Regulation of optic nerve head blood flow in normal tension glaucoma patients.

PURPOSE: To investigate the regulation of the optic nerve blood flow (Fonh) in response to an increase of the perfusion pressure (PPm) in normal tension glaucoma (NTG) patients and in age-matched normal volunteers. METHODS: Measurements were performed in 16 eyes of NTG patients and in 10 eyes of age-matched controls. Laser Doppler flowmetry (LDF) was applied to calculate the relative flux of red blood cells at the temporal rim of the optic nerve head (ONH) in response to increases in PPm. PPm was raised through an increase in systemic blood pressure induced by isometric exercise. Before being tested, all patients had 3 weeks of washout of any local medication. RESULTS: In the NTG group, mean ophthalmic arterial blood pressure increased during isometric exercise from 73 to 89 mmHg (22%), resulting in a 29% increase of the PPm. This increase did not induce any significant change in mean Fonh. For the control group, the 28% increase of PPm also did not significantly affect Fonh. There was a trend for a greater increase in vascular resistance during isometric exercise in the NTG than in the normal control group (47% versus 25%). CONCLUSIONS: The LDF parameters, measured in the ONH, did not indicate an abnormal Fonh regulation in response to an increase of the PPm in either normal subjects or NTG patients. The maintenance of constant blood flow is achieved by an increase in local vascular resistance. Our data show a greater percent increase in vascular resistance in the NTG patients compared to the normal subjects for a similar percent increase in PPm in both groups during squatting. This suggests some alteration of the vessel tone regulatory mechanisms in NTG patients.

Uveitis: is ocular toxoplasmosis only a clinical diagnosis?

Between 1981 and 1994, the detection of specific antibodies against Toxoplasma gondii was performed simultaneously in serum and aqueous humor from 90 patients, and the Witmer-Desmonts coefficient measuring the relative concentration of antibodies produced locally was calculated to confirm the clinical diagnosis of ocular toxoplasmosis. Thirty-seven results were positive (41.1%), 12 uncertain (13.3%) and 41 negative (45.6%). These results are compared with the data obtained by the polymerase chain reaction for the genomic detection of an infectious agent in the aqueous humor that have recently been published.

[Apropos of a case of bilateral perforating corneal ulcer in a patient with Portugese amyloidosis]. / A propos d'un cas d'ulcère cornéen perforant bilatéral chez un patient atteint d'amyloidose portugaise.

PURPOSE: Corneal ulcer is a very rare clinical manifestation in hereditary familial amyloidosis of the Portuguese type, from which only one case has been reported previously. The case of a 35-year-old man illustrates the diagnostic findings and the difficulties encountered in understanding the physiopathology of such a complication. PATIENT: The patient was referred by his general practician because of bilateral visual impairment since few days. Examination disclosed bilateral central perforating corneal ulceration. Corneal sensitivity was normal in both eyes, BUT (break-up time) was 2 sec. and Schirmer II test abolished. RESULTS/CONCLUSION: Corneal ulceration is an unusual complication consecutive to a massive dry eye syndrome.

[Foldable implants in cataract surgery at the Geneva Ophthalmological Clinic]. / Les implants pliables dans la chirurgie de la cataracte à la clinique ophtalmologique de Genève.

PURPOSE: Since 1993, foldable intraocular lenses (Adatomed 90 D, Allergan SI26NB et SI30NB, Chiron C10, Medilas 127) have been implanted through a corneal or scleral tunel after phakoemulsification of the cataract. This retrospective study is made for evaluating the advantages and the disadvantages of these new silicon implants. PATIENTS AND METHOD: The first 250 implantations of a silicon foldable lens compared to 50 rigid PMMA lenses. Problems during implantation, final visual acuity, opacification of the anterior and posterior capsule, decentration of the lens and the stability of the refraction during the 3-19 months following cataract extraction were evaluated. RESULTS: 4 breaks of the capsule, 2 desinsertions of the capsular bag during the implantation of a foldable lens, a difference of less than 0.5 diopter in favour of the foldable lenses, no difference in the incidence of the secondary cataract (p = 0.3) and a more marqued postoperative opacification of the anterior capsule (p = 0.0275) among the foldable silicon lenses were observed. CONCLUSIONS: These results are very encouraging for the visual outcome, but the time of postoperative observations is too short to determine on a long term basis, which is the most important factor for a new implant. To avoid an early opacification of the anterior capsule, a large capsulorhexis, as wide as the optic of the silicon lens, is recommended.

[Conjunctival myxoma. Apropos of an anatomo-clinical case]. / Myxome conjonctival. A propos d'une observation anatomo-clinique.

In the ocular area, myxoma is a benign and uncommon tumor located essentially in the lids, more rarely in the conjunctiva. We report the case of a 31-year-old male suffering from the recent growth of an epibulbar painless tumefaction located in the temporal conjunctiva. This gelatinous mass was excised and has revealed a conjunctival myxoma. Surgical excision and histopathologic examination of such epibulabar lesions are necessary because they are few malignant tumors, like botryoid rhabdomyosarcoma or fibrosarcoma, which may have a similar clinical aspect.

