Rupal Morjaria

Pharmacokinetic evaluation of pegaptanib octasodium for the treatment of diabetic edema

Introduction: Diabetic macular edema (DME) is a leading cause of visual impairment in patients with diabetic retinopathy. Pegaptanib octasodium (Macugen) was the first anti-VEGF agent approved for the treatment of neovascular age-related macular degeneration. It is a selective anti-VEGF agent, which only blocks VEGF. It has been shown to be safe and effective in treatment of DME in randomized controlled trials and it may be a safer first-line treatment in patients with diabetes with a predisposition to cardiovascular risk factors. Areas covered: This review covers the pharmacokinetics of pegaptanib octasodium. The authors also evaluate pegaptanib octasodium’s clinical efficacy, safety and tolerability in DME. Expert opinion: DME is the most common cause of visual loss in patients with diabetes. Pegaptanib has been found to be more effective than laser therapy alone for center-involving DME, its efficacy might be slightly worse than other pan-VEGF blockers, but the number of patients that have significant improvement of vision after treatment are similar to those treated with pan-VEGF blockers. As a selective VEGF blocker, it may have a better ocular and systemic safety profile than pan-VEGF blocking agents. It is reasonable to consider pegaptanib as the first-line treatment for center-involving DME with pan-VEGF blockers reserved for non-responders.

Structural–functional Correlation In Patients With Diabetic Macular Edema

Background/Purpose: Previous studies have shown that patients with diabetic macular edema (DME) with relatively good visual acuity can have slow reading speed. The aim of this study was to evaluate the structural–functional correlation in a cohort of patients with DME and to assess whether the central four retinal points on microperimetry (MP4) could be used as a potentially faster and more reliable method of assessing retinal function in patients with DME than reading speed. Methods: The study was performed on patients with clinically significant DME. The best-corrected visual acuity (BCVA) was recorded with letter counting on a modified ETDRS chart, the maximal reading speed (MRS) was recorded with MNREAD, the retinal sensitivity (MP28 and MP4) was measured with Optos OCT/ Scanning Laser Ophthalmoscopy and the central subfield thickness was measured by Heidelberg Spectralis Spectral Domain Optical Coherent Topography. Results: Of 100 eyes analyzed, 76 eyes were included in the study. The mean BCVA was 76.5 letters (Snellen equivalent 6/18), the mean MRS was 156.8 words per minute, the mean MP4 was 9.81 dB per point, and the mean central subfield thickness was 309.3 microns. It was found that faster MRS is correlated with younger age (P = 0.001), better BCVA (P < 0.0001), and better retinal sensitivity (P < 0.0001) for both MP28 and MP4, but not with central subfield thickness (P = 0.66). Central subfield thickness is correlated with MP28 (P = 0.05) but not with age (P = 0.812), BCVA (P = 0.113), or MP4 (P = 0.485). After correction for age and BCVA, MRS is still correlated with MP28 (P = 0.001) and MP4 (P = 0.015). Conclusion: Patients with DME can have reduced reading speed despite good visual acuity. Maximal reading speed is often reported to be difficult to perform, inconsistent, and affected by language and educational level. However, in this study, the authors found that the central MP4 points are quick and easy to test in most of the patients, and are highly correlated with MRS. Microperimetry might therefore represent a useful additional functional test that could be considered better than BCVA or reading speed in quantifying visual function in patients with DME.

Intravitreal pegaptanib for the treatment of ischemic diabetic macular edema.

