suggest that the levels of 8-IsoP, which is an indicator of the oxidative stress, increase in metabolic syndrome and this can be associated with high blood pressure and visceral adiposity, which are the components of metabolic syndrome.

Increased ischemia-modified albumin and malondialdehyde levels in videothoracoscopic surgery

BACKGROUND:

Videothoracoscopic surgery leads to general organ hypoperfusion by reducing mean arterial pressure, systemic vascular resistance, and end-diastolic volume index. Oxidative stress occurs as a result of hypoperfusion. Evaluation of the short-term effects of videothoracoscopic sympathectomy on serum ischemia-modified albumin (IMA), malondialdehyde (MDA), and nitric oxide (NO) levels in patients with primary hyperhidrosis was aimed.

METHODS:

Twenty-six patients who underwent videothoracoscopic surgery were contributed in this study. Venous blood samples were obtained from these patients 1 h before and after the surgery. IMA, MDA, and NO levels were measured in serum samples by colorimetric methods. Albumin concentrations were also measured for each sample, and albumin-adjusted IMA levels were calculated.

RESULTS:

Postoperative IMA, albumin-adjusted IMA, and MDA values were significantly higher compared to the preoperative values (P = 0.003, 0.027, 0.018, respectively). However, postoperative NO levels were lower than the preoperative values (P = 0.002). There was no significant difference between pre- and postoperative albumin concentrations, and there was no significant correlation between the parameters tested.

CONCLUSIONS:

We can conclude that elevation in MDA and IMA levels after videothoracoscopic surgery was caused by increased oxidative stress due to minimal ischemia-reperfusion injury after the infusion of CO₂ during the surgical process. Videothoracoscopic sympathectomy operation causes a decrease in NO production, and this should be taken in consideration when evaluating nitrosative stress in videothoracoscopic surgery.

Plasma vitamin D levels of patients with allergic rhino-conjunctivitis with positive skin prick test

BACKGROUND

Allergic rhino-conjunctivitis (ARC) and allergic rhinitis are inflammatory diseases that develop through immunoglobulin E in the rhino-ocular mucosa due to allergy. The main symptoms are runny nose, nasal congestion, sneezing, itchy nose, and conjunctivitis.

OBJECTIVE

This study was designed to evaluate plasma 25-hydroxyvitamin D levels in patients with ARC.

STUDY DESIGN

This study was planned as a prospective and cross sectional study. This study was performed in a tertiary referral center.

METHODS

This observational study involved 42 patients with ARC and 35 consecutive, age- and sex-matched healthy subjects. Patients in both groups underwent skin-prick test. Plasma 25-hydroxyvitamin D levels of all subjects were quantified with electrochemiluminescence technique. Results were compared between the groups and p < 0.05 was considered as statistically significant.

RESULTS

Group one included 42 ARC patients (15 male, 27 female, ages between 12 and 43, average age 25.7 ± 8.6); group two included 35 healthy people (15 male, 20 female, ages between 12 and 44, average age 26.9 ± 9.1). Plasma 25-hydroxyvitamin D levels of the subjects with ARC group (7.33 ± 3.61 ng/mL, standard error mean: 0.55, range 3.17-13.68 ng/mL) were significantly lower than the control group (13.37 ± 5.42 ng/mL, standard error mean: 0.91, range 6.84-25.92 ng/mL) (p = 0.010, Independent-Samples test).

CONCLUSIONS

We found lower plasma vitamin D levels in patients with ARC when compared with the control group.

Oxidative stress parameters and serum magnesium levels in patients with seasonal allergic conjunctivitis

OBJECTIVE

To evaluate oxidative stress parameters and serum magnesium (Mg) levels in patients with seasonal allergic conjunctivitis (SAC) during the pollen season.

METHODS

This observational cross-sectional study involved 35 patients with SAC without any other ocular and systemic diseases, and 38 consecutive, age- and sex-matched healthy subjects. Serum malondialdehyde (MDA), adjusted ischemia modified albumin (IMA), and Mg levels were quantified, and the results were compared between the groups.

