[Nyctohemeral variations in intraocular pressure]

Intraocular pressure (IOP) varies and depends on many factors. These variations throughout the nycthemeron (the full 24-h period of a night and a day) are the most interesting to study. With the current techniques, it is impossible to measure continuously without waking the subject. Therefore, IOP must be measured hourly over 24 h with a portable tonometer, which provides short measurements in any posture, without requiring the subjects to rise during the night. Intraocular pressure depends on a nyctohemeral rhythm and in healthy subjects is higher at night than during the day, with a nocturnal peak value (acrophase). In the same normal individual, several 24-h measurements are identical. Each individual has his own 24-h IOP pattern. In glaucoma patients, however, the 24-h IOP rhythm was shown to be reversed, with values higher during the day (a midday peak in IOP) than during the night. The time course of the nyctohemeral curve of intraocular pressure is considered to play a role in the prognosis of glaucoma and can serve to classify the type of glaucoma (POAG, NTG). Lowering IOP is still the only option that is available for treating patients with glaucoma. Variations encountered in the individual's nyctohemeral IOP pattern must be taken into consideration to provide the most effective treatment.

[Surgery for choroidal subfoveal neovascularization in patients with severe myopia. Retrospective analysis of 17 patients]

Treatment of choroidal neovascularization in pathological myopia is still controversial.

METHODS

A retrospective analysis of 17 patients with severe myopia (>-6) and subfoveal choroidal neovascularization who underwent surgical removal of choroidal neovascularization, was performed. The patient population consisted of 2 groups: 9 patients younger than 50 years and 8 patients older than 50 years. All the patients underwent vitrectomy with surgical removal of subfoveal choroidal neovascularization.

RESULTS

We reviewed the postoperative clinical and angiographic findings. In group I, visual acuity improved in 4 eyes (44%), remained unchanged in 4 eyes (44%) and decreased in one eye. In group II, none of the patients had visual improvement, visual acuity remained unchanged in 6 eyes (71%), and decreased in 2 eyes.

CONCLUSION

The visual outcomes in most patients in this series were better than their natural history. Surgical removal of subfoveal choroidal neovascularization associated with severe myopia may provide visual benefit in young patients. A prospective, randomized clinical trial is necessary to determine the place of this surgical procedure.

Identification of novel VMD2 gene mutations in patients with best vitelliform macular dystrophy

ABSTRACT We report five novel VMD2 mutations in Best's macular dystrophy patients (S16F, I73N, R92H, V235L, and N296S). An SSCP analysis of the VMD2 11 exons revealed electrophoretic mobility shifts exclusively in exons 2, 3, 4, 6 and 8. Direct sequencing indicated that these shifts are caused by mono-allelic transition in exons 2, 4, 6, 8 and transversion in exons 3 and 6. Five novel "silent" polymorphisms are also reported: 213T>C, 323C>A, 1514A>G, 1661C>T, and 1712T>C. Hum Mutat 17:235, 2001.

[Diagnostic strategy in uveitis: a prospective study in 125 cases]

BACKGROUND

The diagnosis of uveitis is a difficult one and subject to much debate between ophthalmologists and internists. In 1992, we carried out a prospective study to assess the importance of the internist's consultation, the contribution of an extensive laboratory evaluation and to propose a well considered diagnostic strategy.

MATERIAL

and methods: From 1992 to 1995, all patients seen at consultation at the Grenoble University Hospital had a complete ophthalmologic evaluation, an internist's consultation, an extensive laboratory evaluation and a follow-up for at least 6 months.

RESULTS

One hundred twenty five patients were included. The rate of diagnosis was 72%. The internist's help was useful in at least 68% of the diagnoses. Laboratory and radiography tests provided pertinent information in 77% of the cases. Follow-up allowed finding 11% of the diagnoses. The analysis of the clinical and laboratory tests enabled us to establish a diagnostic strategy chart where the key pint is clinical and ophthalmologic evaluation. A minimal laboratory evaluation systematically performed for all cases of uveitis is proposed and, according to some characteristics of uveitis, a well-targeted laboratory evaluation is recommended.

