Ebru Toker

Refractive errors of medical students in Turkey: one year follow-up of refraction and biometry.

Purpose. This study was conducted to determine the prevalence of refractive errors in Turkish medical students as well as to determine the change in refractive status of medical students within 1 year. Besides general refractive characteristics of the students, the possible relationship between the occurrence of myopia and several factors was also determined. Methods. Two hundred and seven medical students (114 female/93 male) were checked for their refractive status as determined by cycloplegic autorefraction. In addition to keratometric and biometric measurements students also answered a detailed questionnaire. One year later, medical students who participated to the study were re-examined. Results. Myopia occurred in 32.9% of medical students with low myopia (spherical equivalent between −0.75 diopters [D] and −2.99 D) being the most common type (81%). The frequency of myopia was not significantly different between female and male medical students (37.7 and 26.8%, respectively; p = 0.13). Adult onset myopia (onset at age 18 years or older) comprised 14.7% of all myopia cases. Myopic students were significantly more likely to report parental myopia. The percentage of myopes and nonmyopes reporting having one or two myopic parents was 51.5 and 28.8%, respectively (p = 0.002). Parental myopia was also an independent risk factor associated with the occurrence of myopia on multivariate analysis (odds ratio [OR] = 3.69, 95% confidence interval [CI] = 1.98–6.87). Nonmyopes also reported a significantly higher prevalence of outdoor activity before and at age seven (68.4%) than did myopes (48.6%), (p = 0.009). Outdoor activity during early childhood was found to be protective for myopia on multivariate analysis (OR = 0.44, %95 CI = 0.23–0.82). There was no significant difference between myopes and nonmyopes with respect to amount of close-up activity. No significant shift of refraction occurred within 1 year. Conclusions. About one-third of Turkish medical students had myopia. Parental myopia was more common among myopic students and was a risk factor for the occurrence of myopia suggesting a familial predisposition. Outdoor activity in early childhood has had a protective role against the development of myopia in this study sample.

Corneal and conjunctival sensitivity in patients with dry eye: the effect of topical cyclosporine therapy.

Purpose: To evaluate changes in mechanical sensitivity of cornea and conjunctiva in patients with dry eye disease unresponsive to artificial tears therapy and to investigate the effect of topical cyclosporine therapy on sensitivity of the ocular surface. Methods: Thirty-seven patients with dry eye disease and 35 healthy control subjects were enrolled to this prospective study. All patients included in the study completed a 3-month run-in period of using nonpreserved artificial tear supplements, but all failed to achieve adequate subjective or objective improvement. Patients were then instructed to use topical cyclosporine A 0.05% twice a day. Pre- and posttreatment (1, 3, and 6 months) evaluations included, corneal and conjunctival sensitivity testing with the Cochet-Bonnet esthesiometer, subjective symptom scoring, fluorescein and lissamine green staining, Schirmer test, and tear breakup time (BUT). Results: Conjunctival and corneal sensitivities were significantly lower in patients with dry eye compared with controls (P < 0.0001). In patients with dry eye, corneal sensitivity correlated positively with conjunctival sensitivity and negatively with ocular surface staining scores. Conjunctival sensitivity correlated negatively with the duration of dry eye disease, the total symptom severity score, and the severity of dryness symptom and positively with Schirmer test and tear BUT. Corneal and conjunctival sensitivities did not change significantly after artificial tear therapy (P > 0.05). After topical cyclosporine, statistically significant improvements from baseline were observed in corneal sensitivity at 3- and 6-month visits (P < 0.001). For conjunctival sensitivity, statistically significant improvements from baseline were seen at all follow-up visits (P < 0.0001). Topical cyclosporine treatment also led to significant improvements in symptom scores, Schirmer test, tear BUT, and ocular surface staining scores (P < 0.0001). Conclusions: The mechanical sensitivity of cornea and conjunctiva to tactile stimulus is reduced in patients with dry eye. Our findings suggest that topical cyclosporine may be effective in improving this reduced mechanical sensitivity of the ocular surface.

