Volkan Dayanir

The Comparison of Intraocular Pressure Reductions after Isometric and Isokinetic Exercises in Normal Individuals

The lowering effect of physical exercise on intraocular pressure (IOP) has been reported both in healthy people and those with glaucoma, but a comparison of the lowering effect of isometric and isokinetic exercises on IOP has not been conducted in any study. Our aims were to investigate the relationship between intensity of exercise and IOP, and whether a significant difference in IOP lowering effect existed between isometric and isokinetic exercises. Sixty-seven patients with an age range of 23–40 who had no ocular disease were randomly divided into two groups. While 31 patients in the first group, group A, performed isokinetic exercise with the Cybex 6000 dynamometer, 32 patients in the second group, group B, had isometric exercises with the same machine. IOP was measured in the right eye of patients with Shiøtz tonometer just before and 10 min following exercise. Exercise intensity and total energy consumption were determined by the machine for each patient. While IOP values measured before exercise, the degree of exercise applied, and total energy consumption did not differ significantly between groups, both isometric and isotonic exercises lowered IOP significantly. As a result, isometric and isokinetic exercises lowered IOP in ophthalmologically normal subjects with direct relationship to exercise intensity and total energy consumption. Since the pressure lowering effect of isokinetic exercise was more significant, it might prove useful to glaucomatous patients.

Medical control of intraocular pressure after phacoemulsification

Purpose: To compare the effectiveness of oral acetazolamide, topical brinzolamide 1%, and no ocular hypotensive medication after phacoemulsification. Setting: Adnan Menderes University Department of Ophthalmology, Aydin, Turkey. Methods: This prospective randomized double‐blind study comprised 60 eyes of 52 patients having phacoemulsification under topical anesthesia. There were no intraoperative complications. Eyes were randomized to receive oral acetazolamide 500 mg 1 hour preoperatively followed by 250 mg acetazolamide every 6 hours, 1 drop of brinzolamide 1% every 12 hours starting immediately after speculum removal, or no ocular hypotensive medication. Intraocular pressure (IOP) was measured using a Perkins tonometer preoperatively and 4 to 6 hours and 18 to 24 hours postoperatively. Results: The preoperative IOP was not significantly different between the 3 groups. Four to 6 hours postoperatively, the acetazolamide group (P = .002) and brinzolamide group (P = .001) had significantly lower IOP than the control group. The same trend was observed at 18 to 24 hours in the brinzolamide group (P = .001) but not the acetazolamide group (P = .018). The IOP levels were not significantly different between the acetazolamide group and brinzolamide group at any postoperative time point. No eye receiving medication and 2 eyes (10%) in the control group had an IOP of 30 mm Hg or higher 4 to 6 hours postoperatively. Compared with preoperatively, an IOP increase of more than 5 mm Hg was seen at 4 to 6 hours in 3 eyes (15%), 2 eyes (10%), and 14 eyes (70%) in the acetazolamide, brinzolamide, and control group, respectively. Conclusion: Brinzolamide was as effective as acetazolamide in preventing IOP elevation 4 to 6 hours after phacoemulsification and more effective than acetazolamide at 18 to 24 hours.

Orbital blood flow parameters in unilateral pseudoexfoliation syndrome.

Purpose The evaluation of orbital blood flow parameters in patients with unilateral pseudoexfoliation syndrome (XFS) and in age–sex-matched control subjects using color Doppler imaging. Methods This prospective, comparative case series included 33 unilateral XFS patients and 33 age–sex-matched control subjects. Color Doppler imaging was used to evaluate the XFS-affected (Group 1) and -unaffected (Group 2) eyes that were matched with the corresponding side (Groups 3 and 4) of control subjects. All subjects were given a complete ophthalmological examination. A masked radiologist obtained the peak systolic velocity (PSV) and end diastolic velocity (EDV) of ophthalmic (OA), central retinal (CRA), nasal posterior ciliary (NPCA) and temporal posterior ciliary arteries (TPCA) as well as mean velocity of central retinal vein (CRV). Resistivity indices (RI) were calculated. Results Analysis of peak systolic and end diastolic velocity (PSV, EDV) and RI between Groups 1–2 and 3–4 did not show any significant difference. Comparing Groups 1–3 (corresponding eyes of pseudoexfoliation-affected and control subjects) and Groups 2–4 (corresponding eyes of pseudoexfoliation-unaffected and control subjects) revealed significantly low values for OA, PSV and EDV in both eyes of the XFS patients. The OA RI value in Group 1 was found to be significantly higher than that in Group 3 with the cut-off value of 0.72. Conclusion These findings suggest that ophthalmic artery hemodynamic parameters change in both eyes of unilateral XFS patients, illustrating out the systemic nature of the disease. We conclude that XFS decreases OA blood flow velocities and increases vascular resistance through progressive build-up.

Acanthamoeba keratitis due to Acanthamoeba genotype T4 in a non-contact-lens wearer in Turkey

An otherwise healthy 22-year-old man presented with Acanthamoeba keratitis (AK) in the right eye. He was not a contact lens wearer and had no history of corneal trauma. The Acanthamoeba strain isolated from a corneal scraping was identified as morphological group II and genotype T4. Three more Acanthamoeba strains isolated from sites of possible human contact with acanthamoebae in the same geographical region, including a lens storage case, tap water and soil, were subjected to morphological and molecular biological identification. Whereas the strain from tap water also exhibited genotype T4, the two other isolates were identified as morphological group I and genotype T9. To the best of our knowledge, this is the first study identifying an AK-causing Acanthamoeba strain in Turkey and the first isolation of genotype T9 in this country.

