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Advances in MRI technology have led to a better knowledge of visual pathways (1984-2004), with a new descriptive anatomy and functional model. The authors first describe the technical development of MRI over the last thirty years, then describe and illustrate the new descriptive anatomy. Cephalic MRI reveals brain structures that were previously invisible, on different encephalic planes, in the optic pathways, horizontally from the cornea to the calcarin fissure (neuro-ocular plane (NOP), oblique trans-hemispheric neuro-ocular (OTNOP) and neuro-opto-tractal planes (NOTP)), in their orthogonal orientation upon the oculomotor pathways: head and axonal optic nerve pack (visual deutoneurons in their meninges), optic tracts, lateral geniculate bodies, optic radiations and the calcarian fissure. Comparative anatomy with the rhesus macaque is mentioned. Functional neuroanatomy (physiology) benefits from cine-MRI for ocular motricity (OD MRI), growth by the observation of myelinization in children, blood and CSF circulation by MR angiography, local blood volumes by perfusion imaging, neuronal quantification with inflammation or myelin regeneration by spectroscopy (MRS), brain mapping by functional MR ((f)MRI) measuring local CBF enhancement by paradigmatic stimulations. The recent functional imaging method, tractography (or diffusion tensor MRI (DTMRI)), using diffusion MRI techniques, natural vector calculations with diffusion tensor and software power for morphological and statistical directional results, represents the direction of projection, association and commissural white matter tracts. Normal examples are shown and some common clinical consequences are discussed.

Optic nerve sheath decompression is a surgical procedure only used in optic neuropathy complicating idiopathic intracranial hypertension. We describe this technique and compare it with the classic technique of cerebrospinal liquid derivation. Several points contrast optic nerve sheath decompression and cerebrospinal fluid derivation: there is no biomaterial, it is limited to the orbital area, and intracranial pressure remains unchanged. The complications are different, yet analysis of the literature shows the same efficacy in terms of visual function. We recommend a practical management of optic neuropathy complicating idiopathic intracranial hypertension, depending on the functional severity and the therapeutic efficacy. The surgical indication should only concern serious optic neuropathy not responding to medical therapy, with the choice of the surgical technique belonging to the surgeon.

Background: Management of refractory glaucoma is difficult because classic medical and surgical treatments are ineffective in controlling highly elevated intraocular pressure (IOP). Drainage implants are an alternative to cyclodestructive procedures in refractory glaucoma. The double-plate Molteno implant, a tube linked to two polypropylene plates, allows aqueous humor drainage from the anterior chamber towards the posterior subconjunctival spaces. The main postoperative complication is severe hypotony, potentially responsible for a decrease in visual acuity in cases of advanced glaucoma. Surgical modifications such as external tube occlusion can reduce postoperative hypotony. However, tube occlusion may lead to transient postoperative hypertony. Our retrospective study reports on double-plate Molteno implantation with intraoperative external tube occlusion associated with trabeculectomy in some cases., Material and Methods: Thirteen eyes of 13 patients with refractory glaucoma were included in the study (5 cases of open angle glaucoma, 7 cases of secondary glaucoma, one case of primary congenital glaucoma). All had ocular hypertony despite maximal tolerable medical treatment; 84.5% had previously undergone trabeculectomy with mitomycin (1-5 procedures) and 61% had undergone cyclophotocoagulation (1-4 sessions). All underwent double-plate Molteno implantation with external tube occlusion between 1993 and 2001. In three cases, intraoperative trabeculectomy was also performed. Visual acuity, IOP, relevant medical treatment and potential complications were reported at each follow-up visit. Complete success was defined as IOP less than 21 mmHg without treatment, while IOP control with medical treatment was considered as relative success., Results: Mean (+/-SD) follow-up was 2.9+/-2.1 years (range, 9 months to 8 years). Mean (+/-SD) initial and final IOPs were 35.2+/-7 mmHg and 17.1+/-5 mmHg, respectively, i.e., a 50% IOP decrease. Mean (+/-SD) initial and final medical treatments were, respectively, 4.3+/-1.5 (61% with systemic acetazolamide) and 1.3+/-1.4 (without acetazolamide). The complete success rate was 38.5% and relative success 92.3%. Immediate postoperative hypertony occurred in 60% of the cases with external tube occlusion alone (10 cases). This hypertony was controlled with medical treatment in 2/3 of the cases but required surgical reintervention in 1/3 of the cases. For patients with intraoperative trabeculectomy (3 cases), postoperative immediate IOP without medical treatment was 2, 5 and 8 mmHg respectively. Complications reported were flat anterior chamber (1 case), visual acuity decrease (4 cases), lens opacification (1 case), macular edema (1 case), corneal edema (2 cases: 1 transient, 1 corneal decompensation) and long-term refractory hypertony (1 case)., Conclusion: The double-plate Molteno implant is effective in controlling IOP in refractory glaucoma. External tube occlusion prevents complications related to excessive filtration; however, it may lead to transient postoperative hypertony. This hypertony can be avoided when simultaneous trabeculectomy is performed. Corneal decompensation remains the major complication of this surgical procedure.

