[High altitude retinopathy: report of 3 cases]. / Rétinopathie de haute altitude : à propos de 3 cas.

PURPOSE: To report three cases of vision loss occurring at high altitude. OBSERVATIONS: Three patients aged 27 to 52 years presented with scotoma and/or visual acuity deficit upon their return from high altitude expeditions above 6000 m. Fundus examination revealed multiple posterior pole hemorrhages, resolving completely by two months. DISCUSSION: Exposure to hypobaric hypoxia at high altitude leads to adaptation mechanisms in order to maintain retinal oxygenation. Certain individuals have an inadequate autoregulatory response and develop signs of "high altitude retinopathy" (HAR), including retinal hemorrhages most often, with occasional vitreous hemorrhage, optic nerve head edema and retinal vein occlusion. The pathophysiology of HAR is not well understood. Identified risk factors include altitude above 4000 m, rapid ascent and personal susceptibility. Age and fitness are unrelated. Association with acute mountain sickness, high-altitude pulmonary edema and high-altitude cerebral edema is still controversial. CONCLUSION: Retinal hemorrhages occurring after high-altitude hiking are an early manifestation of HAR and are part of high-altitude illness. HAR usually occurs at altitudes above 4000 m, is generally asymptomatic, and spontaneously regresses. A maladaptive autoregulatory response to hypobaric hypoxia appears to be the cause of HAR.

[Optical quality after 2.2mm microincisional cataract surgery with bimanual I/A in 154 eyes]. / Qualité optique après phacoémulsification par mini-incision de 2,2mm associée à une I/A bimanuelle, à propos de 154 yeux.

PURPOSE: A prospective study to analyze the effects of 2.2mm microincisional coaxial phacoemulsification with bimanual irrigation/aspiration on the optical quality of the cornea and whole eye. METHODS: We compare two groups. Group A: 102 consecutive eyes undergoing this three-incision procedure and implanted with an Alcon® SN60WF IQ aspheric intraocular lens. Astigmatism, corneal and total asphericity, as well as H/B ratio were measured by OPD scann II, Nidek®, Japan, preoperatively (Day 0), 15 days postoperatively (Day 15) and 1 month postoperatively (M1). Group B: 52 eyes with corneal astigmatism greater than 1.25D, undergoing the same procedure but implanted with a Toric IOL (Alcon® Toric IQ SN6AT), followed in the same manner but with additional follow-up at 1 year. RESULTS: Corneal surgically induced astigmatism (SIA) was essentially neutral: 0.065D ± 0.86 at Day 30 in group A, and 0.06D ± 0.34 at 1 month and -0.008D ± 0.4 at 12 months in group B. Corneal topographic astigmatism underwent a mean axis shift of 29.95° ± 27.6 in group A compared to 5.3° ± 3.7 in Group B, and remained stable at 1 year. Corneal asphericity did not change significantly between Day 0 and 30 in either group. H/B ratio increased significantly in both groups, with a gain of 22 % to 24 % after surgery. CONCLUSIONS: This three-incision procedure does not degrade the optical quality of the cornea. Postoperative shift in the axis of astigmatism is only an issue in cases of low or asymmetric astigmatism and must be kept in mind for low-power toric IOL implantation.

[Anterior chamber migration of intravitreal dexamethasone implant (Ozurdex®) in pseudophakic eyes: report of three cases]. / Migration en chambre antérieure de l'implant intravitréen de dexaméthasone Ozurdex® chez le pseudophake: à propos de trois cas.

INTRODUCTION: Intravitreal implantation of Ozurdex(®) (Allergan Inc., Irvine, CA, USA) is being used widely for the treatment of macular edema secondary to retinal vein occlusion and in the setting of non-infectious posterior uveitis. We describe a complication little reported in the literature until now: migration of the dexamethasone implant into the anterior chamber. PATIENTS AND METHODS: We report three cases of migration in two pseudophakic patients with iris claw lenses (on the anterior and posterior aspects of the iris) and in one pseudophakic patient with a posterior chamber IOL and zonular rupture. DISCUSSION: The risk of anterior chamber migration of the Ozurdex(®) implant is increased in cases of prior vitrectomy (three cases), prone positioning and dilation of the pupil (mydriasis). Clinical tolerability of the implant in the anterior chamber is poor in all cases, with diffuse corneal edema. Endothelial cell loss occurs, as demonstrated by specular microscopy performed in two of our patients. Removal or repositioning of the Ozurdex(®) implant into the posterior segment must be performed without delay because of the risk of endothelial toxicity. CONCLUSION: Patients without perfect zonular/posterior capsular integrity present a high risk of anterior chamber migration of the Ozurdex(®) implant. In such cases, anti-VEGF therapies should be discussed as an alternative.

[Iridoschisis, a special form of iris atrophy]. / L'iridoschisis, une forme particulière d'atrophie irienne.

