Seizure onset patterns predict outcome after stereo-electroencephalography-guided laser amygdalohippocampotomy.

OBJECTIVE: Stereotactic laser amygdalohippocampotomy (SLAH) is an appealing option for patients with temporal lobe epilepsy, who often require intracranial monitoring to confirm mesial temporal seizure onset. However, given limited spatial sampling, it is possible that stereotactic electroencephalography (stereo-EEG) may miss seizure onset elsewhere. We hypothesized that stereo-EEG seizure onset patterns (SOPs) may differentiate between primary onset and secondary spread and predict postoperative seizure control. In this study, we characterized the 2-year outcomes of patients who underwent single-fiber SLAH after stereo-EEG and evaluated whether stereo-EEG SOPs predict postoperative seizure freedom. METHODS: This retrospective five-center study included patients with or without mesial temporal sclerosis (MTS) who underwent stereo-EEG followed by single-fiber SLAH between August 2014 and January 2022. Patients with causative hippocampal lesions apart from MTS or for whom the SLAH was considered palliative were excluded. An SOP catalogue was developed based on literature review. The dominant pattern for each patient was used for survival analysis. The primary outcome was 2-year Engel I classification or recurrent seizures before then, stratified by SOP category. RESULTS: Fifty-eight patients were included, with a mean follow-up duration of 39 ± 12 months after SLAH. Overall 1-, 2-, and 3-year Engel I seizure freedom probability was 54%, 36%, and 33%, respectively. Patients with SOPs, including low-voltage fast activity or low-frequency repetitive spiking, had a 46% 2-year seizure freedom probability, compared to 0% for patients with alpha or theta frequency repetitive spiking or theta or delta frequency rhythmic slowing (log-rank test, p = .00015). SIGNIFICANCE: Patients who underwent SLAH after stereo-EEG had a low probability of seizure freedom at 2 years, but SOPs successfully predicted seizure recurrence in a subset of patients. This study provides proof of concept that SOPs distinguish between hippocampal seizure onset and spread and supports using SOPs to improve selection of SLAH candidates.

Source localization of ictal SEEG to predict postoperative seizure outcome.

OBJECTIVE: Stereo-electroencephalography (SEEG) is inherently-three-dimensional and can be modeled using source localization. This study aimed to assess the validity of ictal SEEG source localization. METHODS: The dominant frequency at ictal onset was used for source localization in the time and frequency domains using rotating dipoles and current density maps. Validity was assessed by concordance with the epileptologist-defined seizure onset zone (conventional SOZ) and the surgical treatment volume (TV) of seizure-free versus non-seizure-free patients. RESULTS: Source localization was performed on 68 seizures from 27 patients. Median distance to nearest contact in the conventional SOZ was 7 (IQR 6-12) mm for time-domain dipoles. Current density predicted ictal activity with up to 86 % (60-87 %) accuracy. Distance from time-domain dipoles to the TV was smaller (P = 0.045) in seizure-free (2 [0-4] mm) versus non-seizure-free (12 [2-17] mm) patients, and predicted surgical outcome with 91 % sensitivity and 63 % specificity. Removing near-field data from contacts within the TV negated outcome prediction (P = 0.51). CONCLUSIONS: Source localization of SEEG accurately mapped ictal onset compared with conventional interpretation. Proximity of dipoles to the TV predicted seizure outcome when near-field recordings were analyzed. SIGNIFICANCE: Ictal SEEG source localization is useful in corroborating the epileptogenic zone, assuming near-field recordings are obtained.

SEEG in 3D: Interictal Source Localization From Intracerebral Recordings.

