[Allergic and immunopathological diseases of the ocular surface]

Allergic and immunopathological diseases of the ocular surface are inflammations that can occur with mild to severe symptoms that cause visual impairment. Allergic inflammations mainly affect the conjunctiva, causing acute and/or chronic conjunctivitis. Several forms are distinguished: seasonal allergic conjunctivitis, vernal conjunctivitis, atopic keratoconjunctivitis, contact allergy, giant papillary conjunctivitis. The most common is the seasonal form, which is linked to seasons. Allergic ocular surface processes require local treatment with artificial tears, anti-allergic eye drops. If complications occur, topical corticosteroid and cyclosporin treatment may be used. Immunopathological inflammations of the ocular surface are associated with systemic diseases. Keratoconjunctivitis sicca, although occurring in the absence of systemic disease, is a common companion of Sjögren's syndrome and collagen diseases. Ocular pemphigoid belongs to the group of mucous membrane pemphigoids. After the initial conjunctivitis symptoms, subconjunctival fibrosis begins, leading to the development of sym- and ankyloblepharon. In the final stage, the ocular surface is covered by scar tissue (ocular cicatricial pemphigoid) which practically results in loss of vision. Peripheral ulcerative keratitis is usually associated with collagen vascular disease, rheumatoid arthritis. A 3-4 mm long, curved infiltration starting near the limbus becomes ulcerated and then perforates, on which the iris may prolapse. First, systemic treatment is required, which is an interdisciplinary task. Topical corticosteroid and cyclosporine eye drops may be administered. In the case of corneal perforation, amniotic membrane transplantation and/or keratoplasty may be performed. Orv Hetil. 2023; 164(43): 1686-1692.

A Case of Paradoxical Worsening of Dural-Sinus Arteriovenous Malformation Syndrome after Neurosurgery

The authors present a case of a patient with the syndrome of paradoxical worsening of dural-sinus cavernous arteriovenous malformation which was a iatrogenic consequence of embolization of the basal branches of a dural shunt with Yvalon. It is presumed that the thrombogenous Yvalon reached the basal branches of the medial meningeal artery to the superior ophthalmic vein, where it caused complete thrombosis. The impaired ocular and orbital venous outflow caused a dramatic worsening of the ocular congestive symptoms: venous stasis retinopathy with dilated veins, flame-and dot-shaped hemorrhages and a secondary increase in intraocular pressure. The diagnosis of thrombosis of the entire superior ophthalmic vein was confirmed by color Doppler imaging. The mechanism is discussed. Although the ocular pathology is usually self-limiting following the establishment of collateral venous outflow channels, in view of the patient's serious congestive ocular symptoms argon laser photocoagulation and conservative antiglaucomatous local therapy were applied. Once orbital collateral venous drainage was established, the ocular symptoms improved. In the one-year follow-up there was no other complication.

[Hypertension-related eye disorders]

Hypertension affects a significant proportion of the population, however, it is often diagnosed with a delay. The aim of this article is to review the well known and less known eye abnormalities related to hypertension, and place them in the context of population based studies. Hypertension affects various parts of the eye. The originally classified hypertensive retinopathy (retinal microvascular changes) is still relevant, but new features are visible in cases of controlled hypertension. Signs of mild hypertensive retinopathy are more common than expected occurring in nearly 10-15% of the adult non-diabetic population. Hypertensive retinopathy can be an indicator of other hypertensive complications such as neurologic and cardiac complications. Microvascular changes are reversible in well controlled hypertension. Proper treatment of hypertension can reduce the development and progression of diabetic retinopathy and, thus, visual loss due to severe retinal diseases such as retinal vascular occlusion (artery and vein), retinal arteriolar emboli, macroaneurysm, ischemic optic neuropathy and age-related macular degeneration.

[Postoperative therapy after penetrating keratoplasty in herpes simplex keratitis]

INTRODUCTION

Keratitis due to herpes simplex infection is a common cause of corneal damage resulting in impaired vision.

AIM

The aim of this study was to assess the outcome of penetrating keratoplasties in patients treated with systemic antiviral and immunosuppressive drugs.

METHOD

The authors retrospectively analysed data of 12 patients who underwent penetrating keratoplasty. The average age at onset of the first keratitis preceding surgery was 18 years (between 5 and 40 years). The indication for surgery in 9 cases was to improve vision and in 3 patient to prevent corneal perforation. Nine patients were given both acyclovir and mycophenolate mofetil, as anti-viral agent and immunosuppressive treatment, respectively. Two patients were treated with anti-viral agent only while one patient received no systemic therapy. The average follow-up time was 53.1 months (between 16 and 84 months).

RESULTS

Of the 9 patients who underwent surgery for improving vision, 8 patients had transparent grafts during follow up without vascularization. All eight patients had been treated with acyclovir and mycophenolate mofetil. In one patient who had no systemic treatment recurrence and graft rejection was observed. Only one of the surgeries performed in acute stage of inflammation resulted in a properly healed transparent graft without recurrence and rejection. In this patient acyclivir and mycophenolate mofetil therapy had been given previously. In two cases the preventive - full or partial - systemic treatment had no effect. The visual acuity improved in all cases. In three patients visual acuity was influenced by some other factors as well.

CONCLUSIONS

The systemic acyclovir and mycophenolat mofetil therapy is fairly successful in perforating keratoplasty due to herpes simplex infection. Acyclovir decreases the risk of recurrence, while mycophenolate mofetil may prevent graft rejection. The timing of surgery is decisive; it leads to better results when performed in a scarred, noninflammatory state.

Complement activation in the aqueous humor of pseudophakic bullous keratopathy patients

BACKGROUND/AIMS

According to some studies, inflammation is a potential etiological factor in pseudophakic bullous keratopathy (PBK). Our aim was to obtain information on the activation of the complement system in the aqueous humor in this disorder.

METHODS

Aqueous humor samples were collected during keratoplasty of 12 PBK patients, as well as during phacoemulsification surgery of 18 control patients. The concentrations of the protein-protein complexes generated during complement activation (C1rC1sC1inh and C3bBbP) through the classical and alternative pathways, respectively, as well as of the C3 cleavage product C3a, were measured with ELISA methods. The correlation among the complement factors and between the duration of the edema, the stage of the disease, and the level of the complement activation products was examined.

RESULTS

The concentration of C1rC1sC1inh, C3bBbP complex and C3a was significantly higher in the PBK group (p < 0.001) compared to the control group. In PBK patients, a correlation was found between the levels of the C1rC1sC1inh complex and C3a only.

CONCLUSION

Our new findings indicate that in PBK the complement system is activated - via the classical pathway - in the aqueous humor. The activated complement may play a role in increased endothelial cell loss.

[Vision restoration with implants in retinal degenerations]

Up until now there has been no available treatment for diseases causing the permanent impairment of retinal photoreceptors. Currently the development of the retinal prostheses is the earliest to promise a result that can be implemented in the clinical treatment of these patients. Implants with different operating principles and in various stages of progress are presented in details, highlighting the characteristics, as well as the Hungarian aspects of the development. This survey intends to provide an overview on retinal prostheses, implantable in case of degenerative diseases of the retina, by reviewing and assessing the papers published in relevant journals and based on personal experience. Developments in microelectronics in recent years made it possible and proved to be feasible to replace the degenerated elements in the retina with electrical stimulation. Multiple comparable approaches are running simultaneously. Two types of these implants are directly stimulating the remaining living cells in the retina. Hitherto the finest resolution has been achieved with the subretinal implants. Although the epiretinal implant offer lower resolution, but requires shorter surgery for implantation. Retinal implants in certain retinal diseases are proved to be capable of generating vision-like experiences. A number of types of retinal implants can be expected to appear in clinical practice a few years after the successful conclusion of clinical trials.

