FOXF2 is required for cochlear development in humans and mice.

Molecular mechanisms governing the development of the human cochlea remain largely unknown. Through genome sequencing, we identified a homozygous FOXF2 variant c.325A>T (p.I109F) in a child with profound sensorineural hearing loss (SNHL) associated with incomplete partition type I anomaly of the cochlea. This variant is not found in public databases or in over 1000 ethnicity-matched control individuals. I109 is a highly conserved residue in the forkhead box (Fox) domain of FOXF2, a member of the Fox protein family of transcription factors that regulate the expression of genes involved in embryogenic development as well as adult life. Our in vitro studies show that the half-life of mutant FOXF2 is reduced compared to that of wild type. Foxf2 is expressed in the cochlea of developing and adult mice. The mouse knockout of Foxf2 shows shortened and malformed cochleae, in addition to altered shape of hair cells with innervation and planar cell polarity defects. Expressions of Eya1 and Pax3, genes essential for cochlear development, are reduced in the cochleae of Foxf2 knockout mice. We conclude that FOXF2 plays a major role in cochlear development and its dysfunction leads to SNHL and developmental anomalies of the cochlea in humans and mice.

The analysis of posterior segment findings in term and premature infants using RetCam images.

OBJECTIVE: To analyze posterior segment findings in term and premature infants using the RetCam image database. METHODS: RetCam images taken of infants born between January 2012 and December 2015 were reviewed. Group 1 included infants with posterior segment findings other than retinopathy of prematurity (ROP). Group 2 included infants with mild-to-severe ROP. The baseline characteristics, anterior segment findings, and percentage of infants who received treatment were compared among the 2 groups. RESULTS: In total, 331 out of 3440 infants (9.6%) were included. The major diagnoses in group 1 (n = 75) were retinal hemorrhages in 26, optic nerve pathologies in 14, findings associated with a metabolic disease in 6, ocular tumors in 5, persistent hyperplastic primary vitreous in 4, and familial exudative vitreoretinopathy in 4 cases. The mean birth weight (g) (2481.9 ± 700.5 in group 1 vs 1090.5 ± 330.9 in group 2), gestational age (weeks) (35.9 ± 3.4 in group 1 vs 28.2 ± 2.4 in group 2), and postmenstrual age at initial examination (35.9 ± 3.4 in group 1 vs 28.2 ± 2.4 in group 2) were significantly different among the 2 groups (p < 0.001). Thirteen out of 75 cases in group 1 and 124 out of 256 ROP cases received therapy (p < 0.001). Anterior segment pathologies were found in 13.3% of group 1 versus 7.8% of group 2 infants (p = 0.216). CONCLUSIONS: A considerable number of infants suffered from posterior segment disorders other than ROP. The majority of these infants were term babies. Routine fundus screening may be recommended in all newborns to diagnose all posterior segment pathologies other than ROP.

The macular findings on spectral-domain optical coherence tomography in premature infants with or without retinopathy of prematurity.

The purpose of the study was to present spectral-domain optical coherence tomography (OCT) findings in premature infants with or without mild-to-severe retinopathy of prematurity (ROP). Seventy-two infants born <37 weeks of gestation were analyzed, prospectively. Group 1 (n = 18) included infants without ROP. Infants with stage 1, 2, or 3 ROP without indication for treatment formed the second group (n = 15). Group 3 (n = 21) included threshold cases, who would receive laser photocoagulation (LPC) after OCT examinations. Group 4 (n = 18) had already received LPC. The mean central foveal thickness (CFT) (µm) in right eyes was 194.27 ± 19.93, 207.67 ± 25.44, 224.29 ± 21.42, and 222.00 ± 37.80, for groups 1, 2, 3, and 4, respectively (p = 0.01). The presence of a well-formed foveal pit was documented in 60 % of right and 67 % of left eyes in group 1, while a well-formed foveal pit was observed in 14 % of right and 16 % of left eyes in group 3 (p < 0.05). Cystoid macular edema (CME) was shown in 29 % of right and 21 % of left eyes in group 3 (p < 0.05 for right eyes). CME was observed in two of right and left eyes in group 4. Epiretinal membrane (ERM) was shown in one right eye in group 3, two right and four left eyes in group 4 (p < 0.05 for left eyes). Thicker CFT, CME, and failure of a well-formed foveal pit could be related to the severity of ROP. The development of ERM could be the consequence of LPC.

