Clinical impact of high platelet reactivity in patients with atrial fibrillation and concomitant percutaneous coronary intervention on dual or triple antithrombotic therapy.

High platelet reactivity (HPR) on clopidogrel is an established thrombotic risk factor after percutaneous coronary intervention (PCI). The introduction of more potent antiplatelet drugs has partially surpassed this issue. However, in the setting of concomitant atrial fibrillation (AF) and PCI clopidogrel is still the most adopted P2Y12 inhibitor. In the present study all consecutive patients with history of AF discharged from our cardiology ward with dual (DAT) or triple (TAT) antithrombotic therapy after a PCI from April 2018 to March 2021 were enrolled in an observational registry. For all subjects, blood serum samples were collected and tested for platelet reactivity by arachidonic acid and ADP (VerifyNow system) and genotyping of the CYP2C19*2 loss-of-function polymorphism. We recorded at 3 and 12-months follow-up: (1) major adverse cardiac and cerebrovascular events (MACCE), (2) major hemorrhagic or clinically relevant non-major bleeding and (3) all-cause mortality. A total of 147 patients were included (91, 62% on TAT). In 93.4% of patients, clopidogrel was chosen as P2Y12 inhibitor. P2Y12 dependent HPR resulted an independent predictor of MACCE both at 3 and 12 months (HR 2.93, 95% C.I. 1.03 to 7.56, p = 0.027 and HR 1.67, 95% C.I. 1.20 to 2.34, p = 0.003, respectively). At 3-months follow-up the presence of CYP2C19*2 polymorphism was independently associated with MACCE (HR 5.21, 95% C.I. 1.03 to 26.28, p = 0.045). In conclusion, in a real-world unselected population on TAT or DAT, the entity of platelet inhibition on P2Y12 inhibitor is a potent predictor of thrombotic risk, suggesting the clinical utility of this laboratory evaluation for a tailored antithrombotic therapy in this high-risk clinical scenario. The present analysis was performed in patients with AF undergoing PCI on dual or triple antithrombotic therapy. At 1 year follow-up MACCE incidence was consistent, and it was not different in different antithrombotic pattern groups. P2Y12 dependent HPR was a potent independent predictor of MACCE both at 3- and 12-months follow-up. In the first 3 months after stenting the carriage of CYP2C19*2 allele was similarly associated with MACCE. Abbreviation: DAT, dual antithrombotic therapy; HPR, high platelet reactivity; MACCE, major adverse cardiac and cerebrovascular events; PRU, P2Y12 reactive unit; TAT, triple antithrombotic therapy. Created with BioRender.com.

Prevalence and in-hospital outcome of patients with sepsis in an internal medicine ward.

OBJECTIVES: Sepsis is a "life-threatening organ dysfunction caused by a dysregulated host response to infection", which is identified by a >2 point increase from patient baseline in the Sequential Organ Failure Assessment score (SOFAs). The prevalence and outcome of patients with sepsis has been mainly assessed in ICU patients, while few data are available for patients admitted to internal medicine wards. Our purpose was to evaluate the prevalence and the clinical outcome of patients with sepsis in an internal medicine-ward. DESIGN: This is a single-center retrospective observational study evaluating all patients admitted over a 2-month period (October and Novembre 2015) in the internal medicine ward of the San Giovanni di Dio Hospital in Florence. Patients with clinical and/or instrumental signs of bacterial infection were evaluated with SOFAs and divided into patients with and without sepsis. RESULTS: 635 patients were evaluated, and 279 of them (43.9%) were diagnosed with a bacterial infection. The diagnosis of sepsis was made in 93 patients (14.6%). In-hospital mortality and transfer to ICU were observed in 16% of patients with sepsis and in 2.5% of patients without sepsis (p<0.0001). A SOFAs value <2 had a negative predic-tive value of 97.5%, and increasing values of SOFAs were associated with a worse prognosis. CONCLUSIONS: The results suggest that: a) a high proportion of patients hospitalized in an internal medicine ward are affected by sepsis; b) these patients are burdened with high in-hospital mortality or transfer to ICU; c) SOFA score has a high prognostic power.

Fever, abdominal pain, and lymphocytic ascites in a young immigrant from western Africa.

