Management of acute submacular hemorrhage using recombinant tissue plasminogen activator and gas

· Purpose: To assess the effects of intravitreal injection of recombinant tissue plasminogen activator (rTPA) and gas on submacular hemorrhage in age-related macular degeneration (ARMD). · Methods: Eleven consecutive patients (11 eyes) with subretinal hemorrhage due to ARMD involving the fovea with elevation of the neurosensory retina were included in this study. Subretinal hemorrhage occured 12 h to 14 days before onset of therapy. Injection of rTPA through the pars plana in a dose of 50 or 100 μg was performed. Gas instillation (0.2–0.4 ml) followed rTPA injection, either immediately after injection (7 patients) or during the following day (4 patients). · Results: After intravitreal injection of rTPA, subretinal clots were totally or partially liquefied when treatment started up to 3 days after onset of bleeding. In all patients treated with 100 μg rTPA a large exudative retinal detachment of the inferior retina resulted, which reabsorbed spontaneously within 2 weeks. After reattachment of the exudative retinal detachment hyperpigmentation of the retinal pigment epithelium was noted. Temporary opacification of the vitreous was observed between the 2nd and 7th postoperative day in 5 eyes (45.5%). Postoperative visual acuity increased in 5 patients (45.5%). · Conclusion: Intravitreal application of rTPA followed by gas injection is a sufficient and convenient technique for effective removal of freshly formed submacular hemorrhage. Removal is mediated through combined enzymatic (rTPA) and mechanical (gas) effects. This technique offers a quick recovery of vision in eyes with less severe ARMD. Received: 5 January 1998 Revised version received: 25 March 1998 Accepted: 23 June 1998     

Snowflake vitreoretinal degeneration: follow-up of the original family

PURPOSE: The ocular findings, systemic features, and genetic loci distinguishing known genetic causes of vitreoretinal degenerations were studied in the original Snowflake family. DESIGN: Prospective, comparative study and molecular genetic investigation. PARTICIPANTS: Members of the original snowflake vitreoretinal degeneration family. METHODS: Clinical data were collected on 26 family members by history and examination. Thirteen of the 26 total family members underwent prospective examination. Linkage to known vitreoretinal degeneration loci (COL2A1, COL11A1, and the Wagner disease locus) was evaluated with short tandem repeat markers. MAIN OUTCOME MEASURES: Ocular and systemic features of known vitreoretinal degenerations. RESULTS: Six of the 13 prospectively examined subjects had snowflake vitreoretinal degeneration. Corneal guttae (4/5; 80%), early onset cataract (5/6; 83%), fibrillar vitreous degeneration (6/6; 100%), and peripheral retinal abnormalities (5/6; 83%), including minute crystallinelike deposits called snowflakes (4/6; 67%), were common. Retinal detachment was seen in 1 of 6 of these prospectively examined subjects (17%). A total of 14 affected subjects were identified within the family, and in 3 (21%), retinal detachment developed. Orofacial features, early-onset hearing loss, and arthritis typical of Stickler syndrome were absent. Linkage to known vitreoretinal degeneration loci was excluded. CONCLUSIONS: The absence of vitreous gel in the retrolental space and presence of fibrillar vitreous degeneration were consistent with the vitreous structure reported for collagen 11A1 (COL11A1) but not collagen 2A1 (COL2A1) mutations. The absence of systemic features was characteristic of the vitreoretinopathies linked to chromosome 5q13 (Wagner disease and erosive vitreoretinopathy) and mutations in exon 2 of the COL2A1 gene. Snowflakes in the peripheral retina and the absence of nyctalopia, posterior chorioretinal atrophy, and tractional retinal detachment were inconsistent with the chromosome 5q13 vitreoretinopathies. The association of Fuchs' corneal endothelial dystrophy found in this family has not been reported previously in other vitreoretinal degenerations. These findings and the exclusion of known genetic loci suggest snowflake is a distinct vitreoretinal degeneration.     

