Diode laser, vitrectomy and intravitreal triamcinolone. A comparative study for the treatment of diffuse non tractional diabetic macular edema.

PURPOSE: To determine the effectiveness and safety of diode laser, pars plana vitrectomy (PPV) with gas tamponade, and intravitreal triamcinolone (IVT) as possible treatments for diffuse diabetic macular edema (dDME). To determine whether the new macular edema Classification previously proposed by some of the authors may help as a guide in the choice of treatment. METHODS: A retrospective, comparative study of 169 eyes with dDME that underwent treatment. The eyes divided into 3 groups: in the PPV Group, 59 eyes received PPV with gas tamponade; in the DIODE Group, 53 eyes received a laser grid; in the IVT Group, 57 eyes received an intravitreal injection of 4 mg of triamcinolone acetonide. The follow up ranged from 6 to 24 months. The eyes were classified according to the new DME Classification based on OCT. MAIN OUTCOMES: Change in foveal thickness as determined by Optical Coherence Tomography (OCT); change in visual acuity; intra and postoperative complications. RESULTS: Mean visual acuity (VA) improved at 3 months with every treatment. At one year only eyes which underwent PPV still had better VA than the pre-op value, while eyes which underwent IVT and laser treatment showed regression. PPV show the greater percentage of eyes which gain 3 or more lines of VA at one year (17%). Mean foveal thickness improved at 3 months with every treatment. Only the eyes into the PPV Group showed relatively low foveal thickness at one year. Better final VA and foveal thickness were obtained if preop VA is > or = 0.3 and if earlier stages of DME were treated according to the new DME Classification. PPV was the treatment which offered the most stable results with at one year or longer. Similar results were observed into the PPV Groups as a whole and into a subgroup of eyes with preoperative PVD. No complications were encountered with laser diode treatment. Long term complications into the IVT Group were elevated IOP (8%), retinal detachment (3.5%) and posterior cataract (15%). Long term complications into the PPV Group were retinal detachment (3.4%) and cataract (90%). CONCLUSIONS: Diode laser, PPV with gas tamponade and IVT are effective alternative treatments to decrease foveal thickness and improve visual acuity in eyes with DME. However while the results of PPV are stable in the long term follow-up, diode laser and IVT do not offer stable results. Complications may be severe with PPV and IVT. It is necessary to carefully select cases which would benefit from these types of treatments. The authors think that the OCT Classification may serve as a guide for the choice of treatment.

Diabetic macular edema: an OCT-based classification.

PURPOSE: More than ten years after ETDRS, Optical Coherence Tomography (OCT) greatly enhanced our ability to detect macular thickening and has brought new insights on the morphology of edema and on the presence of vitreal traction. In this study we propose a new classification of macular edema based on OCT findings to better catalogue and follow this complex clinical entity. METHODS: Since January 2000 we analysed with OCT 2 (Zeiss Inc.) more than one thousand and two hundred eyes with DME. RESULTS: The classification takes into account five parameters: retinal thickness, diffusion, volume, morphology and presence of vitreous traction. Standard figures and numerical values for every parameter are given. CONCLUSION: Although ETDRS guidelines for laser treatment of DME still remain the only proven therapy for this condition, many other strategies are now on trial, and the vast majority of authors use OCT as the best indicator of therapeutic benefit. The amount of information given by OCT demonstrates that macular edema is a complex clinical entity with various morphology and gravity, and disclaimed the limitations of a simple "clinical" definition. As in many other examples such as macular holes and choroidal neovascularization, a uniform and precise definition of macular edema would increase the possibility to compare and judge the result of different therapeutic strategies. Aim of this classification is to implement the ETDRS clinical definition of DME with the precise and useful data given by OCT to better diagnose, catalogue and follow macular edema.

Relationships between vitreoretinal and refractive surgery.

