Andrea Lembo

En Face Optical Coherence Tomography and Optical Coherence Tomography Angiography of Multiple Evanescent White Dot Syndrome : New Insights Into Pathogenesis

Purpose: To localize the various levels of abnormalities in multiple evanescent white dot syndrome by comparing “en face” optical coherence tomography (OCT) and OCT angiography with various conventional imaging modalities. Methods: In this retrospective case series, multimodal imaging was performed in 9 retinal centers on 36 patients with multiple evanescent white dot syndrome and included widefield fundus autofluorescence (FAF), fluorescein angiography (FA), and indocyanine green angiography, and B-scan and “en face” C-scan enhanced depth imaging and spectral domain OCT. Optical coherence tomography angiography was also performed at the level of the superficial and deep retinal capillary plexus and choroid. Results: Multiple evanescent white dot syndrome lesions were more numerous and more easily detectable with FA and FAF. Two types of lesions were identified with FAF, FA, and indocyanine green angiography: larger widely scattered “spots” (approximately 200 &mgr; in diameter) that were hyperfluorescent with FA, hyperautofluorescent with FAF, and hyporeflective in indocyanine green angiography, representing abnormalities primarily at the retinal pigment epithelium/photoreceptor junction; and punctate “dots” (less than 100 &mgr; in diameter) that were hyperfluorescent with FA, hyperautofluorescent, or isoautofluorescent with FAF, and hypofluorescent with indocyanine green angiography and that localized to the outer nuclear layer. These lesions colocalized with “en face” OCT. The larger confluent “spots” were hyporeflective and colocalized to the level of the ellipsoid zone, whereas smaller hyperreflective “dots” colocalized to the outer nuclear layer. The location of the “dots” in the outer nuclear layer was further confirmed by structural spectral domain optical coherence tomography which showed coalescence of the dots into hyperreflective lines extending from the external limiting membrane to the outer plexiform layer in certain cases. Optical coherence tomography angiography analysis of the retinal microvasculature and choriocapillaris and choroid were entirely unremarkable in 100% of our patients. Conclusion: By combining multimodal imaging, the authors propose that multiple evanescent white dot syndrome is primarily the result of inflammation at the outer photoreceptor level leading to a “photoreceptoritis” and causing loss of the inner and outer segments. Its evanescent nature suggests that the photoreceptor cell bodies remain intact ensuring complete recovery of the photoreceptor inner and outer segments in most cases, compatible with the clinical course of spontaneous resolution of white spots and dots.

Genetics of Congenital Cataract

Congenital cataract is a type of cataract that presents at birth or during early childhood, and it is one of the most easily treatable causes of visual impairment and blindness during infancy, with an estimated prevalence of 1-6 cases per 10,000 live births. Approximately 50% of all congenital cataract cases may have a genetic cause, and such cases are quite heterogeneous. Although congenital nuclear cataract can be caused by multiple factors, genetic mutation remains the most common cause. All three types of Mendelian inheritance have been reported for cataract; however, autosomal dominant transmission seems to be the most frequent. The transparency and high refractive index of the lens are achieved by the precise architecture of fiber cells and homeostasis of the lens proteins in terms of their concentrations, stabilities, and supramolecular organization. Research on hereditary congenital cataract has led to the identification of several classes of candidate genes that encode proteins such crystallins, lens-specific connexins, aquaporin, cytoskeletal structural proteins, and developmental regulators. In this review, we highlight the identified genetic mutations that account for congenital nuclear cataract.

Perivenular Whitening in Central Vein Occlusion Described by Fundus Autofluorescence and Spectral Domain Optical Coherence Tomography

In the retinal tissue, transparency is a clinical index of tissue oxygenation. With central retinal vein occlusion, the most sensitive tissue for manifesting decreased oxygenation will be perivenular, especially in the posterior pole, where oxygen use is higher than in the retinal periphery. Patchy ischemic retinal whitening is located preferentially in a perivenular distribution near the macula. A 40-year-old man came to our institution complaining of loss of vision in the right eye, which had started 2 days previously. His medical and ophthalmologic histories were unremarkable. Initial examination in our department showed visual acuity of 20/32, right eye, and 20/20, left eye. Fundus examination showed dilated veins and scattered hemorrhages, along with a whitening of the macula (Figure 1A, white arrow) and of the perivenular retinal (Figure 1A, black arrow), and fluorescein angiogram showed delayed transit during the venous phase, but no capillary closure or blood retinal barrier rupture (Figure 1B), thus confirming the diagnosis of a mild form of central retinal vein occlusion with thrombus located more posteriorly relative to the lamina cribrosa. Autofluorescence imaging revealed a normal fundus autofluorescence corresponding to the arterioles and patchy hypoautofluorescence located preferentially in a perivenular distribution near the macula because of blockage of autofluorescence from inner retinal edema, which on spectral domain optical coherence tomographic scans corresponded to patchy retinal opacification extended from the inner to the outer plexiform layers (Figure 2, A and B) that may be secondary to ischemia of intermediary neurons within the inner nuclear and inner plexiform layers. One month later, autofluorescence and spectral domain optical coherence tomography showed improvement of symptoms (Figure 3, A and B) and visual acuity of 20/20. We report the presence of perivenular retinal edema in a patient with recent-onset central retinal vein occlusion, best visualized by autofluorescence as a hypoautofluorescent fern-like appearance. The perivenular location of ischemic edema is because of decreased arterial flow that leads to preferential oxygenation of the periarterial retina, which uptakes the available oxygen and subsequently desaturates hemoglobin before it can reach the perivenular space.

