Comparative efficacy of difloxacin and nano-emulsion difloxacin as antibacterial agents against Salmonella enterica Serovar enteritidis in chickenss.

Background: Avian salmonellosis is a group of diseases caused by bacteria from the genus Salmonella with a negative impact on poultry, particularly chickens. In addition, salmonellosis is a global food-borne infection. Aim: The aim of this study was to evaluate the effect of nano-emulsion difloxacin (NED) and commercial difloxacin (CD) water supplement on broiler's growth, feed intake, and body weight, weight gain, growth rate, feed conversion ratio (FCR), and mortality rate (MR). The antibiotic sensitivity was determined both in-vivo and in-vitro for NED against Salmonella enterica Serovar enteritidis in chickens. Methods: 1500 one-day of age chicks were grouped into five groups as follows: group 1 (G1) control negative group, G2 control positive group (infected and not treated), G3 (infected and treated with CD, and G4 and G5 (infected and treated with NED at different doses). Samples, including the intestine, liver, and spleen were collected. Agar well diffusion test and minimum inhibitory concentrations were adopted. Histopathological lesions on different tissues were studied. During 35 days of the experiment, the feed intake, growth rate, growth gain, FCR, and MR were recorded daily. In addition, a variety of analytical techniques including transmission electron microscopic analysis, dynamic light scattering, UV-visible spectroscopy, and zeta-potential analysis were applied to characterize NED. Results: The agar well diffusion test indicated that NED was in-vitro effective against S. enteritidis isolates than CD. The minimum inhibitory concentration was recorded as NED inhibited bacterial growth till well 8 at a concentration of 0.78 µg/ml; on the other hand, the CD inhibited bacterial growth till well 6 at a concentration of 0.62 µg/ml. Growth performance and MRs in the groups treated with NED are significantly reduced. Conclusion: Treatment of broiler's drinking water with NED at doses of 0.5 and 1 ml instead of pure CD was able to enforce a new perspective, antibacterial efficacy, enhancing the productive performance, and reducing the MRs of broilers.

Prevalence, molecular characterization, and antimicrobial resistance among Escherichia coli, Salmonella spp., and Staphylococcus aureus strains isolated from Egyptian broiler chicken flocks with omphalitis.

Background: Bacterial Omphalitis has been reported as a significant cause of mortalities in newly hatched broiler chicks. Aim: This study aimed to assess the occurrence of omphalitis among broiler chickens in Gharbia governorate in Egypt. In addition, the bacteria associated with the occurrence of omphalitis in broiler chickens were also investigated and characterized. Methods: For this purpose, 43 farms in that area were surveyed. The comparative levels of omphalitis caused by Escherichia coli (E. coli), Salmonella spp., and Staphylococcus aureus (S. aureus) were screened in 129 chicks. The drug resistance to eight commonly used antimicrobials in Egyptian poultry farms was screened using the disk diffusion method. Results: The overall incidence rate of omphalitis was 37.21%. In birds with omphalitis, the co-prevalence of S. aureus, Salmonella spp., and E. coli was 87.5%. When compared to healthy flocks, broiler chicks with omphalitis caused by Salmonella spp., E. coli, and S. aureus had a greater mortality rate in the first week of life. However, there were no significant differences in the mortality cases caused by these pathogens. Eighty-seven percent of the cases of omphalitis were linked to E. coli and 75% to Salmonella spp. and S. aureus. From the yolk sac of broiler chicks with omphalitis, E. coli, Salmonella spp., and S. aureus were isolated at rates of 87.5%, 62.5%, and 45.8%, respectively. The isolates of E. coli and Salmonella spp. exhibited great sensitivity to gentamycin and Tetracycline; however, the strongest drug resistance was observed toward cefpodoxime, sulphamethoxazole and trimethoprim, ampicillin, and amoxycillin and clavulanic acid. The recovered isolates of S. aureus showed susceptibility to chloramphenicol (72.37%), oxytetracycline (81.82%), and erythromycin (81.82%). However, every S. aureus isolate that was found resistant to amoxycillin and clavulanic acid, penicillin G and oxacillin. of blaTEM, blaSHV, and blaCTX-M genes has been proposed as the genetic cause of ß-lactam antibiotic resistance in Salmonella spp. and E. coli. MecA and blaZ; however, were found in every strain of S. aureus. Conclusion: The frequency of omphalitis and its associated mortalities was comparatively high in Gharbia governorate. More efforts should be made to adopt strict hygienic standards for controlling and preventing such disease and this will consequently lead to minimizing the use of antimicrobials in poultry farms.