We report a case of a 71-year-old man with sequential visual loss within 3 days due to giant cell arteritis confirmed by a temporal artery biopsy. The anterior ischemic optic neuropathy was associated with cilioretinal artery occlusion on the right eye. He improved after intravenous corticosteroid therapy. Clinical characteristics and treatment are discussed.

Purpose: Late bleb leaks may follow months to years after filtering surgery especially with the use of antimetabolites. Complications related to beb leaks may lead to a decrease in visual acuity through complicated hypotony or ocular infection. Our retrospective study reports the anatomical and functional results of bleb reconstruction involving the resection of the bleb associated with the covering of the trabeculectomy site with a rotational conjunctival flap., Material: and methods: Twelve eyes of eleven patients with filtering bleb leaks occurring 3 months to 5 years after successful trabeculectomy (58.3% with adjunct of antimetabolites) underwent bleb surgical reconstruction between november 1995 and June 1999 and were followed until March 2000. Surgical bleb reconstruction was indicated because of persistent or a recurring bleb leak despite conservative medical treatment and blood bleb injections in seven cases. Complications associated with bleb leaks were chronical hypotony (9 cases), athalamy (1 case), hypotony maculopathy (1 case), and endophtalmitis with athalamy (1 case). Three patients had normal IOP but a bleb leak responsible for epiphora. All eyes were treated surgically through bleb excision and conjunctival closure was performed by rotational conjunctival flap., Results: Mean (+/- SD) preoperative IOP was 5.1+/-3.5mmHg (range: 2 to 14mmHg). Mean (+/- SD) postoperative IOP evaluated before any other operation for uncontrolled IOP was 12.7+/-3.1mmHg (range: 6 to 15mmHg). Mean follow-up was 26.7+/-16.9 months (range: 9 to 64 months). All the complications related to the bleb leak resolved after bleb reconstruction. Surgery definively stopped the leak in 10 cases (83.3%) and allowed IOP control without treatment in 50.0% of the cases. Chronic recurring bleb leaks without hypotony occurred in two eyes and required surgery with conjunctival graft which led to a refractory increase in IOP responsible for loss of vision in one case., Conclusion: Bleb resection associated with the covering of the trabeculectomy site with a rotational conjunctival flap is a safe and effective procedure for the treatment of a late bleb leak and its complications. In most of the cases (83.3%), long-term IOP control can be expected without, medical treatment in 50% of the cases. Patients must be aware of the possibility of a recurring Seidel; however, the incidence of this complication remains low.

We report a case of a 15-year-old child with optic disc drusen with known familial inheritance and disc swelling. Inheritance and visual field defects are discussed.

