[Correlation between refraction and ocular biometry]

PURPOSE

To study the correlation between subjective refraction and biometry obtained by Orbscan and echography in normal eyes. To compare biometric parameters with the subjective spherical equivalent.

MATERIAL AND METHODS

Subjective refraction, biometric parameters using Orbscan, and echography were recorded in 190 normal eyes (including eyes with ametropia) of 95 patients. Biometric parameters (i.e., corneal diameter, anterior chamber depth, central pachymetry, iridocorneal angle, corneal and lens radii of curvature, and axial length of the eye) were compared in different refractive groups and were correlated with the subjective refraction.

RESULTS

Corneal biometric parameters did not correlate with the subjective spherical equivalent and showed no differences between the refractive groups except for the central pachymetry. In the high myopic group (<-6D), the central cornea was significantly thinner (531 micro m versus 549 micro m, p=0.016). The correlation between corneal radius and axial length was strong in emmetropic eyes (r(s)=0.63, p<0.001) and poor but significant in ametropic eyes (r(s)=0.28, p=0.002). Axial length, anterior chamber depth, and iridocorneal angle showed significant differences between the refractive groups (p<0.001) and correlated with the subjective spherical equivalent (r(s[[/INF=0.44, p<0.001). Subjective spherical equivalent showed the strongest correlation with the axial length (rs)=0.82, p<0.001). Subjective spherical equivalent, central corneal thickness, axial length, anterior chamber depth, and anterior corneal radius showed a strong correlation between both eyes (rs[[/INF=0.94, p<0.001).

CONCLUSION

Biometric characteristics of the eye (excluding cornea characteristics) vary with subjective spherical equivalent. Axial length presents the strongest correlation with the subjective spherical equivalent and correlates with the other ocular biometric parameters. Axial length plays a major role in the ocular biometry and refraction.

[A new case of Susac syndrome and a review of the literature]

We report a single case of Susac syndrome (microangiopathy of the brain, retina, and cochlea). A 26-year-old woman developed branch retinal artery occlusion in the right eye, associated with bilateral hearing loss that mostly involved low frequencies. MRI of the brain revealed small multifocal hyperintensities in the white matter of the cerebrum on T2-weighted images with gadolium enhancement. The treatment consisted of anticoagulation and antiplatelet drugs. Seventy-one cases of Susac syndrome have been reported in the literature. The Susac syndrome is more frequent in females and its etiology remains unknown. However, immune inflammatory disorders, vasospastic phenomena, and coagulopathy could be involved in its pathophysiology. Treatment options are not standardized, ranging from antithrombotic drugs to immunomodulatory therapy. The course of the disease is self-limited after an initial fluctuating active phase. The prognosis of Susac syndrome is good in most cases.

Late bacterial keratitis after implantation of intrastromal corneal ring segments

We report a case of bacterial keratitis that occurred after implantation of intrastromal corneal ring segments (Intacs). The patient presented with decreased vision, inflammation, and stromal infiltrates localized at the extremity of an Intacs channel 3 months after surgery. Culture were positive for Clostridium perfringens and Staphylococcus epidermidis. The infiltrates progressed despite treatment with topical fortified and systemic antibiotics. The Intacs were removed. The keratitis slowly resolved, and the patient recovered a best corrected visual acuity of 20/20.

Candida parapsilosis keratitis

PURPOSE

To present clinical, microbiologic, and histopathologic features of keratitis due to Candida parapsilosis.

METHODS

Clinicomicrobiologic evaluation of four patients (four eyes) with culture-proven C. parapsilosis keratitis. The patients were evaluated for symptoms, visual acuity, clinical observations, microbiologic examination of corneal scrapings, and pathologic examination of corneal buttons.

RESULTS

Three cases were observed after penetrating keratoplasty, and one case occurred after inhalation of corticosteroids. Clinical presentation of C. parapsilosis keratitis showed a great diversity. There was one case of crystalline keratopathy and three cases of suppurative corneal infiltrate. Histopathology of corneal buttons showed interlamellar accumulations of yeast. Medical treatment included topical amphotericin B and systemic triazoles. Penetrating keratoplasty was required in three patients.

CONCLUSION

Risk factors for C. parapsilosis keratitis may include corticosteroid use and prior corneal transplantation. The prognosis of C. parapsilosis keratitis with antifungal and surgical therapy may vary from good visual outcome to intraocular extension with phthisis bulbi.

[Clinical management and prognosis in Acanthamoeba keratitis: a retrospective study of 25 cases]

PURPOSE

To assess risk factors, clinical characteristics, diagnosis and outcome in patients with Acanthamoeba keratitis.

METHODS

We reviewed 23 patients (25 eyes) treated for Acanthamoeba keratitis in the XV-XX Hospital between November 1994 and October 2000. Acanthamoeba were found either in corneal scrapings and/or contact lenses and/or storage solutions.

RESULTS

A predisposing factor was found in 22/23 patients: most of them (20/22) were contact lens (CL) wearers, two patients had a recent history of corneal trauma, and 15/23 patients had been treated for presumed herpetic keratitis before examination in our hospital. The average delay between first symptoms and diagnosis was 2 months. All patients were treated with two or three topical antiparasitic eye drops for 2 to 6 months. Five patients received systemic treatment (ketoconazole or itraconazole). Nine eyes received surgical treatment: penetrating keratoplasty in eight cases, conjunctival flap in one case, enucleation in one case. Visual outcome was poor in ten eyes (less than 20/60) because of delayed diagnosis.