Effect of High-intensity Laser Therapy on Carpal Tunnel Syndrome Patients: A Systematic Review and Meta-analysis.

OBJECTIVE: To provide a strong foundation for the use of high-intensity laser therapy (HILT) in carpel tunnel syndrome (CTS,) we conducted a systematic review and meta-analysis to investigate the outcomes of short- and long-term follow-up studies. DESIGN: Systematic review and meta-analysis. RESULTS: Sample sizes of included studies ranged from 16 to 98 patients (total N = 308). Overall, a significant difference between the treatment and control groups were found across majority of the measures. Studies using a four-week follow-up period, however, only found significantly greater benefits for HILT in visual analogue scale (VAS) compared to placebo (p = 0.0191), Transcutaneous electrical nerve stimulation (TENS) (p = 0.0026), and low-intensity laser therapy-20 J/cm2 (p < 0.0002), and exercise (p < 0.0001). For improvement in VAS score over a long treatment period, HILT was also preferred over control group (p < 0.0071). Insufficient evidence exists to determine effect of HILT on nerve conduction examinations. The only statistically significant differences observed in examinations were in relation to sensory nerve action potential (p = 0.0083) and sensory nerve conduction velocity (SNCV) (p = 0.0468). CONCLUSION: Moderate evidence exists regarding efficacy of HILT compared to placebo, HILT + wrist splint, and exercise in a short period of follow-up time but evidence on long-term follow-up is limited.

Synthesis of Cu and CuO nanoparticles from e-waste and evaluation of their antibacterial and photocatalytic properties.

Waste printed circuit boards (WPCBs) contain a plethora of valuable metals, considered an attractive secondary resource. In the current research, a hydrometallurgical process combined ammonia/ammonium chloride leaching and reduction (using L-ascorbic acid) to recover copper and its oxide (CuO) as nanosized particles from WPCBs was investigated. The results of leaching indicated that 96.7% of copper could be recovered at a temperature of 35 °C for a leaching duration of 2 h with ammonium chloride and ammonia concentration of 2 mol/L at a solid:liquid ratio of 1:10 g/cm3. The synthesized particles exhibit spherical and distorted sphere morphology with average particle size of 460 nm and 50 nm for Cu and CuO NPs, respectively. The antibacterial activity of Cu, CuO, and a (1:1) blend of both (Cu/CuO) has been examined against five different bacterial and fungal strains. The highest zone of inhibition was measured as 21.2 mm for Cu NPs toward Escherichia coli and 16.7 mm for Cu/CuO blend toward Bacillus cereus bacteria. The highest zone of inhibition was measured as 13 mm and 13.8 mm for Cu/CuO blend toward Fusarium proliferatum and Penicillium verrucosum fungi. Cu/CuO blend showed notable photocatalytic activity towards Rhodamine B dye under visible light irradiation with 96% degradation rate within 120 min. Using the process developed in this study, copper and its oxide as nanoparticles can be produced from WPCBs and used for multifunctional applications.

A century of "anticoccidial drugs": bibliometric analysis.

Publications are an important measure of scientific and technological progress. The quantitative examination of the number of publications in a certain research topic is known as bibliometrics. Bibliographic studies are widely used to analyse the condition of research, future potential, and current growth patterns in a certain topic. It can serve as a basis for making decisions and implementing strategies to achieve long-term development goals. To our knowledge, no research has been conducted in these domains; so, this work aims to employ bibliometric analysis to provide comprehensive data on publications related to anticoccidial drugs. As a result, the current study uses bibliometric analysis to track the evolution of anticoccidial drugs and its consequences in the academic and public worlds via a survey of relevant scientific and popular publications. The Dimensions database was used to retrieve the bibliographical statistics, which were then cleaned and analyzed. The data was also loaded into the VOS viewer, which generated a network visualization of the authors with the most joint articles. The investigation discovered three stages of publications and citations since the first article on anticoccidial drugs in 1949. The first stage, which ran from 1920 to 1968, was characterized by a scarcity of research articles on anticoccidial drugs. From 1969 to 2000, the second stage was marked by a stable and marginally increased number of articles. The scientific field was characterized by an increasing trend in the number of publications and their citations from 2002 to 2021. The study gave a complete list of the top anticoccidial drugs funding agents, countries, research institutes, most cited publications, and important co-authorship and partnerships. The outcomes of the study will help veterinary practitioners and researchers understand the trends and best sources of knowledge in the field of anticoccidial medications.