Influence of serum levels of sex hormones on intraocular pressure in menopausal women.

PurposeThe purpose of this study was to assess the effect that changes in sex hormone levels have on intraocular pressure (IOP) in menopausal women. Subjects and MethodsThirty menopausal women on hormone replacement therapy and 32 menopausal women who had never received hormone replacement therapy (HRT), matched for age and duration of amenorrhea, participated in this study. Intraocular pressures were measured with Goldmann applanation tonometer. Serum levels were measured for estradiol, free testosterone, and follicle stimulating hormone (FSH). The influence of serum hormone levels on IOP was assessed by correlation analysis. ResultsThe mean IOP of postmenopausal women receiving HRT (13.29 ± 2.28 mm Hg) was not significantly different from that of menopausal women not receiving HRT (13.56 ± 2.5 mm Hg, P = 0.24). Higher testosterone levels were associated with higher IOPs in women receiving HRT (r = 0.48, P = 0.02) and in those not receiving HRT (r =0.42, P = 0.003). No significant correlations were observed between IOP and serum levels of estradiol and FSH in either group. ConclusionOur data provide evidence for a relation between serum testosterone levels and IOP in menopause. Higher testosterone seems to have a tendency to increase IOP in menopausal women.

Tear production during the neonatal period

PURPOSE To measure tear secretion in term and preterm infants to assess whether tear secretion correlates with the maturity of the infants and to evaluate the changes in tear production during the neonatal period. DESIGN Prospective, observational case series. METHODS Ninety-six term and 22 preterm medically stable infants were studied. Post-conceptional age and birth-weight of each infant were recorded. Tear secretion was measured by the Schirmer test before (total tear secretion) and after (basal tear secretion) the instillation of topical anesthetic agent. Both eyes were tested consecutively. The initial tear measurements were performed within the first 2 days of life, and tear measurements were repeated at 2 weeks and 4 weeks after birth. RESULTS The mean total tear production was 16.3 (+/-3.6) mm in term and 7.4 (+/-3.2) mm in preterm infants. The mean basal tear production was 7.3 (+/-3.2) mm in term and 3.5 (+/-1.3) mm in preterm infants. Total tear secretion significantly correlated with birth-weight (r, 0.42, P =.04) and post-conceptional age (r, 0.56, P =.006) in preterm infants. For term infants, total tear secretion significantly increased at 2 weeks (18.1 +/- 3.4 mm, P <.001) and 4 weeks (19.5 +/- 4.1 mm, P <.001) after birth. For preterm infants, a significant increase in total tear production was observed at the fourth week (11.5 +/- 3 mm, P <.001). CONCLUSION Tear production in newborns depends on the maturity of the infants and increases substantially during the neonatal period. Preterm infants have reduced tear secretion compared with term infants.

Tear cytokine levels in vernal keratoconjunctivitis: the effect of topical 0.05% cyclosporine a therapy.

Purpose: The aims of this study were to evaluate the efficacy of topical 0.05% cyclosporine A on clinical signs and symptoms of vernal keratoconjunctivitis (VKC) and to examine its effect on tear cytokine levels. Methods: Twenty-one patients with active VKC and 15 healthy volunteers were included. Patients were treated with topical 0.05% cyclosporine A. Symptoms and signs were scored on the day of enrollment and at the end of month 1 and month 3. Tear and serum samples were collected before and on the third month of treatment. Interleukin (IL)-2, soluble IL-2 receptor (sIL-2R), IL-3, IL-4, IL-5, IL-6, IL-9, IL-13, IL-17, eotaxin, tumor necrosis factor alpha (TNF-&agr;), and interferon gamma (IFN-&ggr;) in cell-free tear and serum supernatants were measured by multiplex bead analysis. Results: At the end of month 1 and month 3 with topical 0.05% cyclosporine A treatment, statistically a significant decrease was observed in sign and symptom scores of the patients (P < 0.0001). Tear IL-2, sIL-2R, IL-9, IL-17, IFN-&ggr;, and eotaxin levels in VKC patients were significantly higher than those in controls (P < 0.05). IL-3, IL-4, IL-5, and TNF&agr; levels tended to be higher in VKC patients. There was also statistically significant reduction from before 0.05% cyclosporine A treatment to after treatment in tear levels of IL-4, IL-5, IL-17A, TNF&agr;, IFN-&ggr;, and eotaxin (P < 0.05). IL-2 and sIL-2R levels tended to be lower than pretreatment levels. Conclusions: Topical 0.05% cyclosporine A is effective in alleviating signs and symptoms of VKC patients and shows its effect probably by decreasing the local production of some inflammatory mediators in tears.