OBJECTIVE: To describe retinal complications after posterior chamber phakic intraocular lens (PCPIOL) implantation and refractive surgery complications after scleral buckling surgery. DESIGN: Retrospective, noncomparative, small case series. PARTICIPANTS: Four patients in whom retinal detachment developed after PCPIOL implantation and two patients with previously placed encircling scleral buckles in whom corneal steepening developed after laser in situ keratomileusis (LASIK). INTERVENTION: The four patients with retinal detachment after PCPIOL implantation underwent vitreoretinal surgery. One of the two patients in whom corneal steepening developed after LASIK underwent buckle removal. MAIN OUTCOME MEASURES: The main parameters evaluated were vitreoretinal findings, corneal topography, and pachymetry. RESULTS: Retinal attachment was achieved for all patients. Mean postoperative best-corrected visual acuity (BCVA) was 20/30. One patient lost one line of BCVA. One patient with corneal steepening achieved partial corneal flattening after buckle removal. CONCLUSIONS: Vitreous base stimulation related to PCPIOL implantation and manipulation during LASIK may trigger retinal complications. Laser in situ keratomileusis in patients with previously placed scleral buckles may result in unexpected corneal steepening.

Central necrotic lamellar inflammation after laser in situ keratomileusis.

PURPOSE: To report four cases of corneal interface complications that occurred after excimer laser in situ keratomileusis (LASIK). METHODS: Four eyes of three patients underwent technically uneventful LASIK. RESULTS: One day after LASIK, patients presented with severe pain, blurred vision, conjunctival infection, and diffuse opacity at the interface. Two days after LASIK, significant features were central opacity, striae in the flap, loss of uncorrected and best spectacle-corrected visual acuity, and corneal sensitivity. The findings did not improve by using drugs or by lifting the flap and irrigating the bed. The central opacity partially resolved over 8 to 12 months, leaving a hyperopic shift (one patient), striae (one patient), and loss of two or more lines of best spectacle-corrected visual acuity (three patients). CONCLUSION: This severe central inflammation after LASIK could be an extreme manifestation of diffuse lamellar keratitis.

Vitrectomy for refractory diabetic macular edema.

Diabetic macular edema may occur or worsen as a consequence of vitreomacular traction in some eyes. The precise role of the posterior hyaloid in the pathogenesis of diabetic maculopathy remains unclear. The determination of which eyes might benefit from vitrectomy is the most challenging aspect in the treatment of this condition. Fluorescein angiography, B-scan untrasonography, and optical coherence tomography may be helpful in this regard. Most often, vitreous surgery is performed when diabetic macular edema persists despite multiple laser treatments. All reports published to date regarding vitrectomy for diabetic macular edema are uncontrolled and nonrandomized patient series. Visual improvement after vitrectomy is related to the duration of edema, as well as the extent of intraretinal lipid and vascular nonperfusion.

Association of xerophthalmia, flecked retina, and pseudotumor cerebri caused by hypovitaminosis A.

PURPOSE: To report an unusual case of hypovitaminosis A with bilateral papilledema and flecked retina that regressed after restoration of vitamin A deficiency. METHOD: Case report. A 27-year-old woman had undergone a biliopancreatic bypass for obesity in 1990. In 1995, she presented with bilateral xerophthalmia, bilateral papilledema, and bilateral flecked retina. RESULTS: Laboratory tests demonstrated low serum levels of vitamin A (0.8 micromol/l) and vitamin E (8.54 micromol/l). Xerophthalmia, papilledema, and flecked retina disappeared after restoration of normal vitamin A blood levels. CONCLUSION: Hypovitaminosis A after biliopancreatic bypass for obesity may be associated with xerophthalmia, pseudotumor cerebri, and flecked retina.

Hereditary hyperferritinemia-cataract syndrome caused by a 29-base pair deletion in the iron responsive element of ferritin L-subunit gene.

