Lacrimal Sac Dacryolith: A Study with Atomic Absorption Spectrophotometry and Scanning Electron Microscopy

Dacryoliths are uncommon causes of partial or complete obstruction of the nasolacrimal drainage apparatus. We report our findings of a dacryolith that we studied by culture, light microscopy, atomic absorption spectrophotometry, and scanning electron microscopy. Although no fungi were recovered by culturing, hyphae-like structures were observed. No inorganic material was detected by atomic absorption spectrophotometry. Scanning electron microscopy of ultrastructure showed the stone was composed of lobes and lobules built on an amorphous core material.

Ganglion Cell-Inner Plexiform Layer Thickness in Different Glaucoma Stages Measured by Optical Coherence Tomography

AIM

To compare ganglion cell (GCL) and inner plexiform layer (IPL) thickness in patients at different stages of primary open-angle glaucoma (POAG), determine their sensitivity and specificity values, and correlate thickness values with mean deviations (MD).

METHODS

This prospective, cross- sectional study was conducted in a group of patients with confirmed POAG who were compared to an age- and gender-matched control group. Glaucomatous damage was classified according to the Hodapp-Parrish-Anderson scale: glaucoma stage 1 (early), glaucoma stage 2 (moderate), and glaucoma stage 3 (severe). The average, minimum, and all 6 sectoral (superotemporal, superior, superonasal, inferonasal, inferior, and inferotemporal) GCL + IPL thicknesses were measured and compared between groups.

RESULTS

The average GCL + IPL thickness of 154 eyes of 93 patients in glaucoma stages 1, 2, 3, and 94 eyes of 47 persons in the control group were 76.79 ± 8.05, 65.90 ± 7.92, 57.38 ± 10.00, and 86.01 ± 3.68 μm, respectively. There were statistically significant differences in the average, minimum, and all 6 sectoral GCL + IPL values among the groups. The areas under the receiver operating characteristic curve for average and minimum GCL + IPL thickness values were 0.93 and 0.94, respectively, sensitivity 91.5 and 88.3%, and specificity 98.9 and 100%, respectively. Both thickness values showed significant correlations with MD. Each micrometer decrease in the average GCL + IPL thickness was associated with a 0.54-dB loss in MD.

CONCLUSION

GCL + IPL layer thickness is a highly specific and sensitive parameter in differentiating glaucomatous from healthy eyes showing progressive damage as glaucoma worsens. Loss of this layer is highly correlated with overall loss of visual field sensitivity.

Surgically Induced Corneal Astigmatism Following Intravitreal Ranibizumab Injection

Purpose :

To evaluate surgically induced astigmatism (SIA) after an intravitreal ranibizumab (IVR) injection.

Methods :

Fifty eight eyes of 58 patients who underwent IVR injection due to age-related macular degeneration (wet form) or macular edema were included in this study. Patients’ pre- and postoperative detailed ophthalmologic examinations were done and topographic keratometric values (K1, K2) were noted. Pre- and postoperative measurements were compared.

Results :

The mean preoperative astigmatism of 0.87 Diopters (D) was found to be 0.95 D, 0.75 D, 0.82 D and 0.78 D on the 1st day, 3rd day, 1st week and 1st month, respectively. After injection, absolute change in astigmatism was found to be 0.08 D, 0.12 D, 0.05 D and 0.09 D on the 1st day, 3rd day, 1st week and 1st month, respectively. The absolute change in astigmatism seemed to be insignificant in terms of refractive analysis, however; when we performed a vectorial analysis, which takes into account changes in the axis of astigmatism, the mean value of induced astigmatism were found to be 0.33±0.22 D, 0.32±0.29 D, 0.41±0.37 D, 0.46±0.32 D on the 1st day, 3rd day, 1st week and on 1st month, respectively.

Conclusion :

Intravitreal injection is a minimally invasive ophthalmologic procedure, however; it may still cause statistically significant induced astigmatism when evaluated from a vectorial point of view.

Heparin treatment for allergic conjunctivitis in the experimental BALB/c model

PURPOSE

To compare the inhibitory effects of dexamethasone and heparin on the infiltration of mast cells in the conjunctiva by using a mouse allergic conjunctivitis model.

METHODS

24 Balb/c mice were divided into four groups: allergy group (positive control), dexamethasone group, heparin group, and negative control group, as groups 1, 2, 3, and 4, respectively. Each group comprised 6 mice, and experimental allergic conjunctivitis was developed in groups 1, 2, and 3. The mice in group 2 were treated with topical 0.1% dexamethasone eye ointment, and the mice in group 3 were treated topically with 5,000 IU/ml standard heparin. Both dexamethasone and heparin were instilled once a day for 4 days. Hanks' balanced salt solution was dropped into both eyes of the mice in group 4 instead of dexamethasone or heparin. Eyeballs and eyelids were removed from the mice in all groups while one eye of each animal was used for histopathological, the other for molecular biological examination.