Strabismus Surgery in Hemophilia: A Novel Surgical Technique and Guideline Recommendations.

Hemophilia is a serious X-linked inheritance coagulation factor deficiency. Clinically, prolonged bleeding or delayed clotting in any area of vascular disturbance is the main manifestation of all hemophilia. We presented a 23-year-old male with a history of left sensory esotropia since the age of three. The patient had not undergone any previous eye surgery and refused to wear glasses. Hematologic studies confirmed a diagnosis of hemophilia A. Upon ophthalmologic examination, the patient's visual acuity was 20/20 in the right eye and 20/120 in the left eye, with deep amblyopia. The patient exhibited left inferior oblique overaction and a V pattern. The ophthalmologic examination otherwise revealed no abnormalities. Preoperative correction of factor VIII was deemed necessary, and the recommended dose was administered to raise the factor VIII level to 52%. The patient underwent bilateral medial rectus recession, left lateral rectus plication, and left inferior oblique myectomy. A new technique utilizing viscodissection with subconjunctival injection of a viscoelastic solution was employed to minimize intraoperative bleeding, resulting in reduced bleeding compared to standard strabismus surgery. No unusual bleeding occurred during the procedure. No postoperative bleeding was observed. The patient was discharged on the fourth postoperative day, having achieved satisfactory cosmetic alignment in the primary position with no complications related to hemophilia. In conclusion, strabismus surgery can be performed safely in strabismic patients with hemophilia. Viscodissection is a helpful novel surgical technique to decrease the risk of bleeding during surgery, and we recommend using this technique in patients using anticoagulants. A multidisciplinary team approach and strict post-operative monitoring are essential in order to achieve optimal results.

Cytokines, Serological, and Histopathological Assessment of Recombinant Vaccination Strategies for Combatting Infectious Bursal Disease in Broiler Chickens.

Infectious bursal disease (IBD) represents a greatly transmissible viral disease found worldwide, causing significant health and production challenges in young chickens. The aim of this research was to assess the immune reaction induced by different vaccines targeting IBD. These vaccines included recombinant (Vac1; HVT-IBD vector), immune complex (Vac2; Bursa-Plex®), and intermediate plus (Vac3; Bursine plus) IBD vaccines. Our assessment relied on serological and histopathological analyses, as well as the pattern of immune-related cytokine expression in the bursal tissue. The vaccinated groups, along with a control positive (CP) group, were subjected to a vvIBDV challenge on their 28th day of life, while the control negative (CN) group received a mock vaccination with PBS. Our study revealed that Vac1 resulted in the most favorable growth performance, as well as maintained normal liver and kidney function, mitigating the impact of IBDV infection. Serological analysis using VP2 ELISA kits indicated that Vac1 induced the strongest immunological response among all vaccines. Histopathological examination demonstrated that Vac1 caused minimal lymphoid depletion observed in the lymphoid organs, followed by Vac2. Analysis of cytokine expression profiles showed significant upregulation in all vaccinated groups, particularly Vac1, during the pre-challenge period. Following IBDV infection, Vac1 resulted in a noteworthy increase in the expression of IL2 and IFN-γ, Vac2 showed a significant upregulation in TNF-α and granzyme, and both Vac1 and Vac3 exhibited increased levels of IL1ß and IL10. In conclusion, our study suggests that the various vaccines triggered immune responses against IBD through both humoral and cell-mediated immunity. However, recombinant followed by immune complex vaccines appeared to induce more robust immunity while also being safer for broiler chickens in contrast to the intermediate plus vaccine.

Isolation, Identification, and Genetic Characterization of Antibiotic Resistance of Salmonella Species Isolated from Chicken Farms.