A novel hereditary developmental vitreoretinopathy with multiple ocular abnormalities localizing to a 5-cM region of chromosome 5q13-q14

BACKGROUND: To undertake a clinical and molecular analysis of a previously unpublished kindred with a phenotypically distinct vitreoretinopathy characterized by associated ocular developmental abnormalities. DESIGN: Family genetic study. PARTICIPANTS: A total of 23 members, both affected and unaffected, of 1 kindred with vitreoretinopathy. METHOD: Individuals within the kindred were examined clinically and blood samples taken for DNA analysis. Genetic analysis was performed for the proximal region of chromosome 5q by means of polymerase chain reaction (PCR). MAIN OUTCOME MEASURES: Detection of vitreoretinopathy and associated abnormalities. RESULTS: This novel, hereditary vitreoretinopathy, showing the classic features of vitreous pathology and early-onset retinal detachments, was associated with a variety of ocular developmental abnormalities, including posterior embryotoxon, congenital glaucoma, iris hypoplasia, congenital cataract, ectopia lentis, microphthalmia, and persistent hyperplastic primary vitreous. There were no associated systemic features. Genetic mapping with markers from the proximal region of 5q13-q14 showed linkage to a 5-cM region between the markers D5S626 and D5S2103. CONCLUSIONS: The 5-cM region is within that implicated in the etiology of both Wagner and erosive vitreoretinopathies. This suggests that this novel condition may be allelic, refines the genetic mapping for vitreoretinopathies that map to 5q13-q14, and implicates a gene important not only in vitreous production but also in early ocular development.     

Identification of a novel locus on 2q for autosomal dominant high-grade myopia

PURPOSE: Myopia, or nearsightedness, is a visual disorder of high and growing prevalence in the United States and in other countries. Pathologic high myopia, or myopia of 相似文献   

Tamoxifen retinopathy: does it really exist?

· Background: Tamoxifen retinopathy is known to be an adverse effect of high-dose tamoxifen treatment. Evidence of ocular toxicity at lower doses is less convincing: the aim of this study was to assess the prevalence of the above-mentioned retinopathy in a population treated with low-dose tamoxifen. · Methods: One hundred and twenty-nine women treated with low-dose tamoxifen (20 mg/day) were examined. Visual acuity measurement, slit-lamp biomicroscopy and fundus examination were performed. Patients were reexamined after 6–12 months. · Results: Refractile retinal opacities, similar to those previously described as tamoxifen retinopathy, were observed in four patients (prevalence 3.1%; mean duration of therapy 806 days). None of them revealed corneal opacities, papillary and/or macular edema, or visual impairment. The ophthalmoscopic aspect did not change after a mean follow-up of 215 days, although one of these patients had interrupted tamoxifen intake. Statistical analysis (Student’s t-test) did not reveal any difference between patients with and those without refractile retinal opacities as far as age, treatment duration and ERG values were concerned. An early hyperfluorescence, reminescent of cuticular drusen, was demonstrated by fluorescein angiography in all four cases. · Conclusions: The present study would seem to confirm that low-dose tamoxifen may induce retinal toxicity in a low proportion of patients, but we cannot be certain that the refractile retinal opacities observed are really caused by tamoxifen, as differentiation from age-related macular degeneration with cuticular drusen appears nearly impossible. Received: 10 November 1997 Revised version received: 5 January 1998 Accepted: 14 January 1998     

