Huseyin Yetik

Determining the lowest trypan blue concentration that satisfactorily stains the anterior capsule

Purpose: To determine the lowest concentration of trypan blue that will stain the anterior capsule satisfactorily to perform a safe continuous curvilinear capsulorhexis and to describe a staining technique using a dispersive viscoelastic material. Setting: Cerrahpasa School of Medicine, University of Istanbul, Istanbul, Turkey. Methods: Trypan blue 0.1% (Vision Blue®) was diluted by half by adding an equal volume of balanced salt solution (BSS®) in a stepwise pattern continuously until the concentration failed to stain the anterior capsule satisfactorily. After the dilution, 4 concentrations of the dye were obtained: 0.050%, 0.025%, 0.0125%, and 0.00625%. The volume of dye used for staining was 0.1 cc at all concentrations. Each concentration of the dye was applied using a classic air‐bubble technique or a technique in which the dye was injected under sodium hyaluronate 3.0%‐chondroitin sulfate 4.0% (Viscoat®) onto the anterior lens surface without using an air bubble to reform the anterior chamber. Each diluted concentration was used in 10 eyes by the same surgeon, with 5 eyes having the air‐bubble technique and 5 having the viscoelastic technique. The 0.1% concentration was used in 5 eyes, all having the viscoelastic technique. Results: Trypan blue in concentrations as low as 0.0125% stained the anterior capsule satisfactorily. In addition, staining was possible under the Viscoat. The viscoelastic technique was faster, safer, and easier to perform than the air‐bubble technique. Conclusions: As trypan blue is a potentially carcinogenic vital dye and its possible long‐term side effects are unknown, the lowest effective concentration should be used. A concentration lower than 0.1% was effective in staining the anterior capsule even under dispersive viscoelastic material.

Scleral Buckling with a Non-Contact Wide-Angle Viewing System

Purpose: To assess the outcome of scleral buckling surgery using a non-contact wide-angle viewing system for fundus visualization in patients with rhegmatogenous retinal detachment without proliferative vitreoretinopathy. Patients and Methods: Sixteen eyes of 16 patients underwent scleral buckling using a non-contact wide-angle viewing system combined with a 25-gauge illumination fibre inserted into the sclera at the pars plana. Results: The mean age of the patients was 53.6 ± 13.7 years and the mean follow-up time was 13.4 ± 2.8 months. Retinal reattachment was achieved in 13 of the 16 eyes (81%). Three eyes underwent vitrectomy with silicone oil injection because of development of proliferative vitreoretinopathy in 2 eyes and scleral perforation due to excessive indentation during cryoretinopexy in 1 eye. Two eyes developed limited subretinal haemorrhage during subretinal fluid drainage. Conclusion: Simultaneous use of a non-contact wide-angle viewing system combined with a 25-gauge light fibre illumination for fundus visualization brings the advantages of microsurgery and indirect ophthalmoscopy into scleral buckling surgery.

Structural features of attached retina in rhegmatogenous retinal detachments.

Purpose To examine the thickness and structural features of the ophthalmoscopically normal-appearing, attached retina in rhegmatogenous retinal detachments by optical coherence tomography (OCT) and compare them with those of the fellow eye. Methods Seventy eyes of 35 patients with rhegmatogenous retinal detachments were included in this study. The retinal detachments were not total. None of the patients had pathologic myopia or a history of ocular surgery. The fellow eyes were ophthalmoscopically normal and used as controls. Attached retinal sites of the eyes with a retinal detachment and the corresponding retinal sites of the fellow eyes were examined by OCT. Three OCT sections were taken from each eye, and thicknesses of three reflective zones corresponding to the inner part of the neurosensory retina (partial neurosensory retina), photoreceptor–photoreceptor outer segment, and total retinal thickness on each OCT section were measured and compared with those of the fellow eye. These three measurements were taken as the main outcome measures and performed on five different sites of each OCT section taken from each eye. Results The mean partial neurosensory retinal thickness of the attached retina in the eyes with a retinal detachment and the corresponding retinal sites in the fellow eyes was 172.74 ± 14.23 &mgr;m and 170.60 ± 16.51 &mgr;m, respectively. There was no statistically significant difference between these two values. The mean photoreceptor outer segment thickness of the attached retina in the eyes with a retinal detachment and the corresponding retinal sites in the fellow eyes was 62.74 ± 12.02 &mgr;m and 58.23 ± 15.14 &mgr;m, respectively. There was a statistically significant difference between these two values. The mean total retinal thickness of the still-attached retina in the eyes with a retinal detachment and the corresponding retinal sites in the fellow eyes were 293.23 ± 27.87 &mgr;m and 277.06 ± 19.12 &mgr;m, respectively. There was a statistically significant difference between these two values. Conclusions The main difference between the two groups of eyes was at the level of the thickness of the black hyporeflective zone, corresponding anatomically to the photoreceptor and photoreceptor outer segment that enlarges in the retinal detachments. Therefore, there may be a subclinical retinal detachment or a global retinal relaxation even in the ophthalmoscopically normal-appearing, still-attached retina. This may be the underlying cause of preoperative and postoperative signs and symptoms. Additional studies are required to confirm these findings.