P21, p27, bax, cathepsin and survivin pathways in macular dystrophy corneas

The purpose of our study was to elucidate pathways of genetically programmed cell death (apoptosis) in corneas with macular dystrophy. 10 corneal buttons (10 patients) with macular dystrophy and 8 buttons (8 patients) from enucleated eyes with chorioideal melanoma (controls) were analysed histologically. Immunohistochemical analysis was performed to investigate the presence of p21, p27, bax, cathepsin and survivin proteins. The number of positive cells was determined by analysis of 100 cells and given in percentages. The bax protein was present in 25.6% of epithelial cells in macular dystrophy corneas but was absent in controls. P21 and p27 were found in 35.7 and 87.5% of epithelial cells of macular dystrophy corneas, respectively, but again not in control tissue. In contrast, a lower percentage of cathepsin-positive (30.7% vs 58.8%) and survivin-positive cells (37.6% vs 52.1%) were present in epithelial cells of macular dystrophy corneas than in control epithelial cells. The difference reached statistical significance in the expression of p21 and p27 genes (p<0.05 in both). P21 was positive in 3% of keratocytes, p27 in 1% of endothelial cells of macular dystrophy corneas but negative in controls (0%). Bax, cathepsin and survivin immunopositivity was not detected in keratocytes or endothelial cells of either group. We conclude that the down-regulation of p21, p27 and cathepsin in epithelial cells of macular dystrophy corneas may be related to defense mechanisms against apoptotic cell death.

Glaucoma capsulare in patients with open-angle glaucoma in Hungary

The data of 403 inpatients with open-angle glaucoma were selected between 1977-1986, 155 had glaucoma capsulare (GC) and 248 suffered from primary open-angle glaucoma (POAG). The incidence rate of GC was 38.4% in the total material. In the GC group, the peak of age distribution was between the ages 70-79 (45.8%). The male/female ratio of the total GC material was 1.67, that in POAG was 0.85. The difference between the two glaucoma groups was significant.

P53, CD95, cathepsin and survivin pathways in Fuchs' dystrophy and pseudophakic bullous keratopathy corneas

Our purpose was to elucidate the pathways of apoptosis of corneas with Fuchs' dystrophy and pseudophakic bullous keratopathy. Sixteen corneal buttons (14 patients, median age 73 years) with Fuchs' dystrophy, 13 with pseudophakic bullous keratopathy (PBK) (13 patients, median age 69 years) and 8 buttons (8 patients, median age 59 years) from enucleated eyes with chorioideal melanoma (controls) were analysed histologically. Immunohistochemical analysis was performed to investigate the expression of p21, p27, p63, survivin, CD95, cathepsin, bax, bcl-2 and Ki67. Positive immunohistochemical reactions were detected in epithelial cells of the corneas, but keratocytes and endothelial cells were not positive in any of the groups or stainings. The number of p27 and survivin positive epithelial cells was significantly lower (p=0.048 and 0.041) and the number of cathepsin positive epithelial cells was significantly higher (p=0.004) in Fuchs' dystrophy corneas compared to controls. In pseudophakic bullous keratopathy, p21 and p27 positive epithelial cells were present in a significantly lower (p=0.02 and 0.005) number than in controls. We conclude that genetically programmed cell death is related to the p27, cathepsin and survivin pathways in Fuchs' dystrophy and to the p21 and p27 pathways in pseudophakic bullous keratopathy.

Cell proliferation and apoptosis in stromal corneal dystrophies

The aim of our study was to evaluate corneal cell proliferation and apoptosis in cases of granular, macular and lattice dystrophy, and to provide evidence which may help to clarify whether apoptosis is a pathogenic factor in any of these dystrophies. The study group comprised 39 eyes (from 33 patients) which had undergone penetrating keratoplasty (PK) for stromal dystrophies: these comprised 12 eyes (from 9 patients, 55.5% males) with granular dystrophy, 13 eyes (12 patients, 33.3% males) with macular dystrophy, and 14 eyes (13 patients, 61.5% males) with lattice type I dystrophy. A further 4 corneal buttons from enucleated eyes of 4 patients with choroideal melanoma served as controls. Immunocytochemical analysis of Ki67 (DNAcon Kit, DakoCytomation A/S, Glostrup, Denmark) was used for evaluation of cell proliferation. Apoptosis was detected by use of the TUNEL (terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling) assay method (Apoptag reagent, Q-Biogene, Strasbourg, France). Statistical comparisons were made using the Mann-Whitney test. No Ki67-positive cells were detected in the study-group or control corneas. In control corneas no apoptotic activity was found. In the study group the mean (normalised) apoptotic keratocyte number was 1.1+/-1.7 in granular dystrophy and 0.5+/-1.1 in lattice type I dystrophy (p = 0.36, 0.63 respectively). Compared to the controls, the difference was statistically significant only for macular dystrophy (1.6+/-1.2; p = 0.01). Keratocyte apoptosis seems to be a concomitant or pathogenic factor in macular dystrophy. However, the pathways that are triggered to result in increased apoptotic cell death remain to be clarified.

The role of lumican and keratocan genes in persistent subepithelial corneal haze following excimer laser photorefractive keratectomy

PURPOSE

A retrospective clinical and a genetic study was carried out of severe subepithelial corneal haze occurring after photorefractive keratectomy (PRK). Since this clinical condition resembles the lumican-null mouse phenotype, mutation analysis of lumican and keratocan was carried out to investigate whether germline genetic alterations have an effect on development of severe corneal haze in humans. Corneal thickness, photoablation depth, and severity of persistent corneal haze were also analyzed. In vivo confocal microscopy examination was also performed to study corneal structure and endothelial cells.

METHODS

Severity of corneal haze was evaluated by slit-lamp biomicroscopy according to Hanna's scale. Corneal structure and endothelial cell shapes and density were viewed with a scanning confocal microscope. PCR-based mutational analysis was performed using temperature gradient gel electrophoresis (TGGE) and direct sequencing.

RESULTS

Preoperative corneal thickness was normal (539+/-23.13 microm, mean+/-SD), and the photoablation depth was 88.94+/-18.64 microm (mean+/-SD). The most severe corneal haze was grade 2.0 on Hanna's scale one year after PRK. In vivo confocal microscopy also showed normal endothelial cell density and morphology. Aside from an intronic polymorphism in a control, no genetic alterations were found in the lumican and keratocan genes.

CONCLUSIONS

There was no evidence that endothelial dysfunction and germline mutation of lumican and keratocan genes participate in the etiology of subepithelial corneal haze. Our findings suggest that the mechanisms of the development of severe corneal opacity are different in humans after PRK compared to the lumican deficient knockout mouse model.

[Photodynamic therapy in age-related macular degeneration]

INTRODUCTION

Exudative form of age-related macular degeneration is the leading cause of legal blindness in elderly.

PURPOSE

The purpose of this study is to report 3.5 years experience with photodynamic therapy in this disorder.

PATIENTS AND METHODS

Patient files of all patients underwent photodynamic therapy with verteporfin in Department of Ophthalmology, Semmelweis University, Budapest in a 3.5 years period were reviewed. Changes in visual acuity were considered as main outcome variable compared to natural history data.

RESULTS

From April, 2000 to September 2003, 302 patients were treated using photodynamic therapy with verteporfin for exudative form of age-related macular degeneration. The mean change of visual acuity were 2.6 and 2,7 lines at 12 and 24 months, respectively, while according to the natural history data 4.2 and 4.5 could have been expected. After 2 years, 83% of the patients had visual acuity better than or equal to 20/200 (this is the level of legal blindness), while only 33% was expected according to natural history data. Visual acuity of 20/80 or better (practical ambulatory vision) was found in 39% of the treated eyes (12% in natural history data). There was no severe adverse event.

CONCLUSIONS

Photodynamic therapy was found to reduce the risk of severe visual loss. The authors' results confirm the data from the international trials. To achieve good results, good patient compliance and continuous access to the treatment are indispensible.

Spatial Distribution of Keratan Sulfate in the Rabbit Cornea Following Photorefractive Keratectomy

PURPOSE

To examine the keratan sulfate content of the stroma and to assess its correlation with the healing process (epithelialization and keratocyte density) after photorefractive keratectomy (PRK).

METHODS

Using an Aesculap Meditec MEL 70(G-scan) excimer laser, -6.0 diopters (6.0-mm diameter, 82 microm photoablation depth), PRK was carried out on the right eye of 32 New Zealand pigmented rabbits. After enucleation (at days 1, 4, 7, 14, and 28 and months 2, 3, and 7; sub-groups of 4 animals), fluorescent immunohistochemistry was performed on sections from the central comea using monoclonal mouse anti-keratan-sulfate antibody, immunohistochemistry with proliferative cell nuclear antigen antibody, and hematoxylin-eosin histology. The left, untreated eyes served as controls. Cellular morphology and spatial distribution of keratan sulfate were recorded, stromal thickness measured, and keratocyte density calculated.

