Biomedical subjects

U Aykan

Publications and source records attributed to U Aykan.

8 recordsLinked to original sources

PubMed2003

The effect of capsulorhexis size on development of posterior capsule opacification: small (4.5 to 5.0 mm) versus large (6.0 to 7.0 mm).

PURPOSE: The most common surgically related cause of reduced vision after extracapsular cataract extraction is posterior capsule opacification (PCO), which occurs in up to 50% of eyes following cataract extraction. This study examined whether small capsulorhexes of 4.5 to 5.0 mm, which lie completely on the 5.5 mm intraocular lens (IOL), and large capsulorhexes of 6.0 to 7.0 mm, which lie completely off the lens optic, are effective in preventing PCO development. METHODS: In this prospective study, 496 eyes of 367 patients underwent standardized phacoemulsification with capsulorhexis and capsular bag foldable acrylic IOL implantation. The patients were randomly assigned to receive either a small capsulorhexis of 4.5 to 5 mm to lie completely on the IOL optic or a large capsulorhexis of 6 to 7 mm to lie completely off the lens optic. Retroillumination photographs were taken at 6 months and then yearly. RESULTS: Throughout the follow-up, there was less PCO in the small capsulorhexis group than in the large capsulorhexis group. CONCLUSIONS.:Small capsulorhexes were associated with less wrinkling of the posterior capsule and less PCO than were large capsulorhexes. PCO after IOL implantation has a multifactored pathogenesis. Small (4.5 to 5.0 mm) capsulorhexis and capsular bag implantation of 5.5 mm acrylic IOL are likely to reduce the PCO incidence when compared with the 6.0 to 7.0 mm capsulorhexis. The significance of the IOL optic diameter in association with the capsulorhexis size should also be documented by further studies.

Aged↗

PubMed1999

The comparison of cyclopentolate and atropine in patients with refractive accommodative esotropia by means of retinoscopy, autorefractometry and biometric lens thickness.

PURPOSE: In this study, we aimed to compare the cycloplegic effect of cyclopentolate HCI 1% and atropine sulphate 1% in patients with refractive accommodative esotropia by means of retinoscopy, autorefractometer and the measurement of lens thickness by biometry. METHODS: Thirty-two patients with refractive accommodative esotropia aged from 5 to 10 (mean 6.8+/-1.4), had a deviation under 10 prism diopters, and underwent retinoscopic, autorefractometric and biometric study in dry and wet conditions. RESULTS: The retinoscopic, autorefractometric and biometric findings of the right eye were 5.10+/-1.21 diopter (D), 5.03+/-1.20 D, 3.43+/-0.16 mm with cyclopentolate, and 5.2+/-1.2 D, 5.2+/-1.2 D, 3.4+/-0.1 mm with atropine. In the left eye, the measurements were 5.2+/-1.4 D, 5.1+/-1.4 D, 3.5+/-0.2 mm with cyclopentolate, and 5.3+/-1.2 D, 5.20+/-1.3 D, 3.4+/-0.2 mm with atropine, respectively. When these obtained data were compared by the Student's t test no statistical significance was found (p > 0.05). CONCLUSIONS: We suggest that the cyclopentolate cycloplegia applied to the patients with refractive accommodative esotropia is sufficient to produce good cycloplegia, with an effect similar to atropine.

Accommodation, Ocular↗

PubMed1998

Penetration of oral and topical ciprofloxacin into human aqueous humor.

PURPOSE: This study was planned to investigate the penetration of ciprofloxacin into aqueous humor following oral and topical application as a prophylactic antimicrobial agent. METHODS: Forty-six patients undergoing cataract surgery were randomly divided into two groups. In the first group, the patients received 500 mg oral ciprofloxacin eight hours before surgery and in the second, 5 drops of 0.3% ciprofloxacin were applied to the patients every twenty minutes, starting 100 minutes before the surgery. By paracentesis, aqueous samples were taken just before the operation so the interval between the first topical application and paracentesis was 100 minutes. RESULTS: The mean concentration of ciprofloxacin in aqueous humor was 0.63+/-0.29 microg/ml in the first group. The concentration was 0.69+/-0.30 microg/ml in the second group. Both of these mean concentrations were higher than the levels of MIC90 of S.aureus , S. epidermidis, P. aeruginosa and Gram (-) bacteriae. CONCLUSION: As a result, both topically and orally applied ciprofloxacin achieved a significant aqueous concentration. Each route studied might be suitable for surgical prophylaxis or treatment of infections.

Administration, Oral↗

PubMedDate not supplied

Ocular findings in Sturge-Weber syndrome.

PURPOSE: We reviewed the rare ocular findings of Sturge-Weber syndrome (SWS) and the results of implantation of the Ahmed valve in cases associated with glaucoma. METHODS: Seven patients (range 18 to 52 years) diagnosed as SWS were reviewed as clinical findings over two years. An anterior chamber maintainer was placed in patients with glaucoma to maintain stable intraocular pressure and minimize the risk of intraocular hemorrhage due to sudden pressure changes during surgery, when an Ahmed valve is implanted. RESULTS: Episcleral venous vessels were prominent in all cases. Diffuse choroidal hemangiomas were seen in three cases. Nevus of Ota was observed in only one case. Three cases had juvenile glaucoma. One also had buphthalmos. No intraocular hemorrhage or choroidal effusion was observed intraoperatively in valve-implant patients. The surgical treatment of the patients with glaucoma gave favorable outcomes. CONCLUSIONS: Rare ocular findings such as choroidal hemangioma and nevus of Ota are sometimes seen in SWS. Drainage valve implantation, with an anterior chamber maintainer, is a good choice for treatment when surgery is done in cases with glaucoma. This method may reduce the risk of intraoperative suprachoroidal effusion and expulsive hemorrhage by stabilizing intraocular pressure within normal limits during the surgery.