Screening for Retinopathy of Prematurity in a Tertiary Hospital in Istanbul: Incidence and Risk Factors

PURPOSE To study the incidence and risk factors of retinopathy of prematurity (ROP) in premature infants examined in a tertiary hospital in Istanbul. METHODS Data of infants screened for ROP from April 2007 to September 2009 were retrospectively reviewed. Possible risk factors and eye examinations were recorded and analyzed using the chi-square test and univariate and multivariate regressions. RESULTS ROP was detected in 177 (34.3%) of the 517 infants enrolled in the study; 64 had mild ROP (77.4%) and 38 had severe ROP (22.6%). The mean gestational age and birth weight of patients who were treated for ROP were 28.6 ± 2.3 and 1,143.5 ± 337.4, respectively. Two of these infants had a gestational age of 32 g or greater and three had a birth weight of 1,500 g or greater. The multivariate regression analyses showed gestational age, birth weight, sepsis, respiratory distress syndrome, and length of oxygen therapy as independent predictors of ROP. CONCLUSION The incidence of ROP observed in this study was higher than that in developed countries and relatively more mature infants were affected. Criteria including gestational age of less than 34 weeks or birth weight of less than 2,000 g would have identified all infants who were at risk.

Vitreoretinal surgery for a subretinal hydatid cyst

PURPOSE To report the vitreoretinal surgery for management of a subretinal hydatid cyst. METHODS Conventional pars plana vitrectomy was performed for the removal of a subretinal hydatid cyst and treatment of retinal detachment in the right eye (RE) of a 34-year-old woman. The cyst content was aspirated by a flute needle after retinotomy and cystotomy. The cyst wall was separated from overlying retina and removed. The retina was attached by liquid perfluorocarbon and silicone oil. Postoperatively, the patient was followed for 15 months. RESULTS After vitreoretinal surgery, the retina RE was attached and recurrence of hydatid disease was not seen in vitreous cavity or subretinal space during the follow-up period. Visual acuity increased from counting fingers to 20/63 at the end of the follow-up time. CONCLUSION A subretinal hydatid cyst that causes retinal detachment may be treated effectively with vitreoretinal surgery.

Early Surgery for Dysthyroid Orbitomyopathy Based on Magnetic Resonance Imaging Findings

PURPOSE To investigate the value of magnetic resonance imaging (MRI) in the determination of the fibrotic phase in dysthyroid orbitopathy, which may be an indication for early surgery. PATIENTS AND METHODS Thirteen patients with dysthyroid orbitopathy who had vertical deviation in excess of 20 PD and associated diplopia in the primary position that did not respond to medical treatment were included in the study. On MRI, the absence of high-intensity foci in the T2 sequence, especially in the coronal planes, indicated that the extraocular muscles were not edematous. These muscles were evaluated as being in the fibrotic phase, and surgery was performed without waiting the recommended 6 months for the stabilization of the angle of deviation. RESULTS The complaint of diplopia disappeared after a single operation in 8 patients, and after a second operation in 4. Thus, success was obtained in 12 of the 13 patients. One patient with persistent vertical diplopia refused a second operation. CONCLUSION Our results indicate that MRI is an effective and reliable method for the determination of the fibrotic phase in patients with dysthyroid orbitopathy who have diplopia in the primary position, and that MRI results have an important role in determining whether early surgery is appropriate.

The association between serum homocysteine levels and retinopathy of prematurity.

Objective: To evaluate the relationship between serum total homocysteine levels and retinopathy of prematurity (ROP). Methods: This prospective case-control study involved premature infants diagnosed with ROP 4 weeks after birth (cases); controls were premature infants not developing ROP during follow-up. Fasting serum total homocysteine concentrations were determined in all participants 4 weeks after birth, using high performance liquid chromatography. Results: A total of 45 and 35 infants were included in the case and control groups, respectively. The mean ± SD (range) serum total homocysteine levels were 10.36 ± 1.72 μmol/l (7.45 - 14.84) in infants with ROP and 8.41 ± 2.12 μmol/l (5.56 - 13.90) in controls. This difference was statistically significant. Mean ± SD total homocysteine levels were higher in infants with more severe ROP (11.45 ± 1.76 μmol/l) compared with mild ROP (9.92 ± 1.56 μmol/l). Conclusions: Elevated serum total homocysteine levels are associated with the development of ROP in premature infants. Further studies with larger patient populations are required, to improve understanding of the relationship between homocysteine and ROP development.

Isolated Anterior Lens Capsule Rupture Secondary to Blunt Trauma: Pathophysiology and Treatment

A 25-year-old man suffered an isolated lens anterior capsular tear and mature cataract formation following blunt injury to his right eye. One week after the trauma, best-corrected visual acuity (BCVA) in the right eye was hand motion. B-scan ultrasonography showed that the lens posterior capsule was intact; no vitreous foreign body or retinal pathology were observed. Orbital computed tomography revealed narrowed anterior chamber and increased lens material volume and lens reflectivity in the injured right eye. The globe was intact and no bone fractures were observed. The cataractous lens material was removed by phacoemulsification and a foldable, acrylic, posterior chamber intraocular lens was implanted in the bag. Postoperative BCVA in the right eye was 20/20.