RESULTS

Keratan sulfate was found on the surface of migrating epithelial cells in the early stage (from days 1 to 7). In the stroma, three phases were noted. (Phase 1) Day 1 to 14, intense granular fluorescence appeared in the anterior stroma with hypocellularity. (Phase 2) Month 1 to 2, newly synthesized lamellar keratan sulfate restored the repopulating anterior stroma. Endothelial cells became keratan sulfate positive, while in the posterior stroma, lamellar-form keratan sulfate increased from week 1 and peaked at month 1 (100% increase). (Phase 3) Month 2 to 7, remodeling and deposition of keratan sulfate was noted, which was produced in phase 2.

CONCLUSIONS

Keratan sulfate was found in the epithelium, stroma, and endothelium. By controlling the interlamellar spacing, keratan sulfate plays a role in postoperative edema, remodeling of the corneal stroma, and simultaneous regulation of inflammation after PRK.

Proliferation and apoptosis in the corneal stroma in longterm follow-up after photorefractive keratectomy

This study aimed at investigating the proliferation and apoptosis of corneal cells following photorefractive keratectomy (PRK) treatment. PRK (-6.0 D correction) was performed with the Asclepion-Meditec MEL70 G-scan excimer laser on the right eye of each of 33 rabbits under combined local and general anaesthesia. Animals were sacrificed at 4 h, 1, 4, 7, 14, 28, 56, and 112 days postoperatively, and corneal samples from these eight groups were examined histologically. Stromal cell proliferation was evaluated by immunocytochemical analysis of Ki67. Apoptosis was detected using the terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) assay method. The untreated left eyes served as controls. Ki67 positivity was detected in the upper stroma on day 1, 4, 7, and 14, and keratocyte apoptosis on day 1, 4, 7, and 14 after PRK, but not at an earlier or later time. Neither Ki67 positivity nor apoptotic activity was observed in the controls (untreated corneas). PRK was found to trigger proliferation and apoptosis of corneal keratocytes. The frequency and spatial distribution of keratocyte proliferation and apoptosis are likely to be important determinants of the corneal wound healing process, but the detailed regulatory mechanisms have not yet been characterized.

[Intraocular tumours]

Intraocular tumours may be benign or malignant. The latter are more numerous, and endanger not only vision but life as well. Two of them deserve special attention: melanoma malignum oculi in adults and retinoblastoma in children. Melanoma malignum may arise from all three areas of the uvea: the iris, the ciliary body and the choroid. The more malignant growths are those which are situated closer to the posterior pole. Histologically the epitheloid cell-type of melanoma is more malignant than those containing only spindle cells. Their treatment depends on the size: in the case of large tumours enucleation is required, while for the smaller ones, radiation therapy can be applied. Retinoblastoma is most common in children of 1-2 years of age. It has familial and sporadic forms. Sixty-seven percent of the inherited-type cases are bilateral. An early symptom in small children is strabismus. A white tissue mass growing into the vitreous is seen on the fundus. A diagnostic feature that can be detected by ultrasound examination is calcification. The tumour may also present intracranially, therefore CT of the skull should be performed in each case. Histologically the tumour contains malignant neuroepithelial cells, which may form a rosette. In the case of large tumours the treatment is enucleation; in bilateral processes the bulbus with the larger mass is removed and the other eye is treated with radiation therapy. In both cases chemotherapy is used according to a prescribed schedule. Metastases to the eye occur most frequently from carcinomas of the breast, lungs or gastrointestinal tract. These are treated with radiotherapy, chemotherapy and hormone therapy. Primary intraocular lymphoma often occurs bilaterally, and may be accompanied by primary lymphoma of the central nervous system (CNS). Some benign tumours are found by chance on routine eye examinations, others due to subjective and objective symptoms.

Epithelial cell, keratocyte, and endothelial cell apoptosis in Fuchs' dystrophy and in pseudophakic bullous keratopathy

PURPOSE

To elucidate the pathomechanism of Fuchs' dystrophy and pseudophakic bullous keratopathy (PBK) by examining cell apoptosis in different corneal layers.

METHODS

The authors studied corneal buttons obtained from 21 eyes following central penetrating keratoplasty: 14 corneal buttons (13 patients, age 70.8+/-10.0 years) with Fuchs' dystrophy, and 7 buttons (7 patients, age 69.6+/-10.2 years) with PBK. Four buttons from enucleated eyes with choroidal melanoma served as controls. Histologic changes were examined using light microscopy with hematoxylin-eosin (HE) staining. The average numbers of apoptotic cells per field of view (125x magnification) in separate samples of the epithelial, stromal, and endothelial layers were determined using the TUNEL (terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling) assay.

RESULTS

In 11 of the Fuchs' dystrophy corneas and 2 of the PBK corneas, apoptotic activity was detected. In the control corneas no apoptotic activity was found. Compared to the controls there was a statistically significant difference in the mean (normalized) apoptotic cell numbers for all three layers (p=0.01 in each case) in the Fuchs' dystrophy corneas, and for the stromal layer (p<0.01) in PBK corneas. The apoptotic cell numbers for the epithelial and endothelial layers of the latter were higher, but the difference was not statistically significant (p=0.07, 0.07).

CONCLUSIONS

Apoptosis may play a role in the pathomechanism of Fuchs' dystrophy and in keratocyte death in corneas with PBK.

[Results of photorefractive keratectomy in myopia with flying spot excimer laser with high speed and small beam diameter]

PURPOSE

To examine the result of photorefractive keratectomy (PRK) with the next generation of flying spot excimer laser for the treatment of myopic refractive errors.

PATIENTS AND METHODS

During the study 164 eyes of 98 patients were assessed. The average age was 29.4 +/- 4.62 years. The myopic eyes were divided into 3 groups: in Group 1. (n = 115 eyes) the eyes between -1.0 D and -6.0 D were evaluated, in this group the preoperative average refraction was -3.43 +/- 1.2 D (SE = spherical equivalent); in Group 2. (n = 31 eyes) the eyes between -6.1 D and -9.0 D were evaluated; the preoperative average refraction was -7.26 +/- 2.4 D (SE). In Group 3. (n = 18 eyes) eyes above -9.0 D were examined; in Group 3. the average preoperative refraction was -10.22 +/- 3.4 D (SE) Follow-up is 6 months. PRK treatments were carried out with the Zeiss Meditec MEL 80 G-Scan flying spot excimer laser, which was operated with a 0.7 mm beam diameter and 250 Hz frequency.

RESULTS

In Group 1. The preoperative correction decreased to -0.14 D (SE); in 71% of the treated eyes uncorrected visual acuity (UCVA) was 1.0; in 24% of the eyes UCVA improved to 1.2. Best corrected visual acuity (BCVA) was unchanged in 65% of the eyes; while in 34 improved (in 24% it improved by more than 2) Snellen lines. In Group 2. the preoperative correction decreased to -0.13 +/- 0.01 D (SE); 67% had 1.0 and 8% had a 1.2 UCVA. BCVA was unchanged in 92% in Group 2.; in 8% BCVA increased by 1 or 2 Snellen lines. In Group 3., the preoperative correction decreased to -0.44 +/- 0.2 D (SE); 96% of the eyes had a 0.8 UCVA; BCVA did not change in 75% of the eyes, 25% of the eyes gained 1 Snellen line.

CONCLUSIONS

Myopic PRK treatments with the 3rd generation of excimer laser were effective and safe. Regarding BCVA, best results were obtained in the low and medium myopia groups.

Laser treatment of cultured retinal pigment epithelial cells-evaluation of the cellular damage in vitro

PURPOSE

Evaluation of the effects of laser photocoagulation on cultured primary retinal pigment epithelial cells.

METHODS

Cells were treated by a diode laser (678 nm) with 800 and 1600 mW for 0.186 second. Cell toxicity was tested by the WST-1 assay, and the uptakes of glutamate and gamma-aminobutyric acid (GABA) were measured.

RESULTS

Laser photocoagulation (1600 mW) caused cell damage and the mitochondrial enzyme activity evaluated by a WST-1 test significantly decreased by 20%-30%. Laser treatment caused a dose-dependent decrease in glutamate uptake but increased GABA uptake.

CONCLUSIONS

Laser treatment and the laser-induced increase in temperature influence transport processes in retinal pigment epithelial cells and may cause cell damage in the posterior part of the retina.

Silicone oil in the subarachnoidal space--a possible route to the brain?