[Postoperative endophthalmitis at the Geneva Ophthalmologic Clinic]. / Les endophtalmies post-opératoires à la Clinique Ophtalmologique de Genève.

The postoperative endophthalmitis is a rare and serious complication of the intraocular surgery, which may result in the loss of the visual function. Retrospectively, the authors reviewed the 14 postoperative endophthalmitis cases at the department of ophthalmology of Geneva between 1983 and 1992. For cataract extractions, the following incidence was observed: 0.115% (8 of 6954 cases). In 36% (5 of 14 cases), the culture was positive. The best treatment was a early vitrectomy associated with antibiotherapy. In 57% (8 of 14 cases), the visual outcome was equal to or better than 0.2.

[Prognostic factors in surgical treatment of epiretinal membranes]. / Facteurs prognostiques du traitement chirurgical des membranes épirétiniennes.

BACKGROUND: Macular epiretinal membranes, whether idiopathic or secondary to vitreo-retinal pathology may result in a lowering of central vision and/or metamorphopsia following a distortion of retinal tissue. Although an adequate surgical peeling procedure is known to result in a functional improvement, the criteria for patient selection for such intervention are, as yet not clearly established. METHODS AND RESULTS: In order to establish prognostic indicators of a good visual recovery, we studied 25 cases of epiretinal membrane. Our results showed an improvement in visual acuity of 2 or more Snellen lines among 34% of our patients, regardless of their initial visual acuity. The duration of symptoms prior to intervention was found to be a prognostic factor whereas the presence of macular edema detected preoperatively on fluorescein angiography had no effect on the final visual outcome. CONCLUSION: A common post-operative complication came to our attention: secondary opacification of the crystalline lens.

Clinicopathological review of 1146 enucleations (1980-90).

The clinicopathological data of 1146 enucleated eyes obtained from 1146 patients (485 females and 661 males; mean age 57.4 (SD 21.6) years) between 1980 and 1990 were reviewed. The most common underlying diseases included trauma (37.4%), malignant tumours (19.6%), systemic diseases (diabetes, vascular diseases) (17.1%), surgical diseases (retinal detachment, glaucoma, cataract, corneal dystrophy) (14.1%), infection and inflammation (7%). The most frequent indications for enucleation were secondary angle closure glaucoma (34.9%), ocular malignant tumours (21.7%), atrophia or phthisis bulbi (18.7%), ocular infectious or inflammatory disease (14.7%), and recent trauma (enucleation was performed within the first month after trauma) (11.2%). Histopathologically, diagnoses included secondary angle closure (691 eyes or 60.3%), rubeosis iridis (550 or 48%), endothelialisation of the iridocorneal angle (198 or 17.3%), and retrocorneal membrane (143 or 12.5%). These data indicate that rubeosis iridis, often followed by irreversible secondary angle closure, represents the most common pathogenetic reason for enucleating eyes. Management procedures must be directed towards the prevention or consequent therapy of rubeosis iridis.

Ocular rectus muscle insertions revisited: an unusual anatomic approach.

Twenty-five normal adult eyes, taken from fresh human cadavers, were specially prepared in view of the measurements of the arc length of different segments of the globe. The distances measured between the anterior limbus and the scleral insertions of the rectus muscles were similar to those in previous studies with respect to the 'spirale de Tillaux' and a high interindividual variability, i.e. medial rectus 6.2 +/- 0.6 mm, inferior rectus 7.0 +/- 0.6 mm, lateral rectus 7.7 +/- 0.7 mm, superior rectus 8.5 +/- 0.7 mm. The distance between each pair of opposite rectus muscle insertions shows a high interindividual variability (horizontal axis 25.45 +/- 1.38 mm, vertical axis 25.55 +/- 1.45 mm), but the ratio between both distances was always equal to 1 (0.997 +/- 0.031) with a statistically significant correlation (2-tailed p = 0.96). This new approach to rectus muscle insertions may be important for a better understanding of some possible anatomically related factors in strabismus.

Congenital zonular cataract. Clinicopathologic correlation with electron microscopy and review of the literature.

A whole subluxated lens with a congenital zonular cataract was obtained after intracapsular extraction from an 83-year-old patient for histopathologic examination. The first electron microscopic description of a congenital zonular cataract revealed the presence of many globules ranging in diameter from 0.1 to 2.5 microns, occasionally accompanied by enlarged intercellular spaces and a few multilamellar bodies. Most of the globules were arranged concentrically around the nucleus like a shell, and only a few globules were concentrated in nodular aggregates in the nucleus. Ultrastructural indications of the relationship between globules and lens fiber membranes have substantiated the idea of the transformation from normal lens fibers into cataractous fibers by primary breakdown of the lens fiber membranes and secondary degeneration or liquefaction of the fiber contents.

[Palpebral nodule with focal madarosis: neoplasm or chalazion? Apropos of a case]. / Nodule palpébral avec madarose focale: néoplasie ou chalazion? A propos d'une observation.