CONCLUSION

Acanthamoeba keratitis is a serious vision-threatening disease. Early diagnosis and treatment are essential for improving visual outcome. Methods such as confocal microscopy and Acanthamoeba-PCR, allowing earlier diagnosis and treatment, will improve the management of Acanthamoeba keratitis.

[Amniotic membrane transplantation in severe corneal epithelial diseases. Preliminary results]

PURPOSE

To evaluate amniotic membrane transplantation (AMT) in severe corneal epithelial diseases.

METHODS

Amniotic membrane transplantation was performed in 14 eyes of 14 patients from four groups: A, five severe ocular burns; B, four cases of cicatricial keratoconjunctivitis; C, three persistent epithelial defects after penetrating keratoplasty; D, two cases of pseudophakic bullous keratopathy. Five patients underwent AMT alone; two patients underwent AMT combined with limbal transplantation; the other three patients had limbal transplantation performed before AMT. Eight patients required combined penetrating keratoplasty. Patients with corneal stable reepithelialization, no corneal neovascularization, and no recurrence of the initial pathology were considered successful.

RESULTS

The mean follow-up was 7+/-3 months. All but three patients underwent corneal reepithelialization within 6 weeks of AMT, with a mean healing time of 31+/-23 days. The success rate was 75% at 6 months (Kaplan-Meier method). Three of four procedures in group B failed. In eight patients, visual acuity improved, in one it worsened, and in the last five patients it remained unchanged. Visual acuity increased by an average of 7+/-9 lines.

CONCLUSION

AMT is a useful technique for ocular surface reconstruction, especially in association with limbal transplantation. It could also improve the prognosis of penetrating keratoplasty in patients with severe corneal conditions.

[Fungal keratitis at the Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts: retrospective study of 19 cases]

PURPOSE

To report the spectrum of fungal keratitis at the Centre Hospitalier National d'Ophtalmologie XV-XX, Paris.

METHODS

We reviewed 19 cases of fungal keratitis from January 1993 to January 2001. We evaluated the different risk factors, fungal identification, topical and systemic antifungal therapy, surgical treatment and outcome.

RESULTS

Nineteen patients were included, 7 women and 12 men, with visual acuity ranging from 9/10 to no perception of light. The mean age was 56.2 years. Patients were hospitalized for an average stay of 16.3 days and all received a diagnostic and therapeutic scraping and 16 received a local antifungal treatment. The most common risk factors were topical steroid treatment (42.1%), corneal graft (31.6%), trauma or foreign body (31.6%). The mean delay between the first signs and fungal keratitis diagnosis was 14 days. Yeast as Candida parapsilosis and albicans were the most frequently isolated fungi (58%), followed by Aspergillus sp. (21%) and Fusarium sp. (21%). The most commonly used topical treatment was amphotericin B, and itraconazole was used as systemic treatment. Five patients had evisceration, 6 had penetrating keratoplasty and 5 retained leukoma.

CONCLUSION

Candida was the most frequently isolated fungi and topical steroid treatment the main risk factor. The prognosis is relatively poor (26% of lost vision) because of a delay in diagnosis and other previous ocular pathology or surgery.

[Orbscan: a new device for iridocorneal angle measurement]

PURPOSE

To evaluate the accuracy and reproducibility of iridocorneal angle measurement obtained with a slit-lamp method (Orbscan).

METHODS

The iridocorneal angle was measured in 100 normal eyes of 50 patients using the Orbscan II device. Angles were measured in eight meridians using both the "plane" and "polynomial" modes. For each eye, two exams were taken successively and the reproducibility was calculated by analyzing the difference between both measurements. Angle value was correlated with subjective spherical equivalent and other biometric measurements obtained by Orbscan (i.e., anterior chamber depth, axial length, corneal diameter).

RESULTS

Reproducibility of the angle measurement was significantly better with the plane mode than with the polynomial mode (5.4%+/-4.7 versus 7.2%+/-6.2; p<0.001). Reproducibility significantly varied with localization (p<0.001). Significant differences were found between reconstruction modes (49.3 degrees +/-4.6 degrees for plane mode versus 42.8 degrees +/-6.7 degrees for the polynomial mode; p<0.001) and according to localization (p=0.02). Correlation with the other biometric measurements was higher for the plane mode than for the polynomial mode. Angle measurement with the plane mode showed significant correlation with subjective spherical equivalent (r(s)=-0.59; p<0.001), the anterior chamber depth measurement (r(s)=-0.74; p<0.001), the axial length measurement (r(s)=-0.34; p<0.002), and the corneal diameter measurement (r(s)=-0.34; p<0.002).

CONCLUSION

The iridocorneal angle measure obtained with the plane mode showed high reproducibility and it significantly correlated with clinical parameters. It appears to be useful for clinical application.

Expression of neurotensin receptors in human corneal keratocytes

PURPOSE

The purpose of the study was to investigate whether cultured human keratocytes express the neurotensin receptors (NTR1, NTR2, and NTR3), to determine the presence of neurotensin (NT) in keratocytes, and to assess the influence of NT on these cells.

METHODS

Human keratocytes were cultured in medium treated with various concentrations (10(-7)-10(-9) M) of JMV449 (a weakly degradable NT agonist). Cell proliferation and viability were analyzed by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS) assay. Apoptosis was studied by nucleus labeling with a fluorescent dye and cold light fluorometry. NT, NTR1, NTR2, and NTR3 mRNA were detected in human keratocytes by means of reverse transcriptase-polymerase chain reaction (RT-PCR). NTR1 protein was detected by Western blot analysis. Functionality of NTR1 was assessed by intracellular calcium ([Ca2+]i) measurement with a dynamic imaging microscopy system.