RESULTS

Mast cells, infiltrating the subconjunctival tissue, were significantly lower in group 2 (p < 0.0001), group 3 (p < 0.0001) and group 4 (p < 0.0001) when compared to group 1.

CONCLUSIONS

Topical heparin could be a viable option in treating IgE-induced allergic eye disease since it is found to be as effective as topical dexamethasone in experimental acute allergic eye disease.

Successful treatment of early relapse of ocular myeloma with bortezomib and steroid after autologous stem cell transplantation

Autologous stem cell transplantation (ASCT) can prolong remission duration, overall and progression free-survival in multiple myeloma (MM). Ocular relapse is rare in MM. Here we present a patient with only ocular relaps and without evidence of bone marrow progression after ASCT. Ig A kappa myeloma, stage IIIA was diagnosed in a 53-year-old man, according to Kyle-Greipp and Durie Salmon. He was treated with three courses of VAD therapy. Then he received high dose melphalan (200 mg/m2), followed by the ASCT. After two months from ASCT, he had bilateral blurry vision, pain, redness in both eyes and diplopia. We detected 5 mm of right-sided proptosis by Hertel exophthalmometry (base 110, 20 mm right eye, 15 mm left eye). Ocular motility of oculus dexter (OD) was restricted in up and lateral gaze. He has diplopia in up gaze. His color vision was 7 of 12 in the right eye and 10 of 12 in the left eye with Ishihara plates. Best corrected visual acuity was 6/10 in the right eye and 7/10 in the left eye. Intraocular pressures were 19 mmHg for OD and 18 mmHg for oculus sinister (OS). Slit lamp biomicroscopy revealed subconjunctival hemorrhages superiorly and temporally in the right eye and bilateral conjunctival hyperemia with chemosis. Fundus examinations of both eyes were unremarkable. Computed tomography and magnetic resonance imaging of orbita revealed a right intraorbital extraconal soft tissue density mass that involved the lacrimal gland and lateral rectus muscle. Prednisolon 1mg/kg/day and bortezomib 1.3 mg/m2 were started (1, 4, 8, 11 days). Eye findings were recovered after one month. Ocular relapse should be considered if there are ocular findings after ASCT for MM. Bortezomib and steroid may be useful for ocular extramedullary relapse of MM (Fig. 2, Ref. 8).

Prevention of suture exposure in transscleral intraocular lens fixation: an original technique

BACKGROUND

In this retrospective study, we evaluated our surgical outcomes of transscleral intraocular lens (IOL) fixation and introduced a simple, quick, and effective method to fixate and bury the sutures in the sclera to avoid suture exposure.

METHODS

Eyes were divided into 3 groups according to surgical technique. Half-thickness scleral flaps were prepared, and polypropylene suture ends were cut short in group 1 (12 eyes). Suture ends were left long without flaps in group 2 (47 eyes) and were buried into the scleral tunnel in group 3 (21 eyes).

RESULTS

The suture exposure rate was significantly lower in group 3 (0%) compared with group 2 (p = 0.006) and group 1 (p = 0.040). There was no significant difference in group 1 (25%) compared with group 2 (27.6%) (p = 1.000).

INTERPRETATION

Burying the suture ends into the scleral tunnel is a simple, safe, and effective technique for avoiding suture exposure in scleral-fixated IOL implantation.

[Case report: Acanthamoeba keratitis]

Acanthamoeba keratitis (AK) is an opportunistic protozoan infection caused by the pathogenic Acanthamoeba and associated with soft contact lens wear. If untreated, it can cause serious visual disability. A 23 year-old female wearing soft contact lenses applied to the Department of Ophthalmology of the Aydin Adnan Menderes University School of Medicine, with symptoms of redness, pain and blurred vision of both eyes. She was given a diagnosis of AK on clinical and laboratory grounds. The agent isolated was found to be T4 genotype "Acanthamoeba castellani". The patient regained visual ability following treatment. Although contact lens wear is the major risk factor for Acanthamoeba keratitis, the disease is usually seen unilaterally whereas in our case a bilateral involvement was observed. Great care should be practiced during contact lens use and there should be strict adherence to hygienic conditions if infections affecting the eye are to be avoided.

