Sympathetic ophthalmia following postoperative endophthalmitis and evisceration.

PURPOSE: To report a case of sympathetic ophthalmia (SO) following purulent postoperative endophthalmitis and final evisceration of the affected eye. METHODS-RESULTS: A 64-year-old male underwent phacoemulsification complicated by endophthalmitis. Five months latter the eye was painful and had no light perception so an evisceration was performed. Two weeks latter granulomatous posterior uveitis developed in the fellow eye. SO was diagnosed and the patient was started on prednisone and cyclosporine. The inflammation subsided and visual acuity improved to 20/30. CONCLUSIONS: Bacterial endophthalmitis cannot prevent the development of SO. Prompt diagnosis and management is the most important factor for visual prognosis.

Myopic traction maculopathy: study with spectral domain optical coherence tomography and review of the literature.

AIM: To describe the tomographic findings of a case of myopic traction maculopathy using Spectral Domain Optical Coherence Tomography (SD-OCT) and present the results of its surgical intervention. DESIGN: Observational case report and review of the literature. METHODS: A 61-year-old male with metamorphopsia was examined clinically and with the use of SD-OCT. The diagnosis of myopic traction maculopathy was made. The patient underwent pars plana vitrectomy with removal of the vitreomacular adhesions, the epiretinal and the internal limiting membrane. RESULTS: Visual acuity increased by two Snellen lines, metamorphopsia disappeared, macular morphology was improved and myopic traction maculopathy was resolved. CONCLUSIONS: Imaging with SD-OCT is capable of documentation and measurement of the early stages of myopic traction maculopathy. Moreover, vitrectomy was beneficial for the visual and anatomic outcome of the patient.

Macular epiretinal membranes.

Epiretinal membranes (ERM) are a common finding in older patients. Although they may be associated with numerous clinical conditions, most epiretinal membranes occur in the absence of ocular pathology. Patients symptoms range from asymptotic to complaints of severe vision loss and metamorphopsia. Epiretinal membranes are commonly classified according to their density, to the severity of retinal distortion and to associated biomicroscopic changes. Pars plana vitrectomy has been found to be effective in removing ERM from the macula, improving the visual acuity and decreasing metamorphopsia. Both idiopathic and secondary ERMs do well after surgery, although secondary ERMs showed a greater amount of improvement than idiopathic ones. Complications are frequent including accelerated postoperative nuclear sclerosis, retinal breaks and RD, macular edema, RPE and, occasionally, macular hole and hypotony. However only RD involving the macula have a worsening prognosis on final outcome.

The expanding role of primary pars plana vitrectomy in the treatment of rhegmatogenous noncomplicated retinal detachment.

The surgical management of rhegmatogenous retinal detachment has evolved dramatically during the past 2 decades. Investigators have introduced and refined alternative techniques to scleral buckling surgery including pneumatic retinopexy and primary pars plana vitrectomy (PPV). Rapid parallel developments in instrumentation, including wide-angle viewing systems, perfluorocarbon liquids, novel vitrectomy machines, intraocular tamponades, and endolaser photocoagulators have led to increasing sophistication in primary PPV surgical techniques for the treatment of rhegmatogenous uncomplicated retinal detachment. However, the precise role of primary PPV in new uncomplicated retinal detachment remains debatable owing to the lack of controlled randomized trials. This article examines primary vitrectomy treatment for rhegmatogenous uncomplicated retinal detachment and presents the specific types of retinal detachments for which primary PPV may be optimal, according to personal and reported results, the surgical instrumentation and technique, as well as the complications and limitations of this surgical method.

Ultrasonographic classification and phacoemulsification of white senile cataracts.