Salmonella is a major cause of foodborne outbreaks. It causes gastroenteritis in humans and animals. This micro-organism causes severe illness in chickens and has a major impact on chicken productivity and the poultry industry. This study aimed to address the prevalence of Salmonella infection in broiler chicken farms in Kafrelsheikh, Gharbia, and Menofeya provinces in Egypt during 2020-2022. This work also aimed to evaluate the genetic characterization and antibiotic resistance of the isolated Salmonella strains. Clinical signs and mortalities were observed and recorded. In total, 832 samples were collected from 52 broiler flocks, including 26 from both one-week-old and 6-week-old chicken farms from different organs (liver, intestinal content, spleen, and gallbladder). The prevalence of Salmonella infections was reported in the study region to be 36.54%. Of the 26 one-week-old farms surveyed, 11 (42.31%) and 8/26 (30.77%) of the six-week-old broiler chicken farms had Salmonella infections. Recovered isolates were serotyped as 9 (47.37%) S. enteritidis O 1,9,12, ad monophasic H: g, m: -, 6 (31.58.%) S. shangani 2, (10.53%) S. gueuletapee 1, (5.26%) S. II (salamae), and 1 (5.26%) untypable. The results showed that Salmonella infection was predominant in one-week-old chicks compared to infection in six-week-old and uninfected flocks. All Salmonella isolates were resistant to ampicillin and erythromycin, while all isolates were sensitive to ciprofloxacin, chloramphenicol, and levofloxacin. The isolates also contained 10.53% (2/19) streptomycin, 10.53% (2/21) gentamicin, 15.79% (3/19) doxycycline, and 26.32% (5/19) lincomycin and colistin. The phenotypically resistant Salmonella samples against ampicillin, erythromycin, and macrolide harbored bla TEM , bla SHV , ermB, ereA, mphA, and ermB, respectively. This baseline data on Salmonella spp. prevalence, serotyping, and antibiotic profiles are combined to define the antimicrobial resistance to this endemic disease. Elucidation of the mechanisms underlying this drug resistance should be of general importance in understanding both the treatment and prevention of Salmonella infection in this part of Egypt.

Advanced methods for missing values imputation based on similarity learning.

The real-world data analysis and processing using data mining techniques often are facing observations that contain missing values. The main challenge of mining datasets is the existence of missing values. The missing values in a dataset should be imputed using the imputation method to improve the data mining methods' accuracy and performance. There are existing techniques that use k-nearest neighbors algorithm for imputing the missing values but determining the appropriate k value can be a challenging task. There are other existing imputation techniques that are based on hard clustering algorithms. When records are not well-separated, as in the case of missing data, hard clustering provides a poor description tool in many cases. In general, the imputation depending on similar records is more accurate than the imputation depending on the entire dataset's records. Improving the similarity among records can result in improving the imputation performance. This paper proposes two numerical missing data imputation methods. A hybrid missing data imputation method is initially proposed, called KI, that incorporates k-nearest neighbors and iterative imputation algorithms. The best set of nearest neighbors for each missing record is discovered through the records similarity by using the k-nearest neighbors algorithm (kNN). To improve the similarity, a suitable k value is estimated automatically for the kNN. The iterative imputation method is then used to impute the missing values of the incomplete records by using the global correlation structure among the selected records. An enhanced hybrid missing data imputation method is then proposed, called FCKI, which is an extension of KI. It integrates fuzzy c-means, k-nearest neighbors, and iterative imputation algorithms to impute the missing data in a dataset. The fuzzy c-means algorithm is selected because the records can belong to multiple clusters at the same time. This can lead to further improvement for similarity. FCKI searches a cluster, instead of the whole dataset, to find the best k-nearest neighbors. It applies two levels of similarity to achieve a higher imputation accuracy. The performance of the proposed imputation techniques is assessed by using fifteen datasets with variant missing ratios for three types of missing data; MCAR, MAR, MNAR. These different missing data types are generated in this work. The datasets with different sizes are used in this paper to validate the model. Therefore, proposed imputation techniques are compared with other missing data imputation methods by means of three measures; the root mean square error (RMSE), the normalized root mean square error (NRMSE), and the mean absolute error (MAE). The results show that the proposed methods achieve better imputation accuracy and require significantly less time than other missing data imputation methods.

Avian Paramyxovirus Type 1 in Egypt: Epidemiology, Evolutionary Perspective, and Vaccine Approach.