RESULTS

No significant differences were found between the groups with respect to age (p = 0.416) and sex (p = 0.362). Serum MDA and adjusted IMA levels of the subjects with SAC (69.54 ± 7.71 μM and 0.74 ± 0.39 ABSU) were significantly higher than the control group (64.61 ± 5.89 μM and 0.57 ± 0.19 ABSU) (p = 0.002 and p = 0.025, respectively). There was no significant difference for serum Mg levels between the groups (p = 0.177).

CONCLUSION

We demonstrated higher levels of oxidative stress parameters in patients with SAC compared to the control group, which imply a possible role of oxidative stress in the pathogenesis of SAC.

Evaluation of the Relationship Between Ischemia-Modified Albumin Levels and Thyroid Hormone Levels

BACKGROUND

A novel ischemia marker named ischemia modified albumin was previously considered as an early marker of myocardial ischemia, however due to recent reports, its contribution was demonstrated in different pathologies such as oxidative stress, diabetes, stroke and cancer. We aimed to investigate the relation between oxidative stress and thyroid dysfunctions determining IMA levels since IMA is closely related with increased oxidative stress.

METHODS

A total of 88 individuals were participated in this study: 34 cases in hypothyroid, 27 cases in hyperthyroid and 27 cases in euthyroid group. Ischemia-modified albumin levels were measured by albumin cobalt binding test and thyroid hormone levels were determined with electrochemiluminescent method.

RESULTS

Ischemia modified albumin levels were significantly decreased in hypothyroid group compared to hyperthyroid and euthyroid groups (p < 0.001). In hyperthyroid individuals ischemia modified albumin levels were higher compared to euthyroid ones (p < 0.001). Ischemia modified albumin was negatively correlated with TSH levels (r = -0.473, p < 0.001), and positively correlated with FT4 and FT3 levels (r = 0.496, p < 0.001 and r = 0.275, p = 0.010, respectively).

CONCLUSION

We suggest that albumin adjusted IMA levels are significantly lower in hypothyroid group than hyperthyroid and euthyroid groups.

Does obesity change the effect of aromatase inhibitors (AIs) on estradiol, leptin, insulin, and IGF-1 serum levels in breast cancer patients?

e11008

Background: The complexity of the relationship between obesity and breast cancer reflects important contributions of obesity-related factors in the adjuvant therapy. The efficacy of adjuvant AIs compared to tamoxifen is lower in obese postmenopausal women. Therefore, we aimed to identify whether the effect of AIs on estradiol, leptin, insulin, and IGF-1 serum levels with respect to the status of the obesity in breast cancer patients. Methods: A total of 34 postmenopausal breast cancer patients treated with adjuvant AIs were enrolled in the study. Pretreatment and 3 months after treatment body weight, height, waist-to-hip (WHR) ratio and body mass index (BMI) were recorded. Blood samples for serum estradiol, leptin, insulin and IGF-1 were drawn after 12 hour starvation and stored in – 70o before and 3 months after the onset of AI treatment. Results: Median age and BMI were 61 years (range 49-84) and 31 (range 22-43), respectively. 18 (%52.9) patients were treated with letrozole and 16 (%47.1) patients were treated with anastrazole. There was no change in the 3 months period in weight, BMI and WHR. Estradiol levels were decreased significantly between the baseline and the 3rd month (p<0.01). There was a slight increase in the leptin levels between the basal and 3rd month (p>0.05). No significant change was detected in insulin and IGF-1 levels in the follow-up period. In the multivariate regression model, there was no difference between the effect of letrozole and anastrazole on estradiol levels. Pretreatment BMI did not alter the effect of AIs on estradiol levels. The only factor related with the effect of the AIs is the pretreatment estradiol levels. Conclusions: This study shows that the suppression of estrogen in obese breast cancer patients with AIs at the standard doses may not be different from non-obese patients. Further researches may show us other mechanisms for the obesity-related factors to improve outcome with aromatase inhibition in obese breast cancer patients.