OBJECTIVE: To classify the white senile cataracts and report the results of phacoemulsification of white cataracts. DESIGN: Prospective, noncomparative case series. PARTICIPANTS: One hundred eyes were included. INTERVENTION: White cataracts were examined biomicroscopically before surgery, and their acoustic structure was analyzed with standardized A-scan echography. White cataract surgery was performed with phacoemulsification via a superior temporal near-limbus corneal approach using a bimanual divide-and-conquer or stop-and-chop technique. Patients were followed after surgery for a period of 9 months. MAIN OUTCOMES MEASURES: The A-scan acoustic structure of white cataracts; successful accomplishment of capsulorrhexis; mean phacoemulsification time, power, and energy; intraoperative and postoperative complications of phacoemulsification; and visual acuity at 9 months after surgery. RESULTS: White senile cataracts were categorized into three different types. Type I included intumescent, white cataracts with cortex liquefaction and high internal acoustic reflections (44 eyes), type II included white cataracts with voluminous nuclei, little amount of whitish solid cortex, and low internal acoustic reflections (49 eyes), and type III included white cataracts with fibrosed anterior capsule and low internal echospikes (7 eyes). Circular capsulorrhexis was completed in 79 eyes and was significantly less successful in eyes with type I intumescent, white cataracts compared with type II white cataracts (P = 0.0034). Mean phacoemulsification time and energy were higher in type II and type III white cataracts. Posterior capsule rupture occurred in ten eyes, and three of these eyes were complicated by vitreous loss. In 95 eyes, the posterior chamber lens was implanted in the capsular bag and in five eyes in the sulcus. After surgery, a transient corneal edema developed in 31 eyes. At the final 6-month examination, the mean postoperative visual acuity was 20/30. CONCLUSION: Current phacoemulsification techniques can safely manage eyes with senile white cataracts. The increased risk of difficulty with continuous capsulorrhexis in type-I and type-III white cataracts and the substantial nuclear hardness in type-II and mainly type-III white cataracts would suggest that current phacoemulsification techniques might not be as successful in these patients as they are in ordinary earlier cataracts.

Primary vitrectomy with perfluoro-n-octane use in the treatment of pseudophakic retinal detachment with undetected retinal breaks.

PURPOSE: This report describes the results of a prospective trial to evaluate the efficacy of pars plana vitrectomy (PPV) in conjunction with perfluoro-n-octane (PFO) as initial treatment of pseudophakic retinal detachment (RD) with no breaks diagnosed preoperatively. METHODS: Fourteen consecutive eyes presenting with pseudophakic RD in which retinal breaks could not be identified preoperatively underwent primary PPV, internal microsurgical identification of the retinal breaks with endoillumination and noncontact wide angle viewing system, PFO retinal reattachment, transscleral cryopexy or endolaser treatment of breaks, PFO-air exchange, and final injection of 20% sulfur hexafluoride. In five eyes, a scleral buckle was also used. Mean follow-up period was 18 months. RESULTS: In 13 of the 14 eyes in which no breaks had been identified preoperatively, breaks were diagnosed during surgery. Perfluoro-n-octane retinal attachment facilitated accurate microscopic treatment of retinal breaks. The retina was reattached with a single operation in all eyes. Eleven eyes had final visual acuity of 20/60 or better. Complications were minimal. CONCLUSIONS: Pars plana vitrectomy in conjunction with PFO expression of subretinal fluid is effective in the initial treatment of pseudophakic RD with no preoperative diagnosis of retinal breaks.

Macular hole formation in diabetic retinopathy: the role of coexisting macular edema.

The aim of this study was to characterise different etiologies for the development of macular holes in diabetic retinopathy. We examined 8 eyes of 8 patients with known diabetic retinopathy who had developed a macular hole. These were classified as follows: related to macular edema (4 eyes), non-related to macular edema (2 eyes), intraoperative (1 eye) or postoperative (1 eye) after pars plana vitrectomy for proliferative diabetic retinopathy. In three patients the macular holes were treated with pars plana vitrectomy and fluid air exchange. In diabetic eyes with macular edema, macular holes may develop because of intraretinal exudation combined with increased vitreomacular attachments and tractions. The mechanism of macular hole formation in diabetic eyes without macular edema probably results from the same increased tangential vitreous traction which is seen in idiopathic age-related macular holes. Iatrogenically induced macular holes during pars plana vitrectomy for proliferative diabetic retinopathy may be also due to intraoperative vitreoretinal tugging. Finally, macular holes developing after vitrectomy may have an etiology not related to vitreous tractions or attachments.

Experimental ocular surgery with a high-repetition-rate erbium:YAG laser.

