Retinal vessel diameters and their correlation with retinal nerve fiber layer thickness in patients with pseudoexfoliation syndrome

AIM: To compare retinal artery-vein diameters (RAVDs) of patients with pseudoexfoliation (PSX) syndrome with healthy controls and investigate the correlations between retinal nerve fiber layer (RNFL) thickness parameters and RAVDs. METHODS: Seventeen eyes with PSX and 17 eyes of age-matched controls were included in the study. All participants underwent routine ophthalmological examination, Humphrey visual field and RNFL examination by using Stratus OCT. Retinal images were obtained by using a retinal camera (Topcon 501X). RAVDs were measured from inferior nasal, inferior temporal, superior nasal and superior temporal arcuates by using IMAGEnet software. Superior, inferior, nasal, temporal and average RNFL thicknesses were recorded. RAVDs and RNFL parameters in groups and correlations were analyzed by Mann-Whitney U and Spearmann correlation tests. RESULTS: Only inferior quadrant and average RNFL thickness were detected thinner in the PSX group compared with control group (P=0.009, P=0.038, respectively). No statistically significant difference regarding RAVDs was found between two groups. CONCLUSION: RAVDs seems to be comparable in the PSX and control group. RNFL is thinner in the inferior quadrant in the PSX group. RNFL thickness and RAVDs show significant correlations in both groups. This correlation doesn’t seem to be specific to PSX.     

Scleral buckling technique for longstanding inferior rhegmatogenous retinal detachments with subretinal bands.

We investigated the effectiveness and safety of conventional surgery on longstanding retinal detachments (RD) with subretinal bands (SRB). We found that conventional surgery were safe and effective method in the treatment of inferior chronic rhegmatogenous RD cases with SRB without other signs of advanced proliferative vitreopathy. Further studies with larger numbers and longer follow up are needed.     

Balanced orbital decompression in Graves' orbitopathy: Upper eyelid crease incision for extended lateral wall decompression

INTRODUCTION. This study reports on the results and complications detected in patients with Graves' orbitopathy who underwent balanced medial and lateral wall orbital decompression through concealed incisions. MATERIALS AND METHODS. The medial and lateral orbital walls of nine consecutive patients (14 eyes) were removed. A transnasal endoscopic spheno-ethmoidectomy was performed for the medial wall decompression. A lateral wall decompression was performed via an upper eyelid crease incision which was extended laterally in a relaxed skin tension line. The lateral aspect of the orbit was sculpted with a high-speed surgical drill from the inferior orbital fissure inferiorly and frontal bone of the lacrimal fossa superiorly to the orbital apex posteriorly, including the thick bone of the greater wing of the sphenoid. RESULTS. The decompression was performed for cosmetic purposes in seven patients (10 orbits) and for exposure keratopathy and restrictive myopathy in the remaining two patients (4 orbits). The average follow-up period was 13.6 months. The mean reduction of proptosis was 4.8 mm. The preoperative diplopia in two cases demonstrating restrictive myopathy worsened during the postoperative period. New onset diplopia was not detected in seven cases operated on for cosmetic purposes. All patients were satisfied with their eye status, visual rehabilitation and cosmetic appearance. CONCLUSIONS. The transnasal endoscopic approach for medial wall and extended lateral wall decompression with hidden eyelid crease incision provides a favorable cosmetic and physiologic outcome with proper retroplacement of the globe.     

Surgical treatment of hereditary lens subluxations

BACKGROUND AND OBJECTIVE: To evaluate the effectiveness and results of pars plana vitreolensectomy approach with transscleral fixation of intraocular lens in hereditary lens subluxations. METHODS: Fifteen eyes of 9 consecutive patients with a mean age of 12.8+/-6.2 years (6-26 years) with hereditary lens subluxation were operated on and the results were evaluated in a prospective study. Surgery was considered if best spectacle corrected visual acuity (BSCVA) was less than 20/70. All eyes underwent a 2-port pars plana vitreolensectomy and transscleral fixation of an intraocular lens (IOL). RESULTS: The mean follow-up period was 12.6+/-7.5 months (6-22 months). There was no major intraoperative complication. Preoperatively, 8 eyes (53.3%) had a BSCVA of counting fingers (CF) and 7 eyes (46.6%) had a BSCVA of 20/200 to 20/70. Postoperatively, 14 eyes (93.3%) had a BSCVA of 20/50 or better. None of the patients had IOL decentration or intraocular pressure (IOP) increase during the follow-up period. There was a macular hole formation in 1 eye postoperatively. CONCLUSIONS: The early results of pars plana vitreolensectomy with IOL implantation using scleral fixation technique had shown that it not only promises a rapid visual rehabilitation but it is also a relatively safe method. More serious complications, however, may occur in the long term.     

