Jose Luis Vallejo-Garcia

Macular Hypotrophy After Internal Limiting Membrane Removal For Diabetic Macular Edema

Purpose: To compare the anatomic and functional effects of three different approaches to nontractional diabetic macular edema. Methods: Retrospective comparative study. Sixty eyes of 60 patients diagnosed with cystoid diabetic macular edema and treated with 1.25 mg/mL intravitreal bevacizumab (Group A), laser photocoagulation (Group B), or vitrectomy with inner limiting membrane peeling (Group C) were included in the study. Changes in number of Early Treatment Diabetic Retinopathy Study letters, central macular thickness, largest diameter of the intraretinal cysts (IC), and choroidal thickness were investigated. Analyses were performed during follow-up visits at Months 1, 3, 6, 9, and 12. Results: Visual acuity only significantly improved in Group A at the last follow-up (P = 0.004). Central macular thickness significantly decreased in every group throughout the follow-up period. Differences in central macular thickness between Groups A and B (P < 0.01), A and C (P < 0.01), and B and C (P < 0.01) were significant. Intraretinal cysts also significantly decreased in each group throughout the follow-up period. Differences in IC size between Groups A and B (P = 0.8), A and C (P = 0.1), and B and C (P = 0.1) were not significant. Choroidal thickness did not undergo any significant change in any group throughout the follow-up period. A significant correlation was also found in Group A between best-corrected visual acuity at month 12 and baseline central macular thickness (R = 0.3; P = 0.006), and in Group B between postoperative best-corrected visual acuity at month 12 and baseline IC size (R = 0.8; P < 0.01, negatively correlated at 92.4%). Conclusion: According to our retrospective data, diabetic macular edema with intraretinal cysts larger than 390 &mgr;m should not be treated with vitrectomy with ILM peeling, because this may induce subfoveal atrophy, defined as the “Floor Effect,” and subsequent visual deterioration.

Role of Inflammation in Endophthalmitis

Inflammation originating from infection of the vitreous cavity is called endophthalmitis. Attention has been focused on the epidemiologic, microbiologic reports, and treatment options; unfortunately, the role of the host immune reaction in the visual function damage is still not well understood. Endophthalmitis occurs most frequently after cataract surgery. In this paper we review the published literature regarding inflammatory mediators and apoptosis during the course of endophthalmitis. Toll-like receptors, cytokines, high-mobility group box 1 proteins, aB-crystallin and apoptosis have been studied during clinical and experimental cases of endophthalmitis. Further understanding of the host-immune reaction to vitreous infection is essential for the development of new therapies. The use of intravitreal antibiotics and corticosteroids, vitrectomy and systemic antibiotics for the preservation of visual function is still discouraging.

Interaction between perfluorcarbon liquid and heavy silicone oil: risk factor for "sticky oil" formation.

Purpose: To investigate in vitro the interaction between perfluorcarbon liquids (PFCLs) and heavy silicone oils (HSOs). Methods: Interactions between different kinds of PFCL [perfluoro-n-octane (PFO) or perfluorodecaline (PFD)] and HSO (either alkane or ether) were studied in vitro by incubating fluids for 7 days at regulated temperatures. The samples were divided into two groups: Group A, PFCL (PFO or PFD) + 5 ml of HSO (silicone oil + alkane or ether) and Group B, HSO (silicone oil + alkane or ether) without PFCL. Each sample was kept at 36°C for 7 days. HSOs were then removed with a 20 g, 7 mm-long cannula under 600 mm Hg of vacuum pressure at two different temperatures: 36 and 22°C. The time needed to remove the oils and the presence of opacity was recorded. Each experiment was repeated three times. Results: In vitro, interactions between PFCL and HSO oil led to the formation of hyper-viscous solutions with significative increase in aspiration time in Group A. (P = 0.006, Kruskal–Wallis test) Temperature was also found to affect HSOs’ saturation, as a decrease in temperature determined an increase in opacity and shear viscosity of the solution (P = 0.02, Kruskal–Wallis test). No differences between alkane and ether (P = 0.74) and n-octane and decaline (P = 0.56) was found. Conclusion: Interactions between PFCL–HSO and variation in temperature lead to the formation of hyper-viscous solutions that could be described as “sticky oil”.

Vitreo-papillary adhesion as a prognostic factor in pseudo- and lamellar macular holes

PurposeTo determine the incidence of vitreopapillary adhesion (VPA) and to investigate its value as a prognostic factor in the surgical outcome of pseudo- (PMH) and lamellar macular holes (LMH).MethodsA total of 76 consecutive patients, diagnosed with PMH (41 eyes) or LMH (35 eyes) were included. Eyes with VPA were alternatively assigned to the surgical or control group. Surgery consisted of a 25G vitrectomy and internal limiting membrane peeling with blue dye staining. There were six visits: baseline, the day of surgery, and 1, 3, 6, and 9 post-operative months. Main outcome measures were the incidence of VPA and changes in the outer retinal layers and visual acuity.ResultsVPA was found in 27% (11/41) of patients with PMH and 37% (13/35) with LMH (P=0.03). In presence of VPA, the best-corrected visual acuity (BCVA) improved in the surgery group from 32±8 to 47±8 letters, whereas the control group went from 34±7 to 31±8 letters. The difference in letters between the surgery and control groups was statistically significant for both distance (P=0.032) and near (P=0.04) vision. Intra-retinal cysts were significantly correlated with a poor functional prognosis (P=0.01). We found the presence of focal damage to the outer retinal layers in LMH and PMH.ConclusionVPA is more frequent in the presence of LMH vsPMH. It significantly influences the tangential forces at the vitreoretinal interface, exacerbating anatomical changes, and worsening the functional prognosis. Functional difference between the surgical and control groups was statistically significant for distant and near vision in presence of VPA.