Purpose Pegaptanib has been shown to be effective in treating diabetic macular edema (DME). In the original Phase II/III trial, however, patients with macular ischemia were excluded. In this study, we treated patients with ischemic DME. Methods Macular ischemia was defined as a 30% increase in the area of the foveal avascular zone (FAZ) at 45 seconds on fundus fluorescein angiography. In addition, the participants had diffuse foveal-involving DME with a central subfield thickness (CST) of >300 μm on spectral-domain optical coherence tomography. Five intravitreal pegaptanib injections were given 6 weeks apart. The final study visit was 6 weeks after the fifth injection. The primary outcome was change in the size of FAZ. Secondary outcomes were change in best-corrected visual acuity (BCVA) and the change in CST. Results Thirty participants were enrolled. Three were unable to complete the full course of treatment. Their outcomes were carried forward for the first part of this analysis. There was no statistically significant change in the mean size of the FAZ from baseline to the final visit. Subclassifying participants as those with minimal/moderate ischemia (16 participants, FAZ area <1,000 pixels) and those with more severe ischemia (14 participants, FAZ area >1,000 pixels) also showed no statistically significant change in the mean area of the FAZ. On average, BCVA increased and CST decreased from baseline to the final visit, but these changes were not statistically significant. Using per protocol analysis on those participants who completed the full course of treatment, the mean BCVA increased from 49.2 to 53.9 letters (P=0.046). Conclusion In this study, intravitreal injection of pegaptanib did not significantly alter the size of the FAZ in participants with varying degrees of ischemic DME. There was, however, a significant improvement in mean BCVA in those who completed the treatment course.

An unusual presentation of patent foramen ovale.

Lesson We report a case of retinal artery occlusion in a young adult in early pregnancy found to have a patent foramen ovale as the source of the embolism. This report suggests the importance of early cardiac investigation in such individuals.

Peripheral ulcerative keratitis as a complication of acute myeloid leukaemia

We report a rare presentation of acute bilateral peripheral ulcerative keratitis (PUK) in a patient with a new diagnosis of untreated acute myeloid leukaemia (AML). To the best of our knowledge, this is the first report of PUK associated with untreated AML and we stress the importance of a rapid and thorough testing to exclude other diagnoses. The patient lost his vision within 10 days to counting fingers. Rapid diagnosis allowed a good visual recovery following prompt treatment with oral steroids and systemic chemotherapy treatment for the AML.

Toxic epidermal necrolysis: the red eye and red herrings in casualty

A 38-year-old woman presented to casualty with bilateral red eyes associated with a recent upper respiratory tract infection. This was initially diagnosed as conjunctivitis, however systemic review revealed an erythematous facial and skin rash, mildly swollen lips and mild swallowing difficulties. The patient was referred for an urgent medical assessment, by which time she was found to have erythema affecting 54% of her body surface area and diagnosed with suspected toxic epidermal necrolysis (TEN). She rapidly deteriorated over 24 hours with a spreading blistering skin rash and airway compromise requiring urgent intubation and admission to the intensive treatment unit (ITU). Subsequent skin biopsies confirmed the diagnosis of TEN, attributed to recent use of ibuprofen. Treatment included broad-spectrum antibiotics and high-dose corticosteroids. The patient had a prolonged hospital stay and developed severe scarring of the ocular surface. She was discharged home and remains under continuing outpatient follow-up with ophthalmology and dermatology teams.

Comparing Macular Thickness Measurements in Patients with Diabetic Macular Edema with the Optos Spectral OCT/SLO and Heidelberg Spectralis HRA + OCT

The aim of this study was to compare measurements of macular thickness, obtained from patients with diabetic macular edema, using two spectral-domain optical coherence tomography (SD-OCT) devices. These were the Spectralis Heidelberg Retina Angiograph + Optical Coherence Tomography (HRA + OCT) (Heidelberg Engineering), which is often considered the gold-standard for OCT measurement, and the Spectral Optical Coherence Tomography/Scanning Laser Ophthalmoscopy (OCT/SLO) (Optos plc), which can additionally perform microperimetry, a useful measure of visual function. In this prospective observational study, each eye had SD-OCT performed with both devices on the same day by the same investigator. Mean retinal thickness was calculated, and compared between the devices, for central and parafoveal zones within 3 mm of the fovea. 62 eyes were included. In the central, superior, temporal, inferior and nasal zones respectively, mean retinal thickness with Spectralis HRA+OCT was (in microns) 310, 343, 344, 332 and 340; measurements with Spectral OCT/SLO were 237, 298, 297, 289 and 290. Pearson correlations between the devices were 0.752, 0.85, 0.928, 0.839, and 0.823 (p < 0.0001). Although absolute measurements between the devices were significantly different and therefore not interchangeable, the correlation between the devices was over 75% and statistically significant in all zones. Thus, the Spectral OCT/SLO could reliably be used for SD-OCT in patients who may also require microperimetry assessment.