Tuberculous peritonitis is an uncommon disease in countries with low tuberculosis (TB) incidence, most often affecting non-white race, foreign-born individuals. We describe a case of TB with peritoneal involvement in a 32-year-old man immigrated to Italy from Burkina Faso, who presented with a history of fever, malaise, abdominal pain and abdominal swelling. Due to its nonspecific clinical presentation and paucibacillary nature, diagnosis of tuberculous peritonitis can be challenging, and requires a high index of suspicion. This report highlights the diagnostic challenges posed by tuberculous peritonitis and emphasizes the importance of imaging (computed tomography, CT) in identifying typical findings, and the value of histological examination of tissue specimens from peritoneum or any site of suspected TB as a tool for diagnosis confirmation.

Triple therapy at discharge from internal medicine wards in heart failure patients with reduced ejection fraction: results from an observational study.

BACKGROUND: Guidelines recommend triple therapy (TT) with ACE inhibitors or ARBs, beta-blockers and mineralcorticoid receptor antagonists in symptomatic heart failure patients with ejection fraction <35 % (HFrEF). Nevertheless, many patients remain untreated. This study was aimed to evaluate the use of TT in HFrEF patients discharged from internal medicine wards of Tuscany, Italy. METHODS AND RESULTS: We analyzed the database of a multicenter observational study which included 770 patients consecutively hospitalized for HF in 32out of 36 Internal Medicine Units of Tuscany, Italy. The value of ejection fraction was available in 490 of the 725 patients discharged alive. Of the 117 patients with HFrEF, only 46 (39.3%) were on TT at discharge while 71 (60.7%) were not. In the latter group we observed a significantly greater percentage of patients with cognitive deficit (25.3% vs 10.8%, p=0.05). In the same group there was a slightly greater percentage of patients with hypertension (61.9% vs 58.6%), diabetes (43.6% vs 36.9%), GFR<60 ml/min (74.6% vs 67.3%), anemia (52.1% vs 45.6%) and atrial fibrillation (40.8% vs 34.7%), but the differences were not statistically significant. CONSLUSIONS: These results indicate that TT is underutilized in internal medicine wards of Tuscany. Untreated patients had a greater rate of cognitive deficit and were probably sicker, more complex and fragile.

Stratification in binary colloidal polymer films: experiment and simulations.

When films are deposited from mixtures of colloidal particles of two different sizes, a diverse range of functional structures can result. One structure of particular interest is a stratified film in which the top surface layer has a composition different than in the interior. Here, we explore the conditions under which a stratified layer of small particles develops spontaneously in a colloidal film that is cast from a binary mixture of small and large polymer particles that are suspended in water. A recent model, which considers the cross-interaction between the large and small particles (Zhou et al., Phys. Rev. Lett., 2017, 118, 108002), predicts that stratification will develop from dilute binary mixtures when the particle size ratio (α), initial volume fraction of small particles (ϕS), and Péclet number are high. In experiments and Langevin dynamics simulations, we systematically vary α and ϕS in both dilute and concentrated suspensions. We find that stratified films develop when ϕS is increased, which is in agreement with the model. In dilute suspensions, there is reasonable agreement between the experiments and the Zhou et al. MODEL: In concentrated suspensions, stratification occurs in experiments only for the higher size ratio α = 7. Simulations using a high Péclet number, additionally find stratification with α = 2, when ϕS is high enough. Our results provide a quantitative understanding of the conditions under which stratified colloidal films assemble. Our research has relevance for the design of coatings with targeted optical and mechanical properties at their surface.

Externally Oriented Thinking Predicts Phosphorus Levels in Dialyzed Patients.

BACKGROUND: The aim of the present study was to investigate the association between alexithymia scores and biological markers of adherence in dialyzed patients. The hypothesis was that higher scores of alexithymia would be associated with lower adherence to treatment. METHODS: Fifty-four adult dialyzed patients were enrolled during a follow-up visit. Participants were asked to complete a self-report questionnaire, namely, the Toronto Alexithymia Scale (TAS-20). Moreover, biological markers levels of adherence to treatment (phosphorus, creatinine, and serum uric acid) were measured. RESULTS: A positive correlation was found between phosphorous levels and TAS-F2 (r = 0.28; P = .04) and TAS-F3 (r = -0.31; P = .02). Stepwise regression with TAS-F2 and TAS-F3 as predictors of adherence to treatment showed a significant model, adjusted R(2) = 0.08, F(1,52) = 5.4; P < .02, where only TAS-F3 was able to predict phosphorous levels (P = .02). CONCLUSIONS: Findings showed that external oriented thinking was able to predict a biological marker of adherence to treatment in dialyzed patients.

