Determination of the toxicity of intravitreal minocycline in rabbit eyes.

PURPOSE: To evaluate the retinal toxicity of intravitreal minocycline in rabbit eyes. METHODS: Intravitreal injection of minocycline with concentrations of 1000, 500, 250, 125 and 62.5 µg in 0.1 ml was performed in 10 New Zealand albino rabbits. Each concentration was injected into two rabbit eyes. For each dose, normal saline was injected in one contralateral eye and the other fellow eye remained non-injected. Electrophysiologic testing was performed before and 4 weeks after injections. The eyes were enucleated 4 weeks after injections and examined using light microscopy. RESULTS: The clinical examination was unremarkable after injections. Electroretinography recordings were significantly affected at all doses in at least one of the a- or b-waves of photopic or scotopic responses. Histopathologic examination revealed marked atrophy and loss of integrity in all retinal layers in all minocycline injected eyes. Contralateral eyes were normal. CONCLUSION: In our study, intravitreal minocycline was toxic to the retina in albino rabbits even at a concentration of 62.5 µg/0.1 ml.

Accuracy of peripapillary OCTA in patients with acute nonarteritic anterior ischemic optic neuropathy.

OBJECTIVE: To evaluate the accuracy of peripapillary optical coherence tomography angiography (OCTA) segmentation in eyes with acute nonarteritic anterior ischemic optic neuropathy (NAION) and healthy eyes. METHOD: In this retrospective study, en face OCTA images of the optic disc of healthy eyes and eyes with unilateral acute NAION were obtained. The disc boundary and radial peripapillary capillary (RPC) segmentation were generated automatically by the instrument software and then corrected by 2 expert investigators. The frequency of segmentation errors and its impact on vessel density and nerve fibre layer (NFL) thickness measurements were evaluated. RESULTS: Thirty-eight eyes of 38 subjects (18 in the healthy group and 20 in the acute NAION group) were studied. A misidentified disc border was noted in 5 healthy eyes (27.7%) and 19 eyes with NAION (95.0%; p < 0.001). Segmentation error at the RPC level was found in 6 healthy eyes (33.33%) and 19 eyes with NAION (95.0%; p < 0.001). The nerve fibre layer thickness and RPC density did not change statistically significantly after error corrections in both groups. CONCLUSIONS: Misidentification of disc border and segmentation error of the RPC layer are common in OCTA images of the optic disc. Accuracy of OCTA imaging in disc boundary detection and RPC network segmentation is reduced in edematous optic discs following acute NAION.

Bilateral Vision Loss in an Adult Patient with Woakes' Syndrome: An Unprecedented Case.

Purpose: To report a rare case of Woakes' syndrome presented with bilateral vision loss. Methods: A 28-year-old male with a 1-year history of vision loss in the left eye was referred to the neuro-ophthalmology clinic after sudden vision loss in his right eye. A detailed review of clinical findings and the presumed pathophysiological basis of vision loss was performed. Results: Neuroimaging revealed bilateral massive nasal polyps, sphenoid sinus mucocele formation, and optic nerve dehiscence inside the sphenoid sinus. The vision in the right eye was restored after pulse corticosteroid therapy; however, the left eye remained severely visually compromised even after nasal polypectomy and mucocele drainage. Conclusion: Sinonasal disorders should be sought for patients with unexplained vision loss, as prompt intervention could be vision-saving in these patients.

Pituitary Apoplexy Secondary to Thrombocytopenia due to Severe Acute Respiratory Syndrome Coronavirus 2 Infection: Report of a Rare Case and Literature Review.

Purpose: To report a 16-year-old female patient with pituitary apoplexy in the setting of coronavirus disease 2019 (COVID-19) infection-related thrombocytopenia in the absence of preexisting pituitary macroadenoma. Methods: The patient had been admitted because of respiratory complications of COVID-19 infection and developed thrombocytopenia, intense headache, and symptoms of cavernous sinus syndrome. Results: Urgent magnetic resonance imaging of the brain depicted a pituitary apoplexy. Conclusion: This case indicated that thrombocytopenia due to COVID-19 could be a predisposing factor for pituitary apoplexy in the absence of underlying pituitary disease.