A case of naso-ophthalmic myiasis

Myiasis is defined as an occupational disease and it is mainly seen in people who are in contact with animals, in particular sheep. We detected nasal and external ophthalmomyiasis caused by Oestrus ovis in a 33-year-old male who worked as a research assistant in the faculty of agriculture. The presenting complaints were severe foreign body sensation and discharge in the nose, cough, and foreign body sensation in the right eye. Ophthalmologic examination revealed many moving larvae in the right eye of the patient. Larvae were removed and nasolacrimal duct irrigation was performed through the inferior canaliculus. Endoscopic nasal examination also showed larvae colonies. The larvae were removed under local anesthesia and were taken to the parasitology laboratory, wherein Oestrus ovis was identified. Minimal endoscopic sinus surgery showed nonspecific chronic inflammation.

The one-eye trial and fellow eye response to prostaglandin analogues

BACKGROUND

To determine if the intraocular pressure (IOP) reduction in one-eye trial correlates with the IOP reduction in the fellow eye when IOP variability during office hours is taken into account.

METHODS

This retrospective observational case series includes 50 high tension (primary open-angle glaucoma, exfoliative glaucoma and ocular hypertension; Group 1) and 21 normal tension (Group 2) glaucoma patients. Charts of bilateral open-angle glaucoma patients at Glaucoma Unit, School of Medicine, Adnan Menderes University who had pretreatment baseline office IOP measurements at 9:30, 11:30 and 15:30; were put on a one-eye trial with prostaglandin analogues, and then subsequently received the same medication in the fellow eye were reviewed. Pretreatment baseline office IOP measurements and reductions in the first and second eyes were compared to determine variability and correlation, respectively.

RESULTS

Both groups showed significant variability in pretreatment baseline office IOP measurements. Peak IOP level was before noon in at least 70% of eyes in Group 1, 50% in Group 2. IOP dropped a mean of 8.8 +/- 4.8 mmHg (34%, P = < 0.0001) in Group 1 and 4.9 +/- 2.4 mmHg (30%, P = < 0.0001) in Group 2 during the one-eye trial. Following bilateral use of the medication a mean drop of 7.5 +/- 4.0 mmHg (31%, P = < 0.0001) in Group 1 and 2.9 +/- 1.9 mmHg (18%, P = < 0.0001) in Group 2 were obtained. The IOP reduction between fellow-eye pairs were significantly correlated in Group 1 (r = 0.541, P = < 0.0001) but not Group 2 (r =-0.310, P = 0.171).

CONCLUSIONS

One-eye trial is a feasible method to determine the effectiveness of prostaglandin analogues and to predict the amount of IOP reduction in the fellow eye in patients with high tension glaucoma.

Orbital blood flow parameters in unilateral pseudoexfoliation syndrome

PURPOSE

The evaluation of orbital blood flow parameters in patients with unilateral pseudoexfoliation syndrome (XFS) and in age-sex-matched control subjects using color Doppler imaging.

METHODS

This prospective, comparative case series included 33 unilateral XFS patients and 33 age-sex-matched control subjects. Color Doppler imaging was used to evaluate the XFS-affected (Group 1) and -unaffected (Group 2) eyes that were matched with the corresponding side (Groups 3 and 4) of control subjects. All subjects were given a complete ophthalmological examination. A masked radiologist obtained the peak systolic velocity (PSV) and end diastolic velocity (EDV) of ophthalmic (OA), central retinal (CRA), nasal posterior ciliary (NPCA) and temporal posterior ciliary arteries (TPCA) as well as mean velocity of central retinal vein (CRV). Resistivity indices (RI) were calculated.

RESULTS

Analysis of peak systolic and end diastolic velocity (PSV, EDV) and RI between Groups 1-2 and 3-4 did not show any significant difference. Comparing Groups 1-3 (corresponding eyes of pseudoexfoliation-affected and control subjects) and Groups 2-4 (corresponding eyes of pseudoexfoliation-unaffected and control subjects) revealed significantly low values for OA, PSV and EDV in both eyes of the XFS patients. The OA RI value in Group 1 was found to be significantly higher than that in Group 3 with the cut-off value of 0.72.

CONCLUSION

These findings suggest that ophthalmic artery hemodynamic parameters change in both eyes of unilateral XFS patients, illustrating out the systemic nature of the disease. We conclude that XFS decreases OA blood flow velocities and increases vascular resistance through progressive build-up.

Fibrotic superior oblique and superior rectus muscles with an accessory tissue band

Congenital fibrosis of extraocular muscles may rarely present by involvement of isolated extraocular muscles. We report a case with an unusual form of congenitally fibrotic superior oblique and superior rectus muscles with an accessory tissue band passing toward the limbus. Magnetic resonance imaging (MRI) findings as well as histopathological and surgical results were evaluated. To the best of our knowledge, there is only one partially similar case in the literature with coexistence of congenitally fibrotic superior rectus and superior oblique muscles, and the features of that case differ from those of our case.

