Complete long-term response to radiotherapy of gastric early-stage marginal zone lymphoma resistant to both anti-Helicobacter pylori antibiotics and chemotherapy.

BACKGROUND: The optimal approach to patients with gastric lymphoma of extranodal mucosa-associated lymphoid tissue (MALT) that resist to anti-Helicobacter pylori (HP) eradication therapy is still to be defined. PATIENTS AND METHODS: From January 1997 to December 2004, we observed 24 patients affected with newly diagnosed early-stage and HP-positive gastric lymphoma of the MALT type. Five of them resisted to oral anti-HP antibiotic regimens and to subsequent one (two patients) or two (three patients) chemotherapy regimens. Age ranged between 51 and 77 years (median 70); three were females. Translocation (11;18) was ascertained in one subject. They were admitted to local radiation therapy with a total dose of 30 Gy. RESULTS: All such resistant patients achieved complete remission after radiotherapy. No relapses were observed after 21, 45, 48, 52, and 67 months of uninterrupted follow-up. Early toxicity was very low and consisted of mild nausea. Late toxicity or secondary malignancy was not recorded so far. CONCLUSIONS: Radiotherapy proved to be effective and safe for early-stage HP-positive gastric extranodal lymphoma of MALT type that is resistant to anti-HP eradication antibiotics and to following chemotherapy. Radiotherapy might be suggested as principal salvage therapy after resistance to HP eradication, instead of chemotherapy.

Splenectomy and the increasing risk of secondary acute leukemia in Hodgkin's disease.

PURPOSE: Following irradiation alone, secondary acute nonlymphocytic leukemia (ANLL) is uncommon; following chemotherapy alone, the risk is increased, but not as much as when combined modality treatments are used. Because ANLL seems more likely to occur in splenectomized patients, attention is focused on an unexpected association between splenectomy and the risk of secondary leukemia. PATIENTS AND METHODS: The risk of ANLL was assessed in 503 patients with Hodgkin's disease (HD) homogeneously treated with combined modality therapy (mechlorethamine, vincristine, procarbazine, and prednisone [MOPP] plus radiotherapy). These patients were diagnosed from 1970 through 1984 and monitored until June 1991. RESULTS: ANLL was observed in one of 145 (0.69%) patients not splenectomized and in 21 of 358 (5.86%) splenectomized patients, demonstrating a significantly higher frequency of ANLL in the group of patients who underwent splenectomy. The group of patients who developed ANLL received a statistically greater number of MOPP courses than did the group not developing ANLL. ANLL was statistically more frequent in those patients who received more than four cycles of MOPP. Sex, symptoms, extent of radiotherapy, splenectomy, age, and number of MOPP courses were assessed for their impact on ANLL incidence by multivariate analysis. CONCLUSION: Cox's proportional hazards regression showed that splenectomy and, as previously described by others, the number of courses of MOPP are prognostic factors that increase the risk of secondary ANLL in HD patients treated with combined modality therapy. These data raise interesting questions regarding the possible role of the spleen in leukemia development.

Vinblastine, bleomycin, and methotrexate chemotherapy plus extended-field radiotherapy in early, favorably presenting, clinically staged Hodgkin's patients: the Gruppo Italiano per lo Studio dei Linfomi Experience.

PURPOSE: To ascertain whether vinblastine, bleomycin, and methotrexate (VBM) (CT) combined with extended-field radiotherapy (EF RT) is effective enough to spare laparotomy in early, favorably presenting Hodgkin's disease (HD) patients. PATIENTS AND METHODS: Fifty patients with clinical stage IA or IIA HD with favorable histology and no bulky masses entered a prospective multicenter study started in January 1988. The median follow-up time was 38 months. RESULTS: All patients achieved a complete remission (CR). Five relapsed after 3 to 40 months and underwent successful salvage therapy. The actuarial remission rate was 0.89% at 3 years and 0.82% at 5 years. Two patients died in CR: one of severe pulmonary toxicity, the other of a second neoplasia (adenocarcinoma of the lung), 2 and 43 months after the end of therapy, respectively. The hematologic toxicity recorded during VBM CT was mild on the whole. Major toxicity was represented by pulmonary side effects and neurologic symptoms. Multiple regression analysis demonstrated that pulmonary toxicity was significantly related only to the amount of RT delivered to the mediastinum and not to the relative dose of bleomycin, to the dose-intensities of the three drugs in the regimen, or to patient age or sex. The same statistical technique showed that the only clinical factor related to grade of neurotoxicity was vinblastine dosage. CONCLUSION: VBM CT combined with EF RT is an effective treatment for early, clinically staged, favorable HD patients. However, the toxicity of this combination suggests that certain modifications should be evaluated.

