Mehmet Borazan

Comparison of secondary implantation of flexible open-loop anterior chamber and scleral-fixated posterior chamber intraocular lenses

Purpose: To analyze and compare the outcomes and complication rates of secondary implantation of flexible, open‐loop, anterior chamber intraocular lenses (AC IOLs) and single‐piece, scleral‐fixated, posterior chamber IOLs (PC IOLs). Setting: Departments of Ophthalmology, Gaziantep University Medical Faculty, Research Hospital, Gaziantep, and Inönü University Medical Faculty, Research Hospital, Malatya, Turkey. Methods: This study comprised 124 eyes of 113 aphakic patients (61 men, 52 women) with insufficient capsule support who had secondary IOL implantation from January 1997 to June 2001. In Group 1 (n = 73 eyes), a flexible, open‐loop AC IOL was implanted and in Group 2 (n = 51 eyes), a single‐piece, scleral‐fixated PC IOL. The mean follow‐up was 34 months (range 6 to 53 months) and took place at several different clinical settings. The mean interval between the initial cataract operation and secondary IOL implantation was 63 months (range 6 months to 12 years). The postoperative outcomes, safety, efficacy, and complication rates were analyzed, and the preoperative and postoperative best spectacle‐corrected visual acuities (BSCVAs) were compared. Results: The postoperative mean BSCVA was 20/34.8 ± 45.2 (SD) in Group 1 and 20/32.1 ± 33.7 in Group 2; the difference was not significant (P = .718). A BSCVA of 20/40 or better was achieved in 62 eyes (84.9%) in Group 1 and 45 eyes (88.2%) in Group 2. A BSCVA of 20/25 or better was achieved in 40 eyes (54.8%) and 33 eyes (64.7%), respectively. The difference between the 2 groups was not significant (P = .472). Complications occurred in 25 eyes (34.2%) in Group 1 and 13 eyes (25.5%) in Group 2 (P > .05). The most frequent complications in Group 1 were early transient corneal edema, intraocular pressure elevation, cystoid macular edema, hyphema, secondary glaucoma, and iris capture or pupil decentration and in Group 2, suture erosion, a tilted or decentered IOL, fibrin reaction, and vitreous prolapse into the anterior chamber. Conclusions: The AC IOLs and PC IOLs were safe and effective for secondary implantation to correct aphakia. Secondary implantation of the scleral‐fixated PC IOL seemed to provide a more favorable outcome and a lower complication rate than the open‐loop AC IOL in complicated cataract cases with inadequate capsule and zonular support. As scleral‐fixated PC IOL implantation is technically more difficult than AC IOL implantation, the decisive factor in choosing a secondary IOL is surgical experience. Long‐term comparison of both techniques is required.

The effect of resveratrol in experimental cataract model formed by sodium selenite.

Purpose: To investigate if resveratrol can prevent sodium selenite-induced experimental cataract model in rats. Methods: Forty-eight Spraque-Dawley rat pups were divided into 3 treatment groups: (1) normal saline–% 5 ethanol injected i.p. on postpatum day 10; (2) Na selenite (30 nmol/g body wt) injected s.c on day 10; (3) Na selenite s.c on day 10 + resveratrol (40 mg/kg) i.p on days 10–13. On day 21, cataract development was graded by slit-lamp examination and photography. Encapsulated lenses and erythrocytes were analyzed for reduced glutathione (GSH) and malondialdehyde (MDA), a marker of lipid peroxidation. Lenses were also analyzed for total nitrite (TN). Results: All control lenses in group 1 were clear. In group 2, all rats developed cataracts (grade 3–grade 6), whereas in group 3, only 9 of 16 rats developed cataracts (grade 2–grade 3). The difference of cataract frequency between groups 2 and 3 was statistically significant (p < 0.05). Group 3 lenses and erythrocytes had higher mean GSH and lower mean MDA levels than those in group 2 (p < 0.05). TN was highest in group 3 and lowest in group 1 (p < 0.05). Conclusions: Resveratrol suppressed selenite-induced oxidative stress and cataract formation in rats. This protective effect was supported by higher GSH and lower MDA in lens and erythrocytes. The presence of oxidative stress in selenite cataract development and its prevention by resveratrol support the possibility that high natural consumption of resveratrol in food can help prevent human senile cataract.