Combination Therapy With Dexamethasone Intravitreal Implant and Macular Grid Laser in Patients With Branch Retinal Vein Occlusion

PURPOSE To test a combination of dexamethasone intravitreal implant with macular grid laser for macular edema in patients with branch retinal vein occlusion (BRVO). DESIGN Prospective interventional, randomized, multicenter study. METHODS Patients with macular edema secondary to BRVO underwent an Ozurdex intravitreal implant at baseline. After 1 month, patients were randomly assigned to 2 study groups. Patients in Group 1 were followed up monthly and retreated with Ozurdex implant whenever there was a recurrence of macular edema or a decrease in best-corrected visual acuity (BCVA). In Group 2 patients macular grid laser was performed between weeks 6 and 8. After that, patients were followed up and retreated as for Group 1. RESULTS In Group 1 at 4 months, mean BCVA was 0.49 ± 0.35 logMAR and central retinal thickness (CRT) was 391 ± 172 μm; both improved significantly at 6 months, to 0.32 ± 0.29 logMAR and 322 ± 160 μm, respectively. In Group 2, CRT was reduced significantly to 291 ± 76 μm at 4 months, and BCVA improved to 0.25 ± 0.20 logMAR. At the final visit, BCVA was 0.18 ± 0.14 logMAR and mean CRT was 271 ± 44 μm. The number of Ozurdex implants at 4 months was 12 of 25 (48%) in Group 1 patients vs 3 of 25 (12%) in Group 2 patients (P = .012). At 6 months 3 of 25 patients (12%) in Group 1 vs 0 of 25 (0%) in Group 2 (P = .23) were retreated. CONCLUSIONS The combination of Ozurdex implant and macular grid laser is synergistic in increasing BCVA and lengthening the time between injections.

Retractor plication versus retractor plication and lateral tarsal strip for eyelid entropion correction

Purpose: Involutional entropion is a common lower lid malposition. Addressing both the horizontal and the vertical lower eyelid laxity in patients with involutional entropion seems to have a more long-lasting effect on maintaining lower eyelid stability; however, there is some disagreement as to which approach is the best surgical intervention. The aim of this study was to determine differences in the surgical outcome of Jones retractor plication (JRP) alone versus Jones retractor plication with a lateral tarsal strip (JRP + LTS) for the treatment of involutional entropion. Methods: A retrospective case series comparison of 118 patients with primary involutional lower eyelid entropion was performed. Jones retractor plication alone was performed in 61 patients, and JRP + LTS in 57 patients. The baseline characteristics of the 2 groups were similar. Patients were retrospectively evaluated from a retrospective case-note review 3 weeks and 6, 12, 18, and 24 months postoperatively. Successful surgery was defined as a normal eyelid position. Results: A total of 115 patients fulfilled the inclusion criteria, 60 in the JRP group and 55 in the JRP + LTS group. Ten patients (16.5%) in the JRP group and 2 patients (3.5%) in the JRP + LTS group had a recurrence of the entropion at or before their 24-month follow-up visit (p = 0.03). Conclusions: These data provide strong evidence that the success rate at 24 months is higher in patients treated with the JRP + LTS procedure compared with JRP alone.

Standard Enucleation with Aluminium Oxide Implant (Bioceramic) Covered with Patient's Sclera

Purpose. We describe in our study a modified standard enucleation, using sclera harvested from the enucleated eye to cover the prosthesis in order to insert a large porous implant and to reduce postoperative complication rates in a phthisis globe. Methods. We perform initially a standard enucleation. The porous implant (Bioceramic) is then covered only partially by the patients sclera. The implant is inserted in the posterior Tenons space with the scleral covering looking at front. All patients were followed at least for twelve months (average followup 16 months). Results. We performed nineteen primary procedures (19 patients, 19 eyes, x M; x F) and secondary, to fill the orbital cavity in patients already operated by standard evisceration (7 patients, 7 eyes). There were no cases of implant extrusion. The orbital volume was well reintegrated. Conclusion. Our procedure was safe and effective. All patients had a good cosmetic result after final prosthetic fitting and we also achieved good prothesis mobility.