RESULTS

RT-PCR and Western blot analysis showed the expression of the NTR1 (mRNA and protein) and NTR3 mRNA in human corneal keratocytes. NT and NTR2 mRNA were undetectable. JMV449 induced a rapid and transient [Ca2+]i increase in human corneal keratocytes that was blocked by the specific antagonist SR48692. JMV449 significantly increased cell proliferation and viability after 72, 96, and 120 hours of culture, with a maximum effect at 10(-7) M (P < 0.005). Finally, JMV449 decreased keratocyte apoptosis, whatever the concentration used (P < 0.005).

CONCLUSIONS

These results indicate that cultured human keratocytes express NTR1 and NTR3 and that NT may exert physiological effects on cornea such as regulation of keratocyte proliferation and apoptosis.

[Corneal acid burning after facial peeling]

We describe the case of a 66-year-old woman who had previously undergone facial peeling and developed severe bilateral corneal burn due to direct contact Exopeel((R)) with her eyes. Despite medical treatment and an amniotic membrane graft, deep stromal opacity persisted in one eye.

[Precision and reliability of Orbscan and ultrasonic pachymetry]

PURPOSE

To compare the accuracy and reproducibility of the orbscan pachymetry and ultrasonic pachymetry in the normal eye and in the penetrating keratoplasty eye.

METHODS

Pachymetric measurements were assessed in 50 eyes of 25 normal patients and 50 eyes of 48 patients who had undergone penetrating keratoplasty using both Orbscan II and ultrasonic pachymetry (Tomey SP-2000). For each eye, 2 successive measures were recorded with both instruments. For both devices, the default setting was used. Orbscan pachymetry maps were divided into 5 groups using a modification of Liu's classification.

RESULTS

Orbscan pachymetry strongly correlated with ultrasonic pachymetry (rs = 0.91; p < 0.001). Ultrasonic pachymetry values and Orbscan pachymetry values showed no significant differences in the normal group (respectively, 557 microns +/- 36 and 555 microns +/- 34; p > 0.05). Ultrasonic pachymetry values and orbscan pachymetry values were significantly different in the penetrating keratoplasty group (respectively, 571 microns +/- 52 and 550 microns +/- 54; p < 0.001). The best value for the acoustic factor for Orbscan pachymetry in the penetrating keratoplasty group was 0.89. Ultrasonic pachymetry reproducibility and Orbscan pachymetry reproducibility were not significantly different (0.86% +/- 0.61 v. 0.67% +/- 0.63; p = 0.13 in the normal group; 1.22% +/- 0.81 v. 1.23% +/- 1.13; p = 0.92, in the penetrating keratoplasty group). Both pachymetry methods showed less reproducibility in the penetrating keratoplasty group than in the normal group (p < 0.02). Thinnest point localization was significantly different in both groups (p < 0.001). In 66% of the normal group, the thinnest point of the cornea was located in inferotemporal quadrant. This point was located at an average of 0.63 +/- 0.25 mm from the visual axis in the normal group and 1.60 +/- 0.81 mm in the penetrating keratoplasty group (p < 0.001). Whereas "Centered round" (40%) and "centered oval" (34%) were the most common patterns in the normal group, "decentered oval" (40%) and "irregular" (30%) were more frequent in the penetrating keratoplasty group (p < 0.001).

CONCLUSION

Orbscan pachymetry strongly correlated with ultrasonic pachymetry. Reproducibility of both methods is excellent and not significantly different. Thinnest point localization and pachymetric map classification are significantly different in normal eyes and in penetrating keratoplasty eyes.

[Idiopathic polypoidal choroidal vasculopathy leading to blindness]

Idiopathic polypoidal choroidal vasculopathy (IPCV) has recently been recognized as a distinct cause of recurrent subretinal hemorrhages and exudates as well as multiple hemorrhagic retinal pigment epithelium detachments in the macula. IPCV is usually considered to have a good visual prognosis. We report the case of a 44-year-old woman with particularly severe bilateral macular and peripheral IPCV. The patient was followed for 13 years and had final visual acuity of counting fingers in the right eye and 20/400 in the left eye. Patients with IPCV with macular choroidal neovascularization tend to have a poor visual prognosis. This case of IPCV should alert the physician to be particularly attentive to the follow-up of these patients.

[Ocular biometric measurements with a slit-lamp method (Orbscan)]

PURPOSE

To evaluate the accuracy and reproducibility of the biometric measurements obtained with the Orbscan((R)) device in normal eyes.

METHODS

Anterior chamber depth, axial length, and corneal diameter were studied in 50 normal eyes of 25 patients using the Orbscan((R)) device and A-Scan ultrasonography. For each eye, two exams were done successively and reproducibility was calculated by analyzing the difference between both measurements.

RESULTS

The reproducibility of anterior chamber depth and corneal diameter measurements obtained by Orbscan((R)) was high (respectively 0.721.25% and 0.831.40%). The anterior chamber depth measurements by Orbscan((R)) and A-Scan ultrasonography were strongly correlated (rs=0.92;p<0.001). The axial length measurement obtained with the Orbscan((R)) device was less reproducible (3.554.11%). For the axial length, the Orbscan((R)) measurements and A-Scan ultrasonography measurement was poorly correlated. (rs=0.64; p<0.001).

