Extramedullary hematopoiesis and paraplegia in a patient with hemoglobin e-Beta thalassemia.

Extramedullary hematopoiesis (EMH) occurs in patients with various hematologic disorders involving a chronic increase in the production of red blood cells, and is often associated polycythemia vera and sickle cell anaemia, but is less common with thalassemia especially with hemoglobin E-beta thalassemia. Spinal cord compression due to EMH is a extremely rare complication of thalassemia and may present with paraparesis or paraplegia with or without sensory impairment. Treatment options mostly include surgery and/or radiotherapy. Whereas cases presenting with paraplegia have been treated with either surgery or radiotherapy with equal frequency and efficacy, almost all reported cases with paraplegia have been treated with surgery with or without radiation therapy. We hereby report a case of hemoglobin E-beta thalassemia with paraplegia treated successfully with radiotherapy.

Entry site neovascularization and vitreous cavity hemorrhage after diabetic vitrectomy. The predictive value of inner sclerostomy site ultrasonography.

OBJECTIVE: To assess the incidence of neovascularization of the inner sclerostomy wound and occurrence of postoperative vitreous cavity hemorrhage (POVCH) after vitrectomy for proliferative diabetic retinopathy (PDR). DESIGN: Consecutive prospective longitudinal clinical study. PARTICIPANTS: Seventy-three eyes (58 patients) undergoing primary vitrectomy for PDR. METHODS: Twenty-megahertz (MHz) high-resolution anterior segment ultrasonography was performed on all sclerostomy sites 2 months postoperatively and repeated at the time of any POVCH. The appearance of the inner sclerostomy wound was divided into 4 classes (normal, spheroidal, tent, and trapezoidal, representing entry site neovascularization). The occurrence, degree, and duration of POVCH and need for revision surgery with vitreous cavity washout (VCW) were recorded. Postoperative vitreous cavity hemorrhage was divided into 3 groups-namely, mild, moderate, and major. MAIN OUTCOME MEASURES: Inner sclerostomy wound appearance on ultrasonography, degree and timing of POVCH, and need for VCW. RESULTS: There were 15 eyes in total with POVCH (20%): one patient had a persistent POVCH that required VCW. Fourteen other eyes (19%) had recurrent POVCH. Four (28%) of these 14 eyes with recurrent POVCH were classified as mild and 3 (21%) moderate: all cleared spontaneously with no further intervention needed. None of these had a trapezoidal image. Seven of the 14 eyes with recurrent POVCH were classified as major. Five of these 7 eyes had a trapezoidal image at 2 months postoperatively, and 4 required VCW (5.5% of total no. of eyes in study). All patients with a trapezoidal image experienced some degree of recurrent vitreous cavity hemorrhage (P = 0.0000024). The odds ratio was approximately 330:1. There was a significant correlation between the severity of POVCH and entry site appearance on ultrasound. In the first year of follow-up, all patients requiring VCW after recurrent POVCH had a trapezoidal image present at 2 months postoperatively (P = 0.009). CONCLUSION: The appearance of a trapezoidal image on 20-MHz high-resolution anterior segment ultrasonography at a sclerostomy site after vitrectomy for PDR was highly correlated with the occurrence of nonclearing POVCH and need for VCW. Conversely, the absence of a trapezoidal image in patients with POVCH was associated with spontaneous hemorrhage clearance.

Predicting macular hole closure with ocriplasmin based on spectral domain optical coherence tomography.

PurposeTo assess the preoperative features of patients with idiopathic macular hole (IMH) and vitreomacular adhesion (VMA) treated with ocriplasmin (OCP) that can predict successful closure.MethodData were prospectively collected on all patients with IMH treated with OCP in three British ophthalmic centres. Several preoperative variables were recorded including the IMH base diameter (BD), minimum linear diameter (MLD), and VMA width measured on spectral domain optical coherence tomography. Several other IMH indices were derived including a 'width factor', defined as the BD minus the MLD in µm. The occurrence of VMA release and hole closure were used as the main outcome measures.ResultsThirty-three patients in total with IMH were treated with OCP. Two patients developed rhegmatogenous retinal detachment and were excluded. The mean age of the remaining 31 patients was 71 years, and 71% were female. VMA release occurred in 19 of the 31 (61%) patients and macular hole closure in 11 (35%). Width factor was the most predictive feature for closure on multivariate analysis. The deviance R(2) was 67% (P<0.001). An IMH with a width factor of <60 µm had a 95% certainty of closure, whereas if >290 µm then there was less than a 5% chance of closure. Neither VMA width nor MLD alone was associated with VMA release or closure.ConclusionsPatients with macular holes where the BD was close in size to the MLD had an improved probability of closure than holes with wider base configurations.