Iron availability regulates ferritin synthesis posttranscriptionally by the interaction between iron-regulatory proteins (IRPs) and an iron responsive element (IRE), a stem-loop sequence located on the 5' untranslated region of ferritin mRNA. IRPs recognize IREs as a sequence/structure motif, blocking ferritin translation. Recently, we and others independently described families with a combination of hyperferritinemia (serum L-ferritin > or = 1,000 microg/L, without iron overload) and congenital bilateral cataract, transmitted as an autosomal-dominant trait. The molecular basis were two distinct point mutations in the highly conserved CAGUG(X) hexaloop of L-ferritin IRE on chromosome 19. A new three-generation family with a similar phenotype and a unique genotype is here reported. DNA amplification by polymerase chain reaction and sequence analysis showed a 29-base pair deletion in the L-ferritin IRE, involving the whole 5' sequence essential to the base pairing of the IRE stem. This deletion is predicted to cause the disruption of IRE stem-loop secondary structure and the nearly complete abolition of the negative control of ferritin synthesis by IRE/IRP binding. Hereditary Hyperferritinemia-Cataract Syndrome (HHCS) appears as a new genetic disorder with a unique phenotype associated with at least four different mutations in the L-ferritin IRE. Hematologists should take into account HHCS in the differential diagnosis of unexplained hyperferritinemia.

Clinicopathologic correlation of localized retinal pigment epithelium debridement.

PURPOSE: To characterize changes in the retina, retinal pigment epithelium (RPE), and choriocapillaris with fluorescein angiography (FA) and histology after hydraulic or abrasive RPE debridement in 26 domestic short-haired cats. METHODS: Hydraulic debridement was produced by injecting balanced salt solution forcefully into the subretinal space. For abrasive debridement, RPE were removed with a silicone-tipped cannula after creating a localized retinal detachment. The FAs were performed after surgery, and tissue was prepared for light microscopy (LM) and scanning electron microscopy (SEM). RESULTS: Sixty-seven blebs were examined by FA 1 hour after surgery, and RPE debridement was confirmed by SEM or LM in 15 blebs from 10 animals. Hyperfluorescence and variable central fluorescein leakage were seen 1 week after surgery in 52 of 53 blebs (which includes all 27 blebs from the 1-week timepoint and 26 of 29 blebs from the 4-week timepoint that were studied by FA 1 week after surgery). Choriocapillary filling delays were seen in no hydraulic debridements, but in 11 of 14 abrasive blebs, especially in areas showing leakage late in the angiogram. In 1 of 13 hydraulic and 12 of 14 abrasive debridements, areas of late dye leakage had no RPE with outer retinal degeneration. At the 4-week timepoint, 1 of 17 hydraulic and 10 of 12 abrasive debridements had foci of delayed or absent choriocapillary perfusion by FA, with degenerated outer retina, no RPE, and choriocapillary atrophy by histologic analysis. CONCLUSIONS: Abrasive debridement is more commonly associated with abnormal FAs and with incomplete RPE repopulation, choriocapillaris atrophy, and outer retinal degeneration than is hydraulic debridement. This clinicopathologic study may give insight into FA interpretation after choroidal neovascular membrane removal in human patients.

Effect of inflammation on intraocular penetration of intravenous ofloxacin in albino rabbits.

The effect of inflammation on the intraocular penetration of ofloxacin was studied in 20 albino rabbits (New Zealand White). Inflammation was induced in the left eye by inoculation of a suspension of 10(9) CFU of heat-killed Staphyloccus epidermidis per 0.1 ml of saline solution (0.9%) in the midvitreous cavity. The other eye was kept as a control. Twenty-four hours following inoculation, ofloxacin was administered in the marginal ear vein at a dose of 15 mg/kg over 20 min with an infusion pump. Animals were sacrificed at different times up to 24 h following drug administration. Ofloxacin levels were determined in aqueous humor, vitreous humor, and serum by a bioassay. Inflammation was scored on the basis of perilimbal and corneal reactions and vitreoretinal statuses. Inflammation had a relevant effect on intraocular penetration of ofloxacin, with levels in the ocular fluids of the inflamed eye markedly exceeding the ones of the control eye. In the uninflamed eye, the levels were rapidly decaying below assay sensitivity and were no longer detectable at approximately 5 h following drug administration while they were still detectable in both ocular fluids of the inflamed eye at 24 h. Ofloxacin levels in the ocular fluids of the inflamed eye were superior to the MIC for several of the bacteria which commonly cause endophthalmitis, including Staphylococcus epidermidis, Staphylococcus aureus, most members of the family Enterobacteriaceae, Haemophilus influenzae, and strains of Pseudomonas aeruginosa.