Bilateral Visual Loss Caused by Pneumosinus Dilatans: Idiopathic Cases are not Always Reversible.

PURPOSE: To report a rare case of primary pneumosinus dilatans (PSD) and to specify the cardinal imaging findings associated with this condition. METHODS: A 20-year-old patient presented with bilateral profound visual loss as a result of primary PSD. A detailed review of clinical findings and presumed pathophysiological basis of vision loss was performed. RESULTS: Other than undiagnosed primary hypothyroidism, no other abnormalities were found. With the diagnosis of PSD, the patient underwent optic nerve decompression through transnasal sphenoidotomy. However, after nine months of follow-up, no improvement in the patient's vision was attained. CONCLUSION: Unlike previous reports of favorable visual results after sphenoidotomy and bilateral decompression of the optic nerves, vision recovery was not achieved in this case.

The Adequate Number of Histopathology Cross-sections of Temporal Artery Biopsy in Establishing the Diagnosis of Giant Cell Arteritis.

PURPOSE: To determine the appropriate number of histopathological cross-sections that are required for a conclusive diagnosis of giant cell arteritis (GCA). METHODS: In this cross-sectional study, the number of sections per slide for paraffin-embedded blocks for 100 randomly selected cases where GCA was suspected and those for negative temporal artery biopsies (TABs) were compared with the number of cross-sections per specimen for eight positive-TABs. All aforementioned examinations were conducted at our center from 2012 to 2016. Then, negative-TABs were retrieved and re-evaluated using light microscopy considering the histopathological findings of GCA. RESULTS: Ninety-five paraffin blocks were retrieved. The original mean biopsy length was 15.39 ± 7.56 mm. Comparison of the mean number of cross-sections per specimen for both the positive- and negative-TABs (9.25 ± 3.37 and 9.53 ± 2.46) showed that 9.87 ± 2.77 [95% confidence intervals (CI)] cross-sections per specimen were sufficient for a precise GCA diagnosis. There was no statistically significant difference in the mean biopsy length (P = 0.142) among the eight positive-TABs. Similarly, no significant difference was observed in the number of cross-sections per specimen (P = 0.990) for positive-TABs compared to those for the negative-TABs. After the retrieval of negative-TABs, the mean number of total pre- and post-retrieval cross-sections per specimen was 17.66 ± 4.43. Among all retrieved specimens, only one case (0.01%) showed the histopathological features of healed arteritis. CONCLUSION: Positive-TABs did not reveal more histological cross-sections than the negative ones and increasing the number of cross-sections did not enhance the accuracy of TAB.

Comparing Two Inferior Oblique Weakening Procedures: Disinsertion versus Myectomy.

PURPOSE: To compare two methods for treating inferior oblique overaction (IOOA): disinsertion versus myectomy of the muscle. METHODS: In this prospective interventional case series, patients were randomly assigned to undergo either IO myectomy or disinsertion. The changes in vertical and horizontal deviations following these two surgical procedures were evaluated. The postoperative IO function of grade 0 or +1 and the fundus extorsion of grade 0 or +1 was considered as the successful outcome. RESULTS: Thirty-six patients (50 eyes) with a mean age of 12.67 ± 4.05 years were included. In the myectomy group, the mean preoperative hyperdeviation in adduction was 29.5 ± 9.32 prism diopter (PD), which decreased to 9.15 ± 7.86 PD after surgery (P = 0.001). In the disinsertion group, these measurements were 32.73 ± 12.42 and 12.65 ± 9.34 PD before and after the surgery, respectively (P = 0.001). The success rate of surgery based on the IOOA grading was 87.4% and 92.3% in the myectomy and disinsertion groups, respectively (P = 0.780). The successful correction rate of abnormal fundus torsion was 91.6% in the myectomy and 88.4% in the disinsertion group (P = 0.821). In comparison, 48% of the cases in the myectomy group and 50% in the disinsertion group were within the normal range of torsional position postoperatively (P = 0.786). There was no statistically significant difference in terms of changes in the horizontal or vertical deviations, V-pattern, and dissociated vertical deviation between the two groups. CONCLUSION: Both surgical techniques seem to be effective for treatment of inferior oblique muscle overaction.