Genetic linkage of snowflake vitreoretinal degeneration to chromosome 2q36

PURPOSE: To identify the chromosomal location of the gene causing snowflake vitreoretinal degeneration (SVD), an autosomal dominant retinal degeneration characterized by small yellow-white dots in the retina, fibrillar anomaly of the vitreous humor, and retinal detachment. METHODS: Clinical data were collected on 31 family members by history and examination. Thirteen family members underwent prospective examination. Genotyping was performed using microsatellite markers spaced at approximately 10 cM intervals. Two-point and multipoint linkage analysis was performed (FASTLINK version of the MLINK program and the VITESSE algorithm, both available at http://linkage.rockefeller.edu/soft/list.html). Direct DNA sequencing of amplified genomic DNA and mRNA was performed for candidate gene analysis. RESULTS: The SVD locus was linked to markers in a region of chromosome 2q36 defined by D2S2158 and D2S2202, based on meiotic breakpoint mapping of affected individuals. A maximum two-point lod score of 5.5 was obtained with marker D2S172 at theta; = 0 within this region. Direct DNA sequencing of all 52 exons of the COL4A3 gene revealed no potentially pathogenic coding sequence variation or evidence for deletion. CONCLUSIONS: The genetic locus for SVD lies in a 9 Mb region flanked by D2S2158 and D2S2202. Localization of SVD to a genomic region distinct from both Wagner disease and the Stickler syndromes indicates that SVD is a distinct genetic entity. The absence of coding sequence variation in the only collagen gene within the disease-region, suggests a novel pathogenesis for vitreoretinal degeneration. Snowflake vitreoretinal degeneration should be considered in the differential diagnosis of families with fibrillar anomaly of the vitreous.     

Complications after implantation of intraocular devices in patients with cytomegalovirus retinitis

· Purpose: The authors report their surgical experience after sustained-release ganciclovir treatment, as well as replacing empty ganciclovir implants in patients with acquired immune deficiency syndrome (AIDS) and cytomegalovirus (CMV) retinitis.  · Methods: Between November 1995 and August 1998, 79 eyes of 49 patients received 99 intravitreal ganciclovir implants. Patients were examined monthly after implant surgery. Follow-up periods ranged from 6 to 128 weeks.  · Results: At the first 3-week postoperative visit, 73 eyes (97.2%) of 46 patients exhibited stable conditions. In 6 eyes (3.8%) of 3 patients, further progression was noted due to resistance to ganciclovir. The most common early complication (within 6 weeks after implantation) was cystoid macular edema, observed in 7 eyes receiving implants. Retinal detachment was the most common late complication (over 6 weeks after implantation) in 11 eyes. In almost all eyes with CMV retinitis and retinal detachment, involvement of more than 25% of the retina was observed. Additional severe complications included extrusion of the first pellet in 2 eyes and cataract as a late complication in 5 eyes. A total of 28 eyes (35.4%) of 16 patients receiving a second implant did not experience significant three-line loss by the end of the follow-up period.  · Conclusion: In the treatment of CMV retinitis, sustained-release ganciclovir implantation seems to be an alternative to intravenous ganciclovir. Early implantation and additional replacement of the device has the potential to decrease the risk of developing retinal detachment. We would recommend additional systemic antiviral CMV therapy to avoid infection of the fellow eye and CMV disease. Received: 5 November 1998 Revised version received: 25 January 1999 Accepted: 18 February 1999     

Retinal degeneration induced by N-methyl-N-nitrosourea in Syrian golden hamsters

 · Background: The sequential retinal changes in Syrian golden hamsters induced by N-methyl-N-nitrosourea (MNU) have not been studied. · Methods: Female hamsters received a single intraperitoneal injection of 90 mg/kg MNU at 50 days of age, and the retina was examined light and electron microscopically, immunohistochemically and by the TdT-mediated dUTP-digoxigenin nick end labeling (TUNEL) method until 20 weeks after the treatment. · Results: The retinal changes were as follows: (1) Photoreceptor apoptosis occurred 1 day after the treatment and resulted in photoreceptor loss at day 7. During the degeneration, Müller cell proliferation was conspicuous at day 5. (2) After the photoreceptor cell loss, migration of the pigment epithelial cells in all layers of the retina which were in contact with blood vessels occurred. Due to the Müller cell proliferation, gliosis was prominent at the later stage. · Conclusions: The MNU injection caused photoreceptor apoptosis followed by pigment epithelial cell migration around the blood vessels, accompanied by gliosis. The primary event and the course of this disease closely resemble those of retinitis pigmentosa in humans. Received: 6 August 1997 Revised version received: 26 November 1997 Accepted: 7 January 1998     