Purpose: Analyzing a personal series of children with acute optic neuritis (AON), we studied, Material and Methods: A retrospective study of 28 eyes in 20 patients (mean age: 10;7 years), examined between 1982 and 1997, with a follow-up ranging from 6 months to 15 years (mean: 5;5 years). We recorded etiologic factors, clinical features (ocular and extra ocular), biological results, and neuroimaging findings., Results: Initial involvement was uni- or bilateral with poor visual acuity (under 20/200 in 22 eyes of 28). Intracerebral inflammation was present in 9 of 13 cases where MRI was performed. We found a cause in only 7 cases (5 viral diseases and 2 recent vaccinations against hepatitis B). Visual recovery was good (over 20/25 in 20 eyes of 28) whatever the treatment, but AON recurred in 5 children. Four children later developed multiple sclerosis., Conclusions: The cause of AON is rarely found. After eliminating an infection, we retained viral disease, complication of a recent vaccination against hepatitis B, and neurological diseases. MRI was the imaging study of choice. Development of multiple sclerosis occurred in 4 cases of 20, the same frequency as in the literature. The risk of later development of multiple sclerosis was 20%. Progression of AON was often excellent. Nevertheless, corticotherapy was added, in form of intravenous boluses followed by decreasing oral therapy for one month.

Purpose: To evaluate the success rate of contact diode transscleral cyclophotocoagulation (TSCPC) in pediatric refractory glaucoma., Patients: and method: Twenty-eight eyes of 28 patients (age range 5 months to 26 years) with medical and surgical refractory pediatric glaucoma due to primary congenital glaucoma (group 1, 20 eyes) or aphakic congenital glaucoma (group 2: 8 eyes), were included in this retrospective study. All eyes underwent one or more TSCPC with the diode laser (Oculight SLX, Iris Medical) with a minimal follow-up of 2 months. Success was defined as intraocular pressure (IOP) between 6 and 20 mmHg after one or more procedures, with no increase in medical hypotensive therapy, and no progression to another hypotensive procedure., Results: Mean baseline IOP was 29.4 +/- 7.8 mmHg (range 25 to 60 mmHg) and mean follow-up was 10.3 +/- 6.9 months (range 2 to 26 months). Success rates evaluated at 6 and 12 months (Kaplan Meier survival curves) were 54.4% and 27.7% respectively, with one-third of the eyes retreated once or more. These success rates were similar in both groups with a mean baseline IOP decrease of 38.9 +/- 15.9%. Postoperative uncontrolled hypertony occurred in the first 3 months in 6 (21.4%) eyes, leading to surgical IOP management. Other complications were decrease in visual acuity (14.3%), inflammation (25.5%) and phthisis (3.5%)., Conclusion: TSCPC with the diode laser is a disappointing procedure for the management of refractory pediatric glaucoma, with poor mid-term IOP control and high incidence of complications including severe uncontrolled IOP increase. For these reasons, this cyclodestructive procedure should be considered as a last resort therapy for patients with refractory pediatric glaucoma.

Purpose: Several research studies have explored the abnormal crossing of the retinogeniculate and geniculocortical optic pathways in human albinos. This prospective study has dealt with visual evoked potentials (VEPs) of human subjects to identify the percentage of albinos with asymmetric VEPs., Patients and Methods: A series of 16 albino patients ranging in age from 6 to 37 years were examined. They had measurable visual acuity, with or without nystagmus. Diffusion of flash stimuli not allowing selective study of the two visual pathways (direct and crossed), two stimulation patterns were used for VEP recordings: monocular full open field then hemi-field stimulation to isolate the activity of each visual pathway., Analysis: In the normally pigmented subject, fibers derived from the nasal half of the retina of each eye decussate at the chiasma, while temporal retinal fibers are uncrossed and project to the ipsilateral hemisphere. In albinos, the majority of temporal retinal fibers subserving the nasal field (from fixation to an eccentricity of about 20 degrees ) anomalously cross with the nasal retinal fibers. Therefore with monocular stimulation, the evoked visual response should be obtained only in the contralateral hemisphere. The asymmetry, morphology and latency for the first major positive peak and the amplitude of the VEP were examined and compared with the normal population., Conclusion: We managed to demonstrate the characteristic VEP asymmetry only in 3 out of the 16 patients. The results presented herein lead to question the absolute validity of VEP abnormality in diagnosis of albinism for clinical purposes.