Effects of thick Tenon's capsule on primary trabeculectomy with mitomycin-C

PURPOSE: To investigate the effects of thick Tenon's capsule on primary trabeculectomy with adjunctive mitomycin-C. METHODS: In this prospective interventional case series of 45 consecutive uncomplicated glaucoma patients, 45 eyes with thick Tenon's capsule underwent primary trabeculectomy with intraoperative mitomycin-C (0.4 mg/ml for 3 min). Success was defined as intraocular pressure (IOP) 相似文献   

Effect of bevacizumab on corneal neovascularization in experimental rabbit model

Purpose:  To investigate the effect of bevacizumab in an experimental rabbit model of corneal neovascularization.
Methods:  The right eyes of 24 white New Zealand rabbits were included in a corneal neovascularization model using alkaline burn. They were divided into four groups. Topical bevacizumab was installed three times daily in group 1, 5 mg bevacizumab subconjunctivally every 2 days in group 2, 10 mg bevacizumab subconjunctivally every 2 days in group 3 and 0.2 cc of normal saline in the same way in group 4 (control group). All eyes were treated for 7 days. Then the animals were killed and corneal specimens sent for histopathological analysis. Tear film and aqueous humour samples were obtained to assess vascular endothelial growth factor (VEGF) levels.
Results:  Seven days after topical bevacizumab treatment the neovascular index in group 1 was lower than that in the control group ( P  = 0.028). In groups 2 and 3 the neovascular index was lower 2 days after subconjunctival bevacizumab treatment than that in control group ( P  = 0.009 and P  = 0.009, respectively). In the control group the VEGF level in aqueous humour increased by 66% from day 7 to 14. In groups 1–3 it decreased by 49.80%, 70.20% and 76.44%, respectively ( P  = 0.043). The VEGF level in tear film of the control group increased by 35.23% from day 7 to 14, which was not significant ( P  = 0.893), while in groups 1–3 it decreased by 57.26%, 34.59% and 67.97%, respectively, which was only significant in groups 1 and 3 ( P  = 0.043).
Conclusions:  Subconjunctival 5 mg/mL bevacizumab is effective in reducing corneal neovascularization in animal models and in reducing VEGF levels. Further research is needed to assess the potential side effects and minimal effective dose.     

The effect of excimer laser keratectomy on corneal glutathione peroxidase activities and aqueous humor selenium levels in rabbits

BACKGROUND: The formation of free oxygen radicals has been demonstrated in the corneal tissue after 193 nm laser irradiation. Cornea has several defense mechanisms that protect against oxidative damage. One of them, glutathione peroxidase (GPx), catalyzes the destruction of hydrogen peroxide and lipid hydroperoxide. Selenium is a trace element which is incorporated into the selenoenzyme GPx. In the present study, the effect of excimer laser keratectomy on corneal GPx activities and aqueous humor selenium concentrations in rabbits was evaluated. METHODS: Animals were divided into five groups, and all groups were compared: controls (group 1), after epithelial scraping (group 2), transepithelial photorefractive keratectomy(PRK; group 3), superficial traditional PRK (50 microm; group 4) and deep traditional PRK (100 microm; group 5). Corneal GPx activities were measured by a modification of the coupled assay procedure. Aqueous humor selenium concentrations were determined using hydride generation atomic absorption spectrometry. RESULTS: Corneal GPx activities were significantly lower only in group 5 ( P<0.05), and the selenium concentration in the aqueous humor did not change in any group. CONCLUSION: Deep corneal photoablation inhibits GPx enzyme activities in the cornea. Therefore, antioxidants may be useful in reducing free radical-mediated complications after excimer laser corneal photoablation.     