Mild and Severe Anal Incontinence after Lateral Internal Sphincterotomy: Risk Factors, Postoperative Anatomical Findings and Quality of Life

<i>Aim:</i> This study aims to evaluate the risk factors for incontinence after lateral internal sphincterotomy (LIS) and assess quality of life in different levels of incontinence. <i>Methods:</i> All consecutive patients (n = 253) with chronic anal fissure who underwent LIS between 2003 and 2006 were retrospectively reviewed. All patients were questioned for possible anal incontinence according to the Wexner Incontinence Score (WIS). Demographics, vaginal delivery history, additional procedures and surgeon’s experience were evaluated as risk factors. Endoanal ultrasound (EUS) was performed in incontinent patients to assess the thickness of the remaining internal sphincter and to evaluate any injury in the external sphincter. Quality of life was questioned with SF-36. <i>Results:</i> Twenty-eight (11.7%) patients suffered from incontinence (mean WIS = 3.6 ± 2.5). The search for a risk factor was unsuccessful when continent and incontinent groups were compared. In subgroup analyses, patients were found to be suffering from mild (WIS <5, n = 19) or severe (WIS >5, n = 9) incontinence. Vaginal delivery history was found more often in the severely incontinent subgroup than in the continent group (p < 0.05). Also, vaginal delivery history and the additional procedures were more frequently observed in the severely incontinent subgroup than in the mildly incontinent subgroup. EUS did not find any external sphincter injury in these cases. WIS had negative correlations with the physical and mental component scores of SF-36. <i>Conclusion:</i> In our opinion, the threat for incontinence is unpredictable; however, vaginal delivery history may increase the risk of severe incontinence.

Apical lymph nodes at the root of the inferior mesenteric artery in distal colorectal cancer: an analysis of the risk of tumor involvement and the impact of high ligation on anastomotic integrity

BACKGROUND

What level of arterial ligation is best in left-sided colon cancer and rectal cancer remains controversial. This study aims to assess the necessity and risk of high ligation from an oncological and technical perspective.

METHODS

The lymph nodes at the origin of the inferior mesenteric artery (IMA) were separated as apical nodes in all patients operated for distal colorectal cancer in our department. The number and status of the nodes were prospectively assessed, and demographic and tumor-related variables were evaluated as risk factors for apical tumor invasion. Anastomotic leaks were also evaluated.

RESULTS

A hundred and three patients (52 [50.5%] males, 60.3+/-12.9 years old) were included. The number of non-apical lymph nodes harvested was 14.5+/-7.1 with an additional 4.4+/-3.2 apical nodes at the high ligation site. Tumor invasion of apical nodes was observed in 6 (5.8%) patients. Two of these (1.9%) had no other positive nodes (skip metastases). Although none of the variables evaluated was found significant for predicting apical node positivity, tumor invasion was detected in 8.5 and 22.2% of patients with pT3 and pN2 cancers, respectively. Among patients, who had an anastomosis (n = 84, 81.6%), anastomotic leak was observed in 7(8.3%) and 1 (1.2%) of these patients required emergency relaparotomy. There was no mortality related to high ligation.

CONCLUSIONS

High ligation of IMA may be routinely performed in patients with distal colorectal cancer, since tumor invasion of apical lymph nodes is neither rare (>5%) nor predictable, and skip metastases may also occur. This is especially true in case of an advanced disease for which apical node positivity peaks. The anastomotic leak rate is less than 10%, and mortality is low after high ligation of IMA.

The correlation among tissue, serum adiponectin levels and histopathological variables in gastric cancer patients

e22199

Background: Adiponectin is a new peptide hormone secreted from the adipose tissue, affecting the proliferation and insulin sensitivity in different cell types.The previous studies showed that the serum levels of adiponectin are decreased in patients with endometrial and breast cancer.In our study, demographic features and histopathological variables and the relationship among adiponectin levels of serum and gastric tissue were analyzed in gastric cancer patients. Methods: Thirty-five consecutive patients with gastric cancer included in this study.The serum levels of glucose, insulin, c-peptide, HbA1c, lipids and adiponectin were measured in patients.In addition, normal and tumor tissue levels of adiponectin were also detected.We analyzed the correlation among these parameters and patients demographic features, such as age, gender, body mass index (BMI) and histopathological variables. Results: Patients characteristics included 24 males (68.5%), 11 females (31.5%); median age was 64 (range:41–85). The mean serum, normal and tumor tissue levels of adiponectin were 49.4±0.8, 48.2±4.2, 48.6±2.9 ng/ml, respectively. There was no relationship among serum, normal and tumor tissue adiponectin levels (p>0.05).There was inverse correlation between the normal tissue levels of adiponectin and insulin (p=0.002).The serum adiponectin levels were significantly associated with tumor localization (p=0.03).However, there was inverse correlation between serum adiponectin levels and perineural invasion (p=0.02).In subgroup analysis, the serum, normal and tumor tissue levels of adiponectin in woman were not different compared with those in male patients (p>0.05).No relations were detected among tumor stage, grade, nodal status, lymphatic and vascular invasion, the other insulin-resistant status parameters and the levels of serum, normal and tumor tissue adiponectin (p>0.05). Conclusions: Our results suggest that no correlations among the levels of serum adiponectin,normal tissue and tumor tissue adiponectin levels,patients demographic features and histopathological variables except for the association of serum adiponectin with tumor localization and perineural invasion detected in gastric cancer patients.

