Ahmed glaucoma valve in various etiologies of refractory glaucoma: Surgical outcomes and success factors.

PURPOSE: To study the epidemiology and mid-term results of the Ahmed glaucoma valve (AGV) in various etiologies of refractory glaucoma in a Lebanese center, and to assess complications and factors that influence the surgical success rate. METHODS: In this retrospective epidemiological study, we reviewed 108 eyes with refractory glaucoma that underwent an AGV implantation in a tertiary care center in Lebanon between January 2002 and August 2014. Findings including best-corrected visual acuity (BCVA), intra-ocular pressure (IOP), number of antiglaucoma medications, factors influencing the surgical outcome, success rate and complications were also reviewed. RESULTS: The mean duration of follow-up was 29.85±21.45 months [range, 3-60 months]. As in other Arab countries and compared to the rest of the world, the rate of neovascular glaucoma (NVG) was particularly high, occurring in 63 eyes (58.3%), and represented the primary cause of refractory glaucoma. Mean IOP was significantly reduced to 17.97±7.35mmHg at the last follow-up visit (P<0.05). Similarly, a significant decrease was noted in the number of antiglaucoma medications (P<0.05). The surgical success rate, defined as a postoperative IOP<21, was significantly higher (62.0%), in older patients, those with baseline BCVA≤2 LogMAR and those with a history of hypertension (P<0.01). Hyphema was the most noted complication. CONCLUSION: The AGV is a safe and effective procedure for lowering IOP in refractory glaucoma patients, with hyphema being the most frequent complication. Both the presence of hyperstension and initial BCVA≤2 LogMAR seem to increase the success rate of the procedure. NVG remains the most common etiology for implantation, probably due to uncontrolled diabetes in the Middle East and North Africa.

Diabetic macular edema: risk factors and concomitants.

PURPOSE: To investigate the systemic and ocular factors associated with diffuse macular edema in patients with diabetic retinopathy (DR) and compare with patients with focal or no macular edema. METHODS: From 160 consecutive patients with DR, we obtained medical and ocular histories, blood pressure and visual acuity. Macular edema was determined by biomicroscopy and stereoscopic fundus photography. Fluorescein angiography was used in the characterization of its leakage, and the vitreoretinal relationship was performed by preset lens biomicroscopy. RESULTS: Among adult-onset diabetes mellitus (DM) patients, 55% had diffuse, 23.5% had focal and 21.5% had no macular edema (p=0.01). The risk of developing diffuse macular edema was 3.2 times greater in patients with high blood pressure (HBP) (95% confidence interval (CI), 1.5 to 6.9). Patients with cardiovascular disease (CVD) had a higher prevalence of diffuse (58.0%) than focal (26.0%) or no maculopathy (16.0%) (p=0.01). The odds for development of diffuse macular edema was 3.4 times greater in patients with vitreomacular adhesion (95% CI, 1.15 to 13.30) than in those with complete posterior vitreoretinal attachment or vitreoretinal separation. The odds for development of diffuse macular edema were 6.2 (95% CI, 1.83 to 21.04) and 7.7 times greater (95% CI, 3.12 to 19.12) in patients with PPDR and PDR, respectively, in comparison with those with NPDR. CONCLUSIONS: In this study, adult-onset DM, HBP, CVD, vitreomacular adhesion and advanced retinopathy were associated with increased risk of development of diffuse diabetic macular edema.

Biomicroscopic findings of posterior vitreoschisis.

The clinical entity of posterior vitreoschisis, splitting of the posterior cortical vitreous, is not well known. We confirmed its presence biomicroscopically in cases with posterior vitreous detachment and found it mostly associated with retinal vascular diseases, usually manifesting as two dense vitreous membranes with defects. When posterior vitreoschisis develops in an otherwise normal eye, it may not manifest as two membranes, but can form a crescent-shaped, optically empty space in the posterior vitreous cavity. Because its management is different, posterior vitreoschisis should be differentiated from other, apparently similar, conditions, especially posterior vitreous detachment.