Phagocytosis of rod outer segments by human iris pigment epithelial cells in vitro

· Background: We set out to evaluate the growth potential of human iris pigment epithelial (hIPE) cells in vitro, to establish whether these cells acquire the ability to phagocytose rod outer sgments (ROS) and to compare the phagocytic activity of hIPE to that of human retinal pigment epithelial (hRPE) cells. · Methods: hIPE and hRPE cells were isolated and cultured from human donor eyes and surgical specimens and growth characteristics were analyzed. HIPE and hRPE of an eye of a 46-year-old donor were used for the phagocytosis assay. Phagocytosis was evaluated by adding ROS isolated from porcine retina to cultures of hIPE and hRPE, which had been labeled with the pH-sensitive fluorescent dye, carboxy-SNAFL. After 4 h the number of ingested ROS was counted with a light microscope. For each cell type phagosomes in 500 cells were counted. The epithelial characteristics of the cells used in this study were evidenced by their morphology. · Results: Morphologically cultured hIPE are indistinguishable from the hRPE cultured from the same donor eye and show a similar pattern of cytokeratin distribution. Cultured hIPE acquire the ability to phagocytose ROS at a level slightly lower than hRPE; hIPE contained 0.76 phagosomes per cell, hRPE 0.99 phagosomes per cell. · Conclusion: The morphology of hIPE in culture and the acquisition of the phagocytic phenotype indicate that these cells have the ability to differentiate into cells that have characteristics in common with hRPE. The acquisition of phagocytic activity suggests that it is feasible to culture hIPE from surgical iridectomies and that these cultured cells can be transplanted into the subretinal space in individuals with retinal degenerations. Received: 5 December 1997 Revised version received: 6 February 1998 Accepted: 9 February 1998     

Comparative study of incomplete posterior vitreous detachment as a risk factor for proliferative vitreoretinopathy

· Background: Abnormal vitreoretinal relationships have recently been implicated in many vitreoretinal disorders. Sites of abnormal vitreoretinal adherences are likely to exist in eyes predisposed to rhegmatogenous retinal detachment (RD), causing either retinal tears or incomplete posterior vitreous detachment (PVD). The present study was designed in two parts to identify the risk for preoperative and postoperative proliferative vitreoretinopathy (PVR) due to incomplete PVD. · Methods: We prospectively evaluated the vitreoretinal relationships using high-resolution kinetic echography in 102 consecutive eyes of 100 patients with rhegmatogenous RD. In the first part, a case-control study was conducted to compare the vitreous status in patients with preoperative PVR (cases) with that in patients with non-PVR-complicated RD (controls). During the second part, patients with noncomplicated RD (65 eyes) who were operated on by a simple retinal attachment procedure were followed up for a mean period of 6.6 months to compare the recurrence of RD due to postoperative PVR according to their vitreous status. · Results: Patients with PVR on study entry had a higher prevalence of partial PVD (28 of 32 eyes, 87%) than did controls (25 of 70 eyes, 35%). The statistical significance of this difference was independent of all other variables studied. After a mean follow-up period of 6.6 months, the incidence of recurrence of RD associated with postoperative PVR was 33% in the eyes with incomplete PVD, compared with 4.9% in the eyes without incomplete PVD. · Conclusions: Our results support the notion that the occurrence of incomplete PVD in RD is a significant risk factor for preoperative and postoperative PVR. Received: 18 June 1997 Revised version received: 9 October 1997 Accepted: 15 October 1997     

Progression of retinopathy and alteration of the blood-retinal barrier in patients with type 2 diabetes: a 7-year prospective follow-up study

