Increased Latency of Visual Evoked Potentials in Healthy Women during Menstruation

Purpose: To evaluate the latency of visual evoked potentials (VEPs) in healthy women during and after menstruation. Methods: Pattern and flash VEPs were performed in 15 healthy women aged 18 to 25 years on the maximum bleeding day (luteal phase) and 7 days after the menstrual cycle (follicular phase). Results: Mean latency was 119.6 msec on the maximum bleeding day and 100.8 msec one week after menstruation on pattern VEP (P < 0.001). Corresponding values for flash VEP were 124.5 msec and 112.7 msec, respectively (P < 0.001). Conclusion: Prolonged VEP latency on the maximum bleeding day indicates that high progesterone levels may have an inhibitory effect on optic nerve conduction velocity

Electroretinogram Changes following Silicone Oil Removal

Purpose: To evaluate electroretinogram (ERG) changes after silicone oil removal. Methods: Scotopic and photopic ERGs, and best-corrected visual acuity (BCVA) were checked before and shortly after silicone oil removal in eyes that had previously undergone vitrectomy and silicone oil injection for complex retinal detachment. Preand postoperative ERG a- and b-wave amplitudes were compared. Results: Twenty-eight eyes of 28 patients including 20 male and 8 female subjects with mean age of 39.3 ± 0.06 (range, 12 to 85) years were studied. Mean interval from primary vitreoretinal surgery to silicone oil removal was 21.04 ± 0.52 (range, 7 to 39) months. Mean duration from silicone oil removal to second ERG was 13.04 ± 1.75 (range, 10 to 16) days. Before silicone oil removal, mean a-wave amplitudes in maximal combined response, rod response and cone response ERGs were 27.4 ± 19.9, 7.2 ± 4.5 and 5.5 ± 3.4 μv, respectively. These values increased to 48.8 ± 31.9, 15.1 ± 14.4 and 17.4 ± 22.2 μv, respectively after silicone oil removal (P < 0.001). Mean b-wave amplitudes in the same order, were 69.41 ± 51, 41.2 ± 30.4 and 25.1 ± 33.9 μv before silicone oil removal, increasing to 165.6 ± 102.5, 81.7 ± 53.7 and 44.7 ± 34.1 μv respectively, after silicone oil removal (P < 0.001). Mean BCVA significantly improved from 1.10 ± 0.34 at baseline to 1.02 ± 0.33 logMAR after silicone oil removal (P < 0.001). Conclusion: The amplitudes of ERG a- and b-waves under scotopic and photopic conditions increased significantly shortly after silicone oil removal. An increase in BCVA was also observed. These changes may be explained by the insulating effect of silicone oil on the retina

Childhood Pars Planitis; Clinical Features and Outcomes

Purpose: To evaluate the demographic and clinical features of childhood pars planitis, and to determine the therapeutic and visual outcomes of the disease. Methods: Medical records of pediatric patients (less than 16 years of age at diagnosis) with pars planitis and at least 6 months of follow-up who were referred to Labbafinejad Medical Center, Tehran, Iran over a 22 year period were reviewed. Results: Overall, 117 eyes of 61 patients including 51 (83.6%) male subjects were included. Mean age at the time of diagnosis was 7.8΁3.2 (range, 3-16) years. Mean best corrected visual acuity (BCVA) was 0.88΁0.76 logMAR at presentation which improved to 0.39΁0.51 logMAR at final visit (P<0.001). Endotheliitis was present in 23 (19.6%) eyes and was significantly more prevalent in subjects younger than 9 years (P=0.025). Cataract formation (41.9%) and cystoid macular edema (19.7%) were the most prevalent complications. Univariate regression analysis showed that better baseline visual acuity (OR=0.38, 95%CI 0.21-0.70, P=0.002), age older than 5 years at disease onset (OR=0.36, 95%CI 0.14-0.9, P=0.029), absence of endotheliitis (OR=0.39, 95%CI 0.15-0.99, P=0.047) and female gender (OR=3.77, 95%CI 1.03-13.93, P=0.046) were significantly associated with final BCVA of 20/40 or better. Conclusion: Childhood pars planitis was much more common among male subjects. Endotheliitis may be a sign of inflammation spillover and is more prevalent in younger patients. Visual prognosis is favorable in most patients with appropriate treatment

Outcomes of Retinal Detachment Surgery in Eyes with Chorioretinal Coloboma

Purpose: To report the anatomical and functional outcomes of surgery for retinal detachment associated with chorioretinal colobomas. Methods: In this retrospective interventional case series, 28 eyes of 28 patients (including 18 male subjects) who had undergone surgery for retinal detachment associated with chorioretinal colobomas were evaluated regarding the type of intervention, final visual acuity and anatomical outcomes, as well as complications. Cases with less than 3 months of follow-up were excluded. Results: Primary surgery included vitrectomy in 25 (89.3%) and scleral buckling in 3 (10.7%) eyes. The internal tamponade used in eyes undergoing vitrectomy was silicone oil in 23 (92%) eyes and 20% sulfur hexafluoride (SF6) in 2 (8%) eyes. Silicone oil was removed in 11 eyes (45.8%). The mean number of operations per eye was 1.57±0.74, mean follow-up was 40±36 months, and the retina remained attached in 26 eyes (92.9%) at final follow-up. Mean preoperative visual acuity was 2.33±0.55 (range, 1.15-2.9) logMAR which significantly improved to 1.72±0.9 (range, 0.09-3.1) logMAR postoperatively (P < 0.001), however, final median visual acuity was counting fingers at 2 m. The most common complications were cataracts (100%) and ocular hypertension (46.4%). Conclusion: The most prevalent surgical procedure for treatment of retinal detachment associated with chorioretinal coloboma was pars plana vitrectomy and the most frequently used tamponade was silicone oil. Although anatomical success was satisfactory, functional outcomes were not encouraging which reflects the complexity of the condition and associated abnormalities