Usage of remifentanil and fentanyl in intravenous patient-controlled sedo-analgesia

Our aim was to investigate the effects of patient-controlled sedo/analgesia with fentanyl or remifentanil during cataract surgery with phacoemulsification method under topical anaesthesia. The ethical committee has approved the prospective, randomized, double-blind study. ASA I-III, 120 patients underwent cataract surgery were randomly allocated to 3 groups. Fentanyl was administered in 0.7 microg/kg loading, 10 microg bolus dose with 5 minutes lockout time, remifentanil was administered 0.3 microg/kg loading, 20 microg bolus dose with 3 minutes lockout time by patient controlled analgesia (PCA) equipment. In the control group, saline solution was given without any analgesic drug. Cardiorespiratory system findings, verbal pain scale and sedation scores were recorded preoperatively and intraoperatively at the 5th, 10th, 15th, 20th and 30th minutes. Discomfort during surgery, pressing the PCA button, and complications were recorded. The verbal pain scale scores was significantly lower in the drug groups than the those in control group at the 15th minute. The sedation scores was significantly higher in the remifentanil group at the 5th minute (p=0.019) and in the fentanyl group at the 10th minute (p=0.007) than those in the control group. The number of patients pressing the PCA button was much higher in the control group than the drug groups (p<0.05). Patient comfort and surgeon satisfaction were higher in the drug groups (p<0.05). Intravenous-PCA sedo/analgesia addition to topical anaesthesia provides an advantage in sedo/analgesia, patient comfort, and surgeon satisfaction. PCA is a convenient and safe method, especially at the beginning of the operation when anxiety is intense, and during healon/lens implantation.

Acanthamoeba keratitis due to Acanthamoeba genotype T4 in a non-contact-lens wearer in Turkey

An otherwise healthy 22-year-old man presented with Acanthamoeba keratitis (AK) in the right eye. He was not a contact lens wearer and had no history of corneal trauma. The Acanthamoeba strain isolated from a corneal scraping was identified as morphological group II and genotype T4. Three more Acanthamoeba strains isolated from sites of possible human contact with acanthamoebae in the same geographical region, including a lens storage case, tap water and soil, were subjected to morphological and molecular biological identification. Whereas the strain from tap water also exhibited genotype T4, the two other isolates were identified as morphological group I and genotype T9. To the best of our knowledge, this is the first study identifying an AK-causing Acanthamoeba strain in Turkey and the first isolation of genotype T9 in this country.

Medical control of intraocular pressure after phacoemulsification

PURPOSE

To compare the effectiveness of oral acetazolamide, topical brinzolamide 1%, and no ocular hypotensive medication after phacoemulsification.

SETTING

Adnan Menderes University Department of Ophthalmology, Aydin, Turkey.

METHODS

This prospective randomized double-blind study comprised 60 eyes of 52 patients having phacoemulsification under topical anesthesia. There were no intraoperative complications. Eyes were randomized to receive oral acetazolamide 500 mg 1 hour preoperatively followed by 250 mg acetazolamide every 6 hours, 1 drop of brinzolamide 1% every 12 hours starting immediately after speculum removal, or no ocular hypotensive medication. Intraocular pressure (IOP) was measured using a Perkins tonometer preoperatively and 4 to 6 hours and 18 to 24 hours postoperatively.

RESULTS

The preoperative IOP was not significantly different between the 3 groups. Four to 6 hours postoperatively, the acetazolamide group (P=.002) and brinzolamide group (P=.001) had significantly lower IOP than the control group. The same trend was observed at 18 to 24 hours in the brinzolamide group (P=.001) but not the acetazolamide group (P=.018). The IOP levels were not significantly different between the acetazolamide group and brinzolamide group at any postoperative time point. No eye receiving medication and 2 eyes (10%) in the control group had an IOP of 30 mm Hg or higher 4 to 6 hours postoperatively. Compared with preoperatively, an IOP increase of more than 5 mm Hg was seen at 4 to 6 hours in 3 eyes (15%), 2 eyes (10%), and 14 eyes (70%) in the acetazolamide, brinzolamide, and control group, respectively.

CONCLUSION

Brinzolamide was as effective as acetazolamide in preventing IOP elevation 4 to 6 hours after phacoemulsification and more effective than acetazolamide at 18 to 24 hours.

Effect of corneal drying on central corneal thickness

PURPOSE

To determine the amount of corneal thinning induced by corneal drying, and to discuss its possible consequences on applanation pressure.

PATIENTS AND METHODS

Two sets of central corneal thickness measurement from 100 eyes of 100 patients were taken by ultrasonic pachymeter at time settings of 0, 15, 30, 45, and 60 seconds. During the first set (group 1), patients were asked to blink voluntarily between the measurements. During the second set (group 2), the same patients were prevented from blinking during the measurements.