Melanocytoma with juxtapapillary nevus: premalignant or benign?

A melanocytoma is a benign heavily pigmented tumor that usually arises at the optic nerve. Originally thought to be a malignant neoplasm, currently, it is believed to be a variant of the melanocytic nevus. Recently, several cases of malignant transformation to malignant melanoma have been reported. We present the case of a 63-year-old man with a melanocytoma and juxtapapillary choroidal nevus that remained stable for more than six years. Although the overwhelming majority of such neoplasms are benign, regular follow-up examinations are recommended because there is a small risk of malignant transformation.

Lipid exudation in age-related macular degeneration.

We reviewed the relationship between lipid exudation and subretinal neovascular membranes associated with age-related macular degeneration. The records of 500 consecutive patients with subretinal neovascular membranes caused by age-related macular degeneration were examined. Seventy-five patients (15%) (85 eyes) manifested lipid exudation in conjunction with subretinal neovascularization. Twelve patients (2.4%) (13 eyes) had a massive lipid exudative response with extensive serous retinal detachment (resembling Coats' disease). Of the 85 eyes with subretinal neovascular membranes and lipid exudation, 71 (84%) had a subretinal neovascular membrane that was classified as ill defined. Improvement of vision with or without treatment was seen in only 14 of these 85 eyes (16.4%). After comparing these 85 eyes to 94 eyes from 76 patients with age-related macular degeneration and subretinal neovascular membranes but no lipid exudation, we found that a subretinal neovascular membrane associated with lipid exudation was more likely to be ill defined (71 eyes [84%] vs 35 eyes [37%]; P = .0001), was more frequently associated with retinal pigment epithelial detachment (30 eyes [35%] vs 15 eyes [16%]; P = .0029), and was more likely not to have stabilization of visual acuity (14 eyes [16%] vs 31 eyes [33%]; P = .025).

Retinal detachment after cataract surgery. Predisposing factors.

The authors studied the characteristics of 376 eyes of 361 patients with primary retinal detachment (RD) and surgical aphakia (103 eyes) or pseudophakia (273 eyes). Of the pseudophakic eyes, 17 had an iris-fixated intraocular lens (IOL), 111 had an anterior chamber (AC) IOL, and 145 had a posterior chamber (PC) IOL. Of the PC IOL cases, 48 (33%) had undergone YAG capsulotomy, and 46% of them developed RD within 6 months after capsulotomy. The frequency of no breaks found in pseudophakic RD (15%) was significantly higher than in RD with simple aphakia (5%). The most frequent reasons were incomplete fundus view due to a small pupil in the iris-fixated (83%) and the AC (44%) groups, and cloudiness of capsular remnants in the PC group (78%). In pseudophakic RD, sizable single tears, located more posteriorly than in RD with simple aphakia, were frequent. The authors speculate that in pseudophakic RD the retinal breaks may resemble those noted in phakic RD.

Retinal detachment after cataract surgery. Surgical results.

The authors studied the results obtained by the Retina Associates in 376 eyes of 361 patients operated on for retinal detachment associated with aphakia or pseudophakia with a postoperative follow-up of at least 6 months. All eyes underwent scleral buckling. The series included 103 eyes with aphakia, 17 eyes with iris-fixated intraocular lens, 111 eyes with anterior chamber (AC) IOL, and 145 eyes with posterior chamber (PC) IOL. The overall success rate for retinal detachment was 93%, without significant difference among the different groups. The aphakia and PC IOL groups had significantly higher prevalence (63% and 60%, respectively) of visual acuity equal to or better than 20/40 compared with the AC IOL group (33%). The prevalence of postoperative corneal edema in the AC IOL group was significantly higher than in the aphakia and PC IOL groups. Preoperative vitreous hemorrhage, large retinal breaks, posterior retinal breaks, total retinal detachment, proliferative vitreoretinopathy, and the need for performing a closed vitrectomy were significant factors in predicting ultimate failure.

Classification of retinal pigment epithelial detachments associated with drusen.