The effects of bupivacaine injection and oral nitric oxide on extraocular muscle in the rabbit.

AIM: Nitric oxide (NO) plays a key role in muscle regeneration, which is the primary response, observed during bupivacaine-induced extraocular muscle (EOM) hypertrophy. Our aims were to investigate the effects of bupivacaine injection into the rabbit EOM and the interaction with NO. MATERIALS AND METHODS: Superior rectus (SR) muscles of 24 New Zealand albino rabbits were studied. Single muscle twitch tension (SMTT) and tetanic muscle tensions at 50, 75, and 100 Hz were recorded using a 15 V stimuli. The rabbits were equally allocated into three groups. Measurements were performed without any drug treatments in group 1. In groups 2 and 3, bupivacaine, 0.5 ml of a 0.50 % solution, was injected into the EOM, and after 21 days, measurements were performed. Oral isosorbide dinitrate (NO donor) at 20 mg/day was given each day prior to measurements in group 3. RESULTS: SMTTs were 69.9 (66.7-77.6), 187.7 (114.9-252.1) and 204.2 (135.3-311.6) mg in groups 1, 2, and 3 respectively. SMTTs for both groups 2 and 3 were significantly higher than that for group 1 (p < 0.05). Compared with group 1, group 2 exhibited a 3.8-11.7 % increase in the tetanic tensions at 50, 75, and 100 Hz, but none of these differences were statistically significant. The increase was 47.5-137.5 % in group 3 relative to group 2, and the differences were statistically significant except at 100 Hz. The enlargement of the muscle fibers after bupivacaine injection was shown histopathologically. CONCLUSION: Bupivacaine injection increased the EOM tension in rabbits to some extent. NO augmented the effect of bupivacaine.

Comparison of endocanalicular laser dacryocystorhinostomy with and without endonasal procedures.

AIM: To evaluate the role of concomitant endonasal procedures in endocanalicular diode laser dacryocystorhinostomy (DCR). MATERIALS AND METHODS: This was a retrospective study, conducted on adult patients with primary acquired nasolacrimal duct obstruction. Thirty-one (seven bilateral) patients formed group 1 and 37 (five bilateral) patients group 2. Group 1 underwent endocanalicular laser DCR. In group 2, concomitant endonasal procedures, namely middle turbinectomy and endonasal mechanical enlargement of the neo-ostium were additionally performed. Mean follow-up period was 14.6 months for group 1, and 11.0 for group 2. RESULTS: Functional success was defined as the absence of epiphora, and anatomical success as the ability to irrigate the lacrimal system. Anatomic and functional success at each visit were compared using chi-square tests (p < 0.05). Total laser energies used for each case were compared using the Mann-Whitney U test (p < 0.05). Anatomical success rates were increased at the third month, sixth month and final visits. The increase was statistically significant. P value was 0.04 for the third and sixth month results comparison. Final anatomical success rates were 27/38 for group 1 and 39/42 for group 2 (p = 0.02). Final functional success rates were 25/38 patients in group 1 and 36/42 in group 2 (p = 0.07). Mean total laser energy used decreased from 300.0 to 165.0 joules (p < 0.001). CONCLUSIONS: Based on our increased anatomical success rates, concomitant endonasal procedures may help increase success rate in endocanalicular diode laser DCR cases.

Lenstar versus ultrasound for ocular biometry in a pediatric population.