The Short-Term Effects of Intravitreal Injection of Bevacizumab on the Plasma Levels of Vascular Endothelial Growth Factor, Insulin-Like Growth Factor-1, and Growth Parameters in Infants with Retinopathy of Prematurity.

PURPOSE: To determine the changes in serum levels of free vascular endothelial growth factor (VEGF), insulin-like growth factor-1 (IGF-1), and growth parameters in infants with retinopathy of prematurity (ROP) who received intravitreal injection of the bevacizumab (IVB). METHODS: A prospective interventional case series study, including 10 infants with Type 1 ROP was conducted. Using the enzyme-linked immunosorbent assay, serum levels of VEGF and IGF-1 were measured before, 1 month and 2 months after treatment with IVB in both eyes. Growth parameters, including weight, length, and head circumference and their Fenton's z-score, were also measured. RESULTS: Serum VEGF levels were suppressed 1 month after IVB (P = 0.007) and then increased between 1 and 2 months (P = 0.064). Z-scores of all growth parameters except weight z-score decreased in the 1st and 2nd months. CONCLUSION: Serum VEGF levels showed a transient reduction after IVB which lasted at least 2 months. Growth velocity of premature infants may be affected by anti-VEGF therapy and should be followed with particular attention.

Temporal Artery Biopsy for Diagnosing Giant Cell Arteritis: A Ten-year Review.

PURPOSE: To assess the use of temporal artery biopsy (TAB) in diagnosing giant cell arteritis (GCA) and to evaluate patients' clinical and laboratory characteristics. METHODS: We conducted a retrospective chart review of patients with suspected GCA who underwent TAB and had complete workup in a tertiary center in Iran between 2008 and 2017. The 2016 American College of Rheumatology (ACR) revised criteria for early diagnosis of GCA were used for each patient for inclusion in this study. RESULTS: The mean age of the 114 patients in this study was 65.54 ± 10.17 years. The mean overall score according to the 2016 ACR revised criteria was 4.17 ± 1.39, with 5.82 ± 1.28 for positive biopsies and 3.88 ± 1.19 for negative biopsies (p <0.001). Seventeen patients (14.9%) had a positive biopsy. Although the mean post-fixation specimen length in the biopsy-positive group (18.35 ± 6.9 mm) was longer than that in the biopsy-negative group (15.62 ± 8.4 mm), the difference was not statistically significant (P = 0.21). There was no statistically significant difference between the groups in terms of sex, serum hemoglobin, platelet count, and erythrocyte sedimentation rate. There were statistically significant differences between the biopsy-negative and biopsy-positive groups with respect to patients' age and C-reactive protein level (P < 001 and P = 0.012, respectively). CONCLUSION: The majority of TABs were negative. Reducing the number of redundant biopsies is necessary to decrease workload and use of medical services. We suggest that the diagnosis of GCA should be dependent on clinical suspicion.

Isolated unilateral sixth nerve palsy in a patient with nasopharyngeal carcinoma.

Objective: To describe an isolated unilateral sixth nerve palsy, as a rare neuro-ophthalmic presentation of nasopharyngeal carcinoma. Methods: We report a 54-year-old female, known case of nasopharyngeal carcinoma who was treated with chemo-radiotherapy, and presented with isolated right sixth nerve palsy. Magnetic resonance imaging (MRI) indicated extension of tumor to intracranial fossa with clival involvement. Results: The patient was referred to an otolaryngologist for further evaluation and necessary intervention due to invasion of the cancer to intracranial fossa with involvement of right abducens nerve. Conclusions: Although, isolated sixth nerve palsies in adults over the age of 50 are usually ischemic; but in enduring cases, neoplastic processes should be considered.