No significant financial relationships to disclose.

Comparison of cecal abrasion and multiple-abrasion models in generating intra-abdominal adhesions for animal studies

BACKGROUND

The formation of postoperative adhesions is a common problem in abdominal surgery that may lead to serious complications. Appropriate animal adhesion models are essential for the investigation of adhesiogenesis and the development of new anti-adhesive products. Although animal models have been developed to study the process of adhesion formation in the abdomen, they are not effective in generating adhesions located over small bowel where adhesions are most commonly observed in clinical practice.

METHODS

Twenty-nine Sprague Dawley rats were subjected to standardized cecal abrasion (group 1; n=9), or two types of multiple abrasion, in which cecal and 3 or 5 abrasions were performed on small bowel (group 2, n=10; and group 3, n=10). An observer blinded to the randomization assessed the difficulty of adhesiolysis on a 6-point scale, and the locations of the adhesions were recorded 21 days after the initial surgery.

RESULTS

Adhesiolysis was significantly more difficult in group 3 than in group 1 (p=0.01). The number of animals that had adhesions between the small bowel segments and the total number of locations where small bowel adhered were significantly greater in group 2 and 3 than in group 1 (p<0.05 for all comparisons).

CONCLUSIONS

Abrasions to the small bowel created consistent adhesions that have clinical characteristics of intra-abdominal adhesions as compared to the standard cecal abrasion model and that can be used in future animal studies on adhesions.

Meshless repair of perineal hernia after abdominoperineal resection: case report

Perineal hernia is a rare complication after major pelvic surgery. Placing non-biodegradable mesh across the pelvic inlet is the best method of repair. A 72-year-old man presented with a perineal hernia 8 years after undergoing an abdominoperineal resection because of rectal cancer. During the repair operation, intestinal spillage occurred, making it impossible to place permanent mesh as planned. Instead, we used the bladder to cover the pelvic inlet. The patient recovered well and after 35 months of follow-up, there was no evidence of hernia recurrence. When mesh placement is not feasible, this bladder mobilization technique can replace it.

Benefits of 'clean sweep' in Peutz-Jeghers patients

OBJECTIVE

Laparotomy is the treatment of choice in Peutz-Jeghers Syndrome (PJS) patients for endoscopically irretrievable symptomatic polyps and polyp-related complications. During the last decade, we have operated on majority of the PJS patients with the purpose of removing all the gastrointestinal polyps (clean sweep), when an operation was indicated. The aim of this study is to evaluate the effect of clean sweep technique on the need for repeated surgery compared to a problem focused approach.

PATIENTS AND METHODS

All patients with PJS treated in our institution since 1964 were studied. They were placed into two groups; those who had a problem-focused operation and those who were operated with the purpose of removing all small and large intestinal polyps. Demographics, presentation, follow-up period and the need for recurrent surgery were compared.

RESULTS

We identified 11 patients (4 males, 7 females). Eight patients (5 females; median age 18.5) had problem-focused surgery for bleeding-anaemia (n = 3) or obstruction-intussusception (n = 5). These patients required 23 further operations within 87 patient-follow-up-years (2.64 operations per 10 years). Three patients (2 females; median age 6) were operated for bleeding-anaemia (n = 1) or obstruction-intussusception (n = 2) using the 'clean sweep' approach. These patients did not require any further surgery within 21 patient-follow-up-years. The gender, presentation and follow-up periods were similar between the groups. However, the 'clean sweep' technique appears to have reduced the need for further operations when it is compared with problem-focused approach (P = 0.01).