Thermodynamics of Vitreoretinal Surgery

ABSTRACT Purpose: To report in vivo the temperature variations occurring continuously inside the human eye during vitreoretinal surgery. Methods: Intraocular temperature was monitored during the entire surgical time in 14 eyes of 14 patients undergoing pars plana vitrectomy. A custom made 23-gauge thermoprobe was inserted through a sclerotomy at 3.5 mm from the limbus. Temperature in the anterior chamber and on the retinal surface was measured at one time point, whilst the temperature in the vitreous cavity was monitored throughout the entire surgery. Time points of particular interest in the vitreous cavity were: at baseline (inflow off – outflow off), at the beginning of the vitrectomy (inflow off – outflow on), at the end of vitrectomy (inflow on – outflow on), during the epiretinal procedures (inflow on – outflow off), under air infusion, under oil and under endolaser treatment ongoing. Results: The mean temperature in the anterior chamber and on the nasal retinal side was 23.6°C (SD 1.8)and 32.3°C (SD 1.1), respectively. The mean vitreous temperature at baseline, before opening the infusion, was 33.6°C (SD 1.4). The mean temperature at the beginning and the end of the vitrectomy was 26.8°C (SD 1.0) and 24.8°C (SD 0.8), respectively. During the epiretinal procedures, the mean temperature was 27.4°C (SD 0.7). Under air infusion, the mean temperature increased to 29.2°C (SD 1.2). The fluctuations in temperature were statistically different between the time points during the vitrectomy (p < 0.001). Conclusion: Vitreoretinal surgery induces measurable changes in temperature in the human eye, with significant fluctuations. In particular, the temperature in the vitreous cavity decreases when both the inflow and the outflow fluid lines are open, whilst it increases under air infusion.

Vitrectomy for primary symptomatic vitreous opacities: an evidence-based review.

Floaters are a common ocular condition which form as a consequence of aging changes in the vitreous. Although in most patients the symptoms are minimal, they can cause significant impairment in vision-related quality of life in a small population of patients. Recently there has been an increase in awareness of the visual disability caused by floaters, and the evidence-base for treatment of this condition using small-gauge vitrectomy has increased. In this review, we define the term ‘floaters’ as symptomatic vitreous opacities (SVO). We suggest a classification dependent on the presence or absence of posterior vitreous detachment and discuss their pathogenesis and natural history. We review their impact on patients’ quality of life related to visual function. We review the psychological factors that may have a role in some patients who appear to be affected by SVO to the extent that they pursue all options including surgery with all its attendant risks. We summarise the available evidence-base of treatment options available for SVO with special emphasis on the safety and efficacy of vitrectomy for this condition.

Complications of macular peeling

Macular peeling refers to the surgical technique for the removal of preretinal tissue or the internal limiting membrane (ILM) in the macula for several retinal disorders, ranging from epiretinal membranes (primary or secondary to diabetic retinopathy, retinal detachment…) to full-thickness macular holes, macular edema, foveal retinoschisis, and others. The technique has evolved in the last two decades, and the different instrumentations and adjuncts have progressively advanced turning into a safer, easier, and more useful tool for the vitreoretinal surgeon. Here, we describe the main milestones of macular peeling, drawing attention to its associated complications.

Vitreous diagnosis in neoplastic diseases

Vitreous body is an intraocular structure, origin of diverse pathologies, but is also the place where cells and inflammatory mediators are released coming from several pathologic processes. These inflammatory reactions can happen in any other ocular location like choroid, retina, optic nerve, or ciliary body and vitreous humor constitutes a stagnant reservoir for these resulting substances and debris. Through the recent techniques of vitreous collecting, handling, and analysis, increasingly more sophisticated and with fewer complications, cellularity and molecules in the vitreous of challenging pathologies for the ophthalmologist can now be studied. The most usefulness for vitreous diagnosis would be the masquerade syndromes, and the best exponent in this group is the primary vitreoretinal lymphoma (PVRL), in which cytology and an IL-10/IL-6 ratio more than 1 is fundamental for the diagnosis.

External subretinal drainage, bevacizumab, and scleral buckling for complete exudative retinal detachment after photocoagulation in retinopathy of prematurity.

BACKGROUND Total serous retinal detachment after laser photocoagulation for retinopathy of prematurity is an infrequent type of retinal detachment in preterm babies. PURPOSE To describe the successful outcome for treatment by scleral drainage, bevacizumab, and scleral buckling for complete serous exudative retinal detachment in a patient with retinopathy of prematurity. METHODS A preterm baby with primary pulmonary hypertension under treatment with sildenafil developed a total (retrolental) serous retinal detachment after photocoagulation for threshold retinopathy. The dense subretinal fluid was externally drained using a bent needle with an infusion placed in the anterior chamber. Additional bevacizumab and scleral buckling helped to control the plus disease and subretinal leakage. RESULTS Retinal apposition was obtained with the described approach. CONCLUSION Total serous retinal detachment is a rare but severe visual complication in retinopathy of prematurity. The described technique may restore the retinae immediately in a visually critical period.

Pneumatic tools for vitreoretinal surgery

One of the difficulties of microsurgery is learning how to control physiological tremors. The pneumatic tool eliminates the physiological tremor, but no tactile feedback is provided. The manual tremor when closing the forceps is completely eliminated and the exact target can be more easily grabbed. Forceps closure pressure can rise up to 50 psi, whereas the scissors can be used in two modes: multicut and proportional. When performing bimanual surgery the pedal range is divided into two steps: in the first step, the forceps are controlled, and in the second step, the forceps remain closed. At the same time the scissors start to work in the preselected mode. No adverse events occurred and no iatrogenic retinal breaks were produced. Precision and control sensation were a grateful surprise.