· Background: The study was carried out to evaluate the correlation between blood-retinal barrier (BRB) permeability and the progression of diabetic retinopathy (DR), defined by development of “need for photocoagulation”, over a 7-year period by means of vitreous fluorometry (VF). · Methods: Forty type 2 diabetic patients with minimal or no retinopathy, aged 40–65 years (mean 53.9 + 7.3 years), were followed up prospectively for 7 years. Investigations including standard ophthalmological examination, fundus photography, fluorescein angiography and VF were performed at entry and 1, 4, 5 and 7 years later. Only one eye per patient was included in the study. Need for photocoagulation was based on Early Treatment Diabetic Retinopathy Study protocols and decided by the attending ophthalmologist. · Results: After 7 years of follow-up a total of 22 of the 40 eyes had received photocoagulation. The eyes that needed photocoagulation were those that had higher VF values at the entry of the study and showed higher rates of deterioration (initial values 5.1 + 1.9 vs 2.8 + 1.5×10^–6 min^–1, P<0.001; annual increase in leakage for the first year, 1.5 + 0.8 vs 0.5 + 1.0×10^–6 min^–1 , P<0.001,). The eyes that did not need photocoagulation during the 7 years of follow-up showed stable VF readings (-0.1 + 1.2×10^–6 min^{– 1}, difference between initial values and 7 years later). · Conclusions: Abnormally high VF values and their rapid increase over time are good indicators of progression and worsening of the retinopathy in diabetes type 2. Received: 4 June 1996 Revised version received: 18 April 1997 Accepted: 8 July 1997     

Posterior chorioretinal atrophy and vitreous phenotype in a family with Stickler syndrome from a mutation in the COL2A1 gene

PURPOSE: To report posterior chorioretinal atrophy (PCRA) and correlate the vitreous phenotype with inheritance of the disease mutation in a family with vitreoretinal dystrophy. DESIGN: Prospective observational case series. METHODS: Twenty-four members of a family with 14 affected individuals were examined, and genetic linkage analysis was performed at the COL2A1, COL11A1, and Wagner disease loci. The vitreous phenotype was prospectively graded as optically empty with retrolenticular membrane, fibrillar, or normal. Ocular ultrasonography and optical coherence tomography (OCT) were performed on selected individuals to study the vitreous structure and vitreoretinal interface. RESULTS: The 6-year-old proband had PCRA and optically empty vitreous without systemic features, suggestive of Wagner disease. The family history was negative for systemic disease, except for one cousin with cleft palate. However, when examined, clinical features of the 14 affected subjects included 5 with small chin, 4 with at least submucosal cleft palate, and 9 with a myopic refractive error greater than 5 diopters. Lens opacity or previous cataract extraction was found in 13 family members. All affected individuals in whom the vitreous could be examined had an optically empty vitreous with retrolental membrane. Posterior chorioretinal atrophy was found in eight of the affected subjects. The finding was not limited to highly myopic subjects, nor did all the high myopes have PCRA. Ultrasonography and OCT revealed vitreous adherent to the retina, but without apparent retinal distortion or edema of the macula. Significant linkage was established to the COL2A1 locus; the other loci were excluded. A single nucleotide insertion mutation (c.2012 2013insC) was identified in exon 34, leading to a downstream premature stop codon in the COL2A1 gene. CONCLUSIONS: Although posterior chorioretinal atrophy and vitreoretinal degeneration have been classically associated with Wagner disease, we demonstrate its presence in a family with typical Stickler syndrome. On the basis of clinical, ultrasonographic, and OCT studies, the etiology of PCRA in this family does not seem to be attributable to vitreomacular traction or myopia. The vitreous findings in this large family confirm reports that mutations in the COL2A1 gene lead to the optically empty vitreous with retrolenticular membrane phenotype.     