BACKGROUND: Stereo-electroencephalography (SEEG) uses a three-dimensional configuration of depth electrodes to localize epileptiform activity, but traditional analysis of SEEG is spatially restricted to the point locations of the electrode contacts. Interpolation of brain activity between contacts might allow for three-dimensional representation of epileptiform activity and avoid pitfalls of SEEG interpretation. OBJECTIVE: The goal of this study was to validate SEEG-based interictal source localization and assess the ability of this technique to monitor far-field activity in non-implanted brain regions. METHODS: Interictal epileptiform discharges were identified on SEEG in 26 patients who underwent resection, ablation, or disconnection of the suspected epileptogenic zone. Dipoles without (free) and with (scan) gray matter restriction, and current density (sLORETA and SWARM methods), were calculated using a finite element head model. Source localization results were compared to the conventional irritative zone (IZ) and the surgical treatment volumes (TV) of seizure-free vs. non-seizure-free patients. RESULTS: The median distance from dipole solutions to the nearest contact in the conventional IZ was 7 mm (interquartile range 4-15 mm for free dipoles and 4-14 mm for scan dipoles). The IZ modeled with SWARM predicted contacts within the conventional IZ with 83% (75-100%) sensitivity and 94% (88-100%) specificity. The proportion of current within the TV was greater in seizure-free patients (P = 0.04) and predicted surgical outcome with 45% sensitivity and 93% specificity. Dipole solutions and sLORETA results did not correlate with seizure outcome. Addition of scalp EEG led to more superficial modeled sources (P = 0.03) and negated the ability to predict seizure outcome (P = 0.23). Removal of near-field data from contacts within the TV resulted in smearing of the current distribution (P = 0.007) and precluded prediction of seizure freedom (P = 0.20). CONCLUSIONS: Source localization accurately represented interictal discharges from SEEG. The proportion of current within the TV distinguished between seizure-free and non-seizure-free patients when near-field recordings were obtained from the surgical target. The high prevalence of deep sources in this cohort likely obscured any benefit of concurrent scalp EEG. SEEG-based interictal source localization is useful in illustrating and corroborating the epileptogenic zone. Additional techniques are needed to localize far-field epileptiform activity from non-implanted brain regions.

Explantation of phakic intraocular lenses: causes and outcomes.

PURPOSE: To describe reasons for explantation of anterior and posterior chamber phakic intraocular lenses (pIOLs), as well as outcomes of the surgery. METHODS: The medical files of patients who underwent pIOL explantation due to complications were reviewed. All patients were divided into three groups based on the type of explanted pIOL: anterior chamber angle-supported (AS pIOL), anterior chamber iris-fixated (IF pIOL), and posterior chamber (PC pIOL). RESULTS: Sixty-two eyes of 41 patients were evaluated. There were 26 (41.9%), 16 (25.8%), and 20 (32.2%) eyes in the AS pIOL, IF pIOL, and PC pIOL groups, respectively. The mean interval between the implantation and removal of the pIOL (i.e., survival time) was 13.6 ± 8.1 years (range 0.01-21.22 years). The mean follow-up after the explantation was 22.5 ± 4.0 months (range 11.3-28.7 months). The main causes of explantation were cataract in the PC pIOL group (60%) and chronic endothelial cell loss in the AS pIOL group (53.8%) and IF pIOL group (56.2%). Overall, the procedure most often combined with pIOL explantation was phacoemulsification and implantation of a posterior chamber IOL (40.3%), followed by keratoplasty (9.6%). Intraoperative complications were significantly more common in the AS pIOL group than the other groups (p < 0.001). CONCLUSIONS: Explantation of anterior chamber pIOLs due to severe endothelial cell loss and the proportion of keratoplasty was more common in patients with a relatively long survival time. Therefore, patients with pIOL implantation should be monitored regularly after surgery.

Efficacy of novel albendazole salt formulations against secondary cystic echinococcosis in experimentally infected mice.

In this study, we evaluated the efficacy, expressed as a mean weight decrease of the whole echinococcal cyst mass, of novel benzimidazole salt formulations in a murine Echinococcus granulosus infection model. BALB/c mice were intraperitoneally infected with protoscoleces of E. granulosus (genotype G1). At 9 months post-infection, treatment with albendazole (ABZ), ricobendazole (RBZ) salt formulations, and RBZ enantiomer salts (R)-(+)-RBZ-Na and (S)-(-)-RBZ-Na formulations were initiated. Drugs were orally applied by gavage at 10 mg kg-1 body weight per day during 30 days. Experimental treatments with benzimidazole sodium salts resulted in a significant reduction of the weight of cysts compared to conventional ABZ treatment, except for the (S)-(-)-RBZ-Na enantiomer formulation. Scanning electron microscopy and histological inspection revealed that treatments impacted not only the structural integrity of the parasite tissue in the germinal layer, but also induced alterations in the laminated layer. Overall, these results demonstrate the improved efficacy of benzimidazole salt formulations compared to conventional ABZ treatment in experimental murine cystic echinococcosis.

The contribution of each anterior cruciate ligament bundle to the Lachman test: a cadaver investigation.