PURPOSE: To evaluate the performance in ocular surgery and the ocular tissue interactions resulting from increasing the maximum repetition rate of a pulsed-mode erbium:YAG laser system from 30 to 200 pulses per second. METHODS: An erbium:YAG laser was used that emitted at 2.94 microm with an output graduated from 0.2 mJ to 25 mJ and a repetition rate from 2 Hz to 200 Hz and that was equipped with a flexible optical fiber attached to various interchangeable 20-gauge endoprobes to perform ocular surgery in enucleated pig eyes. The specific maneuvers were performed in close contact in nontransmitting aqueous media and included inner retinal ablation, retinotomy, lens capsulotomy, lens ablation, iridotomy, and iridectomy. Selected tissue specimens were examined by light microscopy. RESULTS: Increasing the repetition rate to the 200-Hz range significantly improved the smoothness, continuity, and speed of all surgical maneuvers. Compared with the 30-Hz rate, substantially lower energies per pulse were efficient with the 200-Hz rate. The "sticking effect" between the tip of the probe and the target tissue at low-repetition rates, which resulted in discontinuation of the surgical maneuver, particularly during lens surgery, was eliminated with the use of high-repetition rates. Use of high-repetition rates produced a zone of residual thermal damage less than 30 microm in all ocular tissues. The histologic findings of tissue interactions were comparable to those obtained in published studies in which the same wavelength and low hertz rates were used. CONCLUSIONS: The high-repetition-rate erbium:YAG laser technology described is advantageous, compared with low-repetition-rate erbium:YAG lasers, and is applicable in a variety of ocular surgical procedures. Innovations in endoprobe design and further study will determine its role in contemporary ocular surgery.

Initial clinical experience with an erbium:YAG laser for vitreoretinal surgery.

PURPOSE: We tested the efficacy of an erbium:YAG laser for maneuvers in patients undergoing vitreoretinal surgery. METHODS: An erbium:YAG laser equipped with a flexible fiberoptic and interchangeable 20-gauge endoprobes of various tip configurations ranging from 100 to 365 microns was used for specific maneuvers in 13 patients referred for vitreoretinal surgery for diabetic traction detachment, proliferative vitreoretinopathy, retinal detachment with posterior break, and epimacular membrane. The following maneuvers were performed: (1) transection of elevated vitreous membranes, (2) incision of epiretinal membranes, (3) drainage and relaxing retinotomy, (4) transection of subretinal membranes, (5) noncontact ablation of epiretinal membranes in air-filled eyes, (6) ablation of lens remnants, (7) posterior capsulotomy, (8) iris surgery, and (9) retinal vascular coagulation. RESULTS: Forty-eight defined maneuvers were performed with energy levels ranging from 0.2 to 5.0 mJ and repetition rates of 2 to 30 Hz. Transection of elevated membranes, subretinal membranes, and retinotomies were easily performed. Fourteen incisions into vascularized epiretinal membranes in diabetic traction detachment surgery demonstrated a fine margin of coagulation that permitted hemostatic incision. Retinal breaks were created during one of these incisions. Lens remnant ablation, posterior capsulotomy, and iris tissue removal were successful, with a single complication consisting of damage to the posterior surface of an intraocular lens during a pars plana posterior capsulotomy accomplished by means of a side-firing probe. Epiretinal membrane ablations in air-filled eyes were effectively performed in a gradual fashion without hemorrhage. CONCLUSIONS: The erbium:YAG laser offers precise and effective tissue cutting and removal in vitreoretinal maneuvers. Further study will determine the role of this technology in vitreoretinal surgery.

Erbium:YAG laser surgery of the vitreous and retina.

PURPOSE: These studies evaluated an erbium:YAG laser for transection of vitreous membranes, retinotomy, and incision and ablation of epiretinal membranes. METHODS: Elevated vitreous membranes, detachments, and epiretinal membranes were induced in rabbit eyes. An erbium:YAG laser, emitting at a wavelength of 2.94 microns and equipped with a flexible fiber and endoprobes with tips ranging from 75 to 375 microns, was used to perform vitreous membrane transections, retinotomies, and epiretinal membrane incisions and ablations in nontransmitting aqueous media with the endoprobe in proximity to the tissue. Ablations of epiretinal membranes also were performed in transmitting media, including air and perfluoro-N-octane with the endoprobe elevated above the membrane. RESULTS: Twenty-five vitreous membrane transections were made in 16 eyes at distances ranging from 0.5 to 4.5 mm from the retina with radiant exposures ranging from 2 to 50 J/cm2 with nonhemorrhagic retinal damage in a single transection. Sharp, linear retinotomies were created successfully in five eyes. Epiretinal membrane ablations were performed with radiant exposures ranging from 1.8 to 22.6 J/cm2. In aqueous media, results of microscopic examination showed partial- to full-thickness ablation with a maximum lateral thermal damage of 50 microns. In air- and perfluoro-N-octane-filled eyes, there was increased lateral damage with desiccation of residual tissue. In 12 aqueous-filled eyes, 18 linear incisions were successfully performed, with retinal nonhemorrhagic damage in 2 eyes and hemorrhage in 5. CONCLUSION: The erbium:YAG laser may provide new approaches to maneuvers performed in vitreoretinal surgery.