Using this case report, we sought evidence that silicone oil may infiltrate the subarachnoidal space. Vitrectomy combined with silicone oil implantation was performed on the right eye of a 72-year-old woman. The silicone oil was removed 2 months later, because the patient had developed elevated intraocular pressure. The blind and painful eye was subsequently enucleated. By light microscopy, presumed silicone oil bubbles were identified in the optic nerve and the subarachnoidal space of the enucleated eye. These vacuoles were examined by energy-dispersive X-ray analysis (EDAX). In addition, in the vacuoles, immunohistochemistry was used to test for the presence of CD 68-positive macrophages. Silicone oil infiltration sites in the optic nerve, in the central retinal artery, and in the subarachnoidal space were located by light microscopy and confirmed by EDAX. CD 68-positive macrophages were found in the silicone-filled vacuoles. Silicone oil used for endotamponade may infiltrate the optic nerve and even the subarachnoidal space. This supports the assumption that silicone oil, under special circumstances, may even migrate into the brain.

Ultrasound Evaluation of Flap Thickness, Ablation Depth, and Corneal Edema After Laser in situ Keratomileusis

PURPOSE

The aim of our study was to evaluate the predictability of flap thickness and changes in flap edema over time after laser in situ keratomileusis (LASIK).

METHODS

LASIK was carried out in 30 eyes. The corneal flap was created with a Moria CB manual microkeratome with a flap thickness of 130 microm. Photoablation was performed with the Zeiss-Meditec MEL 70(G-Scan) flying spot excimer laser. Ultrasound pachymetric measurements were performed with the Humphrey Model 855 pachymeter.

RESULTS

Preoperative mean corneal thickness was 568.43 +/- 34.6 microm. After LASIK, mean flap thickness was 133 +/- 26.4 microm. After excimer laser treatment, mean central corneal thickness decreased to a mean 392.4 +/- 37.4 microm. Five minutes after repositioning the flap, mean central corneal thickness was 572.1 +/- 43.4 microm. On the first postoperative day, it decreased to a mean 501.6 +/- 46.6 microm followed by additional decreases: mean 487.4 microm on day 5, 481.8 microm after 1 month, and 479.6 microm at 6 months. The actual photoablation depth was 10 microm less than the predicted depth (paired sample t-test, no statistically significant difference, P = .018). A significant linear correlation was found (Pearson, R =.725, P = .001) between predicted and measured photoablation depth.

CONCLUSIONS

Corneal flap thickness had greater variability than expected. After flap creation, stromal and flap edema occurred, but decreased during the first five postoperative days and stabilized thereafter.

Influence of LASIK on scanning laser polarimetric measurement of the retinal nerve fibre layer with fixed angle and customised corneal polarisation compensation

BACKGROUND/AIM

Retinal nerve fibre layer thickness (RNFLT), as measured with scanning laser polarimetry using the fixed angle corneal polarisation compensator (SLP-F), has been found to be reduced after uncomplicated laser assisted in situ keratomileusis (LASIK) compared to the pre-LASIK measurement. Since this virtual RNFLT thinning is attributed to the corneal changes induced by the LASIK, the authors investigated whether customised corneal polarisation compensation (SLP-C), which compensates for the actual corneal polarisation during each measurement, can avoid the LASIK induced, virtual changes of the polarimetric RNFLT values.

METHODS

Scanning laser polarimetry using both the SLP-F and SLP-C methods (GDx-Access, software version 5.0) was performed on 15 consecutive healthy subjects with no eye disease who underwent LASIK for ametropia correction. The SLP measurements were performed before the surgery, then on day 1 and day 6 after LASIK. Thickness data from images of one randomly selected eye per subject were analysed using the ANOVA and Scheffe multiple comparison tests.

RESULTS

Superior maximum, inferior maximum, normalised superior area, and normalised inferior area (SLP parameters representing the RNFLT at the superior and inferior poles of the optic nerve head) remained unchanged with SLP-C (ANOVA, p>0.05) but decreased (superior maximum, normalised superior area, Scheffe test, p<0.05) or tended to decrease (inferior maximum) after LASIK, when measured using SLP-F. In contrast, certain other parameters-namely, superior ratio and inferior ratio (representing the ratios between the superior or the inferior sector and the temporal sector), maximal modulation, and ellipse modulation decreased with SLP-C (Scheffe test, p<0.05), but remained stable with SLP-F (ANOVA, p>0.05) after LASIK. Superior to nasal ratio, symmetry of the superior and inferior RNFLT as well as the parameter showing the probability of having glaucoma (called "the number") remained unchanged with both types of corneal compensation (ANOVA, p>0.05). With SLP-C the parameter ellipse average thickness increased after LASIK (Scheffe test, p = 0.021). No parameter value altered between day 1 and day 6 after LASIK, for either method.

CONCLUSION

The results suggest that the LASIK induced decrease of the polarimetric RNFLT, which is consistently detected with polarimeters when using the fixed angle corneal polarisation compensator, is due to alterations of the corneal polarisation. The use of customised corneal polarisation compensation avoids this virtual decrease of the polarimetric RNFLTHowever, our results suggest an increase of the measured retardation in the temporal quadrant of the SLP-C image after LASIK. Since ratios of parameters using the temporal RNFLT in the denominator are important in the polarimetric glaucoma diagnosis algorithm, their decrease as a consequence of using SLP-C needs further investigation.

Changes in tear protein pattern after photorefractive keratectomy

PURPOSE

Changes in tear protein composition of patients who underwent photorefractive keratectomy (PRK) were analyzed.

METHODS

Tear samples were obtained from 23 eyes of 23 patients immediately before PRK and on the fourth postoperative day with glass capillaries. Tear proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Digital image analysis and evaluation of the densitometric data of the electrophoretic separations were done with BioDoc-Analyze.

RESULTS

Analysis of discriminance found a significant difference in the protein patterns (p < 0.001). This type of analysis of the electrophoretic densitographs uses all peak information simultaneously. A significant decrease (p < 0.005) in three of the main protein peaks--lactoferrin, immunoglobulin A heavy chain, and lysozyme--was also found after PRK.

CONCLUSIONS

Excimer laser ablation of the cornea has an acute effect on lacrimal gland protein secretion. Changes in tear composition may lead to feelings of dryness and to a decrease in tear film stability postoperatively.

Corneal topographic results after eccentric, biconvex penetrating keratoplasty

PURPOSE

To study the surgical outcomes and postoperative corneal topographies in 5 patients who had eccentric, biconvex penetrating keratoplasty (PKP) for peripheral corneal disorders whose extent did not allow the use of round grafts without involving the center of the cornea.

SETTING

1st Department of Ophthalmology, Semmelweis University, Medical School, Budapest, Hungary.

METHODS

Eccentric, biconvex PKP that spared the optical axis of the cornea was performed in 5 eyes. Indications for surgery were perforated peripheral ulcerative keratitis (n = 3), extensive infiltrated peripheral ulcerative keratitis with impending perforation (n = 1), and ulcerated corneal degeneration caused by an intracameral foreign body for 9 years (n = 1). Computer-assisted corneal topography was performed postoperatively. The follow-up ranged from 8 to 27 months.

RESULTS

All grafts were tectonically effective. Postoperative corneal topography showed normal central corneal regularity in 4 cases (1 case, normal pattern with surface regularity index [SRI] and surface asymmetry index [SAI] within the normal range; 3 cases, normal surface regularity within the central area of the cornea but moderate or high central corneal asymmetry). One eye had irregular astigmatism with a high SRI and SAI. In the first 4 cases, the best spectacle-corrected visual acuity was 0.8 (20/25) or better.

CONCLUSIONS

The results show that eccentric, biconvex PKP sparing the central cornea may be an option in some eyes with perforated peripheral corneal disorders. Postoperative visual acuity may be good as the procedure may result in a regular central anterior corneal surface.

Influence of post-LASIK corneal healing on scanning laser polarimetric measurement of the retinal nerve fibre layer thickness

AIM

To investigate the influence of laser assisted in situ keratomileusis (LASIK) on the values for retinal nerve fibre layer thickness (RNFLT) as measured with scanning laser polarimetry (SLP) during the healing process of the cornea after LASIK.

METHODS

SLP with the GDx instrument was performed on 20 consecutive healthy subjects without any eye disease undergoing LASIK for ametropia correction. The SLP measurements were performed before the surgery, and at 1 and 3 days, as well as at 3 months, after LASIK. Thickness data from images of one randomly selected eye per subject were analysed using the ANOVA and Duncan multiple comparison tests. Correlation coefficients between RNFLT data and the treatment parameters were also calculated.