The clinical diagnosis of a partial tear of the anterior cruciate ligament (ACL) is still subject to debate. Little is known about the contribution of each ACL bundle during the Lachman test. We investigated this using six fresh-frozen cadaveric lower limbs. Screws were placed in the femora and tibiae as fixed landmarks for digitisation of the bone positions. The femur was secured horizontally in a clamp. A metal hook was screwed to the tibial tubercle and used to apply a load of 150 N directed anteroposteriorly to the tibia to simulate the Lachman test. The knees then received constant axial compression and 3D knee kinematic data were collected by digitising the screw head positions in 30° flexion under each test condition. Measurements of tibial translation and rotation were made, first with the ACL intact, then after sequential cutting of the ACL bundles, and finally after complete division of the ACL. Two-way analysis of variance analysis was performed. During the Lachman test, in all knees and in all test conditions, lateral tibial translation exceeded that on the medial side. With an intact ACL, both anterior and lateral tibial landmarks translated significantly more than those on the medial side (p < 0.001). With sequential division of the ACL bundles, selective cutting of the posterolateral bundle (PLB) did not increase translation of any landmark compared with when the ACL remained intact. Cutting the anteromedial bundle (AMB) resulted in an increased anterior translation of all landmarks. Compared to the intact ACL, when the ACL was fully transected a significant increase in anterior translation of all landmarks occurred (p < 0.001). However, anterior tibial translation was almost identical after AMB or complete ACL division. We found that the AMB confers its most significant contribution to tibial translation during the Lachman test, whereas the PLB has a negligible effect on anterior translation. Section of the PLB had a greater effect on increasing the internal rotation of the tibia than the AMB. However, its contribution of a mean of 2.8° amplitude remains low. The clinical relevance of our investigation suggests that, based on anterior tibial translation only, one cannot distinguish between a full ACL and an isolated AMB tear. Isolated PLB tears cannot be detected solely by the Lachman test, as this bundle probably contributes more resistance to the pivot shift.

Comparison of transperitoneal and retroperitoneal approaches in abdominal aortic surgery.

BACKGROUND: The transperitoneal approach (TP) to the aorta is the most widely accepted surgical approach in aortic surgery as it is simple, fast and provides excellent exposure of the intra-abdominal cavity and vascular structures. In recent years, there has been an increasing interest in the retroperitoneal (RP) approach to the aorta since it has been described as having a better outcome, i.e., preserving pulmonary function and gastro-intestinal physiology, reducing the intra-operative blood loss, minimising patient discomfort or pain, decreasing the incidence of wound complications and shortening ICU and hospital stay. The aim of this study is to compare the transperitoneal and retroperitoneal approaches in aortic surgery for aorto-iliac occlusive disease (AIOD). METHODS: From December 2003 to June 2006, a total of 153 consecutive patients who had undergone aortic surgery for AIOD, were studied retrospectively. The TP approach was used in 85 patients and the RP approach in 68 patients. Demographic features, intra-operative and postoperative data were analysed and compared according to the approach used. RESULTS: The mean operating time (83.6 +/- 23 vs. 104.4 +/- 30 min, p < 0.001) and mean aortic cross-clamp time (18.4 +/- 3 vs. 15.2 +/- 3 min, p < 0.0412) were significantly longer in the RP group. Peri-operative blood loss (700 +/- 350 vs. 650 +/- 330 ml, p < 0.683) and mortality rate < or = 30 day (1/1.2% vs. 0/0.0%, p < 0.896) were similar between the groups. The operative 30 day mortality rate was 0.7% (1 of 153) overall. The RP group had an earlier return of bowel functions (17.1 < or = 3 vs. 24.2 < or = 5 hrs, p < 0.001), earlier resumption of diet (26.4 < or = 4 vs. 31.4 < or = 5 hrs, p < 0.001), shorter period of intubation (3.5 < or = 2 vs. 6.5 < or = 3 hrs, p < 0.001), ICU stay (1.5 < or = 1 vs. 4.2 < or = 1 hrs, p < 0.001) and hospital stay (4.0 < or = 1 vs. 5.9 < or = 1 days, p < 0.001). Mean effort-pain scores were significantly lower in the RP group (3.8 < or = 1 vs. 5.3 < or = 1, p < 0.001). Incidence of pulmonary complications (4.4%, 3 of 68 vs. 7.3%, 8 of 85, p < 0.001), paralytic ileus (1.5%, 1 of 68 vs. 3.5%. 3 of 85, p < 0.001) were also lower in the RP group. Wound complications were more common in the TP group (4.7%, 4 of 85 vs. 10.3%, 7 of 86, p < 0.001). Most cases in both groups were related to incisional hernia or evisceration. CONCLUSION: This report presents our experience with the use of TP and RP approaches in a patient population merely consisting of AIOD. The RP approach was associated with a significantly lower incidence of postoperative pulmonary complications, rapid recovery of gastro-intestinal functions, shorter ICU and hospital stay, less peri-operative blood loss and lower mean effort-pain scores. We conclude that the RP approach is a safe and feasible technique that exposes patients to less postoperative complications.