[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.

Aqueous humor penetration of ofloxacin given by various routes.

We studied the aqueous humor penetration of ofloxacin after topical, oral, and intravenous administration in 51 consecutive patients undergoing cataract surgery. Aqueous humor concentration (mean +/- SD) was 0.53 +/- 0.35 mg/l when ofloxacin 0.3% eyedrops were instilled topically six times, one drop every three hours, until 90 minutes preoperatively, and 0.63 +/- 0.29 mg/l (P = .45) when two additional instillations were made, one drop every 30 minutes, until 30 minutes before aqueous humor aspiration. Aqueous humor concentration two hours after a single 200-mg oral dose (0.38 +/- 0.15 mg/l) was significantly lower (P = .048) than that 12 hours after the same oral dose (0.58 +/- 0.24 mg/l). Two hours following an intravenous infusion of 200 mg of ofloxacin, aqueous humor concentration was 0.33 +/- 0.19 mg/l. Our results suggest that therapeutic levels above the minimum inhibitory concentration for many bacteria cultured in endophthalmitis can be achieved in aqueous humor after either topical or oral administration, which indicates that this antibiotic passes easily through the corneal and the blood aqueous barriers.

Pathogenetic mechanisms in combined cilioretinal artery and retinal vein occlusion: a reappraisal.

We examined nine patients who presented cilioretinal artery occlusion (CLRAO) associated with retinal vein occlusion (RVO). CLRAO was probably secondary to the raised intraluminal resistance consequent to the RVO in patients showing initially a delayed filling of the cilioretinal artery in fluorescein angiography. Interestingly, these patients presented an ophthalmoscopically more severe form of RVO and had systemic predisposing factors for a RVO. In patients presenting a physiological perfusion of the cilioretinal artery in fluorescein angiography, RVO was a self limited disease and etiologic factors were not found. This may suggest that in these patients the CLRAO probably occurred simultaneously with the RVO after a decrease in perfusion pressure in both retinal and cilioretinal arterial systems. In this combined vaso-occlusive retinopathy the vulnerability of cilioretinal arteries can be explained either by the absence of autoregulation or by their lower perfusion pressure gradient in comparison with retinal arteries.

Microinjection of L-lactate in the preretinal vitreous induces segmental vasodilation in the inner retina of miniature pigs.

PURPOSE: The authors investigated the hypothesis that the retinal vasomotor effect of acute hypoxia is mediated by lactate. METHODS: Retinal vasomotor arteriolar response was measured in the intact eyes of miniature pigs after systemic administration and after local preretinal juxta-arteriolar microinjection of lactate. RESULTS: Injection of L-lactate (physiologically produced lactate) into the systemic circulation decreased the arterial blood pH but did not dilate the retinal arterioles. By contrast, microinjections of L-lactate (0.5 mol/l, pH 2) into the juxta-arteriolar vitreous induced a reversible segmental vasodilation of 32 +/- 4% (standard deviation). This vasodilation did not depend on periarteriolar pH lowering because microinjections of a 0.5 mol/l L-lactate at neutral pH also dilated segmentally the retinal arterioles (37 +/- 5.5%). The effect of lactate was stereospecific because microinjections of the isomer D-lactate (0.5 mol/l, pH 2) did not affect the arteriolar caliber (P = 0.63). Perfusion of the eye with the cyclo-oxygenase inhibitor indomethacin, through cannulization of the sublingual artery, caused a generalized reversible arteriolar vasoconstriction of 51 +/- 9.8% but did not inhibit the segmental vasodilator effect of locally microinjected L-lactate. CONCLUSIONS: It is known that acute hypoxia in the isolated retina causes an increase in lactate production. In the intact eye, there is a retinal vasodilation, which is not inhibited by indomethacin. Hence, it was concluded that retinal, but not blood, lactate is a possible mediator of the acute hypoxia-induced vasodilation.