Transepithelial versus epithelium-off crosslinking in adults with progressive keratoconus

Purpose To compare the efficacy of epithelium‐off corneal collagen crosslinking (CXL) with transepithelial CXL in patients with progressive keratoconus. Setting Department of Ophthalmology, Marmara University School of Medicine, Istanbul, Turkey. Design Retrospective cohort study. Methods Eyes that had transepithelial CXL were compared with eyes treated with epithelium‐off CXL. All patients with a follow‐up of 18 months were evaluated for uncorrected (UDVA) and corrected (CDVA) distance visual acuities, corneal topography, aberrometry, and pachymetry (Pentacam). Results The mean patient age was 22.8 years ± 4.7 (SD) (range 18 to 31 years) in the transepithelial group (30 eyes) and 23.7 ± 3.9 years (range 18 to 30 years) in the epithelium‐off group (30 eyes). The mean UDVA and CDVA significantly improved in both groups (P < .001). There was no significant difference in the CDVA gain between the 2 groups. In the epithelium‐off group, significant improvements occurred in spherical error (P = .002), spherical equivalent (P = .004), maximum keratometry (K), flat K (P = .036), and steep K (P < .001). The reductions in flat K, steep K, and maximum K were greater in the epithelium‐off group (P = .004 for flat K; P < .001 for steep K and maximum K). In the transepithelial group, significant improvements occurred in the cylindrical error (P = .009) and in the index of surface variance and index of surface asymmetry (both P < .001). Conclusion Although transepithelial CXL seemed to have reduced effectiveness in inducing improvement in topographic indices, its effect on visual acuity is likely to be similar to that of epithelium‐off CXL. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Colobomatous macrophthalmia with microcornea syndrome: report of a new pedigree.

Colobomatous macrophthalmia with microcornea syndrome (MIM 602499) is a very rare eye malformation. To date, only two families with a total number of eight patients have been reported. We report on 13 additional cases in a single three‐generation family and describe the eye findings and quantitative parameters of corneal curvature and axial ocular dimensions. All affected relatives had bilateral involvement with typical inferonasal iris coloboma, chorioretinal coloboma, microcornea, and varying degrees of axial enlargement associated with myopia. Additional findings included flatter corneal curvatures and shallower anterior chambers. Iridocorneal angle abnormalities associated with elevation of intraocular pressure were detected in three patients. The pedigree confirms the autosomal dominant pattern of inheritance with complete penetrance.

Influence of Apical Clearance on Mini-Scleral Lens Settling, Clinical Performance, and Corneal Thickness Changes.