Standard open repair versus minilaparotomy approach for abdominal aortic aneurysms: what is the best approach in patients with ischemic heart disease?

AIM: The beneficial effects of minilaparotomy approach in patients undergoing abdominal aortic aneurysm (AAA) repair have been defined. In this respect, the authors compared treatment outcome and procedure-related mortality rates of minilaparotomy technique with those of open standard repair in patients with ischemic heart disease. METHODS: The authors retrospectively reviewed data on 212 patients who underwent elective AAA repair via a minilaparotomy approach at the Hospital of Istanbul over an 8-year period from February 1995 to January 2003. The clinical study included 46 patients who have only ischemic heart disease as a sole risk factor. This group was matched in a case-control fashion to a group of 57 patients with similar characteristics who were operated via standard median laparotomy. All available clinical, pathologic and postoperative data were reviewed and analyzed for postoperative outcome. RESULTS: Mean operative times in mini- and standard laparotomy groups were 190+/-26 min and 165+/-15 min, respectively (P=0.32). Aortic clamping times did not differ significantly between two groups (61+/-12 min vs 53+/-10 min, P=0.43). Blood requirement was lower in minilaparotomy group. Five patients (8.7%) in the standard median laparatomy group died, while one death (2%) occurred in the other group (P<0.01). In patients who have undergone traditional repair, 5 patients suffered from myocardial infarction and 4 patients required prolonged mechanical ventilation. No coronary ischemic event was noticed in minilaparotomy patients. The minilaparotomy group had significantly shorter lengths of hospital (6.2+/-1.1 vs 9.3+/-2.8 days, P=0.03) and intensive care unit (ICU) stays (7.8+/-2.3 vs 14.5+/-3.2 hours, P=0.01). Duration of adynamic ileus (1.9+/-0.6 vs 2.8+/-1.1 days, P=0.02), return to normal diet (3.2+/-1.0 vs 4.6+/-1.3 days, P=0.01) and day of ambulation (1.5+/-0.3 vs 3.2+/-0.7 days, P=0.001) were significantly lower in the minilaparotomy group. The standard median laparotomy group was twice as costly as the minilaparotomy group (3 200+/-600 vs 5 900+/-900 US dollars, P=0.001). CONCLUSION: The minilaparotomy technique has advantages that include less postoperative morbidity and mortality rates, early resumption of intestinal functions, reduced cost, decreased length of stay in the ICU and hospital. There-fore, the authors believe that this approach is still a valid alternative approach in the treatment of patients with AAA having ischemic heart disease as a risk factor.

Epidural anaesthesia and mini-laparotomy for the treatment of abdominal aortic aneurysms in patients with severe chronic obstructive pulmonary disease.

PURPOSE: The purpose of this study is to compare the use of epidural and general anaesthesia techniques in the treatment of abdominal aortic aneurysms (AAA) through mini-laparotomy in patients with severe chronic obstructive pulmonary disease (COPD). METHODS: Between March 2002 and October 2005, 23 patients with severe COPD underwent elective infrarenal abdominal aortic aneurysm repair. Endovascular therapy could not be established due to financial reasons and health insurance policies. All the operations were performed through mini-laparotomy, using epidural anaesthesia on 10 patients (Group I) and general anaesthesia on the remaining patients (Group II). Pulmonary disease was diagnosed by clinical history and pulmonary function tests. The diagnosis of severe COPD was made with the presence of one or more of the following criteria : Room air PaO2 < or = 60 mmHg, PaCO2 > or = mmHg in arterial blood gas samples, FEV1 < or = 50% of predicted value and FVC < or = 75% of predicted value in respiratory function tests. RESULTS: There was no significant difference between the ages, sex, pre-operative morbidity status, operation time and total blood loss of the patients in the two groups. Postoperative intensive care unit requirement, postoperative pulmonary complications and hospital stay were significantly higher in group II. All patients tolerated surgery safely. There was one in-hospital mortality from group II on the 35th postoperative day due to prolonged entubation and sepsis related to pulmonary infections. There was no late morbidity or mortality related to the technique in the postoperative follow-up period of the discharged patients. CONCLUSION: Epidural anaesthesia for abdominal aortic aneurysm repair through mini-laparotomy is feasible and should be especially considered in patients with severe COPD where endovascular treatment could not be performed.