CONCLUSION

This diagnostic strategy enabled establishment of the diagnosis in 92% of the cases and limited laboratory evaluation for 68 patients. We are performing a new prospective study to better validate this diagnostic chart.

[Bacterial contamination of multi-dose ocular solutions. A prospective study at the Grenoble Teaching Hospital]

The bacterial contamination rate of multidose ocular solutions used by hospitalized patients was evaluated by culturing vial dropper tips and residual solution in vials. Bacterial colonies were counted and identified. Overall 39 (23.5%) selected vials were contaminated. Contamination rates were 17.7% (20/113) for vials used by ophthalmology ward patients and 35.8% (19/53) for vials used by internal medicine and gerontology patients (P < 0.02). The most commonly identified organisms were part of the normal commensal flora. Three ophthalmology patients were using vials contaminated with Pseudomonas aeruginosa. A significant (P < 0.01) positive correlation was found between vial contamination rate and duration of vial use. Vials containing an antimicrobial agent were less likely to be contaminated than vials without antimicrobials (P < 0.01). No clinical consequences of vial contamination were identified. However, ocular solution vial contamination carries a risk of infection. Our data are evidence of inadequate efficacy of preservatives present in ocular solutions. The standard practice of using ocular solution vials for seven days in health care facilities may need to be reappraised. Care should be taken to ensure that health care providers and patients understand the rules for ocular solution use. Unit-dose presentations may be preferable over multi-dose presentations for in hospital treatment.

[Description of the prismation method in the rehabilitation of low visions of macular origin]

GOALS

This work aimed at presenting an original rehabilitation method based on the prismation available for patients with organic lesions of the macula. We report results obtained in our first series of patients.

MATERIAL AND METHODS

The treatment was given to 14 patients, 7 women and 7 men, aged from 68 to 92 years, with an average age of 81.64, followed in "Low Vision" consultation, and suffering from bilateral macular diseases. All the patients with age-related macular degeneration developed retinal correspondences. They all received a bilateral prismation over their old correction. The orientation of the prisms taking into account the eccentric fixations. The criteria chosen for surveillance were binocular subjective and objective acuity, contrast sensitivity and vision of colours.

RESULTS

For all the patients concerned, the method led to an immediate subjective improvement of the visual function. Tolerance to optical support was improved. The patients recovered better self-sufficiency in their daily life. The objective binocular for VA was improved by at least one line for 92.86% of the patients, by at least 2 lines for 42.85% and by 3 lines for 7.14%. The binocular contrast sensitivity was better for all the patients. Regarding the vision of binocular colours, the examination performance time was improved for all the patients.

CONCLUSIONS

Prismation allows optimal use of the corresponding eccentric fixation areas. It appears as an interesting new therapeutic method for patients with macular-related low vision. It is complementary to rehabilitation treatment of such patients.

Comparative clinical trial of AMO Vitrax and Healon use in extracapsular cataract extraction

This randomized, single-masked, multicenter clinical trial, comprising 95 patients enrolled at five sites, evaluated the performance of AMO Vitrax and Healon viscoelastic materials during cataract surgery. Patients were examined preoperatively and at one day, four days, one month, and three months postoperatively. The following measurements were recorded and analyzed: percentage of endothelial cell loss from preoperative to three months postoperative; change in intraocular pressure (IOP) from preoperative to 24 hours postoperatively; postoperative corrected visual acuity; subjective assessment of ability of viscoelastic to create and maintain tissue space; intraocular transparency; ease of evacuation. Three months postoperatively, endothelial cell loss was 4.9% (+/- 8.3%) for the AMO Vitrax group and 6.3% (+/- 10.5%) for the Healon group. One day postoperatively, IOP decreased by 1.6 mm Hg and increased by +1.1 mm Hg, respectively. Postoperative visual acuities were similar between the two groups at three months. Subjective assessment of transparency was higher for Healon. Assessment of tissue space maintenance was similar between the two materials. Healon was rated as slightly easier to evacuate.