Purpose: The purpose of this work was to define the timing and magnitude of scleral contact lens settling, the factors influencing settling, and to examine whether the amount of apical clearance has an impact on clinical performance or is associated with hypoxia-induced corneal changes. Methods: Eleven patients (22 eyes) with keratoconus were fitted with a mini-scleral lens (Esclera, Brazil). Three different lenses with successively greater sagittal depths were applied to achieve 3 levels of initial apical clearance: 100 to 200 &mgr;m (low), 200 to 300 &mgr;m (medium), and greater than 300 &mgr;m (high). Corneal apical clearance was measured at 15 min, 1, 2, 4, 6, and 8 hr with optical coherence tomography (OCT). Central corneal thickness was measured with OCT and Pentacam, in the morning and immediately after removal of the contact lens. Results: Mean settling was 26.8±18.8 &mgr;m (42.7%) at 1 hr, 39.5±26.5 &mgr;m (62.9%) at 2 hr, 50.7±31.6 &mgr;m (80.8%) at 4 hr, 57.4±34.6 &mgr;m (91.4%) at 6 hr, and 62.8±38.4 &mgr;m (100%) at 8 hr. Settling rate was significantly lower in low apical clearance group (P=0.01). The smaller diameter lenses settled more (P=0.03). There was a slight statistically significant increase of 1.3% in central corneal thickness measured with OCT (P=0.03). Central corneal thickness measured with Pentacam at three locations increased slightly (P=0.001). Settling showed significant intrasubject and intersubject variations. The amount of corneal swelling and comfort scores did not differ significantly according to apical clearance. Conclusions: The average amount of settling was 62.8 &mgr;m after 8 hr, 80% of which occurred during the first 4 hr. Slight corneal swelling (1.3%) occurred after 8 hr of wear.

Recurrence After Primary Pterygium Excision: Amniotic Membrane Transplantation with Fibrin Glue Versus Conjunctival Autograft with Fibrin Glue

Abstract Purpose: The aim of the present study was to compare the surgical results and recurrence rates of primary pterygium excision with conjunctival autografts versus amniotic membrane grafts fixated with fibrin glue. Materials and methods: In this prospective study, 73 eyes of 65 patients who had undergone conjunctival autograft group (CAG) (n:37) or amniotic membrane group (AMG) (n:36) after pterygium excision were evaluated. Fibrin glue was used for the fixation of grafts in both groups. The patients were followed up for 12 months. Postoperative complications were recorded. The rate of recurrence was defined as the primary outcome measure. Results: In the CAG, partial dehiscence of the graft was observed on the nasal edge on postoperative day 1 in two (5.4%) eyes that healed with secondary re-epithelialization at week 1. Twelve (32.4%) eyes showed a yellowish-orange or hemorrhagic edema of the graft on postoperative day 7 that spontaneously resolved in 1 to 3 weeks. In the AMG, partial dehiscence and folding of the amniotic membrane occurred in two (5.5%) eyes. Two eyes (5.4 %) in the CAG developed corneal recurrence and five eyes (13.8%) in the amniotic membrane graft group developed recurrence; one limbal (2.7%), four corneal recurrences (11.1%) (p = 0.25). Conclusion: Fibrin glue is a safe and effective method for attaching conjunctival or amniotic membrane grafts for wound closure following pterygium surgery. Although the results were not statistically significant, amniotic membrane grafting using fibrin glue seems to have a higher pterygium recurrence rate compared with conjunctival autografting.

Comparative Analysis of Anterior Segment Parameters in Normal and Keratoconus Eyes Generated by Scheimpflug Tomography

Purpose. To assess and compare the anterior and posterior corneal surface parameters, keratoconus indices, thickness profile data, and data from enhanced elevation maps of keratoconic and normal corneas with the Pentacam Scheimpflug corneal tomography and to determine the sensitivity and specificity of these parameters in discriminating keratoconus from normal eyes. Methods. The study included 656 keratoconus eyes and 515 healthy eyes with a mean age of 30.95 ± 9.25 and 32.90 ± 14.78 years, respectively. Forty parameters obtained from the Pentacam tomography were assessed by the receiver operating characteristic curve analysis for their efficiency. Results. Receiver operating characteristic curve analyses showed excellent predictive accuracy (area under the curve, ranging from 0.914 to 0.972) for 21 of the 40 parameters evaluated. Among all parameters indices of vertical asymmetry, keratoconus index, front elevation at thinnest location, back elevation at thinnest location, Ambrósio Relational Thickness (ARTmax), deviation of average pachymetric progression, deviation of ARTmax, and total deviation showed excellent (>90%) sensitivity and specificity in addition to excellent area under the receiver operating characteristic curve (AUROC). Conclusions. Parameters derived from the topometric and Belin-Ambrósio enhanced ectasia display maps very effectively discriminate keratoconus from normal corneas with excellent sensitivity and specificity.