Mehmet Zeki Bayraktar

Comparison of tilt and decentration of 1-piece and 3-piece hydrophobic acrylic intraocular lenses.

Purpose: To determine the amount of tilt and decentration of 1‐piece and 3‐piece hydrophobic acrylic intraocular lenses (IOLs) in patients having cataract surgery. Setting: Department of Ophthalmology, Gülhane Military Medical Academy and Medical School, Ankara, Turkey. Methods: Eighty‐eight patients having phacoemulsification with IOL implantation were divided into 2 groups. One group received a 3‐piece hydrophobic acrylic IOL with 12.5 mm poly(methyl methacrylate) haptics and the other, a 1‐piece hydrophobic acrylic IOL with 12.5 mm haptics. The amount of IOL decentration and tilt was quantitated using Purkinje reflections and photographic documentation at the last postoperative control. The results of the 2 groups were compared. Results: Bag fixation of the IOL and an intact continuous curvilinear capsulorhexis (CCC) were confirmed in all cases at the last postoperative control, which was at a mean of 27.1 months ± 5.4 (SD) and 26.7 ± 4.4 months in the 3‐piece group and 1‐piece group, respectively (P = 0.659). There was no significant difference between groups in the percentage of patients with measurable tilt and decentration and of patients without measurable tilt and decentration (P = .956). The mean IOL tilt was 2.72 ± 0.55 degrees in the 3‐piece group and 2.70 ± 0.84 degrees in the 1‐piece group and the mean IOL decentration, 0.39 ± 0.13 mm and 0.34 ± 0.08 mm, respectively. There were no significant between‐group differences in tilt or decentration (P = .897 and P = .103, respectively). Conclusion: There were no significant differences in tilt and decentration between 1‐piece and 3‐piece hydrophobic acrylic IOLs in eyes with capsular bag IOL implantation and an intact CCC.

Urinary Neopterin Levels in Uveitis: Is It a New Activity Marker?

Purpose: Neopterin is an immunologic marker for the activation of the cell-mediated immune system and it is found to be elevated in autoimmune diseases. We aimed in this study to investigate the relationship between urinary neopterin levels and disease activity in patients with uveitis. Methods: 31 patients with active uveitis and 13 patients with inactive uveitis were compared with 27 age and sex matched controls. Disease activity was evaluated by clinical examination and fundus florescein angiography findings. Samples were studied with High Performance Liquid Chromatography. Results: Urinary neopterin levels in patients with active uveitis, inactive uveitis and control subjects were 274 ± 98, 179 ± 61 and 166 ± 38 μmol/mol creatinine respectively (p < 001). The difference between active uveitis, inactive uveitis and control groups were statistically significant (p < 001). Conclusions: Urinary neopterin levels are found to be increased in patients with active uveitis. Neopterin can be used as a biochemical activity marker to support the clinical findings in patients with uveitis.

Multifocal Electroretinogram in Mild to Moderate Essential Hypertension

Purpose. To investigate the local retinal dysfunctions in mild to moderate essential hypertensive patients by using multifocal electroretinogram (mfERG). Methods. Thirty-one patients with stage 1 or stage 2 hypertension (HT) and 31 age- and sex-matched healthy normotensive (NT) subjects were included. Fourteen of the patients had stage 1 and 17 had stage 2 hypertension. Twenty had grade 1 and 11 had grade 2 hypertensive retinopathy. The local retinal functions from the fovea to the peripheral 30 degrees were evaluated by multifocal electroretinogram by dividing this area to central hexagonal area (CH) and four concentric rings around the central hexagon (Rings 1–4). The amplitude and the implicit times of the positive peak (P1) and the negative peak (N1) of the responses were compared between the control subjects and hypertensive patients. Only the right eyes were included. The differences between the hypertensive patients and control subjects were investigated using independent samples t test, and the differences between grade 1 and grade 2 hypertensive retinopathy and stage 1 and stage 2 hypertension were investigated using Mann-Whitney U test. Results. P1 amplitudes in CH (HT: 129.0 ± 29.5, NT: 149.1 ± 45.5, p = 0.043) and in Ring 3 (HT: 37.0 ± 8.0, NT: 41.7 ± 7.8, p = 0.024) and N1 amplitude in Ring 1 (HT: 26.8 ± 7.4, NT: 30.8 ± 7.8, p = 0.048) in the hypertensive patients was significantly reduced when compared to healthy normotensive subjects. There was no significant difference in terms of P1 and N1 implicit times. There was also no significant difference between the patients with stage 1 or stage 2 hypertension and patients with grade 1 or grade 2 hypertensive retinopathy. Conclusion. Hypertensive subjects have local retinal dysfunctions with respect to healthy controls. This result probably originated from retinal ischemia due to changes in retinal and/or choroidal circulation in systemic arterial hypertension.

Hypericin-enhanced argon laser photocoagulation for subfoveal choroidal neovascular membrane in age-related macular degeneration: a pilot study.