Introduction: We report a case of metastatic orbital tumor revealing hepatocellular carcinoma., Exegesis: Metastatic orbital tumors of hepatocarcinoma are rare. Only six cases have been reported. We compare these cases to our observation. Treatment of the orbital metastasis is important to decrease pain, ophthalmological symptoms and to improve the quality of survival. Radiotherapy and/or surgery can be used. Prognosis for life depends on liver involvement: the modalities of treatment of the hepatocarcinoma have to be discussed for each patient., Conclusion: Seven cases of orbital metastasis revealing a hepatocarcinoma have been documented. Effectiveness of radiotherapy makes the local prognosis good, but prognosis depends on liver involvement, since prognosis of hepatocellular carcinoma is poor.

We reported a retrospective study of 27 children (mean age = 10 years), who presented a loss of vision due to an acute optic neuritis, between 1982 and 1997. The symptoms ar more likely bilateral in children, and frequently associated with systemic viral infection or hepatitis B vaccination. Multiple sclerosis occurs approximately in 20 p. cent of the cases, i.e. less frequently than by adults. Magnetic resonance imaging is now systematic: in 20 children hyperintense nodular abnormalities in a various distribution was demonstrated by 9 children. During the follow-up, 23 eyes of 27 have an excellent recovery of vision, but 4 patients have developed multiple sclerosis. Corticotherapy was uses in 23 cases, in the form of methylprednisolone intravenous flashes in 14 cases.

Purpose: The aim of this retropective study is to evaluate and to compare in glaucoma patients, the mid-term results of the non penetrating deep-sclerectomy (NPDS) with collagen implant or with per operative application of 5 fluorouracile (5 FU)., Material and Methods: The aim of the NPDS, a new filtering surgical procedure, is to remove under a scleral flap the Schlemm's canal and the juxtacanalicular trabecular meshwork responsible for the outflow resistance in order to obtain a sub-conjunctival filtration of the aqueous humor with no opening of the anterior chamber. Forty-two open angle glaucoma patients with uncontrolled intra-ocular pressure and with no risk factor of bleb fibrosis, underwent a NPDS. In 27 eyes (group 1) a sponge soaked with 5 FU (50 mg/ml) was applied for 5 minutes in the scleral bed, and in 15 eyes (group-2) a collagen implant (Staar*) was sutured in the scleral bed. A complete ophthalmologic examination was performed on days 1, 8, months 1,2,3 and each 3 months until the end of the follow-up. In case of increased IOP, goniopuncture with the Nd: YAG laser was performed at any time of the post operative period., Results: The mean intra-ocular pressure (IOP) significantly decreased from 23.5 +/- 5.1 mmHg to 15.5 +/- 2.9 at 11.1 +/- 5.6 months follow-up (group 1, p < 10(-3)) and from 22.6 +/- 6.9 Hg to 16.2 +/- 3.9 mmHg at 8.8, 3.6 months follow-up (group 2, p < 10(-3)) with a significant decrease in the medical treatment (p < 10(-3)). The Kaplan Meier probability of success (IOP < or = 20 mmHg without treatment and with no visual field deterioration) at 6 and 12 months was similar in both groups: 57.3% (group 1) and 66.0% (group 2) with a mean decrease in IOP of 30%. Goniopuncture had to be performed in more than one third of case in each group and was effective to control the IOP in half of the cases. No complication related to hypotony or inflammation occured in the post operative period., Conclusion: NPDS is an interesting alternative to the classical trabeculectomy since the post operative complications are markedly reduced. However, the mid-term control in IOP appears to be slightly lower. The use of a collagen device does not lead to better control in IOP as compared to the use of a sponge of 5 FU.