Surgery of the carotid artery: local anaesthesia versus general anaesthesia.

OBJECTIVE: Carotid artery surgery is safely and commonly performed under general, regional or local anaesthesia. The aim of the study was to compare local and general anaesthesia in carotid artery surgery in order to establish whether differences exist in terms of peri-operative results, use of intra-operative shunts and costs. METHODS: We retrospectively reviewed the data on 426 patients who underwent carotid endarterectomy with either local or general anaesthesia at our institution over a four-year period. All available clinical, pathologic and postoperative data were reviewed and analyzed for postoperative results. Surgical indications, outcome, operative techniques, and complications were compared. RESULTS: A total of 306 carotid endarterectomy operations under local, and 127 under general anaesthesia were performed and analyzed. Groups were similar in terms of age, sex and pre-operative risk factor distribution. The local anaesthesia group was associated with a lower incidence of shunt placement and operative time when compared to the general anaesthesia group. Postoperative intensive care unit requirement, hospital stay and costs were also lower with local anaesthesia. Significant difference in neurological complications and mortality rate was not observed between the two groups. CONCLUSION: Carotid endarterectomy performed under local or general anaesthesia is associated with low morbidity and mortality rates. Local anaesthesia enables the surgeon to assess the neurological status during the procedure. It is also associated with decreased shunt usage, decreased operative time and, in high risk patients, lower intensive care unit requirement and hospital stay.

A novel locus for autosomal recessive nonsyndromic hearing impairment, DFNB63, maps to chromosome 11q13.2-q13.4.

Hereditary hearing impairment is a genetically heterogeneous disorder. To date, 49 autosomal recessive nonsyndromic hearing impairment (ARNSHI) loci have been described, and there are more than 16 additional loci announced. In 25 of the known loci, causative genes have been identified. A genome scan and fine mapping revealed a novel locus for ARNSHI (DFNB63) on chromosome 11q13.2-q13.4 in a five-generation Turkish family (TR57). The homozygous linkage interval is flanked by the markers D11S1337 and D11S2371 and spans a 5.3-Mb interval. A maximum two-point log of odds score of 6.27 at a recombination fraction of theta = 0.0 was calculated for the marker D11S4139. DFNB63 represents the eighth ARNSHI locus mapped to chromosome 11, and about 3.33 Mb separate the DFNB63 region from MYO7A (DFNB2/DFNB11). Sequencing of coding regions and exon-intron boundaries of 13 candidate genes, namely SHANK2, CTTN, TPCN2, FGF3, FGF4, FGF19, FCHSD2, PHR1, TMEM16A, RAB6A, MYEOV, P2RY2 and KIAA0280, in genomic DNA from an affected individual of family TR57 revealed no disease-causing mutations.

[Aortoduodenal fistulae: about two cases]. / Fistule aortoduodénale: à propos de deux cas.

Aortoduodenal fistulae are an unusual complication of aortic pathology or surgery and a life-threatening entity. The results of surgical treatment may be disappointing because of postoperative complications. We report here two cases and discuss the diagnostic investigations and characteristics of aortoduodenal fistulae.

Effects of fibrovascular traction and pooling of tears on corneal topographic changes induced by pterygium.