Isolated Unilateral Infiltrative Optic Neuropathy in a Patient with Breast Cancer

Metastasis to the optic nerve is very rare. We report a case of metastatic breast cancer to the optic nerve head without the involvement of other ocular or orbital structures. The patient, a 39-year-old female who had been previously treated for breast cancer, reported a gradually progressive decrement in visual acuity of the right eye during the past two months. Fundus examination of the affected eye revealed swelling of the optic disc which was infiltrated by a yellowish mass. Further evaluation using optical coherence tomography and fluorescein angiography showed optic disc swelling. Magnetic resonance imaging revealed no pathologic findings. With a diagnosis of unilateral infiltrative optic neuropathy, we referred the patient to an oncologist for further evaluation.

An Updated Review on the Most Common Agents Causing Toxic Optic Neuropathies.

BACKGROUND: Toxic optic neuropathies (TONs) often present with a gradual and bilateral decrease in visual acuity, scotomas and optic disc pallor. Obtaining an accurate history is the critical first step in determining the etiology of TONs. METHODS: This updated review contains a thorough analysis of the current PubMed-indexed literature on the most common agents responsible for TONs, including methanol, ethambutol, amiodarone, linezolid, tumor necrosis factor alpha inhibitors and phosphodiesterase 5 inhibitors. RESULTS: The reviewed articles are mainly case reports presenting new and controversial aspects of the above agents. New treatment strategies, such as erythropoietin for methanol optic neuropathy, are being proposed for TONs, a condition that was previously regarded as untreatable. CONCLUSION: TONs could cause significant disability due to visual impairment. In case of early diagnosis and drug withdrawal, most TONs are treatable. Patients need to be appropriately counseled, and prescribing physicians should be especially made aware of TON-inducing medications.

Visual and Anatomical Outcomes of Spironolactone Therapy in Patients with Chronic Central Serous Chorioretinopathy.

PURPOSE: To evaluate the effect of spironolactone on chronic central serous chorioretinopathy (CSC). METHODS: In this prospective interventional case series, patients with chronic CSC were treated with spironolactone (25 mg daily) for at least 6 weeks. If the subretinal fluid (SRF) had not completely resolved by this time, treatment was continued, and the dosage was increased to 25 mg twice daily. Primary outcome measure was the change in maximum SRF height at the final follow-up visit, as detected by optical coherence tomography. Secondary outcome measures were changes in best corrected visual acuity (BCVA) and central macular thickness (CMT). RESULTS: Sixteen eyes of 14 patients with chronic CSC were enrolled. Mean follow-up time was 6.4 ± 4.3 months. Baseline BCVA was 0.54 ± 0.44 logarithm of the minimum angle of resolution (log MAR), which improved to 0.42 ± 0.43 log MAR at the final visit (P = 0.04). Mean CMT decreased from 282.69 ± 103.23 µm at baseline to 236.75 ± 90.10 µm at final visit (P = 0.11), and the mean of maximum SRF height decreased from 155.63 ± 95.27 µm at baseline to 77.19 ± 95.68 µm at the final visit (P = 0.04). SRF resolved completely in seven eyes (43.75%). CONCLUSION: In eyes with persistent SRF due to CSC, spironolactone therapy was associated with a statistically significant decrease in maximum SRF height, as well as an improvement in BCVA.

Visual and anatomic outcomes after conversion to aflibercept in neovascular age-related macular degeneration: 12-month results.

PURPOSE: To investigate 12-month outcomes of conversion to aflibercept in patients with neovascular age-related macular degeneration resistant to ranibizumab. METHODS: Twenty-two eyes of 19 consecutive patients received 3 monthly aflibercept injections followed by a pro re nata protocol. Spectral-domain optical coherence tomography (OCT) images were obtained before each injection. All 49 cross-sectional OCT B-scans obtained in each examination were investigated and the largest choroidal neovascularization (CNV) size was chosen. The same cross-sectional B-scan sections containing the maximum CNV size were used during the follow-up. RESULTS: After 12 months, best-corrected visual acuity increased from 45.68 ± 20.25 to 59.09 ± 17.50 Early Treatment Diabetic Retinopathy Study letters (p<0.001), central subfield thickness decreased from 399.91 ± 148.85 to 304.55 ± 97.89 µm (p = 0.003), area of CNV declined from 0.38 ± 0.24 to 0.28 ± 0.19 mm2 (p = 0.003), and macular volume improved from 9.64 ± 1.75 to 8.45 ± 0.98 mm3 (p<0.001). There was a significant resolution of intraretinal fluid (p = 0.016), but reduction of subretinal fluid was not significant (p = 0.25). CONCLUSIONS: Visual and anatomic improvement were obtained after conversion to aflibercept.