RESULTS

Somewhat similar results were found for the different retinal areas. The measured values for superior average RNFLT decreased significantly at all time points compared to the preoperative baseline (p<0.003, Duncan test), but increased significantly between postoperative day 1 and the final visit at 3 months (p=0.025, Duncan test). Inferior average RNFLT in the early postoperative days was significantly smaller than at 3 months after LASIK (p<0.05, Duncan test), and tended to be smaller than at baseline. The thickness values before surgery and at the final visit, however, showed no significant difference (p=0.698, Duncan test) in this region. Ellipse average RNFLT was significantly smaller in the early postoperative days than the baseline value before LASIK. However, the measured value had significantly increased again by the time of the final visit (p<0.02, Duncan test). This value at the final visit showed no difference from the baseline value (p=0.46, Duncan test). The changes in the nasal average and temporal average RNFLT were not statistically significant. No correlation was found between the change in the SLP measured thickness values and central corneal thickness at baseline and its change after surgery, nor with the change in cylindrical correction due to LASIK, or the length of the suction time during surgery (p>0.05 for all correlations).

CONCLUSION

The SLP technique is sensitive to the corneal optical properties, and RNFLT as measured with SLP shows changes after LASIK. Most of these changes, however, diminish with time after surgery, and the values tend to return to the preoperative results during the first 3 months of corneal healing following uncomplicated LASIK. It appears that in uncomplicated cases the transient RNFLT changes are artefacts and do not imply pathological thickness alterations due to LASIK.

[Experience with laser in situ keratomileusis]

AIM OF THE STUDY

To evaluate the results of laser in situ keratomileusis (LASIK) in groups with different refractive errors.

PATIENTS AND METHODS

68 LASIK procedure have been performed in the following patient groups: Group 1 (-3.0 D to -6.0 D) n = 14; Group 2 (-6.25 D to -9.0 D) n = 29; Group 3 (-9.25 D to -14.0 D) n = 13; Group 4 (eyes with hyperopic refractive error between +1.75 D and +7.5 D) n = 12. A Moria CB manual mikrokeratom was used, flap thickness was 130 microns. Excimer laser treatment was carried out with Asclepion-Meditec MEL 70 G-Scan flying spot excimer laser. Follow-up time is 6 months.

RESULTS

The preoperative correction decreased in Group 1. from -4.45 D +/- 0.93 D (SE = spherical equivalent) to -0.04 D +/- 0.13 D, in Group 2. from -7.81 D +/- 0.98 D (SE) to -0.56 D +/- 0.9 D, in Group 3. from -11.33 D +/- 1.97 D (SE) to -1.88 D +/- 1.64 D, and in Group 4. from +4.67 D +/- 1.67 D (SE) to +0.24 D +/- 0.50 D 6 months following LASIK. The best spectacle corrected visual acuity (BSCVA) decreased by 2 or more Snellen lines in 4 eyes in Group 2, in 2 eyes in Group 3, and there was no change in Group 1 and Group 4. BSCVA improved by 2 or more Snellen lines in one eye in Group 2, in 2 eyes in Group 3 and there was no change in Group 1 and in Group 4.

CONCLUSIONS

The preoperative correction decreased significantly following LASIK procedure in each patient group. The method was found to be effective, safe and durable during the 6 months follow-up. Application is recommended especially in eyes with a refractive error higher than -6.0 D due to possible intra- and early postoperative complications.

C1r-C1s-C1inhibitor (C1rs-C1inh) complex measurements in tears of patients before and after penetrating keratoplasty

PURPOSE

The aim of this pilot study was to determine the presence of complement activation products in tears from pre- and postkeratoplasty eyes and the fellow eyes in order to investigate the activation of the classical and alternative pathways of the complement system in the early postkeratoplasty period.

METHODS

Tear samples from both eyes of 19 prekeratoplasty patients were tested. From 10 patients, samples were taken before operation, one week and 3 weeks after penetrating keratoplasty. Only baseline and 1 weak samples, and baseline and 3 week samples were available from 5 and 2 patients, respectively, while only baseline tear samples were collected from 2 patients. Tear concentration of two complement activation products, C1rs-C1inh and C3bBbP were determined by enzyme-linked immunosorbent assay.

RESULTS

There was no difference (p = 0.339) between baseline samples of the eyes waiting for operation (0.93 +/- 0.51 AU/ml, mean +/- SEM) and the fellow eyes (0.33 +/- 0.33 AU/ml) in respect of mean C1rs-C1inh complex concentration. The one-week samples of the operated eyes revealed significantly (p = 0.006) elevated levels of C1rs-C1inh complexes (18.8. +/- 6.37 AU/ml), compared to their baseline samples (1.18 +/- 0.64 AU/ml), whereas the one-week values of the fellow eyes did not differ from the baseline values. Compared to the increased one-week values, the three-week values decreased to the baseline values in the operated eyes. C3bBbP could be detected in 3/68 tear samples.

CONCLUSIONS

In our study we demonstrated the increased concentration of C1rs-C1inh complex in several tear samples taken early after human penetrating keratoplasty. These findings provide direct evidence that the classical pathway of complement may be activated in the early postoperative period after penetrating keratoplasty.

The role of ultraviolet-B in corneal healing following excimer laser in situ keratomileusis

Corneal photoablation with the 193 nm argon fluoride excimer laser during photorefractive keratectomy (PRK) in high diopter range is frequently associated with subepithelial haze and consequent refractive regression due to avascular corneal wound healing. The wound healing response can be augmented by Ultraviolet-B (UV-B) exposure originating from sun or solarium. Clinically Laser in situ Keratomileusis (LASIK) even in high diopter range is associated with less subepithelial haze and regression than PRK. In an animal model, the morphologic changes of the rabbit cornea were evaluated following LASIK and secondary UV-B exposure. Light microscpic changes were found to be insignificant. Transmission electron microscopy (TEM) normal epithelium, epithelial adhesion structures and normal anterior stroma showed in the LASIK treated UV-B irradiated rabbit eyes. Around the peripheral LASIK cut, migrating keratocytes with pseudopodia were observed. Under the flap (160 microm depth) the overall stromal collagen structure was normal, some activated keratocytes and mild extracellular matrix formation within and around keratocytes were noted. Within activated keratocytes TEM showed prominent rough endoplasmic reticulum, Golgi apparatus, mitochondria and extracellular vacuoles, which showed resolution with time. These changes were much milder than in PRK treated-UV-B irradiated eyes. Secondary UV-B caused no long-term disturbance in corneal transparency in LASIK and UV-B treated rabbit eyes.

Treatment of intraocular pressure elevation after photorefractive keratectomy

PURPOSE

To study the effect of timolol maleate, dorzolamide, or a combination of both in post photorefractive keratectomy (PRK) eyes with an elevated intraocular pressure (IOP) after topical steroid administration.

SETTING

Refractive Surgery Outpatient Department, 1st Department of Ophthalmology, Semmelweis University, Budapest, Hungary.

METHODS

Forty-five patients with elevated IOP were randomly enrolled in 3 groups: Group 1 received timolol maleate 0.5% twice a day; Group 2 received timolol maleate 0.5% twice a day and dorzolamide 2% 3 times a day; and Group 3 received only topical dorzolamide 2% 3 times a day. Intraocular pressure was measured 3 days and 1, 3, and 6 weeks after the antiglaucoma medication was started.

RESULTS

The mean preoperative IOP was 15.25 mm Hg +/- 1.28 (SD). Following administration of topical fluorometholone, the IOP increased a mean of 27.39 +/- 2.88 mm Hg. Six weeks after the antiglaucoma therapy was started, the mean IOP reduction was 6.6 mm Hg in Group 1, 8.86 mm Hg in Group 2, and 4.64 mm Hg in Group 3.

CONCLUSIONS

A combination therapy of timolol 0.5% and dorzolamide 2% was most effective in treating secondary IOP elevation after PRK. Dorzolamide alone did not adequately control secondary post-PRK IOP elevation.

Photorefractive Keratectomy for Astigmatism With the Meditec MEL 60 Laser

PURPOSE

To evaluate the results of photorefractive keratectomy (PRK) in eyes treated with astigmatic refractive errors.

METHODS

Nine hundred forty eyes were treated with the Aesculap Meditec MEL 60 ArF excimer laser. Treatment groups were: Group 1 (n=746) eyes with compound myopic astigmatism, Group 2 (n=104) eyes with compound hyperopic astigmatism, Group 3 (n=75) eyes treated for mixed astigmatism, and Group 4 (n=15) eyes with simple myopic astigmatism (negative cylinder).