The role of case mix in the relation of volume and outcome in phacoemulsification.

BACKGROUND/AIM: The authors previously demonstrated a decrease in complication rate with an increase in volume of cases performed by a surgeon. All studies of volume and outcome are potentially hampered by the issue of case mix, in that some lower volume surgeons may in fact do fewer cases because they have more complex patients. This study was designed to assess the influence of case mix on the volume-outcome relation in phacoemulsification surgery that had previously been demonstrated. METHODS: This study took place wholly in Sunderland Eye Infirmary. 667 cases from between 1996 and 2001 were randomly selected from the operative lists of the six surgeons involved in a previous study. The case complexity was assessed using a potential difficulty score (PDS) devised from preoperative data predictive of potential surgical difficulty. The PDS was validated by a retrospective analysis of a sample of 100 cases. RESULTS: 528 complete sets of notes were retrieved. The overall PDS scores ranged from 1 to 6. There was a difference between the proportions of patients with each PDS value (p=0.015) in the two groups, which suggested that the low volume surgeons were doing potentially more difficult cases. The median PDS for each volume group were the same (=1.0). Retrospective validation analysis of the PDS score revealed higher mean and median values in complicated cases compared to uncomplicated cases. CONCLUSION: This follow up study re-emphasises the importance of case mix adjustment in comparative assessment of healthcare quality. These results may explain in part the trend previously demonstrated of lower complication rates for higher volume surgeons.

Myopic intrastromal photorefractive keratectomy with the neodymium-yttrium lithium fluoride picosecond laser in the cat cornea.

OBJECTIVE: To evaluate the refractive effects of myopic intrastromal photorefractive keratectomy (IPRK) with the neodymium-yttrium lithium fluoride (Nd-YLF) picosecond laser. METHODS: A 1053-nm Nd-YLF picosecond laser was used to produce myopic IPRK in cat corneas at threshold energy densities. Preoperative corneal topography and ultrasonic pachymetry were performed followed by IPRK in one eye each of 21 cats. No anti-inflammatory medications were administered. Postoperative corneal topography, ultrasonic pachymetry, and slit-lamp examination were performed at scheduled intervals. RESULTS: An average topographic flattening of 11.4 diopters and pachymetric thinning of 50 microns at the center of the treatment zone were observed by 6 weeks following treatment. The average diameter of the zone of flattening was 5.1 mm at 6 weeks and 6.0 mm at 12 weeks postoperatively. At 6 months postoperatively, the average central corneal power was unchanged, while the average central thickness had returned to the preoperative value. A mild subepithelial haze was detected at 1 month following IPRK, which was barely perceptible at the second through sixth months. Regression of the topographic effects of PRK was not observed. CONCLUSION: Intrastromal PRK with the Nd-YLF picosecond laser produces central flattening of the cat cornea with barely perceptible stromal haze and no regression of topographic effect after 6 months in the absence of treatment with anti-inflammatory agents.

Wound healing following intrastromal photorefractive keratectomy with the Nd:YLF picosecond laser in the cat.

BACKGROUND: We studied the histopathology of the stromal wound healing response in the cat cornea following intrastromal photorefractive keratectomy (IPRK) with the Nd:YLF picosecond laser. METHODS: Intrastromal PRK was performed in the anterior stroma of cat corneas with the Nd:YLF picosecond laser. The cats were sacrificed at predetermined intervals ranging from immediately to 6 months postoperatively. Effects of the laser treatment on the epithelium, Bowman's layer, stroma, and the endothelium were evaluated using light and scanning electron microscopy. No anti-inflammatory agents were used. RESULTS: Intrastromal PRK resulted in no perceptible damage to the corneal epithelium or Bowman's layer either acutely or at 6 months. The corneal stroma showed multiple cavitations immediately after intrastromal PRK, which collapsed over several hours, followed by thinning of the cornea over 2 weeks. At 1 month, the stromal collagen was abnormal with surrounding hypercellularity. The endothelium showed no injury, acutely or at 6 months. No thermal effects on stromal collagen were observed at 6 months, and disruption of the lamellar pattern was not apparent after the cavitation bubbles were reabsorbed. CONCLUSION: Intrastromal PRK can effectively remove stromal tissue without acute damage to the adjacent lamellae, epithelium, or endothelium. There is a transient cellular wound healing response associated with a transient stromal collagen abnormality at 2 weeks to 1 month, which was not apparent 2 months after the procedure.