Iridoschisis is a rare degenerative disease characterized by the separation of the anterior iris stroma from the posterior layer. The anterior layer splits into strands, and the free ends float freely in the anterior chamber. We report the case of a 57-year-old man, in whom we incidentally discovered isolated unilateral iris atrophy. The patient had no history of the common causes of atrophy (herpes, pigment dispersion, ocular trauma, etc.). During follow-up, the atrophy gradually worsened, with an increase in the number and bilaterality of the lesions. Ultrasound biomicroscopy (UBM) and optical coherence tomography (OCT) of anterior chamber showed thinning of the anterior iris and cleavage of the iris into two layers, an imaging result which, to our knowledge, has not yet been reported in the literature. Familiarity with iridoschisis is important, due to its frequent association with glaucoma, so that appropriate screening can be carried out at the time of diagnosis and on follow-up.

[Ocular phototoxicity and altitude among mountain guides]. / Phototoxicité oculaire et altitude chez des guides de haute montagne.

PURPOSE: This study aimed to evaluate ocular phototoxicity in mountaineer guides who experience overexposure to ultraviolet related to the altitude at which they work, as well as light reflection on snow. MATERIALS AND METHODS: Ninety-six guides and 90 controls living in plains, over 50 years old, underwent complete examinations. They responded to a questionnaire assessing altitude exposure and protective eyewear. We compared the two groups and performed a logistic regression within the guide group so as to identify risk and protective factors. RESULTS: Guides develop more ocular surface diseases. They exhibit more anterior cortical cataract (P<0.01) and cataract surgery (P=0.01). Only 61.5% of guides had a normal ocular fundus versus 81.1% in control group (P<0.01). They exhibit more drusen (27.2% vs. 15.6%, P<0.01). Among the guide group, exposure at an altitude above 3000 m is risk factor for anterior cortical cataract (OR=1.16, P<0.01). Wearing ski masks (OR=0.50, P=0.04) or photochromic lenses (OR=0.53, P=0.03) reduces this risk. Exposure to snow increases the risk of maculopathy (OR=1.9, P<0.01). Wearing a hat reduces this risk (OR=0.40, P=0.02) and the risk of cataract formation (OR=0.46, P=0.04). CONCLUSIONS: Guides develop more ocular surface diseases, anterior cortical lens opacities and drusen. These results underscore the potential deleterious role of ultraviolet radiation and the importance of light reflection on snow. The best ocular protection includes sunglasses and a hat with a visor or brim.

[Efficacy of prophylactic treatment of intraocular pressure spikes due to intravitreal injections]. / Efficacité d'un traitement prophylactique hypotonisant dans l'hypertonie oculaire induite après injections intravitréennes.

PURPOSE: The purpose of this study was to evaluate intraocular pressure increase after intravitreal injections (IVIs) and the effect of prophylactic pressure-lowering medications. METHODS: A prospective study of 210 anti-vascular endothelial growth factor (VEGF) IVI (0.05 mL of bevacizumab or ranibizumab), that were divided into five groups, group 1: no intraocular pressure (IOP)-lowering medication (n=50); group 2: apraclonidine 1 % one drop 2 hours prior to IVI (n=50); group 3: acetazolamide 250 mg 2 hours prior (n=50); group 4: fixed combination brimonidine+timolol (n=30); group 5: fixed combination dorzolamide+timolol (n=30). IOP was measured before, immediately after (T1), 15 min after (T15) and 45 min after (T45) the IVI using a Perkins tonometer. RESULTS: The mean IOP peak in group 1 was 46.4 ± 4.8 mmHg at T1, 21.7 ± 5.7 mmHg at T15 and 15.4 ± 4.3 mmHg at T45. Apraclonidine 1 % and the fixed combinations produced a significant reduction of IOP at every time point, of around 9 mmHg at T1. The reduction in IOP obtained with acetazolamide was not significant versus group 1 at T1 (-1.6 mmHg, P=0.12), but became significant at T15 and T45 (respectively, P=0.011 and P=0.015). CONCLUSIONS: IOP spikes are high but transient following IVI. Acetazolamide proved to be ineffective in preventing this spike. Topical medications, however, produced a significant reduction in IOP spike as well as in the duration of the increased pressure, with no significant difference between fixed combinations and 1 % apraclonidine at T1. It would seem advisable to prevent this IOP spike in the case of repeated injections, particularly in patients with glaucoma.

[Comparison between Lenstar LS 900 non-contact biometry and OcuScan RXP contact biometry for task delegation]. / Comparaison de la biométrie sans contact cornéen par LENSTAR LS 900 et de la biométrie contact par OCUSCAN RXP dans le cadre de la délégation de tâches.