RESULTS

In Group 1, the preoperative spherical equivalent refraction of -6.10 D with an average of -1.50 D cylinder decreased to -0.95 D with -0.13 D cylinder; uncorrected visual acuity (UCVA) of 20/40 or better was achieved in 86% (642/746 eyes); 20/20 or better in 58% (433/746 eyes); 0.8% (6/746 eyes) lost two lines of spectacle-corrected visual acuity (SCVA); 74% (552/746 eyes) were within +/-0.50 D and 93% (694/746 eyes) were within +/-1.00 D of target refraction. In Group 2, preoperative mean +4.57 D spherical equivalent refraction with an average of +1.57 D cylinder decreased to +1.13 D with +0.38 D cylinder; UCVA of 20/40 or better was achieved in 84% (87/104 eyes); 20/20 or better in 46% (48/104 eyes); 14,4% (15/104 eyes) lost two or more lines of SCVA; 52% (54/104 eyes) were within +/-0.50 D and 82% (85/104 eyes) were within +/-1.00 D of target refraction. In Group 3, mean preoperative -4.20 D cylinder and +3.00 D spherical equivalent refraction decreased to -0.50 D cylinder and -0.50 D spherical equivalent refraction; UCVA of 20/40 or better was achieved in 83% (62/75 eyes); 20/20 or better in 32% (24/75 eyes); 13.3% (10/75 eyes) lost two or more lines of SCVA. In Group 4, mean preoperative -3.98 D cylinder decreased to -0.62 D cylinder; UCVA of 20/40 or better was achieved in 60% (9/15 eyes); none of the eyes achieved 20/20 or better; SCVA remained stable in 6.6% (1/15 eyes) and decreased two or more lines in 20.0% (3/15 eyes); 20% (3/15 eyes) were within +/-0.50 D and 53.3% (8/15 eyes) were within +/-1.00 D of target refraction.

CONCLUSION

PRK with the Meditec MEL 60 laser produced the best results in eyes with compound myopic astigmatism (Group 1). In all other groups, results were less predictable.

Photorefractive Keratectomy for Myopia With the Meditec MEL 70^sub G-Scan^ Flying Spot Laser

PURPOSE

To evaluate the efficacy, predictability, stability, and safety of the Meditec MEL 70G-Scan flying spot excimer laser.

METHODS

One hundred thirty myopic eyes were treated with the Aesculap Meditec Mel 70G-Scan ArF flying spot excimer laser with photorefractive keratectomy (PRK). Patient groups: low myopia (Group 1) from -1.50 to -6.00 D (90 eyes), medium myopia (Group 2) from -6.10 to -9.00 D (31 eyes), high myopia (Group 3) from -9.10 to -14.00 D (9 eyes).

RESULTS

At 12 months in the low myopia group, uncorrected visual acuity (UCVA) of 20/40 or better was achieved in 95.5% (86 eyes), 20/20 or better in 77.7% (70 eyes); 2.2% (two eyes) lost two or more lines of best spectacle-corrected visual acuity (BSCVA); 73.3% (66 eyes) were within +/-0.50 D of the target correction and 98.8% (89 eyes) were within +/-1.00 D. In the medium myopia group, UCVA of 20/40 or better was achieved in 74.2% (23 eyes), 20/20 or better in 25.8% (eight eyes); 3.2% (one eye) lost two lines, 61% (19 eyes) were within +/-0.50 D of desired correction and 83.8% (26 eyes) were within +/-1.00 D. In the high myopia group, UCVA of 20/40 or better was achieved in 22.2% (two eyes); 20/25 or better in 11.1% (one eye); none of the eyes achieved 20/20 UCVA; 22.2% (two eyes) lost two lines of BSCVA; 44.4% (four eyes) were within +/-0.50 D and 66.6% (six eyes) were within +/-1.00 D of the target correction. Refractive stability was achieved between 3 and 6 months. Increased intraocular pressure was detected overall in 7.69%.

CONCLUSIONS

The results of predictability, safety, and efficacy in low and medium myopia with the Meditec MEL 70G-Scan flying spot excimer laser were good, but poorer predictability, regression, and a significant loss of BSCVA were observed in the high myopia group.

Leiomyoma of The Ciliary Body and Hemangiopericytoma of the Choroid

Two unusual uveal tumors occurring in eyes enucleated for presumed malignant melanoma are discussed. One was a leiomyoma of the ciliary body, affecting a 22-year-old female, the other a hemangiopericytoma of the choroid in an 84-year-old male patient. The latter case is the fourth intraocular hemangiopericytoma reported in the literature to date. The histopathologic diagnosis was confirmed by immunohistochemistry and electron microscopy.

Cold pressor test and retinal capillary perfusion in vasospastic subjects with and without capsular glaucoma (a preliminary study)

PURPOSE

Using the cold pressor test the authors investigated the change in retinal and neuroretinal capillary perfusion in vasospastic patients suffering from capsular glaucoma (CG) and in vasospastic control subjects.

METHODS

Changes in retinal and optic nerve head capillary perfusion induced by the cold pressor test (one hand immersed in 4 degrees C water for 30 seconds, then in 30 degrees C water for 2 minutes) was measured using the Heidelberg Retina Flowmeter in 4 patients with CG and in 5 healthy control subjects. Previously all subjects showed a reduction of cutaneous capillary flow higher than 70% in the cold pressor test (vasospastic reaction). One eye per subject was investigated. Two images were obtained for each phase (baseline, cold phase and warm phase), and the better quality image from each phase was selected for the measurements. One location on the temporal neuroretinal rim and one location on the temporal retina outside the peripapillary area were selected for the HRF measurements.

RESULTS

In the CG group neuroretinal rim "Volume" decreased by 26.05%, "Flow" by 25.82% and "Velocity" by 23.91% (p<0.05), retinal "Volume" decreased by 12.30% (p=0.051), and retinal "Flow" by 22.36% (p=0.01) in the cold phase. All these parameters returned to the corresponding baseline values in the warm phase. In the control group a significant decrease was observed in retinal "Volume" (15.96%), "Flow" (17.81%), and "Velocity" (16.11%) in the cold phase (p<0.05), which diminished in the warm phase but remained still significant for "Flow" and "Velocity".

CONCLUSION

Cutaneous cold provocation can induce an immediate decrease in retinal and optic nerve head capillary perfusion at least in a part of the vasospastic subjects with or without capsular glaucoma. This decrease diminishes or disappears quickly when the hand is immersed in warm water. To evaluate the potential role of cold-induced retinal and optic nerve head vasoconstriction in the pathogenesis of capsular glaucoma further investigations are necessary since this reaction was also present in the vasospastic control subjects.

Central bump-like opacity as a complication of high hyperopic photorefractive keratectomy

PURPOSE

A new complication is reported in association with high hyperopic excimer laser photorefractive keratectomy.

METHODS

One thousand consecutive eyes were treated with a Meditec MEL-60 excimer laser (Meditec Inc, Heroldsberg, Germany) for hyperopic refractive error between +1 diopters and +7 diopters.

RESULTS

Three eyes with high hyperopic corrections between +5 and +6 diopters had a central, round bump-like subepithelial scar develop 1 month after hyperopic photorefractive keratectomy, which reduced the uncorrected and spectacle-corrected visual acuity.

CONCLUSION

Central bump-like opacity is a new, visually significant complication of unknown origin associated with high hyperopic photorefractive keratectomy. Possible causes of this complication include drying and edema of the cornea as a result of prolonged exposure, interruption of the peripheral superficial nerve plexus affecting the central anterior stroma, and abnormal epithelial or tear film function resulting from excessive central steeping.

[Pathogenesis and conservative treatment of glaucoma]

Glaucoma is a chronic disease which, if not treated, can lead to blindness. The reason for deterioration of function is neuropathia n. optici developed during the disease. Earlier increased ocular tension was considered to be the cause of neuropathia. By now we have realised that increased ocular tension (that above 21 Hgmm) in only one of the risk factors. The decay of optic nerve fibres is caused by circulatory failure on the one hand, and by the necrosis of ganglion cells on the other hand. In the conservative treatment of glaucoma pilocarpin was used earlier but nowdays the first place has been taken over by the group of betareceptor blockers, which are applied twice a day in the form of dropping. If this proves unsatisfactory, the treatment is complemented with carbonanhydrase inhibitor-drops 2-3 times daily. In certain cases this is followed by prostaglandin F2alfa analog drops once a day, dripped in the evening hours. Carboanhydrase inhibitor can be administered per oral as well: 1-2 times weekly. This latter cannot be given continuously: it is only a temporal solution for a few months in addition to other conservative therapy. Cholinerg drops can join in at any time of conservative treatment. The future method of conservative therapy is the combination of drops with varions effect, which decreases the frequency of daily drippings and enhances the efficacy of treatment.