PURPOSE: To compare the central corneal thickness (CCT), axial length (AL), anterior chamber depth (ACD), and lens thickness (LT) measured with Lenstar with those obtained with ultrasound pachymetry and A-scan contact ultrasound (ASU) in children. METHODS: ODs of 565 school children were included. All measurements were obtained 30 min after instilling 1% tropicamide. For each instrument, three consecutive measurements per each child were performed. Initially, examiner 1 performed measurements with Lenstar to obtain CCT, AL, ACD, and LT. Later, examiner 2 performed measurements with corneal pachymetry to obtain CCT. Finally, ASU was used by examiner 2 to obtain AL, ACD, and LT. Four parameters obtained with Lenstar were compared with those obtained with pachymetry and ASU using Pearson correlation coefficients (r) and Bland-Altman analyses. RESULT: Lenstar measurements were obtained in 557 of 565 subjects(mean age; 10.48 ± 2.11 years, mean spherical equivalent of the ODs; +0.47 ± 1.18 diopters) whereas ASU and pachymetry could be performed in 530 of 565. Four hundred seventy-nine subjects were statistically assessed after 41 subjects were extracted as outliers from 530 subjects in whom all instruments could be performed. Mean difference between pachymetry and Lenstar was 13.20 ± 13.13 µm [95% confidence interval (CI): 12.01 to 14.37]. Mean difference between ASU and Lenstar was -0.72 ± 0.35 mm (95% CI: -0.75 to -0.69) for AL, -0.27 ± 0.32 mm (95% CI: -0.30 to -0.24) for ACD, and 0.24 ± 0.28 mm (95% CI: 0.22 to 0.27) for LT. R values were 0.912 (p < 0.001), 0.904 (p < 0.001), 0.487 (p < 0.001), 0.369 (p < 0.001) for CCT, AL, ACD, and LT respectively. CONCLUSIONS: AL and ACD were found to be greater with Lenstar, whereas CCT and LT measures were smaller. It is concluded that there was agreement between instruments for CCT and ACD, because the small differences between measures were clinically insignificant. AL and LT values cannot be used interchangeably. If these differences are considered, Lenstar can replace ASU and pachymetry for the majority of children.

Comparison of trifocal toric and bifocal toric intraocular lens implantation in patients with cataract and high corneal astigmatism.

AIM: To investigate and compare the quality of life, satisfaction, contrast sensitivity, glare, depth perception, and intraocular lens (IOL) rotation in patients who underwent trifocal toric and bifocal toric IOLs. METHODS: A total of 80 eyes of 40 patients were included in this prospective study. Twenty patients in each group were implanted with trifocal toric and bifocal toric IOL, respectively. Preoperative and postoperative 6-month measurements were recorded for both patient groups. Comprehensive anterior and posterior segment examinations, distance-intermediate-near visual acuity values and the visual function scale questionnaire results were evaluated at these examinations. Patient satisfaction, contrast sensitivity, glare, intermediate-near and distance stereopsis and IOL rotation were also evaluated. RESULTS: No significant difference was found between the groups in terms of distance and near visual acuities (P=0.269, P=0.451). Intermediate visual acuity was significantly increased in the trifocal toric group (P<0.001). The visual function scale results were increased after surgery in both groups (P=0.001 and P<0.001), with no difference determined between them (P=0.158 and P=0.691). The number of patients wearing glasses was low in both groups and there was no significant difference between the groups (P>0.05). The overall satisfaction in the trifocal toric group was significantly higher than in the bifocal toric group (P=0.03). The highest sensitivity was observed at 6 cpd spatial frequency in all patients under photopic conditions (1.80±0.24 logU, 1.74±0.20 logU). Distance-intermediate-near binocular depth perception results in both groups were higher in the trifocal toric group (P=0.02, 0.048, 0.003, respectively). Although there was no significant difference for 3 meters stereopsis, the trifocal toric group had higher depth perception (P=0.577). Mean rotation was 5.76°±3.93° in the trifocal toric group and 12°±7.1° in the bifocal toric group. CONCLUSION: Better results in the middle distance are obtained in the trifocal toric group and less IOL rotation due to digital system-coordinated surgery. Moreover, the overall satisfaction in the trifocal toric group is significantly higher than in the bifocal toric group.