INTRODUCTION: Non-contact biometers have many advantages including the delegation of tasks to orthoptists. This study analyses the reliability of measurements comparing contact and non-contacts techniques. PATIENTS AND METHODS: Comparative measurements were taken on 86 eyes of 45 patients (mean age: 74 years; 44.4 % males) in preoperative phacoemulsification by three orthoptists with experience in this task. Each patient had non-contact measurements (Lenstar LS 900, Haag-Streit) and contact measurements (corneal biometry and ultrasound pachymetry with OcuScan RXP, Alcon) and a keratometry refractometer (TONOREF II, Nidek). The axial length data, pachymetry, power of the intraocular lens (SRK/T formula), anterior chamber depth, and the average keratometry were analyzed by paired comparisons. RESULTS: The non-contact biometer was ineffective in 5.8 % of cases (Parkinson's disease, two cases; dense posterior subcapsular cataracts, three cases). The non-contact pachymetry was statistically significantly higher (546.4 µm vs. 538.6 µm; p<0.001). The axial length was significantly longer for the non-contact measurement (23.21 mm vs. 23.05 mm; p<0.0001). In 25.9 % of patients, this difference was greater than or equal to 0.3mm and affected the power of the implant chosen. The anterior chamber depth measured on non-contact biometry was statistically greater (3.33 mm vs. 3.03 mm; p<0.0001). However, there was no significant difference regarding the average keratometry (43.82 D vs. 43.78 D; p=0327). CONCLUSION: Besides the infectious benefit for patients, absence of cleaning and decontamination of biometric probes, non-contact measurements using Lenstar are an example of a safe activity that can be delegated to assistants. This technique has been used to optimize the refractive outcome of 25.9 % of our patients undergoing refractive cataract surgery.

[Susac syndrome: variable onset modes and disease courses: two case reports]. / Syndrome de SUSAC. Modes d'entrée et évolutions variables: à propos de deux cas.

INTRODUCTION: Susac syndrome is a rare microangiopathy of unknown etiology, which involves the clinical triad of encephalopathy, visual loss, and hearing loss. Several onset and progression patterns are possible. OBSERVATION: Case 1: a 43-year-old woman developed subacute encephalopathy, which had not been diagnosed and had been evolving for 2 months, as well as left sensorineural hearing loss. The fundus exam found central artery branch occlusion in the left retina. The treatment was based on corticosteroids combined with cyclophosphamide and immunoglobulins. Angiographic monitoring revealed persistent asymptomatic arterial alterations despite positive neurological progression. Case 2: a 27-year-old woman presented visual loss in the right eye after recurrent neurological episodes. The triad was completed by deafness in the right ear. Treatment with corticosteroids led to favorable neurological progression and stabilized the ophthalmologic symptoms. DISCUSSION: This syndrome preferentially affects young women. The nearly constant neurological symptoms can differ. Branch occlusions are frequently bilateral and often come with the appearance of vasculitis. Deafness is bilateral, asymmetrical, and of endocochlear origin. Brain MRI shows lesions of the corpus callosum that are distinctive of the syndrome. The disease mainly evolves in a monocyclic way, self-limited in time, and it rarely becomes chronic. Treatment, which has not been codified to date, is based on corticosteroids and, in severe cases, immunosuppressive drugs. Other therapies have not proved to be effective. CONCLUSION: The diagnosis is based on the triad of neurological, ophthalmic, and ENT damage, but sometimes it can be difficult to formulate because of the chronology of symptom onset. Neurological damage, the first manifestation, will help make therapeutic decisions.

[PET-scan in orbital Malt lymphoma and its value in diagnosis and management: a series of four cases]. / Diversité clinique du lymphome de Malt orbitaire et intérêt du PET-scan. A propos de quatre cas.

INTRODUCTION: The orbital location of mucosa associated lymphoid tissue (Malt) lymphoma (ML) is rare and can appear in very different forms. Biopsy is decisive for diagnosis. Although the positron emission tomography (PET) scan is rarely used in ophthalmology, it appears useful in our experience. We report four cases illustrating the diversity of the orbital localization in ML. Case 1 is a 41-year-old woman presenting unilateral corticosteroid-resistant dacryoadenitis. The PET-scan clearly fixed at the orbit. After anatomopathologic confirmation, a 36-Gy orbital radiotherapy was carried out, leading to the clinical and tomographic remission. CASE REPORTS: Case 2 is a 61-year-old patient, presenting a small cell carcinoma of the lung, initially referred for unilateral exophthalmia. MRI highlighted a bilateral orbital infiltration, with a hot spot on the PET-scan. The clinical suspicion of orbital metastasis was not confirmed: the biopsy concluded in ML. Case 3 is a 64-year-old woman, referred for unilateral and resistant conjunctival hyperemia. Clinical diagnosis was myositis of the superior rectus muscle. The PET-scan did not fix in the orbit but revealed a pleural location. The muscular biopsy concluded once again in ML. Case 4 is a 68-year-old woman who had a history of sinusal ML. Diplopia with a second orbital location, non specific in CT but fixed in PET, was found. The biopsy concluded in ML with transformation toward an aggressive lymphoma. CONCLUSION: Although the lacrimal gland location is well-known, unspecific orbital infiltration and orbital myositis are less common, which highlights the value of a non invasive exploration before biopsy. The advantages of the PET scan in orbital ML has not been sufficiently studied. In our experience, it was useful in these four cases. Orbital ML can take on different aspects that are sometimes misleading. PET is very useful in diagnosis before the biopsy, in therapeutic decisions, and in follow-up after treatment even if it does not always fix in the orbit.