Scanning laser polarimetry via intravitreal silicone oil

PURPOSE

To investigate whether scanning laser polarimetry, a promising new technique for early detection of glaucomatous nerve fiber loss, is a suitable method to measure retinal nerve fiber layer thickness in eyes with intravitreal silicone oil.

PATIENTS AND METHODS

Eleven eyes of 11 consecutive patients two days to 16 months after successful vitrectomy and intravitreal silicone oil injection and 12 eyes of 12 consecutive subjects, who never had any vitreoretinal surgery were examined using the GDx Nerve Fiber Analyzer. Three individual images were computed to a mean image using the software in each case.

RESULTS

"Variance", a software-provided parameter, which represents the differences between the individual images used to calculate the mean image was higher in the "silicone oil" group (unpaired t test for different variances, p = 0.02). Good-quality mean images with a "Variance" value similar to that of the control eyes were obtained in seven of the 11 cases. Characteristic artifacts caused by intravitreal silicone oil were observed in five of the 11 cases.

CONCLUSION

Successful scanning laser polarimetry is possible after vitrectomy and intravitreal silicone oil injection, and may help to monitor the retinal nerve fiber layer of these eyes in case of silicone oil induced glaucoma.

[Results of photorefractive keratectomy after treatment of 2053 eyes]

To evaluate the 12 months refractive results of photorefractive excimer keratectomy (PRK) in high number of eyes with different type of refractive error. Between October 1992 and December 1996. 2053 eyes of 1098 patients were treated with the Aesculap Meditec MEL 60 argon-fluoride excimer laser. Refractive results were concluded at the 12th post-PRK month. The following patient groups were used during the study: Group 1.: Eyes between -1.0 D and -6.0 D (n = 651); Group 2.: -6.0 és -9.0 D (n = 216); Group 3.: Eyes with refractive error above -9.0 D (n = 163); Group 4.: Hypermetrop eyes (n = 160); Group 5.: Eyes with myopic astigmatism (n = 746); Group 6.: Eyes with hypermetropic astigmatism; Group 7.: Pure astigmatism (n = 13). In Group 1. The preoperative average -3.94 +/- 1.3 D refractive error decreased during the 1-year follow-up period to -0.47 +/- 0.54 Dpt; in Group 2. The preoperative -7.65 +/- 1.07 D to -1.16 +/- 1.86 D; in Group 3. The preoperative average -13.58 +/- 3.51 D to -3.11 +/- 2.75 D; in Group 4. The preoperative +4.04 +/- 1.77 D to +1.02 +/- 1.16 D in Group 5. The preoperative -6.06 +/- 2.78 D spherical component decreased to -0.95 +/- 1.33 D-ra, whereas the preoperative cylindrical component from -1.5 +/- 1.08 D to -0.13 +/- 0.58 D; in Group 5. The preoperative +4.57 +/- 1.78 spherical component to +1.13 +/- 1.38 D; whereas the preoperative cylindrical component from +1.57 +/- 0.96 D to +0.38 +/- 0.77 D; in Group 7. The preoperative a -3.98 +/- 1.2 D cylinder decreased to -0.62 +/- 0.75 D cylinder. PRK decreased effectively the preoperative correction need in every treatment group. The results are the better, the smaller the preoperative correction need is.

Excimer laser treatment of hyperopia

PURPOSE

The aim of this study was to analyse the clinical results of hyperopic photorefractive keratectomy treatments and to compare the results achieved with the usage of different masks.

METHOD

20 eyes of 16 hyperopic patients were treated, using the Aesculap-Meditec MEL60 193nm ArF excimer laser. The mean duration of follow-up was 9.9+/-3.4 months. Statistical comparison of the results with the two masks was made using the unpaired Student t-test.

RESULTS

Preoperative mean spherical equivalent was +4.23+/-1.18D, which changed to +0.20+/-0.78D at one month and regressed to +1.23+/-1.27D at the last control examination. After 6 months 60% (12 eyes) had spherical equivalent within +/-1.0D of the attempted correction. The statistical analysis showed no significant difference between the results with the two masks.

CONCLUSION

Good preparation for the treatment is of equal importance for the results of the photorefractive keratectomy as compared to the technical circumstances.

Clinical and morphological response to UV-B irradiation after excimer laser photorefractive keratectomy

This paper represents an update on a study that has been reported elsewhere (Nagy ZZ et al: Ophthalmology 104:375-380, 1997). The aim of the study was to evaluate the clinical and light- and electron-microscopic effects of ultraviolet-B (UV-B) exposure on the outcome of photorefractive keratectomy (PRK). A total of 42 pigmented rabbits were used in the study. One eye from each of 12 rabbits received a 193 nm 45-microm deep (-5.0 diopters [D]) excimer laser PRK, one eye from each of 12 rabbits received a 135-microm deep (-15.0 D) excimer laser PRK, and one eye from each of 12 rabbits received a 270 microm deep (-30.0 D) excimer laser PRK. Twenty-one days after PRK, six of the laser-treated eyes from each group were exposed to 100 mJ/cm2 UV-B (280-320 nm). The other six rabbits from the PRK groups received no further treatment. One eye from each of six rabbits received only UV-B irradiation, serving as control. Subepithelial haze was evaluated before and after UV-B irradiation. Clinical changes were followed by laser tyndallometry, confocal corneal biomicroscopy, ultrasound biomicroscopy, and endothelial specular microscopy. Corneal morphology was assessed 4, 8, and 12 weeks after UV-B exposure, employing light microscopic and transmission electron-microscopic techniques (TEM). Eyes only exposed to 100 mJ/cm2 UV-B exhibited keratitis for 2 days, but showed no haze and were histologically normal at all time intervals. The PRK-UV-B-irradiated rabbit eyes exhibited a significant increase of stromal haze compared to the eyes receiving PRK alone; this phenomenon correlated with the depth of photoablation. The severity of clinical findings also correlated with the previously attempted photoablation depth; in PRK-UV-B-irradiated eyes the symptoms were much more serious than in eyes treated with PRK alone. Histologically, the main difference between the UV-B-irradiated and nonirradiated-post-PRK eyes was the presence of anterior stromal extracellular vacuolization in the UV-B-exposed eyes. The vacuolated foci were confined to the PRK treatment area, contained increased numbers of keratocytes and showed a disorganization of normal collagen lamellae. Transmission electron microscopy revealed activated keratocytes containing abundant rough endoplasmic reticulum, prominent Golgi zones, and extracellular vacuoles filled with amorphous material. The haze and morphological changes showed a tendency to incomplete resolution over a period of 12 weeks. Ultraviolet-B exposure during post-PRK stromal healing exacerbates and prolongs clinical symptoms and the stromal healing response, which is manifest biomicroscopically by augmentation of subepithelial haze. The findings suggest that excessive ocular UV-B exposure should be avoided during the period of post-PRK stromal repair and that UV-B may modulate the response of tissues to excimer 193 nm, and perhaps, other laser energy in general.

Scanning laser polarimetry of the retinal nerve fibre layer in primary open angle and capsular glaucoma

AIMS

To evaluate the clinical value of scanning laser polarimetry with the nerve fibre analyser type II in primary open angle glaucoma (POAG) and capsular glaucoma.

METHODS

Scanning laser polarimetry was performed on one eye of 30 patients suffering from POAG, 25 patients suffering from capsular glaucoma, and on 35 healthy control subjects. The retinal nerve fibre layer (RNFL) thickness values were compared among the groups. Reproducibility of the measurements was calculated and the influence of pilocarpine induced miosis on the results was investigated.

RESULTS

RNFL thickness in the superior and inferior sectors, as well as along the total circumference was significantly lower in both glaucoma groups than in the control eyes (p < 0.05). None of the thickness values differed between the two glaucoma groups. Reproducibility was comparable in all groups; the coefficient of variation varied between 3.0% and 8.9% for the different sectors investigated. Miosis had no significant impact either on the thickness values or on the reproducibility (p > 0.05).