Hard-sphere crystallization gets rarer with increasing dimension.

We recently found that crystallization of monodisperse hard spheres from the bulk fluid faces a much higher free-energy barrier in four than in three dimensions at equivalent supersaturation, due to the increased geometrical frustration between the simplex-based fluid order and the crystal [J. A. van Meel, D. Frenkel, and P. Charbonneau, Phys. Rev. E 79, 030201(R) (2009)]. Here, we analyze the microscopic contributions to the fluid-crystal interfacial free energy to understand how the barrier to crystallization changes with dimension. We find the barrier to grow with dimension and we identify the role of polydispersity in preventing crystal formation. The increased fluid stability allows us to study the jamming behavior in four, five, and six dimensions and to compare our observations with two recent theories [C. Song, P. Wang, and H. A. Makse, Nature (London) 453, 629 (2008); G. Parisi and F. Zamponi, Rev. Mod. Phys. (to be published)].

A comparison of efficiency of manual and automatic fibres search with the Maxcan fibre finder.

The aim of this work was to study the efficiency of automatic fibre searching with the Maxcan fibre finder (Cox Analytical Systems, Sweden) in comparison to manual searching. The influence of some parameters (color, thickness, background noise) on the results of a fibre search was considered. Eighteen experimental tapes with different target fibres and different background noises were prepared in the laboratory. Searching of fibres was performed manually and with the Maxcan fibre finder by different operators from four European laboratories. Two laboratories have the Maxcan fibre finder system and the two instruments were used and compared in this study. The results show that searching with the Maxcan is generally as efficient as manual searching, except for very pale or very dark fibres. Note that the tapes used for these experiments were prepared in laboratory, and are not completely representative of the tape that could be obtained in real cases. To generalize the results obtained, further research on real case samples would be necessary.

[After the 2001 European Society of Cardiology Guidelines: is it possible to reduce the number of patients with syncope to be hospitalized?]. / Dopo le Linee Guida 2001 della Società Europea di Cardiologia: è possibile ridurre il numero di pazienti con sincope da ospedalizzare?

AIM: The aim of this paper was to evaluate how many patients with syncope should be hospitalized according to the 2001 European Society of Cardiology (ESC) Guidelines on the management of syncope. METHODS: Starting from August 2002 we prompted a Syncope Unit (SU), as a multi-disciplinary functional structure including the Emergency Department. One of the main objectives of the SU was the implementation of the 2001 ESC Guidelines on Syncope and of the relevant criteria for hospitalization. All the clinical data concerning the patients presenting with syncope were prospectively collected and stored in a dedicated database. RESULTS: Between September 1, 2002 and April 30, 2003, 402 patients were observed for a syncope. Out of these, 19 had a cardiogenic syncope, 3 focal neurologic disorders, 25 a severe trauma, 4 severe orthostatic hypotension and 5 carotid syncope. Therefore, 56 patients out of 402 were found to have indication to therapeutical hospitalization. Among the remaining 346 patients, 83 patients were found to have a structural heart disease and/or an abnormal ECG, 1 had syncope during exercise, 3 presented a familial history of sudden death. Thirty-three were found to have severe comorbidities and further 14 had occasional indication to hospitalization. Thus, 190 out of the 402 patients with syncope (47.3%) presented at least 1 criterion for hospitalization according to the ESC Guidelines. CONCLUSION: The implementation of the ESC Guidelines on Syncope is technically feasible. Nevertheless, even when the Guidelines are strictly observed, a high percentage of patients with syncope has still to be hospitalized. Our data suggest that new criteria should be established for a safe Emergency Department discharge of the patients with syncope, particularly of those with structural heart disease or abnormal ECG.

[Chlamydia pneumoniae and atherosclerosis]. / Chlamydia pneumoniae ed aterosclerosi.