A Prospective Study Evaluating IOP Changes after Switching from a Therapy with Prostaglandin Eye Drops Containing Preservatives to Nonpreserved Tafluprost in Glaucoma Patients

Purpose. To compare the ocular hypotensive effect of tafluprost with prostaglandin analogues (PGAs) in glaucoma patients. Methods. 89 primary open-angle glaucoma patients treated with bimatoprost, latanoprost, or travoprost for at least 3 months complaining for ocular discomfort were switched to tafluprost. IOP was assessed at baseline and 3 months after switching the therapy by daily curve. Primary outcome was to compare the mean daily IOP of tafluprost with PGAs. Results. The mean daily IOP was 16 ± 2.1 and 16.6 ± 2.0 mm Hg at baseline and after switching to tafluprost, respectively (P > 0.05). When analysis was carried out between tafluprost and each previous PGAs, the comparison between latanoprost and tafluprost and travoprost and tafluprost did not show any statistically significant difference in mean daily IOP and at each time point. The comparison between bimatoprost and tafluprost showed a statistically significant difference in mean daily IOP (P < 0.05) and at each time point (P < 0.05). Conclusions. After 3 months of switching tafluprost showed an overall IOP lowering effect similar to others PGAs. When each PGA was compared with tafluprost, bimatoprost showed to provide a statistically significant additional IOP lowering effect.

Short-term changes in intraocular pressure after phacoemulsification in glaucoma patients.

Purpose: To evaluate short-term intraocular pressure (IOP) changes after phacoemulsification in glaucoma and normal patients and the effect of oral acetazolamide (Diamox) to control IOP in these patients. Methods: 120 patients undergoing cataract surgery were included in this prospective multicenter study involving 6 University Eye Clinics: 60 patients with well-controlled primary open-angle glaucoma (POAG) and 60 controls. Half of the study participants received oral acetazolamide, 250 mg, 1 and 6 h after surgery. The treated and untreated groups were matched for age and density of cataract. All patients underwent a standard phacoemulsification procedure and were checked for IOP with Goldmann tonometry in the morning before surgery and then at 3, 6, 21 and 24 h postoperatively by a masked evaluator. Results: The group with POAG showed a significant postsurgical increase in IOP (p < 0.001) at all time points. Six of thirty (20%) untreated POAG patients showed at least 1 IOP reading above 30 mm Hg whereas acetazolamide significantly reduced postoperative IOP at all time points (p < 0.01) and in no case was IOP >30 mm Hg. The control group had high IOP during the first 6 h (p < 0.01), but normal values thereafter. Conclusion: A significant short-term IOP increase may be found after phacoemulsification both in POAG and normal patients; this is not dangerous in normal subjects, but can be potentially dangerous in POAG patients. The use of systemic acetazolamide provided significant control of IOP and could be considered a ‘possible standard’ management of cataract surgery in POAG patients.

Double-vitrectomy for optic disc pit maculopathy.

Background: The origin of the fluid and precise pathophysiology of optic pit maculopathy remain unclear. It has been suggested that submacular fluid originates either from vitreous or cerebrospinal fluid. We report a case of optic pit maculopathy which was unsuccessfully treated with vitrectomy and internal limiting membrane (ILM) peeling, and subsequently resolved with revision of vitrectomy and gas tamponade. Methods: We report a case of optic disc pit maculopathy, well documented by spectral- domain optical coherence tomography, before and after pars plana vitrectomy with ILM peeling, and its revision with gas tamponade. Results: After ILM peeling, there was no improvement either in visual acuity or in the tomographic aspect of the retina. A revision of the surgery was then needed and gas tamponade was performed, which resulted in a complete resolution of the optic pit maculopathy. Conclusion: The absence of improvement after ILM peeling during the first surgical procedure, accompanied by resolution of the clinical picture with gas tamponade during the second surgical procedure, sustained the hypothesis of a subarachnoidal origin of the fluid.

Bilateral retinoblastoma: clinical presentation, management and treatment

Management of retinoblastoma (Rb), the most common intraocular malignant tumor in childhood, is tailored to each individual case and based on the overall situation. We present a case of bilateral Rbs in a 4-month-old girl, referred to our center for bilateral leukocoria. In the right eye, the optic disc was partially visible, and three large foci of retinoblastoma were noted adjective in the vitreous cavity with satellite retinal detachment. The macula was obscured by the tumors. The tumor was therefore classified as group D (International classification of retinoblastoma), and thus underwent intravenous chemotherapy with the standard three-agent protocol of ifosfamide, carboplatin and etoposide (ICE protocol) delivered monthly for six cycles, regressing with a type I calcified pattern. The left eye presented three multifocal yellow-white retinal masses, with a total retinal detachment, and secondary glaucoma. The lesions were classified as group E and, therefore, taking the results obtained by Shields et al. in group E tumors into consideration, underwent enucleation. This case clearly shows that this cancer is curable if detected at a stage in which it is still contained within the retina, subretinal space or vitreous, and that the management of Rb relies on an experienced team of ocular oncologists, pediatricians and pediatric ophthalmologists working together for the single goal of saving the child’s life.