CONCLUSION

The results suggest that scanning laser polarimetry is a useful method for nerve fibre layer analysis in glaucoma, and that it is not influenced by the pupil size.

Ultraviolet-B enhances corneal stromal response to 193-nm excimer laser treatment

PURPOSE

The purpose of the study was to evaluate the biomicroscopic, light microscopic, and electron microscopic effects of ultraviolet-B (UV-B) exposure on the outcome of photorefractive keratectomy (PRK).

METHODS

A total of 24 pigmented rabbits were used in the study. One eye of 16 rabbits received a 193-nm, 45-micron deep (-5.0 diopter) excimer laser PRK. Twenty-one days after PRK, eight of the laser-treated eyes were exposed to 100 mJ/cm2 UV-B (280-315 nm) UV radiation by placing the rabbits in a standard clinically used dermatologic chamber for 7 minutes. Eight PRK-treated rabbits received no further treatment. The remaining eight non-PRK-treated rabbits received 100 mJ/cm2 UV-B only to one eye. Subepithelial haze was assessed before and after UV irradiation. Corneal morphology was assessed 4, 8, 12, and 16 weeks after UV-B exposure, using light microscopic and transmission electron microscopic (TEM) techniques.

RESULTS

Untreated eyes exposed to 100 mJ/cm2 UV-B only exhibited photokeratitis for 2 days, but showed no haze and were normal histologically at all intervals. The PRK-treated UV-B irradiated eyes exhibited a significant increase of stromal haze compared to eyes receiving PRK alone. Histologically, the main difference between the UV-B irradiated and nonirradiated post-PRK eyes was the presence of anterior stromal extracellular vacuolization in the UV-B-exposed eyes. The vacuolated foci were confined to the PRK treatment area and showed increased keratocyte density and disorganization of normal collagen lamellae. TEM showed activated keratocytes containing abundant rough endoplasmic reticulum, prominent Golgi zones, and extracellular vacuoles filled with amorphous material. The haze and morphologic changes showed a tendency to incomplete resolution over the period of 16 weeks.

CONCLUSIONS

The UV-B exposure during post-PRK stromal healing exacerbates and prolongs the stromal healing response and is manifest biomicroscopically by augmentation of subepithelial haze. The findings suggest that excessive ocular UV-B exposure should be avoided during the period of post-PRK stromal repair and that UV-B may modulate the response of tissues to 193-nm excimer laser and perhaps other laser energy in general.

[Examination of subepithelial scar formation after photorefractive keratectomy with the ultrasound biomicroscope]

BACKGROUND

The subepithelial haze and the concomittant refractive regression are the most important complications of photorefractive keratectomies (PRK). The authors examined the subepithelial haze characteristics by ultrasound biomicroscopy (UBM).

MATERIALS AND METHODS

Twenty previously photokeratectomized myopic eyes, which showed a certain level of subepithelial scarring have been examined (age: 34.22 +/- 3.57 years, 12 women, 8 men). The range of PRK treatments varied between -4.0 D and -12.0 D. The subepithelial haze graded according to Hanna et al, between 1.0 and 4.0. The UBM examinations were carried out between 1-3 months following PRK with the 50-80 MHz transducer of a Model 840 Zeiss-Humphrey Ultrasound Biomicroscope.

RESULTS

The severity of subepithelial haze correlated with the previous photoablation depth. Up till haze graded 2.0 according to Hanna et al. UBM showed loss of Bowman membrane and a slight thinning of the central cornea. Between grade 2.0 and 3.0 the reflectivity of anterior stroma increased, above grade 3.0 a hyperreflective 1/3 anterior stroma with irregular borders were observed.

CONCLUSION

Haze phenomen graded below 2.0 is not observable with UBM. Haze, graded more than 2.0 caused an increase of anterior stormal reflectivity. In more serious cases the 1/3 of the anterior stroma might be affected. The UBM-method with a 50-80 MHz probe is suitable to document and follow the serious haze phenomen after photoablations.

Morphological response to UV-B irradiation after excimer-laser photorefractive keratectomy

The purpose of this study was to evaluate the morphological effects of UV-B exposure on the outcome of photorefractive keratectomy (PRK). A total of 42 pigmented rabbits were used in the study. In all, 1 eye of 12 rabbits received a 193-nm and 45-micron-deep (-5.0-D) excimer-laser PRK, 1 eye of 12 rabbits received a 135-micron-deep (-15.0-D) excimer-laser PRK and 1 eye of 12 rabbits received a 270-micron-deep (-30.0-D) excimer-laser PRK. At 21 days after PRK, six of the laser-treated eyes from each group were exposed to 100 mJ/cm2 UV-B (280-320 nm) light by placement of the rabbits in a standard clinically used "dermatological chamber" for 7 min. One eye of six rabbits received only UV-B light, serving as a control. The other six rabbits from the PRK groups received no further treatment. Subepithelial "haze" was evaluated before and after UV irradiation. Corneal morphology was assessed at 4, 8 and 12 weeks after UV-B exposure by light microscope and transmission electron microscope techniques (TEM). Eyes exposed to 100 mJ/cm2 UV-B light exhibited only keratitis for 2 days but showed no haze and were histologically normal at all time points. The PRK-treated, UV-B-irradiated rabbit eyes exhibited a significant increase in stromal haze as compared with the eyes receiving PRK alone; this phenomenon correlated with the depth of photoablation. Histologically, the main difference observed between the UV-B-irradiated and nonirradiated post-PRK eyes was the presence of anterior stromal extracellular vacuolization in the UV-B-exposed eyes. The vacuolated foci were confined to the PRK treatment area, contained increased numbers of keratocytes and showed a disorganization of normal collagen lamellae. TEM revealed activated keratocytes containing abundant rough endoplasmic reticulum, prominent Golgi zones and extracellular vacuoles filled with amorphous material. The haze and morphological changes showed a tendency towards incomplete resolution over a period of 12 weeks. UV-B exposure during post-PRK stromal healing exacerbates and prolongs clinical symptoms and the stromal healing response in rabbits, which is manifested biomicroscopically by augmentation of subepithelial haze. The findings suggest that excessive ocular UV-B exposure should be avoided during the period of post-PRK stromal repair (at least 3 months) and that UV-B light may modulate the response of tissues to 193-nm excimer and, perhaps, other laser energy in general.

[Phototherapeutic use of excimer laser]

The photorefractive excimer laser is not only able to alter the refractive power of the corneas but also suitable to treat superficial corneal pathologies. Authors performed phototherapeutic keratectomies (PTK) in 80 eyes of 77 patients. The age was on average (+/- S.D.) 49.4 +/- 22.03 years. The follow-up time varied between 3-24 months. All treatments were performed with the Aesculap Meditec MEL 60 ArF excimer laser, working in the 193 nm extreme ultraviolet-C range. Authors conclude that the best postoperative results can be achieved with PTK in cases of recurrent corneal erosions and superficial corneal opacities. Favourable outcome could be expected in treatment of infectious corneal ulcers. In cases of bullous keratopathy the subjective complaints decreased and it was successful to postpone the time of perforating keratoplasty. The PTK is not recommended in case of corneal Bowen disease and recurrent pterygia. A hyperopic shifts was observed in 2 eyes. Besides, the traditional surgical methods the phototherapeutic keratectomy is an important progress in treatment of superficial corneal pathologies. Applying the method, the recurrent erosions healed quicker, in most of the cases the transparency of the cornea could be reestablished in the pupillary area and the need for perforating keratoplasty could be postponed or avoided.

Nocturnal blood pressure and intraocular pressure measurement in glaucoma patients and healthy controls

Daytime and nocturnal intraocular pressure (IOP) values and systemic blood pressure (BP) values were compared in 60 non-glaucomatous controls, 54 glaucoma patients with normal visual field, and 46 glaucoma patients with visual field loss. The daytime IOP was measured with a Goldmann applanation tonometer and the nocturnal IOP with a Bio-Rad-Tono-Pen 2. The BP was measured with either a mercury manometer or with a Meditech ABPM-02 Ambulatory Blood Pressure Monitor, which took BP readings at 60 minute intervals. A tendency towards increasing IOP and decreasing BP was detected in the non-glaucomatous controls, within normal limits, and pathological changes of IOP and BP were observed with a significantly high occurrence (5% > P > 2%; Pearson's chi 2-test) in the glaucoma group with visual field loss.