To understand the natural history of retinal pigment epithelial (RPE) detachments (PEDs) associated with drusen, we retrospectively reviewed 125 PEDs that had not undergone laser treatment over an average follow-up period of 28 months. We identified six types of RPE detachments: pseudo-vitelliform, confluent drusen, serous, vascular, and hemorrhagic lesions as well as PEDs associated with a retinal vascular abnormality. We correlated the type of detachment with visual acuity and anatomic outcome. The poorest results were obtained for PEDs associated with neovascularization (vascular, hemorrhagic, and retinal vascular abnormality types). Eyes presenting with pseudo-vitelliform lesions or confluent drusen had the best visual prognosis and anatomic results. Obvious subretinal new vessels developed in 16 (34%) of the serous PEDs over an average follow-up period of 25 months. Subretinal neovascularization was rare in the pseudo-vitelliform and confluent drusen groups. The proposed classification system may be useful in predicting the natural course of PEDs.

Characterization of functional changes in macular holes and cysts.

Precise characterization of functional loss in small retinal lesions is difficult with conventional techniques. Using the scanning laser ophthalmoscope, the authors evaluated functional changes and fixation behavior in 26 eyes with macular holes and 15 eyes with macular cysts. A dense scotoma was present over all macular holes; 24 had no detectable functional alteration at the margins of the hole, and fixation was above the horizontal meridian in all eyes. Nine eyes with cysts had no detectable functional loss over the cyst. Only two eyes had small areas of dense scotoma within the cyst area, and four had areas of relative scotoma. Fixation was central in all eyes. Characterization of functional changes is helpful in differentiating holes from cysts. Photocoagulation at the margin of the holes may result in further functional damage.

Comparative study of vitreoretinal relationships using biomicroscopy and ultrasound.

We prospectively studied 29 consecutive eyes with proliferative diabetic retinopathy that showed media clear enough to enable characterization of vitreoretinal relationships by biomicroscopy. Vitreoretinal relationships were also determined by contact B-scan ultrasound. With both techniques, these relationships were documented by photographs and drawings. Biomicroscopy showed complete posterior vitreous detachment (PVD) in 4 eyes (14%), partial PVD in 18 (62%), and no PVD in 7 (24%). Ultrasound examination revealed complete PVD in 4 eyes (14%), partial PVD in 19 (66%), and no PVD in 6 (21%). The results we obtained using ultrasound agreed significantly with those obtained by biomicroscopy [Cohen's kappa = 0.93, 95% confidence interval = (0.80, 1.06)]. Ultrasound detected vitreous changes more easily than biomicroscopy when mild media opacities were present and when the equatorial areas of the globe were examined. Results suggest that ultrasound is adequate to determine vitreoretinal relationships in eyes with clear media and that it is a good alternative to biomicroscopy in eyes with significant media opacities.

Inactive subretinal neovascularization in age-related macular degeneration.

Inactive subretinal new vessels (SRNVs), showing minimal leakage by fluorescein angiography and little progression, were observed in 15 eyes of 12 patients with age-related macular degeneration. In 8 (57%) of 14 eyes followed for longer than 6 months, the new vessels involuted and produced circumscribed areas of retinal pigment epithelium and choriocapillaris atrophy; 6 (43%) showed a further decrease in the fluorescein leakage during the follow-up period (average, 30.1 months). None of the new vessels organized into an exudative fibrovascular scar. Visual acuity was improved or unchanged during the entire follow-up period in 12 (86%) eyes and deteriorated in 2 (14%). Nine patients (75%) were 80 years of age or older; three (25%) were between 65 and 70 years of age. These observations suggested that SRNV showing minimal fluorescein leakage, particularly when it occurs in patients older than 80 years, do not require photocoagulation because they are usually self-limited.

Vitreous changes and macular edema in central retinal vein occlusion.