Purpose: To evaluate visual benefit, predictability and complications after clear lens phakoemulsification and posterior chamber implantation in highly myopic eyes., Methods: Thirty-three highly myopic eyes were reviewed at a mean postoperative follow-up of 27 months. The mean age of the 19 patients was 31.04 +/- 5.51 years. The mean preoperative spherical equivalent was -19.50 +/- 7.0 D (-12 to -40 D). Preoperative best spectacle corrected visual acuity was compared with the last postoperative one. Postoperative spherical equivalent was compared with the desired value. All complications were reviewed., Results: A mean visual benefit of 0.24 +/- 0.18 (decimal notation) was noted (p < 0.05). The mean postoperative spherical equivalent (-2.57 +/- 1.84 D) was not significantly different from the mean previous value (p = 0.75). Retinal detachment arose in the two eyes of the same patient (incidence of 6.1%). BSCVA decreased slightly in only one of the two eyes (0.1). The incidence of Nd-YAG capsulotomy was 30%., Conclusion: Clear lens phakoemulsification is an effective and predictable method for the correction of high myopia. Retinal detachment is the major complication of this technique, even if a severe decrease of the visual acuity is not usual.

Purpose: Persistent hyperplastic primary vitreous (PHPV) is a rare developmental malformation of the eye. This anomaly is usually unilateral and unassociated with other disease. PHPV may have clinical variations: an anterior and/or a posterior one. Diagnosis and treatment are exposed in our paper., Methods: We study 38 eyes in 34 patients. All patients had an anterior form of PHPV. Nine of them associated a posterior form. Eighteen eyes underwent surgery, the mean postoperative follow-up is 4.7 years. Treatment is discussed, depending on the initial form of PHPV. We report the evolution of the surgical eyes and the untreated eyes., Results: Slit lamp examination and echographic findings (A-scan and B-scan) support the diagnosis. In some cases computed tomography or RMN can be useful. If the cataract is mild in the anterior form of PHPV, treatment of amblyopia and frequent clinical examination can be sufficient. If the cataract is dense, a lensectomy must to be performed. The surgical technique can be difficult. For the eyes with posterior PHPV, the surgical treatment is to be avoided, because of high risk of retinal detachment., Conclusion: PHPV may have clinical variations, mostly with cataract as major sign. In purely anterior presentation, in absence of marked microphthalmos, lensectomy can be useful.

Purpose: To evaluate the effects of transscleral cyclophotocoagulation with the diode laser for refractory glaucoma with respect to intra-ocular pressure, reduction of medical therapy and complications., Methods: The diode laser system (Iris Medical Instrument, Oculight SLX) was used to treat 50 eyes of 47 patients with therapy resistant glaucoma and a poor prognosis with filtering surgery. All eyes had maximal hypotonic therapy and 40 (82%) patients were using carbonic anhydrase inhibitors. Laser energy was delivered to the eye through a quartz glass fiber optic probe [13 to 20 spots over 270 degrees using 3.5 J (1.75 W x 2.0 sec)]. The mean follow-up was 19.4 +/- 9.1 months (from 12 to 29 months)., Results: Intra-ocular pressure significantly decreased from mean baseline 32.4 +/- 9.1 mmHg to 19.7 +/- 8.1 mmHg at the end of the follow-up (p < 0.001). An intra-ocular-pressure below 20 mmHg was obtained in 66% of the eyes. In 13 patients the carbonic anhydrase inhibitors were discontinued. Six of the 8 painful eyes had pain relief. Visual acuity decreased in 17 (34%): cataract progression in 5 eyes, uncontrolled intra-ocular-pressure in 4 eyes, glaucoma progression despite controlled intra-ocular-pressure in 3 eyes, corneal dystrophy in 3 eyes. Chronic uveitis occurred in 5 (10%) eyes. No conjonctival, scleral or direct lens damage was detected., Conclusion: Contact transscleral cylophotocoagulation with the diode laser system can be successfully used to reduce intra-ocular-pressure in therapy resistant glaucoma. The incidence of complications is low with no loss of vision related to cyclodestruction.