A palpebral tumor associated with focal madarosis and no improvement to medical treatment may suggest a malignant neoplasm. Surgical excision of such a lesion was performed in a 56-year-old male and the histopathologic examination revealed a chalazion. Many similar clinical aspects between palpebral neoplasms and chalazions as well as a high frequency of chalazions secondary to palpebral neoplasms justify surgical excision with an obligatory histopathologic examination.

[Insertion of the Tenon capsule onto the rectus muscles]. / L'insertion de la capsule de Tenon sur les muscles droits.

The localisation and definition of the capsule of Tenon insertion on the rectus muscles is of prime importance to the strabismus surgeon. The depth of the superior sub-Tenon space was measured on 22 adult human eyes after fixation in formalin. Although the measurements revealed major differences between the eyes, the following results were found: inferior rectus muscle = 7.8 mm +/- 1.79 (5.2-13.0), medial rectus = 12.6 mm +/- 2.15 (8.4-17.2), superior rectus muscle = 16.7 mm +/- 2.39 (12.7-21.5), and lateral rectus muscle = 19.0 mm +/- 2.19 (14.5-22.0). Histological studies of 2 other human eyes confirmed the notion of a band of insertion on rectus muscles as the posterior limit of the sub-Tenon space. As far as this insertion, the capsule of Tenon is a dense connective tissue composed of many collagen and elastin fibers, but after the band insertion, it becomes virtual through its fusion with the perimysium of the rectus muscle.

[Fungal keratitis with annular infiltration and hypopyon]. / Kératite mycosique avec infiltrat annulaire et hypopion.

Fungal keratitis is a rare disease in Northern Europe. We report the case of a 57-year-old female suffering from a paracentral corneal ulcer, following minor corneal trauma with a branch of a tree. Clinically, the ulcer was associated with a ring infiltrate and a hypopyon. Corneal smears and cultures were negative. As the corneal lesions and the hypopyon progressed despite maximal treatment, penetrating keratoplasty was performed on the assumption of a fungal origin. Histopathologic examination revealed pseudohyphae, morphologically compatible with a candida species. The clinical picture, its differential diagnosis and the diagnostic methods are discussed.

[Acute glaucoma: first manifestation of malignant melanoma of the choroid]. / Glaucome aigu: première manifestation d'un mélanome malin de la choroïde.

Most malignant melanomas of the choroid are discovered during a routine examination of the fundus or following visual symptoms. More rarely, increased intraocular pressure or acute glaucoma represent the first signs of intraocular malignant melanoma. A 66-year-old female presented with an unilateral acute closed angle glaucoma associated with rubeosis iridis and total retinal detachment. Using ultrasonography, a choroidal neoplasm was diagnosed. Histopathologic examination of the enucleated globe confirmed the diagnosis of a necrotic malignant melanoma of the choroid with subretinal hemorrhage. Every blind eye with opaque media requires ultrasonographic and, if enucleated, histopathologic examination.

Distended optic nerve sheaths in Leber's hereditary optic neuropathy.

Distension of the optic nerve sheaths is a feature of Leber's hereditary optic neuropathy (LHON) that has attracted attention only recently. We followed a patient with LHON for 23 years and obtained his eyes for pathological examination after death. We report the first histologic description of distension of the optic nerve sheaths, together with typical histopathological findings of LHON. Distension of the optic nerve sheaths could not be accounted for by any etiology other than LHON, although the precise pathogenic mechanisms remain enigmatic.

[Peeling of epiretinal macular membranes. Results and conclusions of the Geneva Clinic]. / Pelage de membranes maculaires épirétiniennes. Résultats et conclusions de la Clinique de Genève.

Epiretinal macular membranes can cause a lowering of visual acuity and may even lead to a total loss of foveal function in the absence of surgical procedure. The only surgical treatment is vitreo-retinal surgery with peeling of the membrane. In Geneva, we studied 23 patients, all of whom were operated for epiretinal membrane even though visual acuity was greater as 0.2, 10 membranes were idiopathic et 13 secondary. Six patients from this second group had recently undergone cataract surgery. The results were good: 83% of the patients showed an improvement in post-operative visual acuity and 60% gained 2 or more lines on the Snellen scale. The main factors for prognosis were preoperative macular cystoid edema and duration before surgery. The principal post-operative complication encountered was a secondary opacification of the lens with, to a lesser extent, cystoid edema of the macula.

[Anatomic, histologic, and morphometric studies of the ocular rectus muscles and their relation to the eye globe and Tenon's capsule]. / Données anatomiques, histologiques, et morphométriques des muscles droits oculaires et de leurs rapports avec le globe et la capsule de Tenon.

After having been the subject of several studies during the first half of the 20th century, the anatomical and morphological measurements of the ocular rectus muscles have recently been reinvestigated (e.g. L. Apt). At the Anatomy Institute in Geneva, similar measurements were performed on 25 human orbits as well as the depth of the subtenon space. The results show a large variation from one individual to another, although the "Tillaux spiral" was always respected. We have also shown that the ratio of the arc between each pair of opposed rectus muscles is a constant equal to 1 (0.997 +/- SD = 0.031). The subtenon space was defined morphometrically and confirmed histologically. All these measurements are important for practical aspects involved in the surgery of strabismus.