Retinopathy of prematurity: screening guidelines need to be reevaluated for developing countries.

PURPOSE: Timely screening of premature babies is an important initial step in the management of retinopathy of prematurity (ROP) as earlier treatment results in improved visual prognosis. Screening criteria for ROP currently recommended by the American Academy of Pediatrics may not be applicable in developing countries. The aim of the present study is to find out the incidence of ROP in infants with a gestational age (GA) of > or = 32 weeks in Eskisehir, Turkey, to provide information to assist in determining screening criteria. METHODS: A total of 96 infants with a GA of 32-35 weeks who were referred for ROP between January 1, 2004, and December 31, 2008, were studied. ROP screening, follow-up, and appropriate therapies were applied. RESULTS: During ROP screening, there were 42 of 96 (43.8%) infants with no ROP. A total of 54/96 (56.2%) infants were noted to have ROP. Among all infants, 7 (7.3%) had threshold ROP. Two infants with threshold disease were born at the 32nd, 2 at the 33rd, and 3 at the 34th week of gestation. The mean birthweight was 1857.9 (range 1060-3200) grams. CONCLUSIONS. In our study, it was found that more mature infants may also develop threshold ROP and require early treatment. After more information is gained and widespread screening, screening protocols covering more mature infants can be designed especially for developing countries.

The importance of measuring intraocular pressure using a tonometer in order to estimate the postmortem interval.

AIM: The purpose of this study is to evaluate postmortem eye changes and to investigate the relationship between these changes and time elapsed after death. MATERIAL AND METHOD: The eyes of 100 noncriminal cases who had died while being treated at Eskisehir Osmangazi University (ESOGU) hospital were evaluated for corneal turbidity and tache noire macroscopically, and also repeatedly evaluated by ophthalmoscope, pupilometer, and tonometer at intervals until removal from hospital. The postmortem time, corneal turbidity, development of tache noire, pupil size, intraocular pressure (IOP), and fundus findings were recorded. The relationship between these findings and the postmortem interval (PMI) was evaluated. RESULTS: No relationship between tache noire development and postmortem time (P > 0.05) was found. The corneal turbidity ratio increased significantly at 8 hours after decease (P < 0.01). No relationship between right-left pupil size and postmortem time (P > 0.05) was found. There was, however, a significant relationship between the fundus findings and postmortem time. Over time, the first optic disc becomes pale, then vascular clarity decreases and segmentation increases. The right and left IOP related significantly to postmortem time and decreased gradually as time passed (P < 0.05). Application of linear, exponential, and power equations showed that IOP can be used to estimate postmortem time by a 2 hour interval with a 95% probability. CONCLUSIONS: This study shows that corneal turbidity and IOP have a significant relationship with postmortem time and can be used to estimate a postmortem interval with other postmortem findings. This study provides data that would support the idea that such examination might be useful in estimating postmortem interval.

Two-year interval changes in Orbscan II topography in eyes with keratoconus.