AIM: To investigate the effects of fibrovascular traction and the pooling of tears at the pterygium apex on the corneal topographic changes induced by pterygium. METHODS: A total of 16 eyes of 14 cases with primary pterygium were included in the study. A computerized corneal topography system was used for corneal topography examinations. Baseline keratographs were taken two times at straight gaze. A repeat corneoscope photograph was immediately obtained in temporal gaze. Then the tears at the pterygium apex were dried with a cellulose sponge, and a new corneoscope photograph was immediately obtained without allowing one to blink. Corneal topographic maps (numeric maps) were divided into 301 fields in 24 meridians. One colour was allocated to each field, representing its mean refractive power for all groups. In all eyes, keratometric astigmatism at the 3 mm central cornea and total mean corneal refractive power were found. Data were compared using paired-samples two-tailed t-tests. RESULTS: Keratometric astigmatism at the 3 mm central cornea was significantly reduced at the temporal gaze (3.10+/-2.34 D, t=3.40, P=0.027) and dried eyes (2.12+/-1.01 D, t=4.74, P=0.001) according to the first baseline measurement (4.31+/-1.91 D) of the total mean corneal refractive power was found to be 43.45+/-1.28 D (39.29-45.87) at the first baseline measurement. There was no change at the temporal gaze (43.54+/-1.06 D, P>0.05). However, the total corneal refractive power was significantly higher in dried eyes (44.26+/-0.93 D, t=34.92, P<0.001). The steepest region of corneal topography was a superior quadrant, and the flattest area was a nasal quadrant at the baseline. At the temporal gaze, the cornea was significantly flatter in the superior and inferior sides of the pterygium meridian. After dried pooling of tears, topographic abnormalities returned, and the cornea became more uniform and symmetric. CONCLUSION: We conclude that the pooling of tears at the pterygium apex plays an important role, but fibrovascular traction has no effect on the corneal topographical changes induced by pterygium.

BCG vaccination to prevent implantation of endometriosis: an experimental study in rats.

To investigate whether BCG vaccination can prevent endometrial implantation in a rat model. Forty sexually mature virgin Wistar-Albino rats weighing 185-215g were randomly assigned (double-blind) to two groups. The first group (n=20) were injected with BCG 3 weeks before endometrial implantation to the eye. The second group (n=20) with BCG not injected before endometrial implantation was the control. Photobiomicroscopy observation was done weekly and 6 weeks post endometrial implantation all eyes were investigated histologically.Five implants grew in the anterior surface of the iris of the first (vaccinated) group and 17 in the second (control) group. The difference was statistically significant. Systemic prophylaxis with BCG can exert an inhibitory effect on endometrial transplantation.

The refractive changes and long-term (3 years) results of radial keratotomy performed at high altitude.

PURPOSE: To evaluate the development of regression or progression following radial keratotomy (RK) performed at high altitude (1,720 meters) at long-term follow-up (3 years). METHODS: Thirty-nine eyes of 21 myopia patients (between -3.25 D and -11.00 D) whose ages were 19-32 years were included in the study. The RK procedures were performed in standard Russian style. RESULTS: The average spherical equivalent cycloplegic refractions were -5.49 D +/- 2.08 (SD) preoperatively, -1.64 +/- 1.59 D in the short-term (3.41 +/- 1.46 months) and -1.40 +/- 1.71 D in the long-term (30.72 +/- 4.36 months) follow-up period. There was no statistically significant difference between these values at the short- and long-term follow-up measurements (t = -1.57, P =.12). CONCLUSIONS: The refractive changes following RK performed at high altitude occur through a combination of both the direct effect of reduced barometric pressure and the edematous corneal expansion because of hypoxia. An ophthalmologist performing RK surgery at high altitude must consider the long-lasting therapeutic effects of high altitude surgery compared to surgery at sea level.

The effect of pterygium surgery on corneal topography.

OBJECTIVE: The aim of this prospective randomized clinical study was to evaluate the effect of pterygium surgery on the corneal topography using a computerized corneal topography system. PATIENTS AND METHODS: Computerized corneal topography was performed on 27 patients with primary pterygium before and after pterygium excision surgery. The topographical changes that occurred following surgery were evaluated using paired and unpaired two-tailed t-test and Pearson coefficient of correlation analyses. Simulated keratometric astigmatism at the central 3 mm and the total mean refractive powers of the whole cornea were measured before and after surgery. Following surgery, flattened or steepened corneal areas were determined. RESULTS: Simulated keratometric astigmatism at 3 mm was found to be 2.30 +/- 2.08 D (0.2 - 7.63) preoperatively and 0.82 +/- 0.74 D (0.06 - 2.79) postoperatively. The difference between these two values was statistically significant (t = -3.46, P = 0.002). Total mean refractive power of the whole cornea was found to be 42.26 +/- 0.63 (40.80 - 43.64) preoperatively and 43.69 +/- 0.88 (41.50 - 44.90) postoperatively and the difference was 1.42 +/- 0.87. There was a statistically significant high difference (t = 28.36, P < 0.001). When preoperative and postoperative corneal topographies were compared, the whole cornea was found steeper at the postoperative period except a little region in the superior nasal quadrant. CONCLUSION: We believe that corneal topographical changes caused by the pterygium are almost reversible after surgical treatment, and postoperatively the cornea becomes steeper.