Background: Effectiveness of radial keratotomy for undercorrections following photorefractive keratectomy., Methods: Twenty myopic eyes from minus 4.75 to minus 8.25 were treated by Excimer laser photorefractive keratectomy and regressed to a mean myopic refraction of minus 2.20 +/- 0.81 after a follow-up of 10 to 22 months (mean: 16.25). Radial keratotomy was performed using Hoffmann Fyodorov Thornton nomogram. Blade depth was set according to pachymetry performed before surgery under microscopic examination, paracentrally on the meridian of each incision., Results: Postoperative results were evaluated after 6 to 20 months follow-up. After radial keratotomy mean refractive error was minus 0.30 +/- 0.43 and minus 0.32 +/- 0.25 at 3-6 and 6-12 months respectively. Visual acuity, without correction, was prior to radial keratotomy: 2.18 +/- 0.99; 8.125 +/- 0.6 at 3-6 months and 8.43 +/- 1.57 at 6-12 months after radial keratotomy., Conclusion: Radial keratotomy appears to be a safe, simple and predictible technique to treat undercorrections following Excimer laser photokeratectomy.

Thirty patients (47 eyes) underwent a radial keratotomy for low myopia (from -0.75 to -2.5 D). Surgical technique was as follows: optical zone between 3.0 and 4.5 mm according to the degree of the myopia; two radial incisions in vertical superior and nasal horizontal meridian. The incisions were full thickness, obtained either with the "Russian" (centripetal) technique or with a centrifugal technique, but using a special designed knife. Mean refractive result was 1.73 D. For low myopia, our technique seems less traumatic and the refractive effect more rapidly steady.

Background: Radial keratotomy is the most popular method of surgical correction of myopia, but requires further improvements. This study presents a new knife design for radial keratotomy., Methods: Radial keratotomy was performed on 120 eyes of 60 patients with myopia. We utilized two diamond knife designs. The new knife allows a surgeon to perform corneal incisions of varying programmed depth with one movement of the hand, deeper at the limbus. As a control, we used the standard Fyodorov knife. One eye was operated on with one type of knife, the other eye with the other type. The number of incisions was the same with both techniques., Results: After a 2-year follow up of the group of eyes operated on with the new knife, the mean keratometric power changed from 43.20 diopters (D) to 39.30 D, and the mean amount of myopia from -4.37 to -0.32 D. In the group of eyes operated on with the standard knife, the mean keratometric power changed from 43.20 to 39.50 D, and the mean amount of myopia from -4.36 to -0.40 D., Conclusions: The final refractive effect of the new knife was equal to that of standard knives. However, the new knife was more convenient: duration of surgery was shorter, and there was no need to change the length of the blade to deepen the incisions during surgery.

Purpose: Ciliary photocoagulation was used to reduce pressure in eyes with refractory glaucoma or to suppress pain in blind painful eyes. The efficiency of transscleral cyclophotocoagulation (TSCPC) with a clinical diode laser system (Iris Medical Instrument, Oculight SLX) was evaluated., Methods: This diode laser system (wavelengh: 810 nm) provides light energy to the eye through a specially designed quartz glass fiberoptic probe allowing precise location centered 1.2 mm behind the limbus, i.e. in front of the ciliary body. Thirty eight eyes in 38 patients with refractory glaucoma underwent TSCPC with the diode laser., Results: Three months after surgery, intra-ocular pressure was controlled at 20 mmHg or below in 70% of the patients. Patients who most failed with the TSCPC had higher initial IOP (neovascular and congenital glaucoma). Seventy five percent of the painful glaucoma were painless after the laser treatment. Only a few cases (10%) of transient secondary hypertony were observed. The inflammatory response (21%) was mild and transient. No case of scleral perforation, no case of posterior uveitis, cararact or hypotony were observed., Conclusion: The transscleral ciliary photocoagulation laser diode system is efficient to reduce intraocular pressure in refractory glaucoma. Complications are mild compared with other methods of cyclophotocoagulation. A long-term study is necessary to evaluate the results on IOP and the incidence of hypotony.