Ultrasound biomicroscopy of intrastromal photorefractive keratectomy with the Nd:YLF picosecond laser.

PURPOSE: To evaluate corneal morphology in vivo following intrastromal photorefractive keratectomy (IPRK) with the Nd:YLF picosecond laser, using the ultrasound biomicroscope. MATERIALS AND METHODS: Myopic intrastromal PRK was performed in the anterior stroma of cat corneas with the neodymium:yttrium lithium fluoride (Nd:YLF) picosecond laser. Periodic examination of the treated corneas up to 6 months postoperative was performed with high resolution ultrasound biomicroscopy. Corneal thickness, depth of the laser patterns from the corneal surface, alignment of the laser treatment, extent of stromal opacification until resolution, and contour of the corneal surface were measured with the ultrasound biomicroscope throughout follow up. RESULTS: The treated corneas were thickened on ultrasonic biomicroscopy measurement immediately after intrastromal PRK and revealed a densely echogenic shadow parallel to the corneal surface at the treatment site. There was increased stromal echogenicity denoting mild edema. The echoes decreased over time and appeared thinner at 2 months compared to the preoperative and immediate postoperative measurements. At 6-month follow up, the treated corneas were echolucent on ultrasonic biomicroscopy. CONCLUSION: The ultrasound biomicroscope might become a helpful tool in assessing accuracy of treatment parameters of intrastromal PRK as well as in monitoring the response of the cornea to treatment.

Mass spectrometry analysis of the by-products of intrastromal photorefractive keratectomy.

BACKGROUND AND OBJECTIVE: To determine the nature and chemical composition of the cavitation bubbles generated by intrastromal photorefractive keratectomy (IPRK) with the Neodymium: Yttrium Lithium Fluoride (Nd:YLF) picosecond laser. MATERIALS AND METHODS: IPRK was performed on the corneas of three fresh human cadaver eyes with the Nd:YLF picosecond laser. High energy levels of 200 mJ/pulse to 300 mJ/pulse were used to produce the maximum amount of gas within the corneal stroma. The cavitation bubbles produced in the stroma were aspirated using a gas-tight syringe connected to a valve, and the specimens were analyzed with a mass spectrometer. RESULTS: The experiment was performed on three different occasions using one cadaver eye in each experiment. The analysis consistently revealed a mixture of carbon dioxide, carbon monoxide, water vapor, oxygen, and nitrogen. Atmospheric control samples also revealed oxygen and nitrogen. No other components were detected. CONCLUSION: The gaseous by-products of IPRK with the picosecond laser result from the simple breakdown of stromal tissue and contain no toxic or unexpected components. We found that these gaseous products are capable of rapid elimination by absorption or diffusion out of the intact cornea.

Entry site treatment to prevent late recurrent postoperative vitreous cavity haemorrhage after vitrectomy for proliferative diabetic retinopathy.

AIMS: To assess the effectiveness of treatment to the inner sclerostomy sites at the time of vitrectomy for proliferative diabetic retinopathy (PDR) in reducing the incidence of late recurrent postoperative vitreous cavity haemorrhage (POVCH). METHOD: Retrospective study of a consecutive series of 82 eyes undergoing vitrectomy for PDR by a single surgeon treated with either cryotherapy or argon laser directly to the inner sclerostomy site at the completion of surgery (treatment group). These were compared with a previous consecutive series of 82 eyes operated on by the same surgeon who did not have inner sclerostomy site treatment (control group). The occurrence of any POVCH was recorded within the first 6 months of surgery. RESULTS: The composition of the two groups was similar in terms of age, indication for surgery and a variety of other preoperative factors. There were 64 patients in the control group and 65 in the treatment group. There was a significant reduction in the incidence of late recurrent POVCH in the treatment group. Late recurrent POVCH occurred in 12 (15%) eyes in the control group compared with five (6%) in the treatment group (p=0.03). The number of eyes requiring revision surgery within the first 6 months for late recurrent POVCH was four (5%) in the control group and two (2.5%) in the treatment group (p=0.31). CONCLUSION: This study suggests that inner sclerostomy site treatment is effective in reducing the occurrence of recurrent late POVCH in patients undergoing vitrectomy for PDR. A randomised controlled study is needed to clarify this.