CONCLUSION

The anterior chamber depth measurement obtained with the Orbscan((R)) device showed high reproducibility and it was strongly correlated with the measurement obtained by A-Scan ultrasonography. Axial length measurement obtained with the Orbscan((R)) device was less reproducible and poorly correlated with the A-Scan ultrasonography measurement. It was not relevant for clinical application.

[Change in refraction and topography after penetrating keratoplasty suture removal]

PURPOSE

To study the refractive and topographic modifications induced by penetrating keratoplasty suture removal.

METHODS

We prospectively studied 80 corneas from 80 patients who had undergone penetrating keratoplasty. All of the eyes were examined before and after all sutures were removed, respectively at 10.9 5.1 months and 21.5 9.6 months after keratoplasty. Subjective refraction, best spectacle-corrected visual acuity (LogMAR units), keratometry, and corneal topography using the EyeSys 2000((R)) device (axial tangential and refractive power) were recorded. Topographies were classified according to the pattern (Bogan classification) and the asphericity shape (prolate and oblate).

RESULTS

Best spectacle-corrected visual acuity (Log MAR units) increased significantly after suture removal (1.1 1.9 lines, plt; 0.001). Suture removal decreased the subjective cylinder (5.01 D 2.06 with suture, 4.11 2.08 without suture; p=0.009). The change in subjective cylinder correlated with the change in topographic pattern(s)=0.67 p<0.001). Conversely to the "bow tie" patterns, the other topographic patterns were more frequent after suture removal. The change in visual acuity was essentially explained by the change in subjective cylinder(s)=0.40 p=0.002). The average central corneal power decreased significantly after suture removal by 0.83 to 1.81 D (p<0.001), whereas the subjective spherical equivalent increased (hyperopization) (-4.07D 3.73 with suture, -3.48 3.40 without suture; p=0.02). The change in central corneal power significantly correlated with the change in subjective spherical equivalent (r(s)()>0.30 plt; 0.001). The corneal power of the mid-periphery did not significantly change after suture removal. Suture removal significantly modified the asphericity shape distribution. (majority of prolate shape with suture, majority of oblate shape without suture, p<0.001).

CONCLUSION

Keratoplasty sutures induce a central bulge in the corneal graft. Suture removal induces a decrease in the subjective cylinder and it increases the subjective spherical equivalent (hyperopization) through a decrease in the central corneal power. Suture removal modifies the corneal topographic pattern and shape. Visual acuity improvement after suture removal is mainly explained by the decrease in subjective astigmatism.

[Infectious keratitis after penetrating keratoplasty]

PURPOSE

To investigate the prevalence of microbial keratitis, predisposing risk factors, the spectrum of pathogens and the prognosis for graft survival and visual outcome in patients who developed microbial keratitis following penetrating keratoplasty (PK).

MATERIAL

and methods: We reviewed 16 cases (15 patients) of microbial keratitis after PK. In all cases, corneal scrapings were obtained and microbiologically analyzed. Efficacy of treatment was evaluated by anatomical (clarity of graft) and visual recovery.

RESULTS

Principal indications for PK were pseudophakic bullous keratopathy (50%) and microbial keratitis in the previous graft (25%). Sixty-three per cent of infections occurred within 1 year of PK. Principal predisposing risk factors were suture-related problems (44%) and microbial keratitis in the previous graft (25%). All of the scrapings were positive according to the microbiological evaluation with gram-positive cocci (64%), gram-positive rods (12%), fungi (18%), and Acanthamoeba (6%). We found 1 case of polymicrobial infection. Best visual and anatomical results were observed in nonadvanced cases and/or these treated early. After medical and surgical treatments, 8 patients (50%) had a clear graft and 10 patients (63%) had visual acuity less than 20/200.

CONCLUSION

Postoperative control of risk factors and early recognition of infectious complications may decrease the incidence of severe microbial keratitis after PK.

[Urrets-Zavalia syndrome]

We report four cases of Urrets-Zavalia Syndrome (fixed dilated pupil with iris atrophy) observed after penetrating keratoplasty. The precise etiology of the syndrome is uncertain and different mechanisms are reviewed. Care should be taken to avoid the use of mydriatic eye drops after penetrating keratoplasty.

[Correlation between corneal topography and subjective refraction in idiopathic and surgery-induced astigmatism]

PURPOSE

To study the correlation between subjective refraction and corneal topography. To compare the topographic analysis of surgically induced astigmatism (cataract and penetrating keratoplasty) with that of idiopathic astigmatism.

METHODS

Subjective astigmatism, subjective spherical equivalent, best spectacle-corrected visual acuity (LogMAR units), and videokeratoscopy using the EyeSys 2000((R)) device (axial, tangential, and refractive power) were recorded in 100 eyes with idiopathic astigmatism, 100 eyes after cataract surgery, and 100 eyes after penetrating keratoplasty. Topographies were classified according to pattern (Bogan classification) and asphericity (shape factor: prolate or oblate).