There is widespread consensus that atherosclerosis is an inflammatory disease. Between possible pathogenetic mechanisms, infective hypothesis has received increasing attention. Researches have recently focused their attention on the role of Chlamydia pneumoniae, a gram-negative intracellular organism, as infection by this bacterium has been demonstrated frequently associated with atherosclerosis. This review attempts to analyze and critically evaluate available data of the literature about the association between Chlamydia pneumoniae and atherosclerosis in order to provide updated elements of judgement concerning a possible future revolutionary scenario: the consideration of atherosclerosis as an infective disease, susceptible to prevention and treatment by means of antimicrobial therapy. More than twenty sero-epidemiological studies have found a two-fold or greater risk of cardiovascular events in subjects with serological evidence of Chlamydia pneumoniae infection. The organism has been identified in over 50% of atherosclerotic plaques examined by various histopathological techniques, while it has been only rarely found in normal artery tissues; moreover, viable Chlamydia pneumoniae has recently been isolated from coronary and carotid atherosclerotic plaques. Several experimental studies have shown that the biological properties of Chlamydia pneumoniae can explain its potential role in initiating and/or modulating plaque formation. The most relevant issue, i.e. the possibility of preventing or slowing progression of the disease with antimicrobial treatment, is still unsolved: only data from experimental studies on animals and four small intervention trials on humans are available, and their encouraging results require confirmation in larger prospective studies. In conclusion, while the association between Chlamydia pneumoniae and atherosclerosis seems to be established, it is still uncertain whether or not the organism plays a causal role in atherosclerosis and its complications. It is hoped that the results of wide scale clinical intervention trials with antibiotics for the secondary prevention of atherosclerotic diseases now in progress will clarify this problem.

Opioid blockade effect on insulin beta-cells secretory patterns in polycystic ovary syndrome. Oral glucose load versus intravenous glucagon bolus.

In order to evaluate the involvement of endogenous opiates in the insulin disorders of polycystic ovary syndrome (PCOs) a total of 25 PCOs women and 11 normo-ovulatory controls were studied by comparing the effect of a chronic opioid blockade on beta-cells responsiveness to oral glucose load and to intravenous glucagon bolus. Each patient, studied on follicular phase, underwent to oral glucose tolerance test (OGTT), and, 2 days later, to a glucagon intravenous bolus (1 mg); these tests were then repeated after 6 weeks of naltrexone treatment (50 mg orally). Naltrexone treatment did not modify the insulin secretory patterns of control subjects, whereas the same therapy significantly reduced, in hyperinsulinemic PCOs women, the beta-cell hyperresponsiveness both to oral glucose load and to intravenous glucagon (p < 0.05 and p < 0.01, respectively), even if with different mean percent decrease (32% OGTT vs. 45% glucagon, p < 0.05). Moreover, normoinsulinemic PCOs patients showed a slight, but not significantly increase in the beta-cells response to OGTT after opioid blockade, whereas, in the same situation, the insulin release after glucagon bolus was significantly reduced (p < 0.01). Chronic opioid blockade did not modify gonadotropins, steroids and SHBG levels in either group. Our data show that naltrexone treatment is able to reduce the beta-cell response to a direct intravenous secretagogue stimulus in all PCOs patients, while only in hyperinsulinemic PCOs subjects the same treatment is effective in reducing the exaggerated insulin secretion after oral glucose load. The reason for such a discrepancy could be ascribed to a different effect of opioids on first- and second-phase insulin secretion, or, alternatively, to an involvement of other secretagogue factors, such as glucoincretins.

Cardiac autonomic function and sensitivity to pain in postmenopausal women with angina and normal coronary arteries.

An increased sensitivity to painful stimuli and an abnormal cardiac autonomic function have previously been reported in patients with angina and angiographically normal coronary arteries, a syndrome that mainly affects postmenopausal women. In this study we compared both general sensitivity to pain, by evaluating time to forearm ischemic pain (FIP) provoked by sphygmomanometer cuff inflation, and cardiac autonomic function, by measuring heart rate variability (HRV), and QT and QT(c) intervals on 24-hour Holter recordings, in 25 postmenopausal women with angina and normal coronary arteries and in 22 healthy postmenopausal women. Compared with controls, patients had a reproducible strikingly lower time to FIP (149 +/- 121 vs 295 +/- 158 seconds, p <0.001), whereas there were no differences between the 2 groups in HRV variables and mean 24-hour QT and QT(c) intervals. HRV indexes, and QT and QT(c) intervals also showed similar circadian patterns. Thus, our data show that postmenopausal women with angina and normal coronary arteries have an enhanced sensitivity to systemic painful stimuli, but no detectable impairment in cardiac autonomic function compared with a well-matched control group of postmenopausal healthy women.