CONCLUSION

To reduce the need for abdominal surgery and consequent problems in PJS patients, an attempt to remove all detected polyps (clean sweep technique) may be beneficial in these patients.

Small bowel perforation due to blunt trauma directly to the inguinal region: A case report

We report on a patient with intestinal perforation caused by direct blunt trauma to the inguinal region. The patient had been previously diagnosed with an inguinal hernia. The perforation was managed surgically, and he subsequently underwent hernia repair. In our opinion, intestinal perforation caused by inguinal region trauma in patients with inguinal hernias is a rare and unfortunate situation but one that reveals the importance of inguinal hernia repair.

Excision and marsupialization versus sinus excision for the treatment of limited chronic pilonidal disease: a prospective, randomized trial

The treatment techniques for pilonidal disease are either associated with high recurrence rates or complex procedures. This prospective randomized study compared the outcome of excision and marsupialization technique with sinus excision technique. A total of 40 consecutive patients with limited, chronic pilonidal sinus disease were operated with either excision and marsupialization technique (Group 1, n=20) or sinus excision technique (Group 2, n=20). The demographics, perioperative data, complications and recurrences were recorded. Patient satisfaction was evaluated with a specific questionnaire 16-18 weeks after surgery. Demographic data, preoperative symptoms and the acute disease history were similar between the groups. Operation time, hospital stay and work-off periods were significantly shorter and the number of out-patient procedures was significantly more in Group 2. Although satisfaction scores were similar between the groups, the patients who had no complaint, were "completely satisfied" or would "absolutely recommend the operative technique to other patients" were significantly more in Group 2. In conclusion, the sinus excision technique requires a shorter operation time, hospital stay and work-off period than excision and marsupialization in the treatment of limited, chronic pilonidal disease. The sinus excision technique can be performed as an out-patient procedure in most cases, and seems to be associated with better patient satisfaction.

The effectiveness of systemic antibiotics in preventing postoperative, intraabdominal adhesions in an animal model

OBJECTIVE

Postoperative intraabdominal adhesions can be prevented by antibiotic lavage. We assessed whether systemic antibiotics could prevent adhesion formation in a rat model.

METHODS

Cecal abrasion was performed in the peritoneal cavities of 40 Wistar albino rats. Twenty rats were treated with a 5-day course of cefepim and metronidazole; the remaining animals were given saline injections. The animals were sacrificed 14 days after surgery. Adhesion severity scores and histopathologic findings were compared.

RESULTS

The median adhesion severity score was 2 (0-3) in the antibiotic group and 2.5 (1-4) in the controls (P = 0.03). In tissue specimens from controls, the adhesions were marked by mature collagen bundles. In treated rats, the adhesions were immature, characterized by early inflammatory cells, less collagen formation, and no collagen bundles.

CONCLUSIONS

Postoperative systemic antibiotics slow adhesion formation and reduce the severity of the adhesions.

Intravitreal penetration of oral pefloxacin in humans

We measured vitreous and serum levels of pefloxacin after oral administration. Twenty patients with retinal detachments undergoing vitrectomy were recruited into this study. Each patient received 400 mg pefloxacin orally 1 to 12 hours before vitrectomy. Vitreous fluid (0.1 mL) was aspirated at surgery. Vitreous levels of pefloxacin were determined by high-performance liquid chromatography. Six hours after oral administration, an average level of 1.37 microgram/mL of pefloxacin was measured in the vitreous samples. These levels were well above the minimum inhibitory concentration (MIC) for most organisms termed sensitive to pefloxacin. Oral administration of pefloxacin may play an important role in the prevention or management of endophthalmitis.

Treatment of experimental suprachoroidal hemorrhage with subconjunctival injection of tissue plasminogen activator: a negative report

Suprachoroidal hemorrhage was created in 10 albino rabbit eyes. Five eyes were treated with subconjunctival injections of 40,000 IU of tissue plasminogen activator (tPA) daily for 6 days; five eyes served as controls. It took approximately the same amount of time for the suprachoroidal hemorrhages to clear in both the control and treatment eyes. We conclude that subconjunctival injection of tPA does not accelerate the clearance of suprachoroidal hemorrhage.