Limbal relaxing incisions for primary mixed astigmatism and mixed astigmatism after cataract surgery.

Purpose: To evaluate the effect of limbal relaxing incisions (LRIs) in the treatment of primary mixed astigmatism and mixed astigmatism after cataract surgery. Setting: Department of Ophthalmology, Inönü University, Malatya, Turkey. Methods: Limbal relaxing incisions were performed to correct astigmatism in 37 eyes of 26 patients with mixed astigmatism. Twenty‐four eyes had primary astigmatism, and 13 eyes had astigmatism after cataract surgery. The length, number, and depth of the incisions were determined using the Gills and Gayton nomogram. The manifest refractive astigmatism was measured preoperatively and 1 day, 1 week, and 1, 3, 6, and 12 months postoperatively. Surgically induced astigmatism using the vector method, preoperative and postoperative uncorrected visual acuity (UCVA), and best spectacle‐corrected visual acuity (BSCVA) were evaluated. Follow‐up was at least 6 months in all cases. Results: The mean preoperative and postoperative refractive astigmatism was 3.31 diopters (D) ± 1.50 (SD) and 1.59 ± 1.28 D, respectively (P < .001). The mean absolute change in refractive astigmatism was 1.72 ± 0.81 D. No patient lost lines of UCVA or BSCVA. The safety index was 1.21 and the efficacy index, 0.88. The mean preoperative and postoperative UCVA was 0.29 ± 0.22 and 0.54 ± 0.31, respectively (P = .0001) and the mean BSCVA, 0.61 ± 0.30 and 0.74 ± 0.30, respectively (P = .0001). The mean vectorial magnitude was 2.32 ± 1.36 D at the last follow‐up. There were no serious postoperative complications. Conclusion: Limbal relaxing incisions are a simple, safe, and effective method to correct primary mixed astigmatism and mixed astigmatism after cataract surgery.

Heparin in the intraocular irrigating solution in pediatric cataract surgery

Purpose: To investigate the antiinflammatory effects of adding heparin sodium to the irrigating solution to prevent fibrinoid reaction and related long‐term complications after pediatric cataract surgery. Setting: Department of Ophthalmology, Inönü University, Turgut Özal Medical Center, Malatya, Turkey. Methods: Thirty eyes of 18 children who had cataract or other ocular surgery were included in the study. Bilateral cataract surgery was performed in 20 eyes of 10 children and bilateral secondary intraocular lens (IOL) implantation in 4 eyes of 2 children (Group 1). Four eyes of 4 children had unilateral cataract surgery and 2 eyes of 2 children with previous perforating eye injury had synechiotomy and pupilloplasty (Group 2). Heparin sodium was added to the irrigating solution during surgery in 12 left eyes of children with bilateral surgery (Group 1a) and in all eyes in Group 2. Heparin sodium was not added during surgery in 12 right eyes of children having bilateral surgery (Group 1b, control). Early and late postoperative intraocular reactions were recorded and compared. Results: In Group 1a (heparin added), 6 eyes had less fibrinoid reaction and fewer related complications such as posterior synechias, pupil irregularity, and intraocular lens (IOL) decentration than the fellow right eyes. No eye in Group 1a having primary cataract surgery had hyphema or intraocular bleeding. Hyphema occurred on the first postoperative day in 1 eye in Group 1a that had secondary IOL implantation. Conclusions: Adding heparin sodium to the irrigating solution decreased postoperative inflammatory and fibrinoid reactions and related complications such as synechias, pupil irregularity, and IOL decentration in pediatric cataract surgery. However, the use of heparin during surgery can be risky in eyes with a defective blood–aqueous barrier such as after previous ocular surgery.