MOPP/EBV/CAD hybrid chemotherapy with or without limited radiotherapy in advanced or unfavorably presenting Hodgkin's disease: a report from the Italian Lymphoma Study Group.

PURPOSE: We explored the feasibility, toxicity, and preliminary results of a chemotherapy (CT) regimen, mechlorethamine, vincristine, procarbazine, and prednisone (MOPP)/epidoxirubicin, bleomycin, and vinblastine (EBV)/lomustine (CCNU), doxorubicin, and vindesine (CAD), derived through hybridization, shortening, and intensification of a corresponding 10-drug alternating combination CAD/MOPP/doxorubicin, bleomycin, and vinblastine (ABV), effective in treatment of advanced Hodgkin's disease (HD). PATIENTS AND METHODS: Hybridization involved all drugs except CCNU and mechlorethamine, which were administered in alternating cycles; the length of therapy was reduced from nine to six cycles. The average projected drug doses during the six cycles were increased by 42%, with an overall 1.54 dose-intensification; epidoxorubicin was substituted for doxorubicin at equivalent tumoricidal doses. Radiotherapy (RT) was optional and its indications were limited. RESULTS: Eighty assessable patients with previously untreated, advanced or unfavorably presenting HD were treated in nine cooperating institutions between 1988 and 1991. RT was delivered to 22 patients. Remissions were complete (CR) in 75 patients (93%), partial in three (4%), and null in two (3%). The median relative dose-intensity was 0.71 for the overall regimen. Three of five patients who failed to achieve CR, and two of the four who relapsed, received lower relative dose-intensive cycles. Nonhematologic toxicity was acceptable, but there was considerable hematologic toxicity. Fatal gastrointestinal bleeding was seen in one patient. CONCLUSION: Caution is advised due to the short median follow-up period. Nevertheless, in addition to the excellent response rate, (1) the results were reached through abbreviation, intensification, and hybridization of an existing alternating regimen; (2) RT had limited use in this program, which may have contributed to lowering the risk of second tumors; and (3) the results were obtained in a multicenter study (a condition that often impairs results from clinical trials).

Image-aided estimate of tumor burden in Hodgkin's disease: evidence of its primary prognostic importance.

PURPOSE: To explore a more direct method for evaluating tumor burden (TB) in Hodgkin's disease (HD) and to verify its prognostic importance. PATIENTS AND METHODS: The volume of TB at diagnosis was directly and retrospectively measured in 121 HD patients through images of the lesions recorded by computed tomographic (CT) scan of the thorax, abdomen, and pelvis for all deep sites of involvement and many superficial ones, and by ultrasonography (US) for the remaining superficial lesions. RESULTS: The TB, which was obtained from the sum of the volumes of all the lesions measured on CT scans and US and normalized to body-surface area (relative TB [rTB]), showed a median value of 102.6 cm(3)/m(2) (range, 2.2 to 582.8). At multivariate analysis for prognostic value, rTB was the parameter that statistically correlated best with time to treatment failure (P = 2.2 x 10(-6)), followed by erythrocyte sedimentation rate (ESR) (P =.0003), and serum fibrinogen (P =.0112). The prognostic discrimination allowed by rTB alone proved to be clearly superior to that obtained with the score of the International Prognostic Factor Project. The rTB was found to be correlated with many clinical staging parameters (bulky disease, number of involved lymph node regions, serum lactate dehydrogenase, ESR, hemoglobin, Karnofsky index), but its predictability from these variables was low (R(2) =.668). CONCLUSION: Relative TB is emerging as a strong prognostic factor in HD, more powerful than and largely independent of those hitherto known and used. Further studies are needed to confirm these results and exploit their clinical value, particularly the relationship among rTB, drug doses, and response.