Avian orthoavulavirus 1, formerly known as avian paramyxovirus type-1 (APMV-1), infects more than 250 different species of birds. It causes a broad range of clinical diseases and results in devastating economic impact due to high morbidity and mortality in addition to trade restrictions. The ease of spread has allowed the virus to disseminate worldwide with subjective virulence, which depends on the virus strain and host species. The emergence of new virulent genotypes among global epizootics, including those from Egypt, illustrates the time-to-time genomic alterations that lead to simultaneous evolution of distinct APMV-1 genotypes at different geographic locations across the world. In Egypt, the Newcastle disease was firstly reported in 1947 and continued to occur, despite rigorous prophylactic vaccination, and remained a potential threat to commercial and backyard poultry production. Since 2005, many researchers have investigated the nature of APMV-1 in different outbreaks, as they found several APMV-1 genotypes circulating among various species. The unique intermingling of migratory, free-living, and domesticated birds besides the availability of frequently mobile wild birds in Egypt may facilitate the evolution power of APMV-1 in Egypt. Pigeons and waterfowls are of interest due to their inclusion in Egyptian poultry industry and their ability to spread the infection to other birds either by presence of different genotypes (as in pigeons) or by harboring a clinically silent disease (as in waterfowl). This review details (i) the genetic and pathobiologic features of APMV-1 infections in Egypt, (ii) the epidemiologic and evolutionary events in different avian species, and (iii) the vaccine applications and challenges in Egypt.

Emergence of new virulent rabbit hemorrhagic disease virus strains in Saudi Arabia.

Rabbit hemorrhagic disease is an acute fatal highly contagious viral infectious disease that causes high losses among rabbitries. The disease was first reported in China in 1984 and later on in Saudi Arabia in 1996. The aim of this study was to investigate the emergence and pathogenicity of new rabbit hemorrhagic disease virus (RHDV) strains in Saudi Arabia. The pathogenicity was confirmed by inoculation in susceptible rabbits. Three RHDV strains were detected by reverse transcriptase polymerase chain reaction (RT-PCR) using primers targeting VP60 capsid protein gene in infected rabbitries during 2012 and 2013. These strains clustered into two genetically distinct genogroups related to year of isolation (G2 and G3). All new Saudi Arabia viruses clustered with the European strains, while the old strains clustered with strains from China and America. Based on amino acids and nucleotide sequences, the Saudi Arabia strains (RHD/1/SA/2012, RHD/2/SA/2012, and RHD/3/SA /2013) had high identity with Mexico89, Ca11-ITA, and 00-13,FRA virus; on the other hand, there was a relatively high identity with Bahrain strain. The evolutionary relationship of Saudi RHDVs strains revealed significant nucleotides and amino acid substitutions in hypervariable region E, suggesting the emergence of new RHDVs circulating in Saudi Arabia rabbitries. These antigenic changes represented by the antigenic index might be a potential cause of vaccination failure and raises the need to review the vaccination strategies against RHD.

Profitability analysis of a femtosecond laser system for cataract surgery using a fuzzy logic approach.

AIM: To define the financial and management conditions required to introduce a femtosecond laser system for cataract surgery in a clinic using a fuzzy logic approach. METHODS: In the simulation performed in the current study, the costs associated to the acquisition and use of a commercially available femtosecond laser platform for cataract surgery (VICTUS, TECHNOLAS Perfect Vision GmbH, Bausch & Lomb, Munich, Germany) during a period of 5y were considered. A sensitivity analysis was performed considering such costs and the countable amortization of the system during this 5y period. Furthermore, a fuzzy logic analysis was used to obtain an estimation of the money income associated to each femtosecond laser-assisted cataract surgery (G). RESULTS: According to the sensitivity analysis, the femtosecond laser system under evaluation can be profitable if 1400 cataract surgeries are performed per year and if each surgery can be invoiced more than $500. In contrast, the fuzzy logic analysis confirmed that the patient had to pay more per surgery, between $661.8 and $667.4 per surgery, without considering the cost of the intraocular lens (IOL). CONCLUSION: A profitability of femtosecond laser systems for cataract surgery can be obtained after a detailed financial analysis, especially in those centers with large volumes of patients. The cost of the surgery for patients should be adapted to the real flow of patients with the ability of paying a reasonable range of cost.

Cardiotoxicity of Freon among refrigeration services workers: comparative cross-sectional study.