Pupillary light reflexes in patients with Leber’s hereditary optic neuropathy

 Background: According to a recent pupillographic study, patients with Leber’s hereditary optic neuropathy (LHON) show the same pupillary behaviour as normals. Because this raises many questions concerning the real nature of LHON and challenges our concept of the afferent pupillary system, we tried to verify the results of this study. · Methods: Pupillary function was assessed in 34 normal subjects and 40 patients with LHON. Pupillary light reflexes were recorded by means of the Compact Integrated Pupillograph (CIP, AMTech). Under mesopic conditions 200-ms stimuli were presented at two different stimulus intensities. Latency, constriction amplitude and baseline diameter were defined automatically. Pupil light reflexes were compared between LHON patients and normals and between the better and the worse eye in 20 LHON patients with different visual acuities. · Results: For both stimuli there were significant differences in latency between LHON patients and controls. The latency of the pupil light reflex proved to be about 20 ms longer for LHON patients, and the amplitude was significantly smaller for the bright stimulus. Within LHON patients, the eyes with the worse visual acuity had a significantly smaller constriction amplitude than the eyes with the better visual acuity. · Conclusion: The results of our study confirm that LHON really is an optic nerve disease and that the pupillary light reflexes are not normal. Received: 5 January 1998 Revised version received: 28 February 1998 Accepted: 11 March 1998     

The ocular hypotensive effect of late pregnancy is higher in multigravidae than in primigravidae

· Background: Systemic hypertension and degenerative vascular disease are more common in multigravidae than in primigravidae. The present study investigated whether the known ocular hypotensive effect of late pregnancy is influenced by the number of pregnancies. · Methods: Intraocular pressure (IOP) was measured in normotensive third-trimester primigravidae and multigravidae along with nulligravida controls by means of the Goldmann applanation tonometer. Depending upon the number of previous pregnancies, multigravidae were divided into four subgroups. · Results: The IOP of the pregnant group (primigravidae and multigravidae together) was (mean±SEM) 2.1±0.07 mmHg (P<0.001) lower than in the nulligravida control group. The IOP of nulligravidae was 1.7±0.06 mmHg (P<0.001) and 2.5±0.01 mmHg (P<0.001) higher than in third-trimester primigravidae and multigravidae, respectively. In all subgroups of multigravidae IOP was significantly lower (P<0.02) than in primigravidae. The differences among different subgroups of multigravidae were statistically insignificant. · Conclusions: Gravidity influences IOP and should be taken into account in future research. Received: 14 August 1997 Revised version received: 4 May 1998 Accepted: 26 May 1998     

PRK-induced anisometropia in the rabbit as a model of myopia

· Background: Current animal models of myopia, such as the chick and the tree shrew, have characteristics that limit their applicability to human myopia and/or their use among researchers. The purpose of this study was to establish a rabbit model of myopia based on photorefractive keratectomy (PRK)-induced anisometropia. · Methods: A group of five pigmented rabbits was treated with a monocular –5 D PRK at 5 weeks of age. At 10 weeks of age, two of the eyes were retreated with a second –5 D PRK procedure to compensate for partial regression of the refractive effect. A second group of six pigmented rabbits was treated with a monocular –6 D PRK at 10 weeks of age. Longitudinal measurements of corneal curvature, refraction, and axial length were performed until the rabbits were 13 and 21 weeks of age in groups 1 and 2, respectively. The rabbits in each group were from the same litter. · Results: Keratometry and retinoscopy measurements confirmed the refractive effect of the PRK procedures. At the final measurement point in group 1, the PRK-treated eyes were significantly longer than the untreated eyes (16.01±0.45 mm vs 15.45±0.56 mm). In group 2, the PRK-treated eyes were significantly longer by 0.19 mm and 0.20 mm at ages 19 and 21 weeks, respectively. · Conclusions: PRK-induced anisometropia is an effective technique to induce hyperopic error compensation in the rabbit as a model of myopic development. The technique is effective if the PRK procedure is performed at either 5 or 10 weeks of age. However, after PRK at 5 weeks of age, partial retreatment may be necessary due to regression of the PRK effect. Received: 27 April 1998 Revised version received: 15 June 1998 Accepted: 23 June 1998     