RESULTS

Mean central corneal thickness at 0 second in groups 1 and 2 were 547.0 +/- 37.4 microm, and 546.7 +/- 37.6 microm, respectively. Corneal thickness did not change significantly in group 1, but did significantly decrease in group 2. Rate of thinning increased linearly during the first 30 seconds, and then leveled around 0.3 microm/s up to 60 seconds. Mean corneal thickness decreased 3.0% during the 60 second drying. The decrease in thickness was significant when each time point in group 2 was compared with the preceding one (P < 0.01). Neither age nor 0 second corneal thickness in group 2 showed a significant correlation with the amount of corneal thinning at 60 seconds.

CONCLUSION

Corneal thickness may significantly decrease during 1 minute of drying. Decreased thickness may result in underestimation of applanated pressure as well as central corneal thickness.

The effect of Seprafilm on adhesions in strabismus surgery-an experimental study

PURPOSE

Seprafilm (Genzyme, Cambridge, MA) is a bioabsorbable membrane composed of sodium hyaluronate and carboxymethylcellulose. Adhesions occurring after strabismus surgery may affect surgical outcome. The purpose of our study was to histopathologically evaluate the influence of Seprafilm on postoperative adhesions.

METHODS

Seven adult male New Zealand albino rabbits were used. The superior rectus muscle was resected 3 mm, and a fornix-based limbal conjunctival dissection was made inferonasally in both eyes. In one eye of each rabbit, Seprafilm was inserted between the conjunctiva and superior rectus and under the dissected inferonasal conjunctiva. The fellow eye of each rabbit, having undergone superior rectus resection and inferonasal conjunctival dissection without Seprafilm, served as the control group. The rabbits were killed and the eyes were enucleated at 6 weeks after surgery. Histopathological sections were analyzed for inflammation and fibrosis by staining them with hematoxylin-eosin and Masson trichrome, respectively. Inflammation and fibrosis were graded on a scale of 0 to 4.

RESULTS

Compared with the control eyes, there was no significant difference with regard to inflammation either at the area of superior rectus resection or the area of conjunctival dissection (P.655 and P.157, respectively). Significantly less fibrosis occurred in the surgical areas where Seprafilm was used compared with the control group (P.046 and P.015, respectively) both at the area of superior rectus resection and the area of conjunctival dissection.

CONCLUSION

This study shows that Seprafilm significantly decreases postoperative adhesions between the conjunctiva, muscle, and sclera. Application of Seprafilm may prove useful in strabismus surgery especially where adhesion formation may influence the outcome and in cases where recurrent conjunctival dissection may be needed.

Botulinum toxin A in the treatment of adherence syndrome

The effect of botulinum toxin A is investigated in the treatment of adherence syndrome related to strabismus surgery. An 18-year-old boy with decompensated right congenital fourth nerve palsy underwent ipsilateral superior rectus muscle recession and inferior oblique muscle disinsertion. During the early postoperative period, a right hypotropia with limitation of elevation developed and the result of the forced duction test was positive for passive elevation of the right eye. Botulinum toxin A was injected into the right inferior rectus muscle on the 15th postoperative day and orthophoria was achieved 1 week later. A repeat injection of botulinum toxin A was performed 6 months later. On follow-up 2 1/2 years later, his eyes remained orthophoric with limitation of elevation in the right eye and the patient was satisfied with the result. This case demonstrated that adherence syndrome can be treated successfully by botulinum toxin A injection if it is administered during the acute phase, before the development of fibrous scar tissue.

The presence of a single tyrosine residue at the carboxyl domain of vascular endothelial growth factor receptor-2/FLK-1 regulates its autophosphorylation and activation of signaling molecules

Vascular endothelial growth factor receptor (VEGFR)-2 plays a critical role in vasculogenesis during embryonic development and pathological angiogenesis, but little is known about the molecular mechanisms governing its functions. Here we investigated the role of tyrosine 1212 on mouse VEGFR-2 autophosphorylation and its signal transduction relay in endothelial cells. Mutation of tyrosine 1212 on VEGFR-2 to phenylalanine severely impaired the ligand-dependent autophosphorylation of VEGFR-2 and its ability to associate with and activate Src. This mutation also reduced the VEGFR-2 ability to phosphorylate phospholipase Cgamma1 and mitogen-activated protein kinase (MAPK). Unlike mutation of tyrosine 1212 to phenylalanine, replacement of tyrosine 1212 with glutamic acid preserved the ligand-dependent activation of VEGFR-2 and activation of VEGFR-2-associated signaling proteins including Src, phospholipase Cgamma1, and MAPK. Further analysis showed that Src activation is not required for activation of VEGFR-2, since cells co-expressing wild type receptor with kinase dead Src or wild type Src displayed no apparent effect in the ligand-dependent autophosphorylation of VEGFR-2. Similarly, expression of wild type VEGFR-2 in fibroblast (SYF) cells obtained from the triple knockout Src family kinases showed normal ligand-dependent autophosphorylation. Collectively, these results suggest that phosphorylation of tyrosine 1212 of VEGFR-2 plays a crucial role in the activation of VEGFR-2 and subsequently VEGFR-2-mediated angiogenesis.