PURPOSE: To define topographic characteristics and quantitatively document changes in corneal topography parameters in relation to the progression of keratoconus over time using the Orbscan II topography system (Bausch & Lomb). SETTING: Eskisehir Osmangazi University Medical School, Department of Ophthalmology, Meselik, Eskisehir, Turkey. METHODS: This study comprised 79 eyes (79 patients) with keratoconus who had Orbscan II topography examinations at least twice with a mean interval of 24 months +/- 3.2 (SD). Topographic parameters including location radius, elevation compared to a best-fit sphere, pachymetry, mean tangential curvature, and mean spheric curvature were evaluated with special reference to the central point of the cornea, the apex, and the thinnest point. The change in each parameter was calculated using the paired t test. RESULTS: The mean patient age was 31.6 +/- 14.9 (SD) [corrected] The increase in apex elevation (mean: 0.056 +/- 0.033 mm baseline versus 0.069 +/- 0.037 follow-up) (P<.02) and displacement of the location of the apex were statistically significant. The mean thinnest-point pachymetry decreased from 369 +/- 53 mum at baseline to 343 +/- 61 mum at follow-up (P = .03). The mean simulated keratometry minimum value was 48.21 +/- 5.5 diopters (D) and 54.09 +/- 6.2 D, respectively, a statistically significant increase (P = .02). The mean radius, mean elevation, mean tangential, and mean spheric curvatures of the apex did not change significantly. CONCLUSION: The Orbscan II topography system provided useful and detailed numerical information on keratoconic corneas and documented their progression quantitatively by serial topographic analysis.

The influence of central corneal thickness and corneal curvature on intraocular pressure measured by tono-pen and rebound tonometer in children.

PURPOSE: To find out the effect of central corneal thickness (CCT) and radius of the corneal curvature on intraocular pressure (IOP) measurements using rebound tonometer (RBT) and Tono-Pen in healthy schoolchildren. METHODS: IOP was measured with Tono-Pen and RBT, respectively, in 165 healthy schoolchildren with a mean age 9.8+/-3.1 (range: 7 to 12 y) years. Corneal radius of curvature (in mm) was determined using a keratometer before CCT and IOP measurements. CCT was measured using an ultrasonic pachymeter after all IOP determinations had been made. The effect of CCT, radius of the corneal curvature, and sex on measured IOP was evaluated by linear regression analysis. RESULTS: The mean IOP readings were 17.47+/-2.7 mm Hg using Tono-Pen, and 16.81+/-3.1 mm Hg using RBT. Tono-Pen measured IOP values slightly greater than that of RBT (P=0.006). Mean CCT was found to be 561.37+/-33 microm. A significant association between measured IOP and CCT was found with each device (r=0.220 for the Tono-Pen, r=0.373 for the RBT; P=0.006 for the Tono-Pen and P<0.0001 for the RBT). The IOP increased 2.2 and 3.7 mm Hg for every 100-microm increase in CCT for the Tono-Pen and the RBT, respectively. The relation between IOP and CCT was not different for boys and girls. Mean radius of the corneal curvature readings was 7.68+/-0.41 mm (42.75+/-1.37 D) for both sexes. There was no significant relationship between either the mean corneal curvature readings, or CCT and IOP (r=0.02; P=0.4 for CCT and r=0.01; P=0.5 for IOP). CONCLUSIONS: Both the Tono-Pen and RBT have a systematic error in IOP readings caused by its dependence on CCT. The CCT measurements should be considered to ensure proper interpretation of IOP measurements in children, like in adults. The corneal radius of curvature had no significant effect on measured IOP with each device.

Surgical treatment of strabismus fixus associated with high myopia.

A 55-year-old woman had convergent strabismus fixus associated with high myopia. Bilateral medial rectus recession and loop myopexy of lateral and medial rectus muscles was performed. The clinical characteristics and the possible surgical treatment modalities were discussed. This surgery seems effective on both the restoration of dislocation of the eyeball and the improvement of ocular motility.

Turkish Neonatal and Turkish Ophthalmology Societies consensus guideline on the retinopathy of prematurity.

Retinopathy of prematurity is a pathophysiological condition that occurs in relation to abnormal proliferation in the retinal vessels in premature babies. Its exact pathogenesis is not known. In Turkey, the increased chance of survival in premature babies with much younger gestational age and much lower birth weight in parallel with the developments in neonatal care causes retinopathy of prematurity, which has led to vision problems and blindness to emerge as a more frequent problem. Early diagnosis and timely and appropriate treatment of retinopathy of prematurity contributes to the developmental process and increases the quality of life by preventing vision loss. It should be kept in mind that retinopathy of prematurity may also lead to serious medicolegal problems.