ProMACE-cytaBOM versus MACOP-B in intermediate and high grade NHL. Preliminary results of a prospective randomized trial.

One hundred seventy-nine patients with intermediate or high-grade non-Hodgkin's lymphoma were randomized to receive either ProMACE-CytaBOM (P-C) or MACOP-B (M-B). At last follow-up 71 patients in the P-C arm and 78 in the M-B arm were assessable for response. Forty-one patients treated with P-C (58%) and 49 patients treated with M-B (63%) achieved a CR. Moreover 18 and 22 patients achieved PR with P-C and M-B, respectively. Twenty-five patients relapsed, 12 in the P-C arm and 13 in the M-B arm. Thirty-nine patients died, 32 from disease progression, 5 from treatment related causes, and 2 from other causes. No differences between the two treatment groups were observed as regard to relapse or death-rate. At 27 months the survival rate was of 71.9% for patients treated with P-C and 70.7% for those treated with M-B. At 2 years the RFD rate was 64% and 60% for patients in P-C and M-B arm, respectively. Patients treated with M-B experienced an high rate of methotrexate-related toxicity. ProMACE-CytaBOM and M-B seem provided with similar activity. However P-C seem less toxic and more manageable in an outpatient setting.

Changing clinical presentation of multiple myeloma.

We compared the presentation features of three series of patients with multiple myeloma diagnosed between 1960 and 1971 (Kyle R, Mayo Clin Proc, 1975, 50, 29, n = 869), 1972 and 1986 (Clinica Medica, University of Pavia, n = 345) and 1987 and 1990 (Cooperative Group for Study and Treatment of Multiple Myeloma, n = 341). In the most recently diagnosed patients, the percentage of those who had symptoms related to multiple myeloma (i.e. any of bone pain, systemic symptoms, disturbances related to hypercalcemia, neurological involvement and hyperviscosity) was reduced (90 vs. 86 vs. 66%) (P less than 0.001), while the percentage of asymptomatic patients diagnosed by chance was increased (not reported, and 14 vs. 34%). In the most recent series, a lower percentage of spontaneous bone pain (68 vs. 60 vs. 37%, P less than 0.001) paralleled a lower incidence of advanced bone disease (osteolyses and pathological fractures, 60 vs. 64 vs. 34%), and renal failure (serum creatinine greater than 1.2 mg/dl) was also less common (56 vs. 44 vs. 33%, P less than 0.01), at least partially due to a decreased incidence of both hypercalcemia (30 vs. 20 vs. 18%, P less than 0.001) and of hyperuricemia (serum uric acid greater than 7 mg/dl, 47 vs. 32 vs. 26%, P less than 0.01). Systemic symptoms (weakness, infections, fever or weight loss) were reported more seldom by recently diagnosed patients, due to a decreased frequency of anaemia (haemoglobin less than 12 g/dl), leukopenia and thrombocytopenia, as well as of the systemic effects of bone pain and of renal insufficiency. These data indicate that multiple myeloma is diagnosed earlier now than in the past, and this must be taken into account when comparing survival data in treated series.

Interaction between infrared radiation and vitreous substitutes.

OBJECTIVE: To characterize the interaction between midintrared radiation of cutting lasers used or proposed for vitreoretinal surgery and fluid vitreous substitutes commonly used in vitreoretinal surgery. METHODS: Optical transmittance of vitreous substitutes was measured with a double-beam spectrophotometer. Measurements were performed in a wide spectral range of infrared radiation, including the 2120-nm wavelength of the holmium-YAG laser and the water absorption peaks at 1440, 1930, and 2940 nm. RESULTS: The wavelengths considered have a penetration depth varying from 410 to 1 microns in Ringer's solution, balanced salt citrate-buffered solution, balanced salt bicarbonated-buffered solution, hyaluronate sodium, and hydroxypropyl methylcellulose ophthalmic solution, from 2000 to 13 mm in perfluorocarbon liquid, and from 52 to 2.5 mm in silicone and fluorosilicone oils. CONCLUSIONS: Midinfrared optical radiation exhibits dramatic differences of penetration depth in different vitreous substitutes. High-absorbing liquids should be used mainly with contact laser procedures and could provide a shield for remote structures. Low-absorption vitreous substitutes allow noncontact laser surgical procedures, but they also may cause direct optical damage to remote tissues. The knowledge of wavelength transmittance of vitreous substitutes is necessary to evaluate and optimize the efficacy and safety of cutting laser sources.