RESULTS

The asphericity shape distribution was significantly different between the 3 groups (p<0.001). The shape of idiopathic astigmatism was almost always prolate (90%) whereas the oblate shape was more frequent in the penetrating keratoplasty group (75%). There was no significant difference in topographic pattern distribution between the 3 groups (p=0.11). The asymmetric bow tie pattern was the most common topographic pattern. Topography pattern classification was significantly correlated with the subjective astigmatic cylinder. (r(s)=0.60, p<0.001). Unlike the round and oval patterns, the bow tie pattern was associated with the high subjective cylinder. Correlation between the subjective cylinder, the refractive power cylinder, and the axial power cylinder was strong (r(s)=0.92 p<0.001), but it was weak for the tangential power cylinder (r(s)=0.72 p<0.001). The correlation between the subjective spherical equivalent and central cornea power was poor (r(s)<0.37, p<0.001). Subjective astigmatic cylinder showed the strongest correlation with best spectacle-corrected visual acuity (r(s)=0.70, p<0.001), whereas the predicted corneal acuity, corneal uniformity index, asphericity, and refractive power symmetry index were poorly correlated with it (r(s)<0.54, p<0.001).

CONCLUSION

Despite the difference in the asphericity shape, the topographic pattern was similar in the 3 groups. The pattern type was significantly correlated with the subjective astigmatic cylinder. Topographic indices failed to predict visual acuity, while the subjective cylinder showed a strong correlation with visual acuity.

Regulation of human corneal epithelial cell proliferation and apoptosis by dexamethasone

PURPOSE

To investigate whether human corneal epithelial cells express the glucocorticoid receptor (GR) and to assess the influence of dexamethasone (DEX) on these cells.

METHODS

Human corneal epithelial cells were cultured in medium supplemented with various concentrations of DEX (ranging from 10(-10) to 10(-4) M). Cell proliferation was analyzed by 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-sulfop henyl) -2H-tetrazolium inner salt (MTS) assay at 2, 4, and 6 days of culture. Apoptosis was studied by nucleus labeling using a fluorescent dye and immunostaining by APO 2.7 at 6 days of culture. GR mRNA was detected in corneal epithelium and cultured corneal epithelial cells by means of reverse transcription-polymerase chain reaction (RT-PCR). Immunocytochemical staining of the epithelial cells was performed with a monoclonal anti-human GR.

RESULTS

RT-PCR and immunocytochemistry showed the expression of GR (mRNA and protein) in corneal epithelial cells. DEX significantly increased corneal epithelial cell proliferation with concentrations ranging from 10(-10) to 10(-6) M, with a maximum effect at 10(-7) M (P < 0.005). However, DEX also induced apoptosis of cultured corneal epithelial cells at any concentration used.

CONCLUSIONS

These results indicate that human corneal epithelial cells express the GR and proliferate in response to DEX stimulation which also induces corneal epithelial cell apoptosis.

[Marginal corneal perforation associated with herpes simplex virus in a patient with essential cutaneous porphyria]

We report a case of herpetic perforated peripheral corneal ulcer in a patient with cutaneous porphyria and hepatitis C. The patient underwent peripheral lamellar keratoplasty. Antiherpetic antibodies were found at a significantly higher level in the aqueous humor than in the serum. Outcome was favorable with antiviral treatment. We discuss the causal role of the hepatitis C virus, porphyria and herpes simplex.

[Acute closure-angle glaucoma after treatment with ipratropium bromide and salbutamol aerosols]

We report a case of acute angle-closure glaucoma in a patient treated with bronchodilator nebulization. An 82-year-old man with chronic obstructive bronchopathy was treated for acute respiratory decompensation with salbutamol and ipratropium bromide aerosols. Twenty-four hours after beginning the treatment, the patient developed acute angle-closure glaucoma which resolved rapidly with appropriate treatment. The case emphasizes the importance of precautionary measures (waterproof glasses and inhalation masks). In addition patients with a high risk of angle-closure glaucoma should be detected prior to prescribing bronchodilating aerosols.

[Comparison of EyeSys videokeratoscope algorithms in the evaluation of idiopathic and postoperative astigmatism]

PURPOSE

To compare the accuracy and reproducibility of the Eye Sys videokeratoscope algorithms for analyzing idiopathic and surgery-induced astigmatism analysis.

METHODS

Refractive astigmatism, videokeratoscopy (axial, tangential and refractive power), autorefractometry, autokeratometry, and keratometry were recorded in 20 patients with idiopathic astigmatism, 40 patients who had undergone cataract surgery and 40 patients who had undergone penetrating keratoplasty. For each eye, 2 successive videokeratoscopy were recorded.

RESULTS

Both cylinder and axis provided by the tangential algorithm are significantly less reproducible than the cylinder and axis provided by the axial and refractive algorithms (P < 0.001). Cylinders provided by the axial and refractive algorithms showed a stronger correlation with subjective cylinder (rs > 0.89; p < 0.001) than the cylinder provided by the tangential algorithm (rs = 0.66; p < 0.001). Both keratometric axis and autokeratometric axis showed the strongest correlation with subjective axis (rs > 0.92; p < 0.001). The accuracy and reproducibility were higher for the topographic "bow tie" patterns than for the other topographic patterns.

CONCLUSION

The axial and refractive algorithms of the Eye Sys videokeratoscope are more accurate and reproducible than the tangential algorithm for analyzing idiopathic or surgery-induced astigmatism.

[Effect of sodium hyaluronate administered at the end of penetrating keratoplasty on reepithelialization of the graft]

PURPOSE

To investigate the effect of sodium hyaluronate on reepithelialization time after penetrating keratoplaty.

METHODS

We prospectly studied 56 consecutive penetrating keratoplasties. One group of patients (n = 22) received dexamethasone ointment at the end of surgery. The second group (n = 34) received sodium hyaluronate and topical dexamethasone. Postoperative reepithelialization time and graft central thickness were recorded.