Identification of tyrosine residues in vascular endothelial growth factor receptor-2/FLK-1 involved in activation of phosphatidylinositol 3-kinase and cell proliferation

Activation of vascular endothelial growth factor receptor-2 (VEGFR-2) plays a critical role in vasculogenesis and angiogenesis. However, the mechanism by which VEGFR-2 activation elicits these cellular events is not fully understood. We recently constructed a chimeric receptor containing the extracellular domain of human CSF-1R/c-fms, fused with the entire transmembrane and cytoplasmic domains of murine VEGFR-2 (Rahimi, N., Dayanir, V., and Lashkari, K. (2000) J. Biol. Chem. 275, 16986-16992). In this study we used VEGFR-2 chimera (herein named CKR) to elucidate the signal transduction relay of VEGFR-2 in porcine aortic endothelial (PAE) cells. Mutation of tyrosines 799 and 1173 individually on CKR resulted in partial loss of CKR's ability to stimulate cell growth. Double mutation of these sites caused total loss of CKR's ability to stimulate cell growth. Interestingly, mutation of these sites had no effect on the ability of CKR to stimulate cell migration. Further analysis revealed that tyrosines 799 and 1173 are docking sites for p85 of phosphatidylinositol 3-kinase (PI3K). Pretreatment of cells with wortmannin, an inhibitor of PI3K, and rapamycin, a potent inhibitor of S6 kinase, abrogated CKR-mediated cell growth. However, expression of a dominant negative form of ras (N(17)ras) and inhibition of the mitogen-activated protein kinase (MAPK) pathway by PD98059 did not attenuate CKR-stimulated cell growth. Altogether, these results demonstrate that activation of VEGFR-2 results in activation of PI3K and that activation of PI3K/S6kinase pathway, but not Ras/MAPK, is responsible for VEGFR-2-mediated cell growth.

Pharmacological mechanism of topical lodoxamide treatment in vernal keratoconjunctivitis: a flow-cytometric study

The aim of this study was to investigate the possible effect of lodoxamide 0.1% ophthalmic solution (LOS) on tear T lymphocytes, especially Th2 (T helper 2 subgroup of helper T lymphocytes), in the tear specimens of patients with vernal keratoconjunctivitis (VKC) and to explore the mechanism of the anti-allergic effect of this drug. Twenty-eight active VKC patients were randomly divided into two groups each containing 14 patients. We obtained tear samples from all patients at the beginning of the study. LOS was prescribed to the study group (group A), but the controls (group B) received placebo over the course of 6 weeks. Tear samples were also collected from all patients following a 6-week course of treatment with either LOS or placebo. The percentages of Th1, Th2 and Th cells in the tear samples were measured by using a flow-cytometric technique and the results were compared to each other by using Wilcoxon matched-pairs signed-rank and Mann-Whitney U tests. We found that LOS treatment decreased the percentages of Th2 and Th cells in the tears of group A patients, while placebo had no effect on these values. Th1 cell count in the tears of both groups of patients did not show any significant change between the pre- and posttreatment stages. Our data suggest that LOS exerts, at least, some part of its anti-allergic effect via decreasing the Th2 cell number in the tears of VKC patients.

Receptor chimeras indicate that the vascular endothelial growth factor receptor-1 (VEGFR-1) modulates mitogenic activity of VEGFR-2 in endothelial cells