BACKGROUND: Freon includes a number of gaseous, colorless chlorofluorocarbons. Although freon is generally considered to be a fluorocarbon of relatively low toxicity; significantly detrimental effects may occur upon over exposure. The purpose of the present study is to investigate whether occupational exposure to fluorocarbons can induce arterial hypertension, myocardial ischemia, cardiac arrhythmias, elevated levels of plasma lipids and renal dysfunction. METHODS: This comparative cross-sectional study was conducted at the cardiology clinic of the Suez Canal Authority Hospital (Egypt). The study included 23 apparently healthy male workers at the refrigeration services workshop who were exposed to fluorocarbons (FC 12 and FC 22) and 23 likewise apparently healthy male workers (unexposed), the control group. All the participants were interviewed using a pre-composed questionnaire and were subjected to a clinical examination and relevant laboratory investigations. RESULTS: There were no significant statistical differences between the groups studied regarding symptoms suggesting arterial hypertension and renal affection, although a significantly higher percentage of the studied refrigeration services workers had symptoms of arrhythmias. None of the workers had symptoms suggesting coronary artery disease. Clinical examination revealed that the refrigeration services workers had a significantly higher mean pulse rate compared to the controls, though no significant statistical differences were found in arterial blood pressure measurements between the two study groups. Exercise stress testing of the workers studied revealed normal heart reaction to the increased need for oxygen, while sinus tachycardia was detected in all the participants. The results of Holter monitoring revealed significant differences within subject and group regarding the number of abnormal beats detected throughout the day of monitoring (p < 0.001). There were no significant differences detected in the average heart rate during the monitoring period within subject or group. Most laboratory investigations revealed absence of significant statistical differences for lipid profile markers, serum electrolyte levels and glomerular lesion markers between the groups except for cholesterol and urinary beta2-microglobulin (tubular lesion markers) levels which were significantly elevated in freon exposed workers. CONCLUSIONS: Unprotected occupational exposure to chlorofluorocarbons can induce cardiotoxicity in the form of cardiac arrhythmias. The role of chlorofluorocarbons in inducing arterial hypertension and coronary artery diseases is unclear, although significantly elevated serum cholesterol and urinary beta2-microglobulin levels raise a concern.

The Kelman Duet phakic intraocular lens: 1-year results.

PURPOSE: To evaluate the efficacy and safety of the Kelman Duet phakic intraocular lens (PIOL) for correction of moderate and high myopia. METHODS: Kelman Duet PIOLs were implanted in 169 eyes of 110 patients with moderate or high myopia. In all cases, implantation of the lens was feasible through an incision of less than 2.5 mm without complications. Uncorrected visual acuity (UCVA), manifest refraction, best spectacle-corrected visual acuity (BSCVA), intraocular pressure, central corneal endothelial change, and complications were recorded preoperatively and during 12 months of follow-up. RESULTS: Following PIOL implantation, 23 (13.61%) eyes required LASIK retreatment for the correction of residual astigmatic refractive error and were excluded from the refractive analysis. Best spectacle-corrected visual acuity remained the same or improved in 95.04% of eyes, 81.30% of eyes (100) were within +/-1.00 diopter (D) of emmetropia, and 57.72% (71) were within +/-0.50 D. Intraocular pressure increased slightly in the first 4 weeks postoperatively but stabilized to the preoperative level by 3 months. Mean endothelial cell loss at 12 months was 5.43%. Oval pupils developed in 10.1% of eyes. Haptic exchange or reposition was performed in 7.76% of cases. CONCLUSIONS: The Kelman Duet PIOL was safe and effective for the correction of moderate to high myopia in this study with 1-year follow-up and offered the advantage of using a 2.5-mm or less incision width. Accurate haptic sizing remains a challenge and haptic exchange to correct haptic size mismatching is possible.

Correction of hyperopia by intracorneal lenses: two-year follow-up.