Peptichemio induction therapy in myelomatosis.

Fifteen patients with multiple myeloma, two of whom had plasma cell leukemia, were treated between May 1974 and December 1978. Peptichemio was administered intravenously at doses of 40-80 mg/48 h, courses including 4-17 administrations in association with moderate doses of prednisone (15-50 mg/day) and androstanes at high dosages (250 mg weekly). In two patients PTC was associated with vincristine (VCR) administered on the first day of the course. Eight patients were previously untreated, four had been resistant to melphalan (MPH) and/or cyclophosphamide (CTX), and three had been treated irregularly with one or both of these alkylating agents. The criteria of response to therapy are reported. Out of a total of 15 PTC courses administered we obtained 13 responses, eight complete and five partial; no response was achieved in the other two patients. In the four patients who were resistant to MPH and/or CTX we obtained three responses, which were maintained with the same alkylating agent to which they had been resistant previously. The time needed to obtain a response in 90% of the patients was 6 weeks. Peptichemio was shown to be effective in patients in an advanced stage of the disease, in patients with light-chain myeloma and in those with plasma cell leukemia. The association of VCR potentiated the antitumor effect, but also increased the myelotoxicity. The PTC treatment was well tolerated. It is suggested that PTC be used in induction treatment of myelomatosis and in patients resistant to traditional alkylating agents.

ProMECE-CytaBOM vs MACOP-B in advanced aggressive non-Hodgkin's lymphoma: long term results of a multicenter study of the Italian Lymphoma Study Group (GISL).

A randomized trial was designed in order to compare the efficacy and feasibility of ProMECE-CytaBOM (P-C) and MACOP-B (M-B) in patients with advanced, aggressive non Hodgkin's lymphoma (NHL). P-C and M-B were chosen due to their association with a very high complete remission rate when compared to other published protocols. The study was conducted on 210 patients with intermediate or high-grade NHL in stage I bulky, or stages II-IV, randomized to receive either 6 courses of P-C delivered every 28 days (106 patients), or 12 weeks of M-B chemotherapy (104 patients). In both regimens doxorubicin was replaced by a 20% higher dose of epidoxorubicin (i.e. 30 mg/m2 of the analog). At the end of induction therapy patients could receive additional radiotherapy to residual masses or to sites of previous bulky disease. The two groups of patients were compared for response rates, number and severity of therapy related side effects, overall survival, disease-free survival, and time to treatment failure. Sixty-five patients (62%) treated with P-C and 69 patients (67%) treated with M-B achieved a complete remission, with no significant differences between the two treatment arms (P = 0.13). The overall objective response rate (complete + partial remission) was 74% for patients treated with P-C, and 81% for patients treated with M-B, respectively. The 4-year relapse-free survival rate was 59% for P-C and 69% for M-B, respectively (P = 0.11).(ABSTRACT TRUNCATED AT 250 WORDS)

Photorefractive keratectomy for compound myopic astigmatism with an eye cup erodible mask delivery system.