RESULTS

There was no statistical difference between both groups for epithelialization (4.6 + 3.2 days in the hyaluronate group and 4.4 + 2.3 days in the dexamathasone group) and for graft thickness at day one (710 + 85 microns for the former group and 713 + 84 microns for the latter group) and at day of reepithelialization (663 + 80 microns for the former group and 703 + 99 microns for the latter group). The epithelium aspect was different at the first postoperative day between both groups.

CONCLUSION

The use of sodium hyaluronate at the end of penetrating keratoplasty improves the graft epithelium aspect at the first postoperative day, but it does not influence reepithelialization time. Further studies are needed to investigate the mechanism of sodium hyaluronate effect on corneal epithelium.

[Use of topical cyclosporin in microcrystalline keratopathy due to Streptococcus]

Infectious crystalline keratopathy is an exceptional but serious complication of penetrating keratoplasty. Streptococcus viridans and a steroid treatment are very often found. The treatment is always lengthy and difficult. The high number of bacteria and the steroid treatment, necessary to prevent rejection, worsen the infection. We report a case of Streptococcus crystalline keratopathy that evolved, despite the treatment, simultaneously toward abscess and acute rejection. Topical cyclosporin treatment was used to maintain an immunosuppression without worsening the infection.

In vitro effects of dexamethasone on human corneal keratocytes

PURPOSE

To investigate whether cultured human keratocytes express the glucocorticoid receptor (GR) and to assess the influence of dexamethasone (DEX) on these cells.

METHODS

Human keratocytes were cultured in medium supplemented with various concentrations of DEX (ranging from 10(-10) to 10(-4) M). Cell proliferation was analyzed by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-s ulfophenyl)-2H-tetrazolium inner salt (MTS) assay at 2, 4, and 6 days of culture. Some experiments were performed in the presence of mifepristone (RU38486), an antiglucocorticoid molecule. The early phase of apoptosis was studied by means of keratocyte staining with a fluorescein conjugate of annexin V and propidium iodide, and cells were analyzed by flow cytometry. Glucocorticoid receptor mRNA was detected in keratocytes by means of reverse transcription-polymerase chain reaction (RT-PCR). Immunocytochemical staining of the cells was performed with a monoclonal anti-human GR.

RESULTS

RT-PCR and immunocytochemistry showed the expression of GR (mRNA and protein) in cultured keratocytes. Dexamethasone significantly increased keratocyte proliferation with concentrations ranging from 10(-9) to 10(-5) M, with a maximum effect at 10(-7) M (P < 0.005). Dexamethasone's proproliferative effect was inhibited by RU38486. However, DEX also induced apoptosis of cultured keratocytes at any concentration used.

CONCLUSIONS

These results indicate that cultured human keratocytes express the GR and proliferate in response to DEX stimulation (10(-9)-10(-5) M), which also induces keratocyte apoptosis.

[Treatment of unilateral limbal stem cell deficiency syndrome by limbal autograft]

PURPOSE

To evaluate the improvement of the ocular surface after limbal autograft in patients with unilateral limbal stem cell deficiency related to chemical burns.

MATERIALS AND METHODS

Limbal autograft was performed in five patients with unilateral limbal stem cell deficiency related to chemical burns. Thereafter, four patients underwent penetrating keratoplasty. The limbal graft was obtained from the fellow eye, and was secured with interrupted sutures. Patient follow-up ranged from 10 to 47 months. Limbus and corneas were studied by means of light microscopy.

RESULTS

All five patients reported subjective improvement. Vascularization decreased in one cornea. Visual acuity improved in one eye and did not change in the remaining four eyes. After penetrating keratoplasty, graft reepithelialization was achieved after respectively 3, 4, 21, and 30 days. Light microscopy showed the presence of goblet cells in the limbal epithelium in four cases. After limbal autograft, the corneal epithelium was devoid of goblet cells in three out of four cases.

CONCLUSION

Limbal autograft improves the ocular surface and the prognosis of subsequent penetrating keratoplasty in patients with unilateral limbal stem cell deficiency related to chemical burn.

[Astigmatism after penetrating keratoplasty. Videokeratoscopic analysis on a series of 60 grafts]

PURPOSE

To study the factors which induce post keratoplasty astigmatism. To assess the reliability of different methods in the astigmatism measurement and to study the visual acuity predicting factors.

METHODS

We retrospectively studied the corneal topography in 60 eyes with penetrating keratoplasty after suture removal, using the CAS* (Eye Sys). The diagnosis was keratoconus in 65% of the cases and bullous keratopathy in 15% of the cases. The graft was secured with a single running suture in 38.3% of the cases, interrupted sutures in 23.3% of the cases, or a combination of both running and interrupted sutures in remaining 28.3%.

RESULTS

The suture method, diagnosis and surgeon did not influence subjective refraction nor visual acuity. The topographic pattern correlated with subjective cylinder (rs = 0.52 p = 0.02). The refractive power cylinder ("Holladay diagnostic summary") correlated well with subjective cylinder (rs = 0.81 p < 0.001) and visual acuity (rs = -0.63; p < 0.001). The Javal keratometry remains the best method to measure astigmatism axis (rs = 0.58; p < 0.001).

CONCLUSIONS

The Holladay diagnostic summary (refractive power) is a useful tool for evaluating qualitative outcome of corneal transplantation.

Light microscopic evaluation of human donor corneal stroma during organ culture

PURPOSE

To try to facilitate evaluation of corneal stroma during organ culture by means of light microscopy.