Adolescent↗

PubMedDate not supplied

Palbebral anthrax.

PURPOSE: Anthrax is a rare infection transmitted to humans from animals or animal products. In cutaneous anthrax it may produce lesions of the eyelids which can lead to cicatricial ectropion. METHODS: We examined three women and five men with anthrax of the eyelids. Intravenous penicillin G was used alone as therapy. RESULTS: All patients presented with a localized itchy erythematous papule of the eyelid. A necrotising ulcer formed in each case, resulting in black eschar. The lesions resolved, with only mild cicatrization of the eyelid in all the patients. CONCLUSIONS: Anthrax is primarily an infectious disease of domestic animals but it is also seen in humans. Eyelids are rarely affected but cutaneous anthrax should be considered in any patient with a painless ulcer or black eschar who has a history of exposure to animals.

Adult↗

PubMedDate not supplied

Review of sterile, postoperative, anterior segment inflammation following cataract extraction and intraocular lens implantation.

PURPOSE: To evaluate unexpected, acute intraocular anterior segment inflammation following uneventful cataract extraction by phacoemulsification and foldable posterior chamber intraocular lens (PCIOL) implantation. METHODS: This retrospective study evaluated five cases of postoperative inflammation that occurred after cataract extraction with foldable PCIOL implantation. Medical records were reviewed to analyze the unexplained postoperative inflammation. RESULTS: The five patients who developed inflammatory activity during the postoperative period responded well to corticosteroid treatment. Toxic maculopathy developed in one patient after aggressive antibacterial therapy. Vitrectomy was performed for one patient with prolonged vitreal inflammatory activity. CONCLUSIONS: Noninfectious endophthalmitis developing upon surgery may be caused by a multifactorial process or an interindividual variable response to a common factor as a hypersensitivity reaction. It should be remembered in inflammatory cases after surgery in order to prevent the toxic, irreversible side effects of bacterial endophthalmitis treatment.

Acute Disease↗

PubMedDate not supplied

The effects of three-piece or single-piece acrylic intraocular lens implantation on posterior capsule opacification.

PURPOSE: To evaluate the development of posterior capsule opacification (PCO) in patients implanted with 5.5 mm optics, single-piece or three-piece acrylic intraocular lens (IOL) in cataract surgery prospectively. METHODS: This study was carried out on 267 eyes of 249 patients implanted with three-piece, 5.5 mm optics, acrylic IOL and 252 eyes of 244 patients implanted with single-piece, 5.5 mm optics, acrylic IOL by phacoemulsification technique between September 2001 and February 2003. A total of 519 eyes of 493 patients were prospectively evaluated for PCO development during the 25-month period. All the patients were analyzed periodically with anterior segment retroillumination photography. The data provided were analyzed with chi-square method. RESULTS: The results between the two groups for PCO development were not statistically significant. However, there was a prominent opacification of the posterior capsule where the optic and haptic junction of IOL was positioned in some patients implanted with single-piece IOL. During the follow-up period, no patients implanted with either three-piece or single-piece acrylic IOL required Nd:YAG laser capsulotomy. CONCLUSIONS: Biocompatibility and reduced rate of PCO development are among the leading features of new generation IOLs. The intracapsular implantation of 5.5 mm optics acrylic IOLs resulted in decreased incidence of PCO and therefore greater patient satisfaction. Further studies investigating the effects of IOL optics, haptic structure and length, capsulorrhexis size, and IOL material and design features on PCO development will clarify the subject.

Acrylic Resins↗

PubMedDate not supplied

The effects of artificial tear application on contrast sensitivity in dry and normal eyes.

PURPOSE: To investigate the effects of artificial tear application on contrast sensitivity in dry and normal eyes. METHODS: A total of 55 patients with normal (10/10) corrected or uncorrected visual acuity referring to GATA Gulhane Military Medical Academy Haydarpasa Ophthalmology Outpatient Clinic were evaluated in regard to dry eye diagnostic criteria, and assigned into the dry eye group (Group 1; 35 patients) and the control group (Group 2; 20 patients). All patients were given a contrast sensitivity testing at low and high spatial frequencies using the gradual contrast sensitivity chart before and at 5 minutes after application of artificial tears, and the two groups were compared. Wilcoxon test was used in statistical analysis, accepting a p value of <0.05 as significant. RESULTS: In the dry eye group, there was a statistically significant increase in contrast sensitivity scores both at low and high frequencies after application of artificial tears (p<0.05). In the control group, although there was a significant increase in low frequency scores after artificial tear application (p< 0.05), there was not a significant change in high frequency scores (p>0.05). CONCLUSIONS: The decreased contrast sensitivity in dry eyes improves with application of artificial tears. Therefore, the impeded quality of vision seen in dry eye patients could be restored closer to normal with artificial tear therapy. Besides, contrast sensitivity testing could be used in the follow-up of artificial tear therapy.

Adult↗