BACKGROUND: The erodible mask is a new energy delivery system for the 193-nm argon fluoride excimer laser. It consists of a polymethyl-methacrylate button, whose profile is transferred by photoablation onto the corneal surface. We present the 6- and 12-month results of this technique in the correction of compound myopic astigmatism. METHODS: We performed the mask procedure on 21 eyes of 16 subjects (mean age, 30.7 years; range, 24 to 46) to correct combined myopia and astigmatism. Attempted myopic correction ranged between -1.50 diopters (D) and -10.00 D (mean, -7.07 D). Attempted astigmatic correction ranged between -1.50 D and -4.00 D (mean, -2.46 D). RESULTS: Mean procedure error was: sphere +0.74 D (range, -3.00/+5.00), cylinder -1.41 D (range, -3.50/0.00) at 1 month after surgery; sphere +0.18 D (range, -2.50/+ 3.50), cylinder -1.56 D (range, -4.00/0.00) at 6 months; and sphere -1.30 D (range, -3.00/0.00), cylinder was -1.25 D (range, -2.00/-0.50) at 12 months (10 eyes). During follow up, haze values were never higher than 1, except for one case of haze 2 that regressed to 0 during follow up. Postoperative uncorrected visual acuity improved in all eyes where emmetropia was envisaged; none of the eyes lost spectacle-corrected visual acuity lines 6 or 12 months after surgery. CONCLUSIONS: The erodible mask proved effective and fairly predictable mainly in the correction of the spherical component of refractive error, while the correction of astigmatism revealed greater unpredictability, with a constant trend to undercorrection.

Photorefractive keratectomy for hyperopia using an erodible disc and axicon lens: 2-year results.

BACKGROUND: This paper presents the results over a 2-year follow-up of the first human trial of photorefractive keratectomy (PRK) for correction of hyperopia using an erodible disc excimer laser delivery system (Summit) coupled to an axicon lens. METHODS: We treated 25 eyes of 21 patients for a mean correction of +3.38 +/- 0.97 D (range, +1.00 to +4.00 D). The hyperopic correction was made using an erodible disc inserted on the laser optical pathway; an axicon lens was then used to create a blend transition zone. Eyes were evaluated at 1, 3, 6, and 12 months after surgery. For a smaller series of 11 eyes, we also present 24-month results. RESULTS: Mean refractive error 1 month after treatment (25 eyes) was -2.35 +/- 1.55 D (range, +1.00 to -6.50 D). Eight eyes (32%) had a spectacle-corrected visual acuity loss greater than 1 line. Twelve months after treatment, mean spherical equivalent refraction was -0.47 +/- 0.80 D (range, +1.25 to -2.25 D). Nineteen eyes showed an improvement (range, 3 to 8 lines) in uncorrected distance visual acuity and 23 showed improvement in uncorrected vision at reading distance (1 to 7 lines). CONCLUSION: This technique proved effective in reducing hyperopia, but predictability must be demonstrated in a larger treatment group. Safety was confirmed by the absence of delayed reepithelialization and the absence of spectacle-corrected visual acuity loss greater than 1 line at 1 year after surgery.

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.

Keratometric index, videokeratography, and refractive surgery.

PURPOSE: To clarify the confusion resulting from the use of slightly different refractive indices in calculations related to optical modeling of the cornea for refractive surgery, corneal diagnostics, and cataract surgery. SETTING: Scientific Institute H.S. Raffaele, Milan, Italy. METHODS: The cornea is represented as a centered optical system composed by 1, 2, or 3 spherical interfaces, in progression of modeling accuracy. Optical analysis is performed with the usual formulas of paraxial geometrical optics as well as with ray tracing. Simple models are also provided for corneas having both incisional and photoablative refractive surgery. Values of geometrical parameters are taken from the Gullstrand eye model. RESULTS: Using the keratometric index of refraction of 1.3375 is validated for estimating optical power differences on untreated corneas or after incisional keratotomy. It is not as accurate in assigning absolute values of dioptric power, where the value 1.3315 is more appropriate. For photorefractive keratectomy (PRK), however, the proper stromal index of refraction, 1.376, must be used for ablation calculations and dioptric change estimates. CONCLUSION: Videokeratographic instruments should include three distinct values of refraction index (1.3375, 1.376, and 1.3315) for an accurate and complete characterization of dioptric power maps. In cataract surgery, corrections must be introduced in the calculation of intraocular lens power for patients who have previously had PRK.

Effects of thymostimulin with combination chemotherapy in patients with aggressive non-Hodgkin's lymphoma. A report from the Italian Lymphoma Study Group (GISL).