[Do radiologists develop perceptual learning contrast sensitivity?]. / Esiste nei radiologi l'apprendimento percettivo nella sensibilità al contrasto?

A slight difference in brightness between objects close to each other and with no clear-cut outlines separating them can be recognized by the visual function called contrast sensitivity. This function is particularly developed in the radiologist, whose task is to analyze images in many shades of grey and with no clear-cut outlines, due to kinetic and radiogeometrical shading. Assuming that professional habit might develop this function, the authors compared contrast sensitivity in a group of 26 radiologists with contrast sensitivity in a control group (30 non-radiologists). The Vistech VTCS 6500 test was chosen for the task because of its practicality and reliability. The test consists in the recognition of the orientation of 5 series of alternate bright and dark lines differencing in thickness and contrast. The results obtained in the two groups were studied and compared with the statistical test of the analysis of variance, the T-test by Student and the U-test by Mann-Whitney. Contrast sensitivity was surprisingly higher in the radiologists group, in 4 of 5 series of images with bright and dark lines, than in controls and the difference was statistically significant: p < 0.001 with the test and the U-test. A deviation standard increase in contrast sensitivity was found also in radiologists with short-term professional activity (a few years). To explain these results, two hypotheses one suggested by the authors: radiologists pay greater attention to image details, because of their profession; perceptual learning--that is an improvement in the image-research cortical function--might occur, because of constant training. In the radiologist to conclude repeated stimulation of research capabilities in low-contrast images is thought to improve the efficiency of this cortical function.

Skin substitutes in the treatment of deep partial skin thickness burns in children: clinical experience and long-term results.

This report describes the use of skin substitutes in the treatment of deep partial skin thickness burns in childhood. These are lesions that, if treated inadequately, can result in severe scarring. However, if treated appropriately, they can heal without any sequelae, which is obviously crucial for aesthetic and psychological reasons. This review contains children admitted to the authors' Burn Unit over a 5-year period (1984-88) with deep partial skin thickness lesions which were treated with synthetic and/or biosynthetic skin substitutes and without surgical procedures. This group of children has been compared with another group hospitalized for burns of the same depth and treated with conventional closed wound management. First, short-term results are presented, highlighting healing time, followed by the long-term results from an aesthetic and functional viewpoint.

Hemiretinal differences in speed of light detection in esotropic amblyopes.

Nine esotropic amblyopes were tested monocularly in a simple reaction time (RT) paradigm with brief suprathreshold flashes of light presented at various eccentricities along the horizontal meridian of the nasal or temporal hemiretinae. All were clinically amblyopic in one eye only. RT was significantly longer in the amblyopic than in the other eye at 1, 5 and 10 deg but not at 25 and 35 deg from the fovea. Another clearcut finding concerned hemiretinal differences: in the non-amblyopic eye, as in control subjects, RT was faster in the nasal than in the temporal hemiretina and such a difference increased with the eccentricity of stimulus presentation. In the amblyopic eye, however, the only significant hemiretinal effect was at 10 deg with a temporal retina advantage and at 35 deg with a nasal retinal advantage. Furthermore, unlike in normal control subjects and the non-amblyopic eye of our esotropes, in the amblyopic eye there was no increase in RT with the eccentricity of stimulus presentation, except for the most peripheral visual field positions. It can be concluded that esotropic amblyopia affects the speed of suprathreshold light detection in the most central 10 deg of visual field and that the nasal hemiretina is clearly more impaired than the temporal hemiretina.

Injection therapy with triamcinolone hexacetonide in the treatment of burn scars in infancy: results of 44 cases.

In many cases deep second degree and third degree burns cause severe scarring. The authors have reported here their experience of the treatment of hypertrophic scarring from burns carried out on 44 children with intralesional injections of a long-acting cortico-steroid (Triamcinolone hexacetonide) using the jet spray technique.