METHODS

Corneal stroma of 53 consecutive organ-cultured corneas was studied by means of light microscopy during endothelial quality control. Out of 9 corneas with bad stromal evaluation, 2 were studied by means of transmission electron microscopy, and 7 were grafted. From the remaining 44 corneas with a normal light microscopic appearance, 35 were grafted.

RESULTS

Stromal abnormalities consisted of bright visible structures with a cell-like shape corresponding to keratocyte injuries (i.e. cellular edema, light and dark vacuoles, cell membrane disruption and, finally, internal cytolysis) as observed by TEM. At 3 months postoperatively no clinical differences between the two groups of transplants were observed.

CONCLUSION

Corneal stroma can be evaluated qualitatively and easily by means of light microscopy during organ culture. Further studies are needed to investigate whether the presence of lysed keratocytes in the graft's stroma actually influences the outcome of transplantation.

[Ultrastructural and immunohistochemical study of 3-dimensional cultures of human keratinocytes on a collagen gel]

PURPOSE

To investigate the ultrastructural and immunochemical features of three-dimensional cultures of human keratocytes in collagen gel matrix.

METHODS

Human keratocytes were obtained from primary cultures of stromal explains. They were cultured in bovine type I collagen gel matrix for 6 weeks. Keratocyte-populated gels were analyzed by means of immunochemistry and transmission electron microscopy.

RESULTS

Human keratocytes cultured in collagen gel matrix developed processes and formed networks of connecting cells. They showed positive staining for vimentin, collagen I, V, and VI, and connexin. Electron microscopy showed elongated cells with processes and gap junctions. Keratocytes synthesized collagen fibrils and filaments. No fibrils' organization similar to that observed in the normal human corneal stroma (i.e. parallel bundles of collagen fibrils) was observed.

CONCLUSION

Ultrastructure and immunochemical phenotype of three-dimensional cultures of human keratocytes in collagen gel matrix are similar to those observed in situ. These cultures represent a useful in vitro model to study the different corneal stroma components.

[Culture of human keratocytes. Influence of culture conditions and ultrastructural aspects]

BACKGROUND

To investigate the influence of fetal calf serum (FCS) and fibroblast growth factor (FGF) on human keratocyte growth in vitro and cell differentiation, and to describe cultured human keratocyte ultra-structure.

METHODS

Human keratocytes were cultured in TC 199/Ham F12 media, supplemented or not with 10% FCS, aFGF, and bFGF. Keratocyte growth was studied. Cultured keratocytes were analyzed by means of immunochemistry and transmission electron microscopy.

RESULTS

Without fetal calf serum, cell population doubling occurred after 7 days of culture and no alpha smooth muscle-actin cell expression was observed. With serum, cell population increased by 1 log after 7 days of culture and all of the cells were alpha SM-actin + bFGF or aFGF-addition to the serum-containing medium resulted in a dramatic decrease in this alpha SM-actin expression. Nuclei were found to be oval and regular in cross-sections, and round and indented in frontal sections. Numerous cytoplasmic organelles were observed, as were cell expansions, gap junctions, omega-shaped structures, and fenestrations. Cultured keratocytes synthesized collagen fibers and filaments.

CONCLUSION

Fetal calf serum allows human keratocytes to grow with a myofibroblast cell phenotype, whereas addition of FGF results in a fibroblast cell phenotype. Ultrastructure of cultured keratocyte is similar to that observed in situ.

[Cultures of corneal epithelium on hydrogel for synthetic epikeratoplasty]

PURPOSE

To improve the LLH480 hydrogel cytocompatibility and to assess the interactions between corneal epithelium and biomaterials.

METHODS

Rabbit corneal epithelium organotypic cultures were carried out on hydrogel samples coated with fibronectin, laminin, type IV collagen, or heparan sulfate proteoglycan. The control group consisted of epithelial cultures carried out on hydrogel with no coating. Cellular migration was quantified, and statistically analyzed. 8-day cultures were processed for transmission electron microscopy.

RESULTS

Epithelial migration on hydrogel was significantly increased (p < 0.001) in the heparan sulfate proteoglycan group, significantly decreased (p < 0.05 and p < 0.001) with laminin or type IV collagen coating, and showed no significant modifications in the fibronectin group. Transmission electronic microscopy showed a monolayer of epithelial cells adherant to the surface of the hydrogel. Deposit of extracellular matrix and sketch of adhesion focal points were also noted.

CONCLUSION

LLH480 cytocompatibility can be improved by heparan sulfate proteoglycan coating.

In-vitro development of corneal epithelial cells on a new hydrogel for epikeratoplasty

This study demonstrates the adhesion and growth of bovine corneal epithelial cells on the surface of a new hydrogel. The hydrogel, containing 78% of water and 22% of AN-69 polymer (poly(acrylonitrile-sodium methallyle sulfonate)), was obtained by phase inversion of polymer-dimethylformamide solution in physiological saline (0.9% NaCl). Experiments were also carried out using hydrogel treated with arginine, human albumin and collagen IV. Covering of hydrogel samples by epithelial cells was completed within ten days, with good cell viability. The epithelial cells spread out and formed a consistent cell layer, confirmed by immunocytochemistry experiments against cytokeratins. Transmission electron micrographs showed numerous desmosomes between cells and the presence of some membrane differentiations at the cell/hydrogel interface. This study suggests therefore that the hydrogel might be suitable for the development of artificial epikeratoplasty grafts.

[Dural carotid-cavernous fistula with uveal effusion syndrome]

We report the case of a patient with a dural carotid-cavernous fistula. The examination showed a proptosis, a chemosis, an increased intraocular pressure and a choroidal detachment. The diagnosis was confirmed by arteriography. The treatment consisted of the embolisation of the feeders originating from the external carotid artery. The ocular improvement was only partial, but choroidal detachment regressed.