PURPOSE: To assess the safety and efficacy of intracorneal lenses as a surgical alternative for the correction of hyperopia. SETTING: Al-Azhar University and El Magrabi Eye Hospital, Cairo, Egypt. METHODS: Twenty-three eyes of 21 patients who had a mean hyperopia of 4.3 diopters (D) +/- 0.71 (SD) (range +2.5 to +6.0 D) received Permavision lenses (Anamed Inc.), which are made of a highly permeable hydrogel with a water content of 78% and a refractive index close to that of corneal tissue (1.376). The Moria M2 microkeratome was used to make a 160 microm corneal flap with a diameter of +/-8.5 mm. The intracorneal lens was placed beneath the flap after minimal interface irrigation. RESULTS: Clinical examination showed mild corneal edema and a myopic shift during the first week postoperatively. In 17 eyes (73.9%), the postoperative uncorrected visual acuity was similar to the preoperative best corrected visual acuity (BCVA); 1 eye (4.3%) lost 1 line of preoperative BCVA. In 5 eyes (21.7%), various degrees of lens opacification with some degree of corneal haze were seen after uneventful follow-up. Decentration of 0.5 to 1.0 mm was seen in 2 eyes (8.6%), 1 of which had the lens explanted because of significant opacification. Induced astigmatism was evident in 1 eye (-1.5 D). A total of 16 eyes (69.6%) were within +/-0.5 D of target, and 20 eyes (86.9%) were within +/-1.0 D (87%). No flap melting or extrusion of the lens was recorded in 24 months of follow-up. Night halos and glare were reported in 3 eyes; all had a lens diameter of 5.0 mm. CONCLUSIONS: Intracorneal hydrogel lenses were tolerated relatively well by stromal tissue, providing a reasonably stable and predictable way to correct moderate hyperopia. However, induced astigmatism, stromal opacification, decentration, and night halos and glare occurred in a significant number of eyes. To ensure safety, deep flap cuts are preferred and these eyes should be watched carefully to avoid decentration of the lens in the early postoperative period.

LASIK using the NIDEK EC-5000 for the correction of hyperopic astigmatism.

PURPOSE: To assess the refractive outcomes of LASIK for the surgical correction of hyperopic astigmatism using the NIDEK EC-5000 excimer laser. METHODS: LASIK was performed on 46 eyes from 26 patients (19 men and 7 women) for the correction of congenital hyperopic astigmatism. The NIDEK EC-5000 excimer laser and the Moria M2 microkeratome were used in all procedures. Cylindrical ablations were performed on the negative axis out to a 6-mm diameter. RESULTS: The mean preoperative cylindrical refraction was +3.15+/-0.70 diopters (D) (range: +1.75 to +4.50 D), and the mean 24-month postoperative refraction was +1.27+/-0.78 D (range: +0.50 to +3.25 D). Vector analysis showed a 2.17+/-1.27 D reduction in the equivalent cylinder. Preoperative mean uncorrected visual acuity (UCVA) was 20/100, and 24-month postoperative UCVA was 20/30. One eye lost one line of best spectacle-corrected visual acuity at 24 months postoperatively. Complications related to the LASIK flap occurred in 2 (4.3%) eyes. Partial regression of the astigmatic effect began at 4 to 6 months but stabilized by 1 year. CONCLUSIONS: LASIK is a safe but limited alternative for the correction of astigmatism in eyes with hyperopic astigmatism. Early regression of the astigmatic effect in the first 6 months seems to be the primary disadvantage of this technique.

Correction of hyperopia with intracorneal implants.

PURPOSE: To evaluate the safety and efficacy of intracorneal lenses as a surgical alternative for the correction of hyperopia. SETTING: Al-Azhar University, Cairo, Egypt, and Louisiana State University Eye Center, New Orleans, Louisiana, USA. METHODS: PermaVision lenses (Anamed Inc.) were implanted in the left eye of 20 albino rabbits that were followed for 6 months by confocal microscopy. The lenses are made of a highly permeable hydrogel with 70% water content and a refractive index close to that of corneal tissue (1.376). The Carriazo-Barraquer microkeratome (Moria) was used to create a 150 microm corneal flap with a diameter of 8.5 mm or larger. The intracorneal lens was placed under the flap after minimal interface irrigation. RESULTS: At 3 days, confocal microscopy showed interface edema that resolved after 1 week. No flap melting or excursion of the lens was noted. In 1 eye, a deep lamellar keratitis was seen. At 6 months, the edge of the lens showed excellent compatibility, with no keratocytic activity or intrastromal fibrosis. CONCLUSIONS: Intracorneal hydrogel lenses were well tolerated by stromal tissue in rabbits. They are potentially safe and can be considered as an alternative for the correction of hyperopia. Further clinical studies are required to confirm their safety in humans.