The condition of the posterior vitreous was determined in 56 eyes with central retinal vein occlusion (CRVO). Using a life-table analysis, it was studied in 56 eyes. The incidence of posterior vitreous detachment (PVD) in the CRVO eyes at the first vitreous examination did not differ significantly from that in 64 age-matched control eyes. However, the incidence of PVD in CRVO eyes increased from 39.3% at the first vitreous examination to 58.5% after 6 months, and to 69.6% 1 year from the examination. The incidence of PVD in CRVO eyes during follow-up was statistically higher than that of the controls (P = .009). The incidence of PVD after the first vitreous examination was significantly higher in eyes with hemorrhagic retinopathy than in eyes with venous stasis retinopathy (P = .04). In the 34 eyes with macular edema, the edema lasted significantly longer in those with vitreomacular attachment (VMA) at the first examination than in those without VMA at this time (P = .02). VMA may play an important role in the pathogenesis and chronicity of macular edema in CRVO.

[Static microperimetry with the laser scanning ophthalmoscope]. / La micropérimétrie statique avec l'ophtalmoscope à balayage laser.

We have used the scanning laser opthalmoscope (SLO) with a personal computer to develop static microperimetry techniques. They allow to see in real-time on a television monitor the precise retinal localization of the stimulus and fixation. The testing is performed under strict conditions. The size of stimuli can vary between 6 and 30 minarc on a side. 255 different intensity levels are possible with the instrument. We have selected 12 of them, representing a logarithmic scale. Stimulus duration can vary between 50 and 500 ms. Examples of macular pathology including subretinal neovascularization, drusen and macular edema are given.

Shiny multifocal chorioretinitis with papillitis.

We report a case of unilateral inflammation involving the retinal pigment epithelium-choriocapillaris complex and the optic disc, characterized by multiple, small, shiny, yellowish-white subretinal lesions involving the midperiphery of the retina and associated with optic disc edema. These lesions showed hypofluorescence in the early transit phase of the fluorescein angiogram and leakage in the late phase. Perivascular staining of the retinal vessels and diffuse optic disc leakage were also present. A benign course associated with marked visual improvement and resolution of the inflammatory lesions occurred.

Importance of the vitreous in young diabetics with macular edema.

The authors assessed retrospectively the clinical records of 80 patients (137 eyes) with diabetic retinopathy who were 50 years of age or younger and who had undergone a vitreous examination. The group comprised 53 patients (91 eyes) with macular edema and 27 patients (46 eyes) without macular edema. Vitreous studies using the El Bayadi-Kajiura lens determined whether the posterior vitreous was attached to the retina in the macula. Forty (42.1%) of 91 eyes in the edema group and none (0%) of the 46 eyes in the nonedema group had a detached posterior vitreous. This difference was statistically significant, indicating that young diabetic patients with macular edema have a significantly higher rate of posterior vitreous detachment than those without macular edema.

Photocoagulation of chorioretinal anastomoses in far-advanced age-related macular degeneration.

In age-related macular degeneration, communication between the retinal and choroidal circulations occurs spontaneously or following unsuccessful laser photocoagulation of subretinal new vessels. The resulting chorioretinal anastomotic complex, which includes the subretinal new vessels and their feeder retinal vessels, usually shows marked exudation and produces an extensive serous detachment of the neurosensory retina in the posterior pole, often associated with hard exudates. Eleven eyes with chorioretinal anastomotic complexes were treated using the monochromatic green argon laser. Adequate closure of the chorioretinal anastomotic complexes by photocoagulation resulted in retinal flattening in the posterior pole with resolution of the hard exudates and improvement of vision in eight of the 11 treated eyes.

Use of cross-polarized light in anterior segment photography.

A photographic technique improved the quality of anterior segment photography by using one polarizer in the illumination path and another polarizer that was perpendicularly oriented to the first in front of the camera film back. A significant improvement was noted by impartial masked observers who assessed standard photographs of the iris, conjunctiva, and sclera. A crosslike artifact, observed in photographs using cross-polarizers, was present and originated from corneal birefringence. The significance of the artifact and its possible diagnostic applications were determined.