The purpose of this study was to test the efficacy and safety of thymostimulin (TS) administered in addition to conventional chemotherapy in patients with intermediate- and high-grade non-Hodgkin's lymphoma (IG, HG-NHL). A total of 150 patients with newly diagnosed IG- or HG-NHL were entered in a multicenter trial to compare the effectiveness of two different third-generation regimens (MACOP-B versus ProMACE-CytaBOM) and were randomized to receive chemotherapy (CT) alone or CT + TS. In both regimens doxorubicin was replaced by a 20% higher dose of epidoxorubicin. TS was administered i.m. at a dose of 1 mg/kg daily on days 22-28 of each drug course to patients treated with ProMACE-CytaBOM, and on days 22-29, 50-57, and 77-85 to patients treated with MACOP-B. There were 134 fully evaluable patients: 68 treated with CT alone and 66 treated with CT + TS. Patients treated with CT + TS had a higher complete remission (CR) rate compared to patients given CT alone (59.1% vs 42.4%; P = .05). CR were significantly higher for patients treated with CT + TS in the groups with IG-NHL (P = .01), in those aged less than 60 years (P = .05), with good performance status (P = .05), and normal hemoglobin levels (P = .05). Four-year survival rates are 64.5% for patients treated with CT + TS and 43.0% for those treated with CT alone (P = .30). No difference between the two treatment arms have been observed as regards drug-related toxicity and the number and severity of infectious episodes. The use of TS during the 7 days before chemotherapy has been associated with a significantly superior CR rate. The advantage of CT + TS was mostly obtained in patients with IG-NHL, and those with good performance status or normal hemoglobin levels. In these patients TS may have potentiated the host reactions against the tumor, leading to an increase in NK activity and the production of cytokines. This postulated increase in the effectiveness of chemotherapy after TS might also explain the absence of the expected myeloprotective action.

Reed-Sternberg cell leukaemia.

A case of Reed-Sternberg (R-S) leukaemia is described, and the results of the morphological, cytochemical and cytokinetic studies on the circulating neoplastic cells are reported. Detailed data are given for each of the 3 types of abnormal circulating cells: abnormal mononuclear (AM) cells, Hodgkin's (H) cells and R-S cells. Our results cannot discriminate whether R-S cells derive from monocyte-macrophages or from B-cell lineage. However, some data suggest that H and R-S cells may likely originate from AM cells. The unfavourable clinical significance of the appearance of circulating R-S cells is discussed taking into account the other few cases reported in literature.

Tonsillectomy: a prognostic factor in Hodgkin's disease?

The clinical features and course of Hodgkin's disease (HD) were investigated in 160 previously tonsillectomized patients and compared with 375 nontonsillectomized ones. In both groups, sex, social class, histologic type, stage and symptoms were almost identically distributed. Tonsillectomized patients showed a higher incidence of initial cervical forms (p less than 0.05) and more frequently developed the disease under 35 years of age (p less than 0.001), thus also reflecting the different policies of the otolaryngologists in the past few decades. Moreover, the tonsillectomized patients enjoyed a significantly better survival (p approximately equal to 0.01) than the nontonsillectomized ones. Adjusted survival curves for age and site of initial involvement proved that the favorable prognostic value of tonsillectomy was not due to the altered distribution of these 2 factors in the 2 groups; in addition, an earlier diagnosis in tonsillectomized patients could be excluded. The favorable effect of tonsillectomy in HD patients might be related specifically to the reduced portion of immunologically reacting oropharyngeal lymphoid tissue remaining after tonsillectomy. A decreased output of the specific immune-complexes, which are responsible for the disease, according to Vianna's theory, might be hypothesized in tonsillectomized patients.

Compound myopic astigmatism correction using a mask in-the-rail excimer laser delivery system. Preliminary results.