Growth hormone enhances estradiol production follicle-stimulating hormone-induced in the early stage of the follicular maturation.

OBJECTIVE: To investigate the ability of GH to increase the steroidogenic response of the ovary to FSH in the early stage of human follicle development in vivo. DESIGN: Ovarian sensitivity to FSH and/or GH during the early follicular phase of the human menstrual cycle was evaluated in a prospective study. SETTING: Normal human volunteers in the Department of Obstetrics and Gynecology, Università Cattolica Sacro Cuore. PATIENT(S): Twenty-four normal patients with normo-ovulatory cycles and tubal factor infertility. INTERVENTION(S): Pure urinary FSH (75 IU) or saline were injected IV in the early follicular phase with or without a pretreatment with human GH (0.1 IU/kg IM for 3 days). MAIN OUTCOME MEASURE(S): Plasma levels of LH, FSH, E2, and T in samples collected for a period of 26 hours after saline or FSH IV injection. RESULT(S): Follicle-stimulating hormone injection increased E2 and E2:T stimulated area under the curve (AUC) with respect to saline administration. Moreover, the E2 secretion was increased significantly in the group treated with GH plus FSH as compared with that found in the group receiving FSH alone. Growth hormone itself was unable to increase any steroidogenic response by ovary in terms of both E2 and E2:T AUC values. CONCLUSION(S): The results of present study demonstrate in vivo a synergistic effect of GH on the FSH-induced follicular steroidogenesis, suggesting a potential relevance of GH in the reproductive biology.

[Hypertension, hyperpotassemia and normal glomerular filtration (Gordon's syndrome): a case report]. / Ipertensione, iperpotassiemia e normale filtrato glomerulare (sindrome di Gordon): descrizione di un caso.

We describe a case of a 26 year old patient affected by a rare syndrome characterized by hyperkalemia, arterial hypertension and normal glomerular filtration rate (Gordon's syndrome), probably due to a renal tubular defect in the reabsorption of sodium or chloride. The patient, who had hyperkalemia since the age of 4 years, was referred to our Centre because of hypertension not well controlled with antihypertensive treatment. After drug therapy wash-out, we confirmed the existence of hypertension (180/100 mm Hg; ambulatory BP monitoring: 24-h mean BP = 151/91 mm Hg; 7 am-11 pm = 157/95; 11 pm-7 am: 133/82) and blood and urine tests showed hyperkalemia (6.6 mEq/L), hyperchloremia (115 mEq/L), mild metabolic acidosis (pH = 7.35, HCO3 = 19 mEq/L), low levels of plasma renin activity ( < 0.2 ng/ml/h), slight increase of plasma (1.08 nM/L) and daily urine aldosterone (129 nM) and normal serum creatinine (1.1 mg/dl) and glomerular filtration rate (91 ml/min). These data allowed to exclude the presence of renal failure and hyporeninemic hypoaldosteronism, which are the most common diseases with hypertension and hyperkalemia, and suggested the diagnosis of Gordon's syndrome. After 1 month of treatment with chlorthalidone (12.5 mg o.i.d) we observed the normalization of BP (130/80 mm Hg; ambulatory BP monitoring: 24-h BP: 132/76 mm), serum potassium (5,1 mEq/L) and the other blood and urine tests. These results were confirmed 6 months later and at present the patient has good clinical conditions.

Automatic centering of the microscope image for vitreoretinal surgery.

PURPOSE: The authors report on their device, the surgical image tracker, which provides automatic compensation for movements of the surgical image within the microscope field of view, during vitreoretinal procedures. METHODS: The authors developed a compact device acting as an automatic image tracker, based on video monitoring of the surgical image and translation of the operating microscope. Basic components are a standard color charge-coupled device camera and a specifically designed frame grabber for discrimination and tracking of the target image. Operation of the device is fully compatible with the usual pedal adjustments. RESULTS: Ready, fast, and correct automatic centering of the microscope field of view has been achieved successfully in all typical operating conditions. Video recording always is equally well centered. System operation also is effective with panoramic optics and diffuse illumination. CONCLUSION: The surgical image tracker appears to be a valuable tool to obtain well auto-centered surgical images, eliminating a bothersome task during vitreoretinal surgery.

[The use of ambulatory pressure monitoring for evaluating antihypertensive treatment in clinical practice]. / Impiego del monitoraggio pressorio ambulatoriale per la valutazione del trattamento antipertensivo nella pratica clinica.