[Ocular toxoplasmosis. Comparison between two biological methods to study aqueous humor]

To diagnose ocular toxoplasmosis with certainty is often difficult and requires anti Toxoplasma gondii antibodies screening in the aqueous humour. We evaluated the results obtained in 30 controls and 5 patients investigated, using the ELISA and indirect immunofluorescence techniques to determine Desmonts's C coefficient and the sera/aqueous humour densities ratio obtained with ELISA. None of the chorioretinitis-free controls showed a false positive result. Negative serum antibodies levels indicated an absence of ocular toxoplasmosis. The sensitivity of this method depends on several biological parameters, notably the extent of ocular inflammation. Evaluating the C coefficient by the ELISA technique increases this sensitivity.

[Erythrocyte aggregation in vivo and diabetic microangiopathy. Physiopathologic determinants and clinical correlations]

Conjunctival angioscopy is a non invasive way for visualization and quantitative evaluation of the microcirculation. Grading red blood cell aggregation is possible in vivo using Ditzel's four grades score. The two-dimensional organization of conjunctival microvessels allows morphometric quantification of microvascular density. The aim of our study was to evaluate the determinant factors of erythrocyte aggregation and the place of conjunctival angioscopy in the early detection of diabetic microangiopathy. Conjunctival parameters were red blood cell aggregation (Ditzel's score) and morphometric evaluation of capillary, venular and arteriolar density. Criteria of diabetic microangiopathy were microalbuminuria and retinal fluorescein angiogram. Both conjunctival angioscopy and retinal angiogram were scored independently. Results obtained in 30 type 1 diabetic patients, with multifactorial statistical analysis, show that red blood cell aggregation in vivo is an essential discriminant factor for diabetic retinopathy and nephropathy. This rheological phenomenon depends more on duration of diabetes (analysis of variance p = .0005, r = .65) and metabolic control than on albuminemia or fibrinogenemia such as in non-diabetic patients. Manual morphometric data confirmed vascular rarefaction associated with excessive red blood cell aggregation (beta = .50). These results suggest that grading red blood cell aggregation in vivo is an interesting tool for physiopathological and clinical studies of diabetic microangiopathy.

[Primary empty sella turcica syndrome]

Authors relate a typical case of primary empty sella turcica. Its physiopathogenesis is not yet well known, ophthalmological manifestations are non specific and variable, and authors point out difficulties in treatment.

[Human collagen IV lenses and epikeratoplasy in monkeys. Study of epithelial cicatrization]

A previous study showed the good tolerance of the human type IV collagen lenses implanted by epikeratoplasty in 8 monkeys. It also showed type IV collagen is a good material for the reepithelialization. But we have been interested in the stability of the epithelial healing. The ultrastructural study found anchoring structures. However these were inconstant. So the authors try to understand better the mechanisms of this synthesis of the anchoring structures and describe the future ways of this experimental study.

Biocompatibility of human collagen type IV intracorneal implants

A new biomaterial made from human placental collagen type IV has been developed in corneal inlays for refractive keratoplasty. Eight dogs received intracorneal lenses to investigate biocompatibility. Postoperative follow-up observation of 2 years revealed that the eyes remained clear and without inflammatory reaction. Endothelial cells were unaltered. Histological and ultrastructural studies showed no signs of inflammation, ulceration, or encapsulation. No fibroblastic activity was evident at the lens stroma interface.

[Tilted disk syndrome. Symptomatologic aspects and diagnostic problems. Apropos of a case]

The tilted disk syndrome is a frequent congenital abnormality. The case reported here associates tilt of the disk crescent hypopigmentation of inferonasal quadrant and macula ectopy. We study the visual field defects which are attributed to a localized ectatic inferonasal area. We discuss then the opportunity to perform neurological examination.

[Congenital glaucoma and Von Recklinghausen's disease]

A child with buphthalmos and glaucoma, facial hemihypertrophy and plexiform neuroma of eyelid secondary to neurofibromatosis is described. Diagnostic, pathogeny, treatment are discussed.