Treatment of experimental suprachoroidal hemorrhage with intravenous tissue plasminogen activator

Suprachoroidal hemorrhages were created in 15 albino rabbit eyes by injecting 0.1 cc of autologous blood into the suprachoroidal space. One day later, 10 of these eyes were treated with intravenous tissue plasminogen activator (TPA). Doses of 1 mg per kg were given to each rabbit over 2 to 3 hours by intravenous infusion. Five eyes served as control. The rate of clearance of hemorrhage was compared in the two groups. Average day of clearance was 14 days for the treated group, and 20.2 for the untreated control group. In this study, TPA given intravenously appears to accelerate the clearance of suprachoroidal hemorrhage.

Calcein angiography: a preliminary report on an experimental dye

Calcein is a new experimental dye for fundus angiography. Injected intravenously, calcein shares most of the characteristics of sodium fluorescein, but it also has some advantages over fluorescein because it lasts longer in the circulatory system. Calcein may be useful in experimental and clinical angiography of the fundus. This study gives the results of angiograms taken with a standard fundus camera after calcein injection.

Measurement of retinal blood velocity and flow rate in primates using a liposome-dye system

A recently developed liposome-dye method was used to make quantitative measurements of blood velocity and volumetric flow rates in the retina of the rhesus monkey. After systemic injection of a liposome-encapsulated fluorescent dye (calcein), the release of a bolus of the dye in the retina was triggered by an ophthalmic argon laser. Initially, calcein was entrapped at a high concentration and the fluorescence of the dye in the lipid vesicle was quenched. After laser exposure, the liposomes released a bolus of dye at the laser exposure site in a specific vessel of the retina. The released dye formed a well-defined, fluorescent wavefront in the exposed artery or vein. By measuring the distance the dye traveled in the vein over a set time interval, it was possible to measure blood velocity in retinal vessels of various diameters, and to calculate volumetric flow rates in those vessels.

External limbal sclerostomy with contact Nd:YAG laser versus surgical knife

An ab externo limbal sclerostomy was made into the anterior chamber using either a contact neodymium: yittrium aluminum garnet (Nd:YAG) laser probe or a surgical superblade. 5-fluorouracil was injected subconjunctivally as an antiproliferative agent to prevent or decrease cell proliferation and scar formation. The contact Nd:YAG laser use was accompanied by minimal complications. The intraocular pressure was lowered for a longer period in the contact Nd:YAG group compared with the other (knife) group. External sclerostomy with an Nd:YAG laser may offer an alternative in the surgical management of recurrent or intractable glaucoma.

Repetitive, selective angiography of individual vessels of the retina

Recent experiments have shown the feasibility of using laser or microwave energy for the externally controlled release of both dyes and drugs from temperature-sensitive liposomes (lipid vesicles). In the present study, calcein, a fluorescent dye, was used to improve the in vivo capabilities of this controlled release system. In vitro studies showed that the encapsulation efficiency was improved when compared to carboxyfluorescein, the fluorescent dye used previously. The improved liposome and dye system was used to obtain repetitive, "selective angiograms" in isolated segments of the retina in rabbits and in a nonhuman primate (Macaca mulatta) over a period of up to 2 hours after a single liposome injection. Conventional fluorescein angiography of the primate retina one week after the end of the experiments showed no visible damage, even after more than 400 individual laser exposures.

Tissue plasminogen activator in the treatment of experimental retinal vein occlusion

The thrombolytic effect of recombinant tissue plasminogen activator was studied in 28 randomly selected rabbit eyes to lyse photochemically induced retinal vein occlusion. Occlusion was confirmed histologically and assessed by fluorescein angiography. Sixteen eyes were treated with recombinant tissue plasminogen activator given intravenously and 12 control eyes were given similar volumes of normal saline solution. Fluorescein angiography was performed before and at various intervals after treatment. Four hours after treatment, the retinal vein was patent in 16 eyes (100%) treated with recombinant tissue plasminogen activator, as opposed to one eye (8.3%) treated with normal saline. The results indicate that tissue plasminogen activator is effective in lysing experimentally induced retinal vein thrombi.