Vascular endothelial growth factor (VEGF) provokes angiogenesis in vivo and stimulates growth and differentiation of endothelial cells in vitro. Although VEGF receptor-1 (VEGFR-1) and VEGFR-2 are known to be high affinity receptors for VEGF, it is not clear which of the VEGFRs are responsible for the transmission of the diverse biological responses of VEGF. For this purpose we have constructed a chimeric receptor for VEGFR-1 (CTR) and VEGFR-2 (CKR) in which the extracellular domain of each receptor was replaced with the extracellular domain of human colony-stimulating factor-1 receptor (CSF-1R), and these receptors were expressed in pig aortic endothelial (PAE) cells. We show that CKR individually expressed in PAE cells is readily tyrosine-phosphorylated in vivo, autophosphorylated in vitro, and stimulates cell proliferation in a CSF-1-dependent manner. In contrast, CTR individually expressed in PAE cells showed no significant in vivo, in vitro tyrosine phosphorylation and cell growth in response to CSF-1 stimulation. The kinase activity of CKR was essential for its biological activity, since mutation of lysine 866 to arginine abolished its in vivo, in vitro tyrosine phosphorylation and mitogenic signals. Remarkably, activation of CTR repressed CKR-mediated mitogen-activate protein kinase activation and cell proliferation. Similar effects were observed for VEGFR-2 co-expressed with VEGFR-1. Collectively, these findings demonstrate that VEGFR-2 activation plays a positive role in angiogenesis by promoting endothelial cell proliferation. In contrast, activation of VEGFR-1 plays a stationary role in angiogenesis by antagonizing VEGFR-2 responses.

The comparison of intraocular pressure reductions after isometric and isokinetic exercises in normal individuals

The lowering effect of physical exercise on intraocular pressure (IOP) has been reported both in healthy people and those with glaucoma, but a comparison of the lowering effect of isometric and isokinetic exercises on IOP has not been conducted in any study. Our aims were to investigate the relationship between intensity of exercise and IOP, and whether a significant difference in IOP lowering effect existed between isometric and isokinetic exercises. Sixty-seven patients with an age range of 23-40 who had no ocular disease were randomly divided into two groups. While 31 patients in the first group, group A, performed isokinetic exercise with the Cybex 6000 dynamometer, 32 patients in the second group, group B, had isometric exercises with the same machine. IOP was measured in the right eye of patients with Shiotz tonometer just before and 10 min following exercise. Exercise intensity and total energy consumption were determined by the machine for each patient. While IOP values measured before exercise, the degree of exercise applied, and total energy consumption did not differ significantly between groups, both isometric and isotonic exercises lowered IOP significantly. As a result, isometric and isokinetic exercises lowered IOP in ophthalmologically normal subjects with direct relationship to exercise intensity and total energy consumption. Since the pressure lowering effect of isokinetic exercise was more significant, it might prove useful to glaucomatous patients.

Prevention of lens damage associated with cigarette smoke exposure in rats by alpha-tocopherol (vitamin E) treatment

PURPOSE

To evaluate the possible protective effect and mechanism of alpha-tocopherol (vitamin E) treatment on lens degeneration associated with in vivo exposure to cigarette smoke and to further clarify the role of iron in cigarette smoke-generated lens damage.

METHODS

Twenty-eight male Wistar rats were randomly divided into four equal groups. Rats in groups 3 and 4 were exposed to cigarette smoke for 1 hour each day over 90 consecutive days, and rats in groups 1 and 2 were treated in similar fashion but only exposed to room air. Additionally, vitamin E was given to the rats in groups 2 and 4 via intramuscular route. At the end of the study, both eyes of all the animals were enucleated; one eye was prepared for histopathologic examination, and the fellow eye was used for the measurement of iron and calcium levels.

RESULTS

Significantly higher iron and calcium levels were observed in the lenses of group 3 rats than in other groups. Similar comparisons performed between groups 1 and 2, groups 1 and 4, and groups 2 and 4 did not show any significant difference. Distinct histopathologic changes in the anterior lens epithelium, such as hyperplasia, hypertrophy, epithelial multilayering, and the presence of epithelial cells over posterior lens capsule, observed in group 3 rats were not present in other groups.

CONCLUSIONS

Cataractogenesis after cigarette smoke exposure was associated with an accumulation of iron and calcium in the rat lens, and vitamin E supplementation protected such accumulations and cataractogenesis.

Arterial blood flow characteristics in central retinal vein occlusion and effects of panretinal photocoagulation treatment: an investigation by colour Doppler imaging

AIMS

To determine whether an increase in vascular resistance in the central retinal and ophthalmic arterial circulations contributes to the development of central retinal vein occlusion (CRVO), or haemodynamic alterations in central retinal and ophthalmic arteries occur secondary to the vein occlusion as increased intravascular pressure is transferred through the capillary bed to the arterial side and the effect of panretinal photocoagulation treatment on these circulations in ischaemic cases.

METHODS

The ophthalmic and central retinal arteries of the affected and non-affected eyes of 20 patients with non-ischaemic CRVO, 13 patients with ischaemic CRVO, and 22 control subjects were investigated by colour Doppler imaging. Panretinal photocoagulation (PRP) treatment was applied to the eyes with ischaemic CRVO. Maximum and minimum blood flow velocities, and resistivity indexes were calculated in the affected and healthy eyes of patients and in the control eyes.