Effect of caffeic acid phenethyl ester on corneal neovascularization in rats

Purpose. Caffeic acid phenethyl ester (CAPE), a biologically active component of propolis from honeybee hives, has potent antiinflammatory and antioxidant properties. We aimed to evaluate the ability of topically applied CAPE in comparison with known steroidal (dexamethasone sodium phosphate) and nonsteroidal (indomethacin) topical agents to reduce corneal neovascularization (CNV) induced by silver nitrate cauterization in rats. Methods. Following silver nitrate cauterization on both eyes, male rats were randomly assigned to the study and control groups, each consisting of ten rats. The inhibitory effects of the test drugs against a placebo (isotonic saline) on CNV were tested and compared to each other using a previously described method in which extent of neovascularization and burn stimulus intensity were scored by a masked examiner. Briefly, burn stimulus intensity was scored from 0 to +3 according to the height of blister from corneal surface, and extent of neovascularization was recorded from 0 to +6 according to the distance from limbus to the end point of CNV toward the central corneal burn. Results. The mean burn stimulus score were not different among the groups (P = 0.807). Percent inhibition of CNV compared to the placebo control and its significance were 31.5 %, P = 0.011 for indomethacin; 56 %, P < 0.001 for dexamethasone; and 52 %, P < 0.001 for CAPE. Dexamethasone was significantly (P < 0.05) more effective than indomethacin in inhibition of neovascular growth. CAPE was found to be superior (P < 0.05) to indomethacin and almost as effective as (P > 0.05) dexamethasone in reducing CNV. Conclusion. Topically applied CAPE was demonstrated to have an inhibitory effect, comparable to that of topical dexamethasone, on CNV in this rat model. Antiinflammatory and antioxidant properties of CAPE may contribute to its suppression on CNV.

Aqueous humor and plasma levels of vascular endothelial growth factor and nitric oxide in patients with pseudoexfoliation syndrome and pseudoexfoliation glaucoma.

PurposeTo investigate levels of vascular endothelial growth factor (VEGF) and nitric oxide (NO) in the aqueous humor and plasma of patients with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG), compared with controls. MethodsThis prospective study involved 37 patients with PXS, 15 with PXG, and 32 control subjects in whom cataract surgery was indicated. Aqueous humor and plasma VEGF and NO levels were measured with enzyme-linked immunosorbent assay and chemiluminescence methods, respectively. ResultsAqueous humor and plasma VEGF concentrations were higher in patients with PXS and PXG than in controls (P<0.001). Aqueous humor NO concentrations were higher in patients with PXS and PXG than in controls (P<0.05 and P=0.001, respectively). Plasma NO concentrations did not differ between the 3 groups. Aqueous humor and plasma VEGF and NO levels were not significantly different in patients with PXS versus PXG. VEGF and NO levels showed no significant correlation among the 3 groups (P>0.05). ConclusionsElevated aqueous humor VEGF and NO levels and plasma VEGF concentrations in eyes with PXS and PXG can be explained by the ischemic nature of these disorders. The lack of correlation between VEGF and NO levels may indicate impaired downregulation, which may have a role in the progression to PXG.

Comparison of the effects of argon and neodymium:YAG laser iridotomy on cytokines in the rabbit aqueous humor.

Purpose We compared the effects in rabbits of iridotomy using the argon or Nd:YAG laser on cytokines such as interleukin 1–beta (IL-1β), interleukin 6 (IL-6), interleukin 8 (IL-8), and tumor necrosis factor-alpha (TNF-α). Methods Twenty pigmented rabbits (20 eyes) underwent argon and Nd:YAG iridotomy under general and topical anesthesia. Group 1 (10 right eyes) was treated with the argon laser and group 2 (10 right eyes) with the Nd:YAG laser, using an equal number of shots and the same laser parameters for each group. Left eyes in both groups were evaluated as controls. Aqueous humor specimens were collected from each eye preoperatively and 1 and 3 days postoperatively. Results Aqueous IL-6 and TNF-α levels rose more on day 1 in the Nd:YAG group than the argon group. IL-6 and TNF-α levels were significantly higher on days 1 and 3 than the preoperative and control levels (p<0.05). TNF-α levels on day 1 were significantly lower in the Nd:YAG than the argon group. There were no significant differences between the two laser groups for IL-6 on days 1 and 3. IL-1β and IL-8 did not change Conclusions Our findings suggest that cytokines, particularly IL-6 and TNF-α, may be inflammatory mediators in the early inflammation following argon and Nd:YAG laser iridotomies. These results also indicate that cytokines contribute to the acute effects of Nd:YAG and argon laser applications on inflammation.