[Surgical treatment of astigmatism caused by penetrating keratoplasty using the Hanna arcuate keratome]

PURPOSE

High postkeratoplasty astigmatism is a common postoperative complication which can limit the final functional result. Arcuate incisions are a possible surgical treatment. They can be performed with the arcuate keratome which provides regular incisions. The aim of this study was to evaluate the results obtained with this device in the correction of high postkeratoplasty astigmatism.

METHODS

We retrospectively studied ten eyes operated for high postkeratoplasty astigmatism with the Hanna arcuate keratome. Arcuate keratomy procedures were performed on the graft button in all. Before surgery, mean uncorrected visual acuity was 0.07 +/- 0.05. Best spectacle-corrected visual acuity was 0.33 +/- 0.20 and mean subjective cylinder was 6.1 +/- 1.71 D.

RESULTS

After one month postoperatively, the mean best spectacle-corrected visual acuity (0.45 +/- 0.20) was significantly improved (p < 5%) and mean subjective cylinder (2.85 +/- 1.29 D) was significantly decreased (p < 5%). Vector analysis showed a 5.59 D (+/- 3.63) mean astigmatism correction. Modifications of the spherical equivalent were not statistically significant. Astigmatism irregularity was not modified.

CONCLUSION

Arcuate keratotomy carried out with the Hanna arcuate keratome is effective in reducing high postkeratoplasty astigmatism. It is easier to perform than the standard manual technique. However, astigmatism correction predictibility should be improved.

[Value of implantation in the capsular bag during combined operation of penetrating keratoplasty and cataract surgery]

PURPOSE

To evaluate the clinical results of the triple procedure performed using phacoemulsification.

METHODS

We prospectively studied 23 consecutive triple procedures carried out during a 3-year period. The average follow-up was 18 months. The main indications for grafting were Fuchs' endothelial dystrophy (30%) and infectious keratitis (26%).

RESULTS

A capsulorrhexis was performed in 70% of the cases whereas a "can opener" was performed in the remaining 30%. A divide and conquer phacoemulsification method was used in 43% of the cases. Hydrodissection was used for lens removing in 27% of the cases. The posterior lens capsule was inadvertently broken and a flexible anterior chamber lens was inserted in one case. Twenty-two posterior chamber lenses were inserted in the capsular bag (16) or in the sulcus (6). The estimated 1-year graft survival was 76.8% overall, and 92.9% when high-risk recipients were excluded. Causes of graft failure were immune rejection (n = 4), persistent epithelial defect (n = 1) and uncontrolled glaucoma (n = 1). The average endothelial density during the second year was 1,401 cell/mm2. Average corrected visual acuity was 20/45 at 12 months. Average astigmatism was 3.9 D. No retinal complication was observed.

CONCLUSIONS

In-the-bag placement of posterior chamber lens is a safe and useful technique during the triple procedure. Phacoemulsification may be useful when the nucleus is hard and voluminous.

Nonfreeze myopic keratomileusis for myopia in 158 eyes

BACKGROUND

A prospective evaluation of non-freeze myopic keratomileusis is reported.

METHODS

One hundred and fifty-eight eyes of 98 consecutive patients underwent nonfreeze myopic keratomileusis, with BKS 1000 (Eyetech-M.V.A.A.G, Balzers, Liechtenstein) refractive set. The preoperative myopia ranged from -6.25 to -28.00 D. Mean follow up was 591.3 days (range, 90 to 1500 days).

RESULTS

The logarithmic mean preoperative spectacle-corrected visual acuity was 0.48 +/- 0.31 (20/40), and 0.44 (20/50) +/- 0.30 after 2 years and longer, whereas mean uncorrected visual acuity was 0.32 +/- 0.28 (20/70) in 34 of 82 (41.5%) eyes. After 2 years and longer, 21 of 82 (25.6%) eyes were within 1.00 D of emmetropia, and 43 of 82 (52.4%) were within 2.00 D. The subjective spherical equivalent refraction confidence interval at 90% was 9.28 D (-6.85 to +2.43 D). No refractive instability was detected during follow-up. We detected a trend toward improvement of spectacle-corrected visual acuity with time. However, after 2 years and longer, there was an increase in astigmatism of more than 1.00 D, when compared to the preoperative values, and 14 of 82 (17%) eyes lost two or more lines of spectacle-corrected visual acuity (statistically significant: p < .01).

CONCLUSION

The nonfreeze myopic keratomileusis procedure, with BKS 1000, substantially reduces moderate to high myopia, but predictability of refractive outcome is only fair, and the frequency of optical complications including irregular astigmatism is higher than desired.

[Astigmatism and its treatments]

Astigmatism is a refractive error related to corneal asphericity. Congenital astigmatism is most frequent, and its correction with spectacles has been known for a long time. Contact lenses may sometimes be useful, but they may not allow a satisfactory visual correction. Anterior segment surgery (cataract, penetrating keratopasty, etc.) may often cause postoperative astigmatism. Improvement in ophthalmic surgery, and the patient's need for a rapid and effective visual recovery (as anatomical result is obtained), have highlighted prevention and treatment of post-surgical astigmatism. Astigmatism treatment is complex and varies according to its intensity and cause. Refractive surgery, modifying corneal shape, may be an elegant solution in cases where vision is low, in spite of a perfect corneal transparency.