Effects of photorefractive keratectomy and cataract surgery on ocular optical errors of higher order

  · Background: This pilot study was carried out to assess the effects of photorefractive keratectomy (PRK) for myopia and myopic astigmatism and cataract surgery on the ocular optical aberrations of higher degrees.  · Methods: The optical aberrations were measured in 12 patients before and after PRK and in 10 patients after cataract surgery with a video aberroscope for clinical use (based on Tscherning’s aberroscope) designed by the authors. To characterize the optical performance of the eye the deviation of the wavefront of a foveal image point from its ideal (spherical) shape (wavefront aberration) was determined. The wavefront aberration is represented mathematically in Zernike polynomials. The first 14 Zernike coefficients K_i were determined and compared with data from normal eyes with full visual acuity. · Results: Most Zernike coefficients were considerably greater after PRK than before surgery. These changes differed significantly from the variability of repeated individual measurements. In particular, coefficients corresponding to astigmatism, spherical aberration or coma were highly significantly increased (P<0.001). After cataract surgery, the averaged Zernike coefficients exhibited no significant differences from normal values, except the coefficient K₅ (astigmatism at 0° or 90°). However, coefficients showed a significant high variability, especially the coefficients for spherical aberration or astigmatism.  · Conclusion: Both PRK and cataract surgery are operations which may considerably increase the ocular optical errors of higher order. These aberrations are not predictable and can affect the visual acuity despite optimal sphero-cylindrical correction, in particular under mesopic conditions. Received: 5 November 1998 Revised version received: 8 March 1999 Accepted: 8 March 1999     

Familial macular cone dystrophy: diagnostic value of multifocal ERG and two-color threshold perimetry

· Background: It is difficult to detect receptor dysfunction in patients with marked bilateral visual loss but only mild morphological alterations of the fundus. · Methods: Two patients, father and son, with visual acuity loss to 20/100 were examined. Using the multifocal ERG, 61 local cone ERGs from each eye were derived from the central visual field. The dark-adapted two-color threshold perimetry using stimuli of 500 nm and 656 nm for rod and cone function was investigated along the horizontal meridian of the visual field. · Results: In the multifocal ERG of both patients a macular response was absent. From eccentricity at and anterior to 5°, good multifocal cone activity was recorded. Cone thresholds were markedly diminished in the macula. The rod thresholds were borderline in the father and normal in the son. · Conclusions: Multifocal ERG is a novel technique, very well suited to reveal the topography of cone function. Using two-color threshold perimetry affords an opportunity to differentiate between rod and cone functional defects. Both together helped to establish the diagnosis of macular cone dystrophy in the present family. Received: 5 January 1998 Revised version received: 29 July 1998 Accepted: 13 August 1999     

Rubeosis iridis after vitrectomy for diabetic retinopathy

· Background: Iris rubeosis and neovascular glaucoma (NVG) are serious complications of vitrectomy for proliferative diabetic retinopathy. The present study analyzes incidence and risk factors of these complications. · Methods: Preoperative and postoperative iris rubeosis were compared in 389 diabetic eyes after vitrectomy. Minimum follow-up was 6 months (median 26 months). Risk factors were studied using multivariate logistic regression analysis. · Results: Following vitrectomy, in 8.5% of the eyes stromal iris rubeosis developed de novo; NVG occurred in 5%. Significant risk factors for postoperative rubeosis were preexisting iris neovascularizations and postoperative retinal detachment. Six months after surgery, regression of preexisting iris rubeosis was observed in 57% of the eyes. In eyes without preoperative iris rubeosis, progression was found in 13% of cases 6 months postoperatively. · Conclusion: With current surgical techniques iris rubeosis is more commonly regressive than progressive after vitreous surgery in diabetic eyes. Received: 3 December 1997 Revised version received: 18 February 1998 Accepted: 27 February 1998