OBJECTIVE: To describe the clinical experience of our Centre in the assessment of antihypertensive therapy with 24-hour ambulatory blood pressure monitoring (ABPM). DESIGN AND PATIENTS: We retrospectively studied all the 241 out-patients on antihypertensive therapy submitted to ABPM (SpaceLabs 90207, USA) between March 1992 and March 1993 for clinical purposes. We evaluated: 1) the clinical indications for the test; 2) the modifications of drug treatment suggested by the ABPM results; 3) the referring physicians' acceptance of these suggestions; 4) the changes of office BP measured before and 3-6 months after ABPM. RESULTS: 1) The indications for ABPM were: resistant or poorly controlled hypertension (n = 170-71%); suspected "white coat effect" (n = 51-21%); assessment of symptoms (n = 20-8%). 2) The analysis of ABPM suggested to modify drug treatment in 51% of the patients; a "white-coat effect" was found in 18% of the patients. 3) The ABPM suggestions about treatment were accepted by the referring physicians in 89% of the patients. 4) Office BP decreased from 163 +/- 18/99 +/- 9 mm Hg (before ABPM) to 151 +/- 13/91 +/- 7 (3-6 months after ABPM), (p < 0.001). CONCLUSIONS: The use of ABPM in our Centre, which is based on specific clinical indications, provided indications to modify the drug treatment in a high percentage of patients.

Effect of opioid blockade on insulin metabolism in polycystic ovarian disease.

A total of 17 women affected by polycystic ovarian disease (PCOD) were studied to evaluate the involvement of endogenous opioids in the pathophysiology of the hyperinsulinism in PCOD by administering naltrexone, an oral opioid antagonist. An oral glucose tolerance test (OGTT) was performed at baseline (on day 5 of the cycle) and repeated after 6 weeks of naltrexone administration. Plasma glucose, insulin and connecting peptide (c-peptide) concentrations were evaluated in all samples. Based on their insulinaemic response to OGTT, patients were classified as hyperinsulinaemic or normoinsulinaemic. Naltrexone treatment significantly (P < 0.007) reduced the insulin response to OGTT in the hyperinsulinaemic group without affecting the c-peptide incremental area; in the normoinsulinaemic group there was a slight, but not significant, increase in both c-peptide and insulin incremental areas. The two groups showed similar c-peptide incremental areas after naltrexone treatment. There was no significant difference in the c-peptide:insulin incremental areas molar ratio between the two groups; after treatment, a significant increase in this ratio was observed in both groups. When we considered the data as an expression of the fractional hepatic extraction of insulin, we found a lower value for hyperinsulinaemic in comparison with normoinsulinaemic patients (not significant), and a significant (P < 0.01) improvement of this parameter in the hyperinsulinaemic group after naltrexone administration. In conclusion, we suggest that the contribution to hyperinsulinaemia in PCOD patients may be at least in part due to both increased pancreatic secretion and reduced hepatic removal of insulin. Chronic pharmacological inhibition of opioid tone could improve the insulin plasma concentration by acting chiefly on the liver metabolism of insulin in hyperinsulinaemic patients.

Automatic eye tracker for excimer laser photorefractive keratectomy.

Acute overlapping of successive laser pulses onto the cornea during photorefractive keratectomy (PRK) is important to avoid refractive distortions. Most excimer laser systems performing corneal ablation lack control of the patient's eye movements and they cannot track the target corneal zone. We developed an eye-tracker based on television monitoring of the pupil and on automatic electro-mechanical deflection of the laser turning mirror, and we applied it to the ExciMed UV200 ArF work station (Summit Technology, Inc., Waltham, Mass.). Basic components are a black and white CCD camera and two fast stepping motors. The circuitry for target discrimination and tracking, and the optical imaging system are designed specifically. The tracker assembly does not interfere with the laser beam path nor with the operator's observation. Tracking of the pupil has been successfully achieved on different color irides, with an accuracy better than 0.1 mm in a 6 x 6 mm2 tracking field. Response time is less than 100 ms. Recordings of eye movements during PRK are presented. Tracking ablations have been performed on moving test eye-balls with plastic corneas. The proposed automatic system appears to be a reliable and effective method for the compensation of patient eye movements appears to be a reliable and effective method during PRK procedures.