PURPOSE To evaluate the efficacy and safety of hypericin-enhanced argon laser photocoagulation (H-ALP) in the treatment of subfoveal choroidal neovascular membrane (CNM) secondary to age-related macular degeneration (ARMD). METHODS After preliminary studies for definition of parameters, argon-green laser was administered 4 hours after single dose of oral 1800 mg hypericin (Saint-Johns wort tablets, 0.3%, 300 mg) with a subthreshold light fluence, 24 J/cm2 in 34 eyes (20 with subfoveal classical and 14 with subfoveal occult CNM). Additionally, histopathologic examination was done in two eyes destined for enucleation and exenteration. Maintenance therapy (one tablet, twice a day) was performed for the following 6 months. Anatomic (complete closure of CNM) and functional success (improvement of final visual acuity in three or more Snellen lines) were analyzed with minimum 6-month follow-ups. RESULTS Histopathologic examinations revealed photothrombosed choriocapillaries together with minimal retinal pigment epithelial disruption in H-ALP exposed areas. One to four (mean 1.88+/-0.91) treatment sessions were applied in 6 to 29 months (mean 12.2+/-5.1 months) follow-up period. Twenty-three (67.6%) eyes had 12 months follow-up. Two eyes in each group had functional success (20% in subfoveal classical and 14.3% in subfoveal occult CNM), which had a minimum 12-month follow-up. Anatomic success was achieved in 16 of 20 (80%) eyes with subfoveal classical and 10 of 14 (71.4%) eyes with subfoveal occult CNM. Severe gastric irritation was noted in 1 (2.9%) and pigment epithelial rupture in 2 (5.9%) patients. CONCLUSIONS H-ALP is a novel and low-cost treatment for subfoveal CNM secondary to ARMD. It seems its efficacy depends on the photodynamic and antiproliferative properties of hypericin. Comparative studies are required to apply this new technique in ophthalmic practice.PURPOSE To evaluate the efficacy and safety of hypericin-enhanced argon laser photocoagulation (H-ALP) in the treatment of subfoveal choroidal neovascular membrane (CNM) secondary to age-related macular degeneration (ARMD). METHODS After preliminary studies for definition of parameters, argon-green laser was administered 4 hours after single dose of oral 1800 mg hypericin (Saint-Johns wort tablets, 0.3%, 300 mg) with a subthreshold light fluence, 24 J/cm2 in 34 eyes (20 with subfoveal classical and 14 with subfoveal occult CNM). Additionally, histopathologic examination was done in two eyes destined for enucleation and exenteration. Maintenance therapy (one tablet, twice a day) was performed for the following 6 months. Anatomic (complete closure of CNM) and functional success (improvement of final visual acuity in three or more Snellen lines) were analyzed with minimum 6-month follow-ups. RESULTS Histopathologic examinations revealed photothrombosed choriocapillaries together with minimal retinal pigment epithelial disruption in H-ALP exposed areas. One to four (mean 1.88+/-0.91) treatment sessions were applied in 6 to 29 months (mean 12.2+/-5.1 months) follow-up period. Twenty-three (67.6%) eyes had 12 months follow-up. Two eyes in each group had functional success (20% in subfoveal classical and 14.3% in subfoveal occult CNM), which had a minimum 12-month follow-up. Anatomic success was achieved in 16 of 20 (80%) eyes with subfoveal classical and 10 of 14 (71.4%) eyes with subfoveal occult CNM. Severe gastric irritation was noted in 1 (2.9%) and pigment epithelial rupture in 2 (5.9%) patients. CONCLUSIONS H-ALP is a novel and low-cost treatment for subfoveal CNM secondary to ARMD. It seems its efficacy depends on the photodynamic and antiproliferative properties of hypericin. Comparative studies are required to apply this new technique in ophthalmic practice. (Eur J Ophthalmol 2006; 16: 119-28).

An Assessment of Intraocular Pressure Change in Healthy Subjects During Air Flight

Purpose: To investigate the effect of air flight on intraocular pressure (IOP). Methods: Baseline IOP of 25 healthy volunteers was measured at a ground level of 1760 feet above sea level (ASL) using Tono-Pen XL™. Measurements were repeated after reaching an altitude of 19,000 feet and then on the second hour during a routine flight. Cabin pressure was kept around 8000 feet. IOP measurement was repeated after landing (3.5 hr after taking off). Change in the IOP was evaluated. Results: Mean ± SD IOP was 14.2 ± 2.7 mmHg at ground level and was 14.0 ± 2.2 mmHg after gaining maximum altitude (p = 0.78). Mean IOP dropped to 12.3 ± 2.5 mmHg on the second hour of flight and 12.0 ± 1.7 mmHg after landing. Decrease in IOP on the second hour (13.4%, p = 0.005) and after landing (15.7%, p = 0.001) were significant. Conclusion: IOP significantly decreased on the second hour measurements during a routine flight, and this change was sustained after landing.

Comparison of Tilt and Decentration between Phacoemulsification and Phacotrabeculectomy

Purpose: To determine the extent of intraocular lens (IOL) tilt and decentration values after combined surgery in patients with cataract and glaucoma. Materials and Methods: A total of 106 cataractous eyes undergoing IOL implantation were divided into 2 groups. Group 1 comprised 42 eyes undergoing phacotrabeculectomy surgery for cataract and primary open-angle glaucoma (POAG), and group 2 comprised 64 eyes undergoing phacoemulsification surgery for senile cataract. The length of IOL decentration and the angle of IOL tilt were quantitated by using Purkinje reflections and photographic documentation. Results: The differences regarding both the IOL tilt (2.84 ± 0.37; 2.97 ± 0.37, respectively) and decentration (0.39 ± 0.27; 0.49 ± 0.35, respectively) was insignificant (p > 0.05) between groups. Conclusion: There is no increased effect of phacotrabeculectomy on tilt and decentration of IOLs in eyes with POAG when compared with eyes which underwent phacoemulsification surgery.