The Six Syndromes of the Sixth Cranial Nerve

The sixth cranial nerve runs a long course from the brainstem to the lateral rectus muscle. Based on the location of an abnormality, other neurologic structures may be involved with the pathology related to this nerve. Sixth nerve palsy is frequently due to a benign process with full recovery within weeks, yet caution is warranted as it may portend a serious neurologic process. Hence, early diagnosis is often critical for some conditions that present with sixth nerve palsy. This article outlines a simple clinical approach to sixth nerve palsy based on its anatomy

Electroretinographic Changes Following Retinal Reattachment Surgery

Purpose: To explore functional visual recovery after retinal reattachment surgery employing full-field electroretinography (ffERG). Methods: In this case series, scotopic and photopic ffERGs were compared 2 days before, and 1, 3 and 6 months after successful scleral buckling for total rhegmatogenous retinal detachment (RRD). Main outcome measures were changes in ERG a-and b-wave amplitudes postoperatively. Results: Twenty eyes of 20 patients including 14 male and 6 female subjects with mean age of 34.7±8.2 (range, 23 to 50) years were enrolled. Preoperatively, mean a-wave amplitude in the maximal combined response was 27.5±11.7 μV which was increased to 110.7±41.9 (P<0.001), 175.7±53.1 (p<0.001) and 174.6±51.4 (P<0.001) μV at 1, 3 and 6 months, respectively. Mean preoperative a-wave amplitude of the cone ERG response was 2.1±0.8 μV, which was increased to 2.2±0.9 (P=0.03), 5.1±1.7 (P<0.001) and 5.3±1.6 (P<0.001) μV at 1, 3 and 6 months, respectively. Mean preoperative b-wave amplitude in the maximal combined response was 97.6±28.9 μV which was increased to 179.2±44.9 (P<0.001), 264.2±56.3 (P<0.001) and 267.8±54.2 (P<0.001) μV at 1, 3 and 6 months, respectively. Mean preoperative b-wave amplitude of the cone ERG response was 2.9±0.9 μV which was increased to 3±0.9 (P=0.32), 9.9±1.9 (P<0.001) and 9.8±1.9 (P<0.001) μV at 1, 3 and 6 months, respectively. Conclusion: After retinal reattachment surgery, photoreceptor and visual function show parallel improvement. The scotopic ERG response recovered faster than the photopic response. Incomplete recovery of ERG parameters indicates that photoreceptor cell damage in retinal detachment is not completely reversible

Electroretinogram Changes in the Sound Eye of Subjects with Unilateral Necrotizing Herpetic Retinitis

Purpose: To evaluate electroretinogram (ERG) changes in the contralateral normal appearing eye of patients with unilateral acute necrotizing herpetic retinitis (NHR). Methods: This interventional case series includes subjects with acute unilateral NHR. All patients were treated with intravenous followed by oral acyclovir and systemic steroids. Main outcome measures were changes in a- and b-wave amplitudes of scotopic and photopic full-field ERG in the sound eye, 1 and 3 months after therapy as compared to baseline. Twenty normal subjects served as controls. Results: Forty eyes of 20 patients including 12 male and 8 female subjects with mean age of 44.1±11.5 (range 22 to 66) years were studied. Twenty unaffected eyes were the subject of the current study. The retina in all of these eyes remained intact during the course of the study. In the sound eyes, mean b-wave amplitude of the maximal combined response ERG before initiation of treatment was 229.5±38.8 microvolts which increased to 356.1±34.0 (P<0.001) and 365.8±32.7 (P<0.001) microvolts 1 and 3 months after treatment, respectively. Corresponding figures for b-wave amplitudes of the cone response ERG were 24.9±6.0, 47.0±12.9 (P<0.001) and 52.8±12.7 (P<0.001) microvolts, respectively. Visual acuity of all sound eyes remained unchanged throughout the study. Conclusion: Despite normal retinal appearance and intact visual acuity in the sound eyes of patients with NHR, electrophysiological changes were observed. Prompt diagnosis and management of NHR and continuation of medication for 3 months may reverse subclinical ERG changes and reduce the risk of progression to overt clinical disease

Modeling a Telemedicine Screening Program for Diabetic Retinopathy in Iran and Implementing a Pilot Project in Tehran Suburb

Purpose. To model a community-based telescreening program for diabetic retinopathy (DR) in Iran and to implement a pilot project at the Iranian Diabetes Society (IDS) branch in a Tehran suburb. Methods. In this mixed model study, a web application called the “Iranian Retinopathy Teleophthalmology Screening (IRTOS)” was launched. The educational course for DR screening was established for general practitioners (GPs). Registered patients in IDS branch were recalled for fundus photography; images were transferred to the reading center via IRTOS to be graded by GPs, and patients were informed about the results via mobile messaging. All images were independently reviewed by a retina specialist as the gold standard. Patients who required further assessment were referred to an eye hospital. Results. Overall, 604 subjects with diabetes were screened; of these, 50% required referral. The sensitivity and specificity for diagnosis of any stage of DR by trained GPs were 82.8% and 86.2%, respectively, in comparison to the gold standard. The corresponding values for detecting any stage of diabetic macular edema (DME) were 63.5% and 96.6%, respectively. Conclusions. Telescreening was an effective method for detecting DR in a Tehran suburb. This screening model demonstrated its capacity for promoting diabetic eye care services at the national level. However, the sensitivity for detecting DME needs to be improved by modifying the referral pathway and promoting the skill of GPs