[Uveitis complicating posterior segment neovascularization. Six cases]. / Uvéites compliquées d'une néovascularisation du segment postérieur. A propos de 6 cas.

Subretinal or preretinal neovascularisation may be occasionally observed during the evolution of certain forms of uveitis. Subretinal neovascularisation commonly begins at the level of the chorioretinal uveitic scars. Consequently, the alteration of the retinal pigment epithelium-Bruch's membrane-choriocapillaris complex is the apparent cause. Laser photocoagulation of the neovascular front, when indicated, is the treatment of choice. In contrast, preretinal neovascularisation is observed at the active stage of uveitis. Fluorescein angiography findings suggest that it is probably correlated with the importance of inflammation since in most of the cases there is no retinal ischemia. Therefore, in order to obtain a regression of the neovascular tufts the treatment should be directed against the inflammatory process. In this study the authors report five cases of subretinal neovascularisation which developed at the level of chorioretinal post-inflammatory scars and one case of papillary neovascularisation which occurred during the active stage of an unilateral intermediate uveitis and in which new vessels regressed completely following systemic steroid treatment.

[Profile of pO2. I. Profile of transretinal pO2 in hypoxia]. / Profils de la PO2. I. Profils de la PO2 transrétinienne en hypoxie.

Transretinal PO2 measurements during systemic hypoxia, made during variations of the PO2 by steps of 10 mmHg between 120 and 30 mmHg, have shown that the PO2 values measured at the inner-retina up to half the thickness of the retina remained stable. On the other hand, those measured at the choroid and at the outer-retina decreased in a linear manner according to the variations of PaO2. These results suggest a regulation in the retinal blood flow, allowing the PO2 to remain stable for the different steps of hypoxia studied. On the other hand, the values measured at the choroid and at the outer-retina showed the absence of regulation in the choroidal blood flow during hypoxia. Systemic hypoxia may affect the metabolism of the photoreceptors and the pigmentary epithelium.

[Profile of pO2. Regulation of papillary pO2]. / Profils de la PO2. II. Régulation de la PO2 papillaire.

PO2 measurements using a double barelled recess type microelectrodes were measured in the optic nerve head of miniature pigs during systemic hyperoxia (100% oxygen breathing) and variations of the systemic blood pressure by intravenous injection of Adrenaline or trinitrine. During either systemic hyperoxia, or progressive variations of blood pressure, the intervascular PO2 remained stable. These results suggest a regulation of the tissue PO2 of the optic nerve head, as the retina does, at constant values.

[Metabolic factors of vasomotor regulation of the inner retina]. / Facteurs métaboliques dans la régulation de la vasomotricité au niveau de la rétine interne.

Lactic acid, the end metabolic product of anaerobic glycolysis is probably the mediator of the hypoxia induced vasodilation on retinal arterioles. In this study we explored the mechanisms of the retinal vasomotor effect of this metabolite by performing preretinal juxtaarteriolar pulsatile pressure microinjections on the intact eye of anesthetized and artificially ventilated miniature pigs. Microinjections of the levorotatory isomer L-lactic acid (pH: 2) induced a local maximal dilation of retinal arterioles. This vasodilator effect, like that of systemic hypoxia, was not mediated by the release of prostaglandins. Preretinal pulsatile pressure juxtaarteriolar microinjections of neutral-pH solution of L-lactic acid also induced a segmental retinal arteriolar dilation. In contrast, microinjections of the dextrorotatory isomer D-lactic acid (pH: 2, solution), which is not produced by the retina, did not affect significantly the arteriolar diameter. Consequently, the vasodilator effect of lactic acid does not depend on periarteriolar pH modification and probably interferes with retinal metabolism since only the natural levorotatory metabolite is recognized.

[Regulation of papillary pO2]. / Régulation de la PO2 papillaire.

PO2 measurements using a double barelled recess type microelectrodes were measured in the optic nerve head of miniature pigs during systemic hyperoxia (100% oxygen breathing) and variations of the systemic blood pressure by intravenous injection of Adrenaline or trinitrine. During either systemic hyperoxia, or progressive variations of blood pressure, the intervascular PO2 remained stable. These results suggest a regulation of the tissue PO2 of the optic nerve head, as the retina does, at constant values.