PURPOSE: The latest development in the erodible mask technology is an excimer laser containing the mask in the laser optical pathway. This paper reports the results of the first human series of consecutive treatments performed for the correction of compound myopic astigmatism. METHODS: We have treated 83 eyes. Spherical equivalent attempted correction ranged between -1.75 and -11.75 D (mean -7.07+/- 2.45 D), astigmatic attempted correction ranged between -1.00 and -5.00 D (mean -2.42+/- 1.02 D). The sphere correction was made by diaphragm using a multi-zone software with three ablation zones: 100% of the total attempted correction for the central 5.0 mm zone, 70% for the second 6.0 mm zone, 30% for the outer 6.5 mm zone. Cylinder correction was made sequentially after myopic correction using the appropriate mask. RESULTS: One month after treatment, mean refractive error was + 1.07 +/- 1.24 D (range + 4.50/-1.75 D) for spherical equivalent, and -0.49 +/- 0.57 D (range + 0.75/-2.00 D) for astigmatism. Forty-eight eyes (57.8%) had uncorrected visual acuity of 20/40 or better. At six months, mean refractive error was +0.42 +/- 0.97 D (range + 3.75/-1.00 D) for spherical equivalent, and -0.44 +/- 0.51 D (range +0.25/-3.00 D) for astigmatism. Vector analysis showed that 57 eyes (68.7%) had 5 or less degrees rotation. Seventy-two (86.7%) and 54 eyes (65.1%) had uncorrected visual acuity equal or better than 20/40 and 20/25 respectively. One eye (1.2%) showed a best corrected visual acuity loss of more than one line, but 8 eyes (9.6%) had a gain of more than one line. One-year results on a smaller series (33 eyes) overlap with the six-month results. CONCLUSIONS: The mask in-the-rail excimer laser delivery system appears to be effective and predictable in the correction of compound myopic astigmatism. We observed no significant regression of the astigmatic correction over time. Longer follow-up on larger series is necessary to draw final conclusions.

Acoustic transients following excimer laser ablation of the cornea.

Pressure transients occurring inside the eyeball as a consequence of excimer laser ablation of the cornea were measured at various distances along the optical axis, on enucleated porcine eyes. Positive (compressive) pressure spikes up to 90 bars were observed, lasting 100 ns, and developing, as they propagated in the eyeball, satellite rarefaction pulses with negative pressure as high as -40 bar. Such rarefaction wavefronts can trigger the formation of cavitation bubbles, in both the anterior and posterior chamber, depending on the ablation geometry. The potential risks associated with these photoacoustic phenomena, particularly for retina and corneal endothelium, are outlined.

Hyperopia correction using an erodible mask excimer laser delivery system coupled to an axicon: preliminary results.

PURPOSE: This paper presents the results of the first human trial on the correction of hyperopia using an erodible mask excimer laser delivery system coupled to an axicon. METHODS: We treated 17 eyes of 17 patients (age range 34-62 years) for the correction of +3.21 +/- 1.04 D (range +1.00 to +4.00 D). The hyperopic correction was made using an erodible mask inserted on the laser optical pathway, to produce a circular ablation measuring 6.5 mm in diameter. An axicon was then used to create a blend transition zone from 6.5 mm up to 9.4 mm in diameter. Eyes were evaluated at one, three and six months after surgery. RESULTS: Reepithelization was always observed by the fifth postoperative day, despite the large area of deepithelization (diameter 9.5 mm). Mean refractive error one month after treatment was -2.44 +/- 1.59 D (range 0.00 to -6.50 D). Five eyes (29.4%) had a best corrected visual acuity loss more than two to three lines; all eyes showed mild annular haze not involving the central part of the cornea. Six months after treatment, mean refractive error was -0.88 +/- 0.99 D (range +0.50 to -3.00 D). Compared to preoperative status, 13 eyes (76.5%) showed an improvement in uncorrected distance visual acuity (1-8 lines), and 14 eyes (82.4%) showed an improvement in uncorrected vision at reading distance (3-7 lines). Two eyes (11.7%) showed a best corrected visual acuity loss of two of three lines. CONCLUSIONS: These preliminary results indicate this approach is effective in reducing hyperopia, while its predictability has still to be proved in a larger treatment group with longer follow-up. A cautious approach to this technique is still advisable, especially for higher hyperopic corrections, in view of the large best corrected visual acuity loss seen in two eyes at six months.