Measurement of angle kappa with synoptophore and Orbscan II in a normal population.

PURPOSE: To obtain normative values of angle kappa in a normal population by synoptophore and Orbscan II and to compare the reliability of these devices. METHODS: Three hundred consecutive healthy individuals were enrolled in the study. A complete orthoptic and ophthalmologic examination was performed. Synoptophore and Orbscan II corneal topography were used to measure angle kappa. To evaluate the association of the angle kappa and refraction measures, individuals were further classified according to the degree of myopia and hyperopia. The spherical equivalent error measures were grouped into six categories: > or = -3.00 diopters (D); -2.75 to -1.50 D; -1.25 to -0.50 D; +0.50 to +1.25 D; +1.50 to +2.75 D; and > or = +3.00 D. Paired t test and Pearson's correlation test were used for statistical analysis. RESULTS: The mean age of the individuals was 28.74 +/- 1.63 years (range: 20 to 40 years). The angle kappa values obtained by synoptophore and Orbscan II were normally distributed. In the myopic group, angle kappa values decreased significantly towards negative refractive errors. In contrast, a correlation existed between large positive angles and positive refractive errors in the hyperopic group. Angle kappa values obtained by Orbscan II were significantly higher in all groups when compared to synoptophore (P < .0001). A significant correlation was noted between synoptophore and Orbscan II measurements (r = 0.932, P < .0001). CONCLUSIONS: A significant correlation exists between positive refractive errors and large positive angle kappa values. Refractive surgeons must take into account angle kappa, especially in hyperopic patients, to avoid complications related to decentration of the ablation zone.

Reproducibility and tolerability of the ICare rebound tonometer in school children.

PURPOSE: To establish the intraobserver and interobserver reliability of the rebound tonometer (RBT) in healthy schoolchildren and to test patient tolerance in an unanesthetized eye. SUBJECTS AND METHODS: To examine the reproducibility of the RBT, 2 experienced ophthalmologists undertook 3 consecutive intraocular pressure (IOP) measurements with the RBT without an anesthetic in 304 eyes of 152 healthy schoolchildren. Any pain or discomfort experienced by the children was recorded. Intraobserver and interobserver reliabilities were established by calculating correlation coefficients (r). RESULTS: Of the 152 patients, 78 (51.3%) were males and 74 (48.7%) were females. The mean patient age was 11.2+/-2.6 years (range: 7 to 15 y). Mean IOP values obtained by examiners 1 and 2 were 16.48+/-2.82 mm Hg and 17.27+/-3.27 mm Hg for the right eyes and 17.15+/-3.36 mm Hg and 17.06+/-3.21 mm Hg for the left eyes. Intraobserver correlation coefficients for examiner 1 were 0.970 for the right eyes and 0.974 for the left eyes. For examiner 2, intraobserver correlation coefficients were 0.963 for the right eyes and 0.970 for the left eyes. The interobserver correlation coefficients were 0.798 for the right eyes and 0.858 for the left eyes (all P<0.0001). With the RBT, 98.6% of the subjects felt no pain and/or discomfort. CONCLUSIONS: Measurement of IOP with the RBT is a highly reproducible method in schoolchildren showing high intraobserver and interobserver correlation and it seems to be very comfortable when performing IOP measurements in schoolchildren without an anesthetic.

Effect of central corneal thickness and radius of the corneal curvature on intraocular pressure measured with the Tono-Pen and noncontact tonometer in healthy schoolchildren.