Surgical treatments in inferior oblique muscle overaction.

PURPOSE: To compare the outcomes of surgical procedures in the treatment of inferior oblique muscle overaction (IOOA) as a common disorder of ocular motility. METHODS: This retrospective study was performed on patients with primary and secondary IOOA who underwent three surgical treatment procedures including disinsertion, myectomy and anterior transposition, between 2001 and 2011. Type of strabismus, ocular alignment, presence of pre-and post-operative dissociated vertical deviation (DVD), pre- and post-operative degree of IOOA were obtained using specified checklist. RESULTS: A total of 122 eyes of 74 patients with mean age of 13 ± 11.7 (range, 1-51) years were included in this study. Disinsertion was performed on 12 eyes (9.8%), myectomy in 91 eyes (74.6%) and anterior transposition in 19 (15.6%). Preoperative V-pattern and DVD existed in 67 and 17 eyes; after surgery they remained in only 10 and 8 eyes, respectively. The success rate (IOOA <+1), in disinsertion, myectomy and anterior transposition groups were 91.7%, 97.8%, and 89.5%, respectively and these measures did not change after 6 months. Overall, 53.3% (n = 65) and 38.5% (n = 47) of eyes had preoperative esotropia and exotropia. Preoperative hypertropia and hypotropia were observed in 16.4% (n = 20) and 3.3% (n = 4) of eyes, respectively. After surgery there were no cases of additional strabismus. However, residual hypertropia was seen in 9 eyes, while preoperative hypotropia increased in one patient who underwent anterior transposition surgery. Esotropia and exotropia were not observed in any surgical treatment groups postoperatively. CONCLUSION: We conclude that all these three procedures are effective for treatment of primary or secondary IOOA with minimum side-effects.

Anterior segment study with the Pentacam Scheimpflug camera in refractive surgery candidates.

PURPOSE: The purpose of this study was to evaluate the anterior segment measurements according to refractive status in a sample of the Iranian population. SETTING: Rassoul Akram Hospital, Tehran University of Medical Sciences. MATERIAL AND METHODS: IN THIS STUDY, REFRACTIVE SURGERY CANDIDATES WERE ASSIGNED ACCORDING TO THE REFRACTIVE ERROR TO ONE OF THREE GROUPS : emmetropia, myopia, and hyperopia. Myopic eyes were further divided to four subgroups : simple myopic group, simple myopic astigmatism group, high myopic group, and high myopia with astigmatism group. Anterior segment measurements with the Pentacam Scheimpflug system were performed in the right eye of all subjects. RESULTS: The study sample was comprised of 283 subjects with a mean age of 29.1 ± 7.5 (standard deviation) years. Mean keratometry reading, Anterior chamber depth (ACD) and volume measurements were significantly higher in the myopic group and mean keratometry reading and anterior chamber angle measurements were significantly lower in the hyperopic group (P < 0.05, all comparisons). Maximum anterior elevation (AEmax) and maximum posterior elevation (PEmax), Q value, progression index, minimum corneal thickness, and corneal volume measurements were similar for all groups (P > 0.05, all comparisons). In the myopic subgroups, AEmax and PEmax and maximum keratometry (Kmax) were significantly higher, and ACD was lower in the astigmatic groups (P < 0.05, all comparisons). The Q value was less negative in low myopia (P < 0.05). CONCLUSIONS: Myopic eyes had steeper corneas than hyperopic eyes and anterior chamber measurements were significantly higher in the myopic eyes. In myopic eyes, AEmax and PEmax and Kmax measurements were higher, and ACD measurements were lower in the astigmatic groups.