Alterations in ocular surface and corneal thickness in relation to metabolic control in patients with chronic renal failure

AIM: Ocular surface changes and ocular symptoms may be encountered in patients with chronic renal failure (CRF) undergoing haemodialysis. The ocular surface changes and its relationship with metabolic control in CRF patients were aimed to be emphasized in this study. METHODS: Thirty-eight CRF patients (75 eyes) undergoing haemodialysis were enrolled. Patients underwent a complete ocular examination together with Schirmer, tear break-up time tests, pachymetric measurements and conjunctival impression cytologies. Blood calcium, phosphate levels and total body volume changes after haemodialysis were recorded. RESULTS: The most common findings were conjunctival calcification with red eye (81.3%) and dry eye (62.7%, according to tear break-up time test) in 75 eyes of 38 patients. Impression cytologies were graded as 0 in 57.3% of eyes and 2-3 in 40% of eyes showing positive correlation with the extent of conjunctival calcification (R = 0.486, P = 0.0001). Serum calcium and phosphate levels were also positively correlated with the degree of conjunctival calcification (R = 0.684, P = 0.0001 and R = 0.428, P = 0.0001, respectively) as well as with the grades of impression cytology (R = 0.587, P = 0.0001 and R = 0.385, P = 0.0001, respectively). Furthermore, the mean corneal thickness decreased significantly (9.31 +/- 26.9 mum) following haemodialysis (Paired t-test, P = 0.002). CONCLUSION: Dry eye and irritational symptoms are major ocular symptoms in CRF patients. Serum calcium and phosphate levels seem to have a prognostic importance for the ocular findings and symptoms in patients with CRF.     

Effect of mitomycin C on ciliary body and intraocular pressure with various application depths: an experimental study

BACKGROUND: To evaluate the effects of mitomycin C (MMC) on intraocular pressure (IOP) and ciliary body via transmission electron microscopy when applied under conjunctiva or different depths of sclera, without performing any filtering surgery. METHODS: Thirty-six eyes of 36 New Zealand albino rabbits were used in this study. MMC was prepared in a concentration of 0.4 mg/mL and 0.05 cc (20 microg) was soaked in preprepared sterile surgical sponges. Six groups each consisting of six eyes were formed and IOP was measured preoperatively. Group 1 was the control group: the superior conjunctiva was opened and only irrigated with balanced salt solution (BSS). In group 2, MMC soaked sponges were applied under the conjunctiva. In groups 3 and 4, a scleral flap of approximately 1/3 scleral thickness was prepared and in groups 5 and 6, and a scleral flap of approximately 2/3 scleral thickness was prepared, all with a standard size of 4 x 4 mm. MMC soaked sponges were applied under these areas for 5 min in eyes in groups 3 and 5 followed by an irrigation of the relevant areas with 10 cc BSS, whereas only irrigation with BSS was done in groups 4 and 6 as control groups. No filtering procedure was performed in any of the eyes. Eyes were enucleated on the 30th day following measurement of IOP and the ciliary body regions were evaluated using transmission electron microscopy. Kruskal-Wallis test was used for the statistical assessment of IOP between groups. RESULTS: The deep scleral flap group (group 5) showed statistically significantly more IOP reduction than both the superficial scleral flap group (group 3; P = 0.004) and the subconjunctival group (group 2; P = 0.002) on postoperative day 30. Electron microscopic evaluation of the surgical groups revealed a wide range of different histopathological effects due to different MMC application methods. The histopathological changes were more evident in the group 5, where MMC was applied under deep scleral flap. CONCLUSIONS: Subscleral application of MMC seems to provide greater IOP decrease than subconjunctival application, possibly caused by a more significant ciliary body toxicity. This may be the beginning of a non-penetrating, easy to perform and safe method to decrease IOP in glaucoma patients, which the authors call 'toxic ciliary ablation surgery'. However, the long-term results and complications must be assessed with further studies.