Primary aortoduodenal fistula complicated by abdominal aortic aneurysm.

A 74-year-old male patient was operated in Vakif Gureba Hospital for aortoduodenal fistula developing from abdominal aortic aneurysm. The patient was diagnosed as abdominal aortic aneurysm after physical examination and computed tomography in another center. Appearing of melena and hematemesis gastroduodenoscopy and radionuclide scanning was performed as diagnosis. After 6 days gastrointestinal bleeding recurred in massive haemorrhage and the patient was operated with a diagnosis of aortoenteric fistula as emergency. A midline laparotomy was performed. There was a fistula between infrarenal abdominal aortic aneurysm (with diameter 8x10 cm) and the 3rd portion of the duodenum. The duodenum was resected segmental and the fistula was disconnected. Following aneurysmotomy a prosthetic graft was placed in the aortobiiliac position. The patient was discharged at the 42nd postoperative day. Primary aortoenteric fistula is a very rare consequence of untreated abdominal aortic aneurysm. The segments of intestine most frequently involved in aortoenteric fistula are the 3rd and 4th portions of the duodenum. Clinical presentation is recurrent episodes of gross gastrointestinal haemorrhage. These cases have high mortality and morbidity unless evaluated as quickly as possible and appropriate surgical intervention performed.

Changes in anterior chamber depth and axial length measurements after radial keratotomy.

PURPOSE: To evaluate the changes that occur in anterior chamber depth and globe axial length after radial keratotomy (RK) surgery in cases with different degrees of myopia. METHODS: One hundred and twelve eyes that underwent RK were studied. The eyes were divided into two groups: 70 eyes with a correction of myopia of 4.00 D and under after RK (group 1) and 42 eyes with a correction of myopia of more than 4.00 D (group 2). Routine examinations were done in all cases. Ultrasonic biometry and central anterior chamber depth and axial length were measured pre-operatively and on the third day, second week, third month and sixth month post-operatively. RESULTS: Pre-operatively the average globe axial length was longer in group 2 than group 1. When all post-operative measurements were compared with pre-operative measurements in group 1, there was a decrease in anterior chamber depth and globe axial length, but no significant difference was found except on the third day (t = 3.15, p = 0.003). In group 2 there was an insignificant decrease in axial length but the decrease in anterior chamber depth was significant at all measurement times except for the sixth month. CONCLUSIONS: Refractive changes related to biometric changes after RK are not important compared with the total refractive corrections of RK. These changes should be considered, however, when planning RK procedures.

A comparative study on the effect of radial keratotomy in patients who live at sea level and high altitude.

PURPOSE: To compare the refractive and keratometric results of matched pairs of patients who underwent radial keratotomy (RK) at sea level and high altitude. METHODS: The results of 30 eyes that underwent RK procedures in two clinical centres at different altitude were analysed. One centre was at sea level (Istanbul) and the other at an altitude of 1720 m (Van). The patients in the two centres were matched regarding gender, age, degree of myopia, number of incisions and optic zone size. There were 15 eyes in each group. All operations were performed with a diamond blade using a Russian technique by the same surgeon. RESULTS: The mean pre-operative spherical equivalent cycloplegic refractions (SECR) were -6.33 +/- 1.15 D and -6.32 +/- 1.01 D in the Istanbul and Van groups, respectively (p = 0.96). The mean post-operative SECRs were -1.93 +/- 1.03 D and -0.28 +/- 0.57 D in the Istanbul and Van groups, respectively (p < 0.001). The mean SECR changes were 4.40 +/- 0.92 D and 6.03 +/- 1.13 D in subjects who had undergone RK at sea level and at 1720 m, respectively (p < 0.001). CONCLUSION: These results show that a higher myopic correction can be provided in patients who undergo RK at high altitude compared with those operated on at sea level. The RK nomograms used by refractive surgeons performing RK surgery at high altitude may need to be redesigned in the light of future studies with long-term follow-up.