Introduction: To determine the visual outcome of surgical therapy and conservative management, we retrospectively reviewed all our patients with ectopia lentis and Marfan's disease., Material and Method: Thirty-five eyes of 18 patients (age 8 to 47, average 25.3) were studied. Eight eyes were followed conservatively, the remaining 27 eyes underwent a lensectomy either with the Klöti vitreous stripper (18) or using other techniques (9)., Results: Over follow-up periods ranging from 0.5 to 13 years (average 6.2 years) low visual acuity was found in non-operated eyes. Retinal detachment occurred in 2 out of 8 eyes. Eyes undergoing other surgical techniques had a mean final visual acuity of 0.2. Retinal detachment occurred with high frequency (6 out of 9 eyes). Lensectomy-vitrectomy was a safe and effective procedure with a mean final visual acuity of 0.6. No retinal detachment or secondary glaucoma were found., Comment: Our study suggests that performing lensectomy-vitrectomy with the Klöti vitreous stripper is the best surgical approach in ectopia lentis with Marfan's disease. This technique allows the vitreous to be handled more effectively and has led to improve results.

In 2 clinical cases of bilateral optic disk oedema, the optic disk oedema was part of a so-called benign, or rather idiopathic, intracranial hypertension. Aetiological investigations were unable to detect any intracranial or systemic anomaly, except the fact that both patients had been on a long-term treatment. The first, a 35-year-old man, was taking Roaccutane (isotretinoin) for acne, for at least 5 years, Supradyne (containing vitamin A) minimum 1 pill per day. The second patient, aged 16 years, had also been treated for acne with Roaccutane and Mynocine (minocyclin) for several months. Minocyclin and vitamin A, contained in these substances, are likely to have induced the idiopathic intracranial hypertension, and consequently the optic disk oedema. Indeed, discontinuing the treatment and rachicentesis led to a significant resolution of symptoms. A good history of the clinical cases thus remains a key-element in the process of diagnosis-making and should be strictly conducted in cases with bilateral optic disk oedema, particularly when seen in young patients.

Three cases of ocular myasthenia gravis were observed. The first patient, a 74-year-old man was found to have complete left ophthalmoplegia and ptosis unchanged at examination on month after onset. The second patient, a 42-year-old man, developed incomplete right ophthalmoplegia with pseudoanterior internuclearis ophthalmoplegia, then ptosis two days later. The third patient, a 70-year-old man, presented with sudden onset complete right palsy of the third nerve. Diabetes mellitus or intra-cranial lesions were suspected in all three patients although laboratory tests, tomodensitometry, nuclear magnetic resonance imaging, or arteriography gave no confirmation. Ptosis was relieved and eye movement was improved after the intravenous edrophonium test, but electromyography was negative. The three patients were treated with anticholinesterase agents and showed unequivocal improvement. The second patient underwent thymectomy. Clinicians should inform patients of the contraindications of drugs in this disease. The diagnosis of pure oculomotor forms of myasthenia gravis is sometimes difficult to establish and should be suspected in cases of unexplained oculomotor palsy.

Corneal microperforations induce a corneal astigmatism since refractive effect is increased on the perforated meridian. To counteract this induced refractive error, we performed "flag" or tangenital incisions on the perpendicular meridian.

Seventy eight patients (156 eyes) were treated by radial keratotomy. Patients with spherical axial myopia were selected (including 39% of physiological astigmatism cases). After radial conventional technique the against-the-rule astigmatism > 1.0 D is 31.6% and between 1.0 and 2.0 D is 3.4% versus 0.6% (< 1.0 D) and 0.1% (1.0-2.0 D) with the modified technique. To decrease the frequency of the against-the-rule postoperative astigmatism after RK procedure we performed 1 or 2 vertical additional flag-incisions on the horizontal meridian to counteract the effect of the corneal oedema on the superior incisions.

Leber's optic neuroretinitis is a particular form of optic neuropathy characterized by swelling of the optic disc and a stellate pattern of exsudative deposits in the macula. It occurs most often in healthy young subjects who have acute monolateral visual loss, often preceded by presumed viral illness. The etiology is unknown and viral infection has been suggested in the pathogenesis of this condition. The prognosis for visual recovery is reported to be excellent, but late visual sequelae have been described: loss of vision or visual field loss. This entity should be recognized and distinguished from more serious diseases causing septic neuroretinitis or papillitis.