PURPOSE: To determine the effect of central corneal thickness and radius of the corneal curvature on intraocular pressure (IOP) measurements using the Tono-Pen and a noncontact tonometer in healthy Turkish schoolchildren. SUBJECTS AND METHODS: IOP was measured with the Tono-Pen and a noncontact tonometer in 602 eyes of 602 healthy schoolchildren with a mean age of 10.1 +/- 1.6 years. Central corneal thickness was measured using an ultrasonic pachymeter after all IOP determinations had been made. The effect of central corneal thickness, radius of the corneal curvature, and sex on measured IOP was explored by linear regression analysis. RESULTS: The mean central corneal thickness was found to be 564.92 +/- 32 microm. The mean IOP readings were 17.9 +/- 2 mm Hg using the Tono-Pen, and 16.7 +/- 2 mm Hg using a noncontact tonometer. The Tono-Pen measured IOP values slightly greater than the noncontact tonometer (P < .0001). A significant association between measured IOP and central corneal thickness was found with each device. The IOP increased 2.1 and 4.2 mm Hg with every 100-microm increase in central corneal thickness for the Tono-Pen and the noncontact tonometer, respectively. The dependence of IOP on central corneal thickness did not differ between boys and girls. There was a significant association between the Tono-Pen and noncontact tonometer differences and central corneal thickness; the noncontact tonometer tended to overestimate IOP in eyes with thicker corneas. CONCLUSIONS: The Tono-Pen readings appeared to be less affected by corneal thickness than those of the noncontact tonometer. The corneal radius of curvature had no significant effect on measured IOP with each device. Because the Tono-Pen was relatively easy to use and less affected by corneal thickness, it may be an alternative method for measuring IOP in children.

The angle kappa in strabismic individuals.

PURPOSE: To determine angle kappa values in strabismic individuals by means of a synoptophore. METHODS: One hundred-and-eight strabismic subjects and 102 healthy subjects who served as a control group were enrolled in the study. A complete ophthalmologic examination, including determination of refractive status, best-corrected visual acuity measurement, slit-lamp biomicroscopic anterior segment evaluation, intraocular pressure measurements with a Goldmann applanation tonometer, and dilated fundus examination, was done on all study participants. Orthoptic examination included Krimsky prism reflex test, prism cover test, and duction tests. Strabismic patients were grouped into two categories according to their deviation types: exotropic and esotropic. A synoptophore (Clement Clarke, London, England) with a specially designed slide (Maddox test slide series A White Binding No: 16; Clement Clarke, London, England) was used to measure angle kappa. RESULTS: Of the 108 strabismic patients, 62 were males and 46 were females with a mean age of 23.38 +/- 3.68 years (range: 8 to 82 years). There were 54 males and 48 females with a mean age of 32.74 +/- 1.63 years (range: 7 to 68 years) in the control group. The exotropic group had significantly higher angle kappa values than either the controls or the esotropic group (independent sample t-test, p < 0.001). None of the study participants had negative angle kappa values. Higher average kappa values were obtained in left eyes than in right eyes in all three groups (student t-test, p < 0.01 for all groups). CONCLUSION: This study showed that exotropic patients have higher angle kappa values when compared to esotropic patients. Ophthalmologists must take the kappa angle into account when performing a Hirschberg or Krimsky test in young and uncooperative patients in order to improve surgical results.

Vasoactive intestinal peptide, a promising agent for myopia?

AIM: To investigate the role of vasoactive intestinal peptide (VIP) in form-deprivation myopia (FDM). METHODS: FDM was created in three groups of eight chicks by placing a translucent diffuser on their right eyes. Intravitreal injections of saline and VIP were applied once a day into the occluded eyes of groups 2 and 3, respectively. Retinoscopy and axial length (AL) measurements were performed on the first and 8th days of diffuser wear. The retina mRNA levels of the VIP receptors and the ZENK protein in right eyes of the three groups and left eyes of the first group on day 8 were determined using real time polymerase chain reaction (PCR). RESULTS: The median final refraction (D) in right eyes were -13.75 (-16.00, -12.00), -11.50 (-12.50, -7.50), and -1.50 (-4.75, -0.75) in groups 1, 2, and 3, respectively (P<0.001). The median AL (mm) in right eyes were 10.65 (10.00, 11.10), 9.90 (9.70, 10.00), and 9.20 (9.15, 9.25) in groups 1, 2, and 3, respectively (P<0.001). The median delta-delta cycle threshold (CT) values for the VIP2 receptors were 1.07 (0.82, 1.43), 1.22 (0.98, 1.65), 0.29 (0.22, 0.45) in right eyes of groups 1, 2, and 3, and 1.18 (0.90, 1.37) in left eyes of group 1, respectively (P=0.001). The median delta-delta CT values for the ZENK protein were 1.07 (0.63, 5.03), 3.55 (2.20, 5.55), undetectable in right eyes of groups 1, 2, and 3 and 1.89 (0.21, 4.73) in left eyes of group 1, respectively (P=0.001). CONCLUSION: VIP has potential inhibitory effects in the development of FDM.