Lacrimal sac dacryolith: a study with atomic absorption spectrophotometry and scanning electron microscopy

Dacryoliths are uncommon causes of partial or complete obstruction of the nasolacrimal drainage apparatus. We report our findings of a dacryolith that we studied by culture, light microscopy, atomic absorption spectrophotometry, and scanning electron microscopy. Although no fungi were recovered by culturing, hyphae-like structures were observed. No inorganic material was detected by atomic absorption spectrophotometry. Scanning electron microscopy of ultrastructure showed the stone was composed of lobes and lobules built on an amorphous core material.

Central corneal thickness and corneal curvature in pseudoexfoliation syndrome with and without glaucoma.

PurposeTo determine the central corneal thickness (CCT) and corneal curvature (CC) in pseudoexfoliative (PE) eyes with and without glaucoma. MethodsCharts of 551 consecutive patients undergoing preoperative examinations for cataract surgery between April 2006 and May 2009 in our clinic were reviewed retrospectively. Fourty-eight PE patients (48 eyes; 19 with glaucoma, 29 without glaucoma) and 48 age-matched and sex-matched control patients were enrolled in the study. The CCT, CC, intraocular pressure, and axial length were measured by ultrasonic pachymeter, autorefractokeratometer, Goldmann applanation tonometry, and ultrasound biometry, respectively. The independent samples t test and paired samples t test was used for the comparisons of the groups. ResultsMean CCT was significantly thinner in all PE and nonglaucomatous PE (Pseudoexfoliation syndrome “PES”) eyes than in control eyes (P=0.004 and P=0.005, respectively). There was no difference in CCT between PE glaucoma (PEG) and control eyes (P=0.089). There was no difference in mean keratometry (K) and axial length in the study and control groups. In 22 unilateral PE eyes, mean CCT and K readings were insignificant between the PE eyes and fellow non-PE eyes. ConclusionsCCT was significantly thinner in eyes with PES compared with control eyes; however, difference between the PEG and control eyes was insignificant. In addition, mean K readings were not different in study and control eyes. Thinner CCT in eyes with PES, both as it is an independent risk factor and as a result of artificially lower intraocular pressure readings, may be an illuminating cause for development and rapid progression of glaucoma in the patients with PES.

The one‐eye trial and fellow eye response to prostaglandin analogues

Background:  To determine if the intraocular pressure (IOP) reduction in one‐eye trial correlates with the IOP reduction in the fellow eye when IOP variability during office hours is taken into account.

Botulinum Toxin A in the Treatment of Adherence Syndrome

The effect of botulinum toxin A is investigated in the treatment of adherence syndrome related to strabismus surgery. An 18-year-old boy with decompensated right congenital fourth nerve palsy underwent ipsilateral superior rectus muscle recession and inferior oblique muscle disinsertion. During the early postoperative period, a right hypotropia with limitation of elevation developed and the result of the forced duction test was positive for passive elevation of the right eye. Botulinum toxin A was injected into the right inferior rectus muscle on the 15th postoperative day and orthophoria was achieved 1 week later. A repeat injection of botulinum toxin A was performed 6 months later. On follow-up 2 1/2 years later, his eyes remained orthophoric with limitation of elevation in the right eye and the patient was satisfied with the result. This case demonstrated that adherence syndrome can be treated successfully by botulinum toxin A injection if it is administered during the acute phase, before the development of fibrous scar tissue.

Prevention of suture exposure in transscleral intraocular lens fixation: an original technique.

BACKGROUND In this retrospective study, we evaluated our surgical outcomes of transscleral intraocular lens (IOL) fixation and introduced a simple, quick, and effective method to fixate and bury the sutures in the sclera to avoid suture exposure. METHODS Eyes were divided into 3 groups according to surgical technique. Half-thickness scleral flaps were prepared, and polypropylene suture ends were cut short in group 1 (12 eyes). Suture ends were left long without flaps in group 2 (47 eyes) and were buried into the scleral tunnel in group 3 (21 eyes). RESULTS The suture exposure rate was significantly lower in group 3 (0%) compared with group 2 (p = 0.006) and group 1 (p = 0.040). There was no significant difference in group 1 (25%) compared with group 2 (27.6%) (p = 1.000). INTERPRETATION Burying the suture ends into the scleral tunnel is a simple, safe, and effective technique for avoiding suture exposure in scleral-fixated IOL implantation.

Ophthalmic artery blood flow parameters in pseudoexfoliation glaucoma

Purpose To investigate orbital flow parameters of ophthalmic artery (OA) in patients with pseudoexfoliation glaucoma (XFG) by ultrasonography. Methods This case-control study included 38 patients with XFG and 32 healthy control subjects. Color Doppler imaging was performed to evaluate orbital flow parameters of OA. Receiver operating characteristic analyses were performed to define the best cutoff value. Results In the XFG group, decreased peak systolic velocity (p = 0.114), end diastolic velocity (p = 0.002), and increased resistivity index (RI) (p<0.001) at OA compared to healthy controls were observed. A cutoff value 0.72 for OA RI was found to have a sensitivity of 66% and specificity of 94%. Conclusions The results support the findings of increased vascular resistance in OA XFG. High sensitivity and specificity obtained for OA RI may be useful in evaluation of future therapeutic vascular agents.