Use of caffeic acid phenethyl ester and cortisone may prevent proliferative vitreoretinopathy.

PURPOSE: To investigate whether caffeic acid phenethyl ester (CAPE) and cortisone prevent proliferative vitreoretinopathy (PVR). METHODS: Twenty pigmented rabbits were used in this study. All rabbits except controls received an intravitreal injection of 0.15 ml (75,000 U) of platelet-rich plasma into their left eye. The animals were divided into four groups: group I was treated with intraperitoneal injection of 0.5 ml (15 micromol/kg) of CAPE for 3 days, group II received 0.15 ml (4 mg/kg) of intravitreal cortisone, group III received nothing (blank group), and group IV (control group) received only 1 ml of 1% ethanol intraperitoneally daily for 3 days. Proliferative changes were graded in a masked fashion by indirect ophthalmoscopy for a 15-day follow-up period. The malondialdehyde (MDA), reduced glutathione (GSH) and total nitrite (NO) levels were measured in the vitreous humor. RESULTS: The grades of PVR were B-C in group I, and C-D in group II. The PVR grade in the control group was C-D. The mean MDA level in group I (4.0+/-0.8 micromol/l) was significantly lower than in the blank group (6.0 micromol/l) (p < 0.05). The mean GSH level in group I (71.0+/-11.2 micromol/l) was significantly different than in the blank group (p < 0.05). The MDA and GSH levels in group II were 4.7+/-0.6 micromol/l and 53.8+/-7.8 micromol/l, respectively. Both these levels were not significantly different from the blank group (p > 0.05). The NO levels in both treatment groups were significantly lower than in the blank group (p < 0.001). CONCLUSION: These findings suggest an inhibitory effect of CAPE on PVR. The inhibitory effect was supported by lower MDA and NO with higher GSH levels in treatment groups than in the blank group. There was no detected significant effect of cortisone for preventing PVR experimentally.

Decreased aortic root elasticity-as a novel systemic manifestation of the pseudoexfoliation syndrome: an observational study.

OBJECTIVEnTo assess the aortic root function in patients with pseudoexfoliation syndrome (PEXS).nnnMETHODSnIn this case- controlled observational study, aortic root function in 31 PEXS patients (mean age 71 ± 9 years) and 29 controls of similar ages (mean age 69 ± 9 years) were evaluated by M-mode transthoracic echocardiography. Aortic cross-sectional compliance (CSC), Petersons elastic modulus (index beta), aortic stiffness index (ASI) and aortic root distensibility (ARD) were calculated by M-mode echocardiography to evaluate the aortic root function. The findings of two groups of patients were compared by Mann-Whitney U test.nnnRESULTSnThe CSC and ARD were significantly decreased in patients with PEXS. The CSC was 12.2 ± 6.3 cm²/mmHg in patients with PEXS and 17.5 ± 11.6 cm²/mmHg in the control group (p=0.015). The ARD was 1.56 ± 0.80 cm²/dyne in patients with PEXS and 2.23 ± 1.48 cm²/dyne in the control group (p=0.021). The other two indices of aortic root function were not significantly different between the two groups.nnnCONCLUSIONnAortic root function decreases in patients with PEXS. PEXS may be regarded as a risk factor for cardiovascular and cerebrovascular events.

Dislocation of a scleral-fixated posterior chamber intraocular lens into the anterior chamber associated with pseudophakic bullous keratopathy.

A 48-year-old patient with a scleral-fixated posterior chamber intraocular lens had dislocation of the intraocular lens into the anterior chamber and associated pseudophakic bullous keratopathy. The patient underwent intraocular lens extraction and partial penetrating keratoplasty. Because an anterior chamber intraocular lens is easier to implant and has fewer complications, surgeons may want to consider this as the first choice for treatment. If the scleral-fixated posterior chamber intraocular lens is used, it must be implanted properly and meticulously to avoid complications.