The reliability of central corneal thickness measurements by ultrasound and by Orbscan system in schoolchildren.

PURPOSE: To compare the central corneal thickness measurements obtained by ultrasound (US) pachymetry and the Orbscan II system in healthy schoolchildren. METHODS: A total of 356 schoolchildren aged 7 to 12 years underwent central cornal thickness (CCT) measurement with Orbscan II and ultrasonic pachymetry. All eyes were examined first with the Orbscan II and then by US pachymetry. The mean of the difference, standard deviation (SD), and 95% limits of agreement, with and without applying the acoustic correction factor, were determined. The differences between the devices in measuring mean CCT were calculated with paired-sample t test. Pearson correlation test was used to determine the correlation between variables. p < 0.05 was considered to be statistically significant. Linear regression analysis was used to quantify the correlation between the two methods. RESULTS: Orbscan II measurements were significantly higher than US pachymetry measurements without applying the manufacturer-recommended acoustic correction factor (0.92) correction (580.39 +/- 37 microm and 562.95 +/- 32 microm, respectively) (p < 0.0001). When this acoustic correction factor was applied, the Orbscan II measurements demonstrated significantly lower results when compared with those of US pachymetry (533.96 +/- 34 microm and 562.95 +/- 32 microm, respectively) (p < 0.0001). The linear regression analysis lines showed approximately 45-degree slope indicating a strong correlation between these methods (US pachymetry = 145.71 + 0.72 x Orbscan II value without acoustic correction factor (microm), r = 0.89, p < 0.0001). There was a high degree of variability in differences between the 2 devices in individual subjects. The range was between 25 to -55 microm without the acoustic correction factor and 67 to -5 microm with the acoustic correction factor. CONCLUSIONS: Although US pachymetry and Orbscan II demonstrated a strong linear correlation, there was a high degree of variability in differences between the two devices in individual subjects who participated.

Combined cataract and strabismus surgery with adjustable sutures.

BACKGROUND AND OBJECTIVE: To report the results of combined cataract and strabismus surgery using an adjustable suture technique in patients of different ages. PATIENTS AND METHODS: Twenty patients underwent combination surgery between March 1999 and January 2004. All adjustments of the muscle sutures were done 24 hours postoperatively to prevent diplopia, and topical anesthesia was used for all but 1 patient. Bilateral lateral rectus recession was performed for 5 patients; medial rectus resection and lateral rectus recession was performed for 11 patients, and medial rectus recession and lateral rectus resection was performed for 4 patients. Extracapsular cataract extraction and phacoemulsification plus intraocular lens implantation was done according to the type of cataract. RESULTS: Preoperative visual acuities ranged between 20/8000 and 20/400. Eighteen of the patients had a cataract and 2 of the patients had aphakia due to previous cataract surgery. Considerable improvement in vision was obtained in 10 patients, and a postoperative visual acuity of 20/25 was achieved in 1 patient. Deviations improved from between 30 and 45 prism diopters preoperatively to between 2 and 8 prism diopters postoperatively. CONCLUSION: Combined cataract and strabismus surgery with adjustable sutures can be an alternative to the conventional method. It is less time-consuming for both the patient and the surgeon, and provides faster cosmetic and functional rehabilitation in a single operation.