RESULTS

Average blood flow velocity in the central retinal and ophthalmic arteries of patients with non-ischaemic CRVO did not differ from their fellow eyes, but a significantly lower average blood flow velocity was found in the ophthalmic and central retinal arteries of the patients with ischaemic CRVO compared with their fellow eyes. Patients with ischaemic CRVO had significantly lower blood flow velocities in their ophthalmic and central retinal arteries than non-ischaemic cases that were further reduced following PRP treatment.

CONCLUSION

This study suggests that impaired arterial blood flow observed in patients with CRVO may be partly related to secondary changes in the retrobulbar arterial circulation as a result of enhanced arterial resistance following CRVO. These data also demonstrate that PRP treatment decreases retinal and ophthalmic blood flow velocities in patients with ischaemic CRVO.

A flow cytometric study about the immunopathology of vernal keratoconjunctivitis

BACKGROUND

Vernal keratoconjunctivitis (VKC) is a bilateral seasonal conjunctival inflammation. Exact pathogenesis of the disease is unknown, but some evidences suggest TH lymphocyte-mediated immune reactions.

OBJECTIVE

The aim of this study was to investigate the role of the T lymphocyte and its subsets in the pathogenesis of VKC.

METHODS

We obtained tear samples from patients with VKC and normal volunteers during active (spring) and quiescent (winter) periods. The patients' records were also obtained for assessment of symptom scores. The percentages of CD4/29+, CD4/45RA+, CD4+, and CD8+ in tear samples were established by using flow cytometry, and the results of all three groups were compared with each other by using the Wilcoxon matched-pair signed-rank test and the Mann-Whitney U test.

RESULTS

The percentages of CD4/29+ and CD4+ cells in tears of patients with VKC increased significantly in the active period and decreased to normal levels in the quiescent stage. In contrast, the percentages of CD4/45RA+ and CD8+ cells in tears of patients with VKC did not show any significant change between spring and winter. The patients' symptoms were significantly lower in the quiescent period (winter) compared with the active stage (spring).

CONCLUSION

We propose that increased numbers of CD4+ and CD4/29+ cells in tears may be exacerbating the disease during the spring season.

Further studies on the immunopathology of atopic keratoconjunctivitis using flow cytometry

Atopic keratoconjunctivitis (AKC) is an ocular manifestation of systemic hypersensitivity. Although the pathogenesis of AKC is not fully understood, some previous data suggest that a decrease in numbers of suppressor T lymphocyte (Ts) and increase of Th, especially Th2 (the second subgroup of helper T lymphocyte), at the ocular surface may play an important role in the occurrence of the disease. In this study, the percentages of naive-Th (CD4/45RA+) and memory-Th (CD4/29+) cells, and the Th/Ts and memory-Th cells/naive-Th cells ratios were measured in the blood and tear samples of patients with AKC, atopic patients without ocular involvement and normal volunteers, using flow cytometry. Groups were compared using the Mann-Whitney U test. We found that patients with AKC had significantly higher memory-Th cell concentration, and Th/Ts and memory-Th cells/naive-Th cell ratios both in the tear and blood samples compared to normal subjects. While no significant difference existed between the tear samples of the atopic patients without ocular involvement and normal volunteers with respect to the above values, atopic patients had higher percentages of memory-Th cells and higher Th/Ts and memory-Th cells/naive-Th ratios in their blood than normal subjects. The percentages of memory-Th cells, and the Th/Ts and memory-Th cells/naive-Th cell ratios in the tear samples of AKC patients were also found to be higher than that of the atopic patients without ocular involvement, but no significant difference was present between the blood samples of these groups. The percentages of naive-Th cells did not show any significant difference between groups either in tear or blood samples. Since the mean memory-Th cells/naive-Th1 cells ratio in the tear samples of the patients with AKC was higher than in their blood samples, we propose that the localized accumulation of memory-Th2 cells, in addition to the increase of Th/Ts ratios in the external eye may cause AKC in atopic individuals.

Congenital orbital teratoma: a clinicopathologic case report

A 5-day-old infant boy was noted to have severe left proptosis at birth. The left eye protruded superotemporally through the palpebral fissure and had exposure keratopathy. There was frank left afferent pupillary defect. Computerized tomography (CT) showed a left orbital soft tissue mass with foci of calcification. Magnetic resonance imaging (MRI) studies revealed a left orbital mass with solid and cystic portions without intracranial extension. As the eye was considered to be nonsalvagable, a lid-sparing type, modified exenteration was performed. Histopathologic examination demonstrated various mature tissues of all three embryonic germinal cell lines. This case represents one of the rare examples of true congenital orbital teratoma, which is an uncommon cause of hideous proptosis in the neonate. MRI may prove useful in differentiating this tumor from more common conditions.