فهرست مطالب
Journal of Ophthalmic and Vision Research
Volume:11 Issue: 2, Apr-Jun 2016
- تاریخ انتشار: 1395/03/31
- تعداد عناوین: 24
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Page 131PurposeTo determine the effect of using toric soft contact lenses on corneal biomechanical properties.MethodsWe enrolled 33 healthy patients with mean age of 23.18 ± 4.06 and minimal cylinder power of 1 D (-1.98 ± 0.808 SD) and negative history of contact lens use; keratoconic patients were excluded from the study. Toric soft contact lenses (BIOFINITY, Comfilcon A, Coopervision, Southampton, UK) were fitted in all participants. The Ocular Response Analyzer (Reichert Ophthalmic Instruments, Depew, New York, USA) was used to measure corneal hysteresis (CH), corneal resistance factor (CRF), and the Pentacam HR (Oculus, Inc., Lynnwood, WA, USA) was used to measure central corneal thickness (CCT) and mean keratometry (K mean) before and one week, one month, and three months after using the toric soft contact lenses.ResultsCH and CRF were decreased significantly one month after using the contact lens; mean CH decreased from 9.99 ± 1.44 to 9.59 ± 1.54 mmHg, and mean CRF decreased from 9.96 ± 1.71 to 9.63 ± 1.73 mmHg (P = 0.013 and P = 0.017, respectively). Mean CCT and K mean did not show a significant change during the period of toric soft contact lens use.ConclusionCH and CRF decreased significantly one month after fitting toric soft contact lenses while CCT and K mean did not change significantly. Corneal biomechanical parameters may alter with toric soft contact lens use and such changes may have implications with long-term use such lenses.Keywords: Corneal Hysteresis, Corneal Resistance Factor, Toric Soft Contact Lens
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Page 136PurposeTo evaluate the efficacy of photorefractive keratectomy (PRK) using the advanced personalized treatment (APT) nomogram for correction of moderate to high astigmatism.MethodsThis prospective interventional case series included 60 consecutive eyes of 30 patients undergoing wavefront-guided PRK (Zyoptix 217 Z100 excimer laser, Bausch & Lomb, Munich, Germany) using the APT nomogram and iris registration for myopic astigmatism. Mitomycin-C was applied intraoperatively in all eyes. Ophthalmic examination was performed preoperatively and 1, 3 and 6 months postoperatively.ResultsPreoperatively, mean sphere was -1.68 ± 2.08 diopters (D), mean refractive astigmatism was -3.04 ± 1.05 D and mean spherical equivalent (SE) was -3.12 ± 1.77 D. Six months postoperatively, mean sphere was 0.60 ± 0.64 D (PConclusionConsidering the acceptable residual refractive error, low rate of hyperopic overcorrection, acceptable uncorrected visual acuity, and low risk of postoperative corneal haze, PRK using the APT nomogram with iris registration and mitomycin-C use is a safe and effective modality for treatment of moderate to high astigmatism.Keywords: Advanced Personalized Treatment, Astigmatism, Iris Registration, Photorefractive Keratectomy
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Page 141PurposeTo determine whether photorefractive keratectomy (PRK) has a significant effect on optic nerve head (ONH) parameters and peripapillary retinal nerve fiber layer (RNFL) thickness measured by the Heidelberg Retina Tomograph 3 (Heidelberg Engineering GmbH, Heidelberg, Germany) in eyes with low to moderate myopia.MethodsThis prospective, interventional case series, includes 43 consecutive myopic eyes which were assessed on the day of PRK and 3 months postoperatively using the HRT3. Among the stereometric parameters, we compared disc area, linear cup disc ratio, cup shape measure, global rim area, global rim volume, RNFL height variation contour and mean RNFL thickness; out of the Glaucoma Probability Score (GPS) we assessed changes in global value, rim steepness temporal/superior, and temporal/inferior, as well as cup size and cup depth before and after PRK.ResultsMean refractive error before and after PRK were −3.24 ± 1.31 and −0.20 ± 0.42 diopters, respectively. No significant change occurred in disc area, linear cup disc ratio, cup shape measure, rim area and rim volume among the stereometric parameters; and in rim steepness temporal/superior and rim steepness temporal/inferior in the GPS before and after PRK using the default average keratometry. However, RNFL height variation contour, mean RNFL thickness, and cup size and depth were significantly altered after PRK (PConclusionPRK can affect some HRT3 parameters. Although the most important stereometric parameters for differentiating normal, suspect or glaucomatous patients such as rim and cup measurements in stereometric parameters were not changed.Keywords: Glaucoma, Heidelberg Retina Tomograph, Myopia, Photorefractive Keratectomy
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Page 146PurposeTo report changing trends in indications and techniques of corneal transplantation in Iran.MethodsWe reviewed eye bank records of 47,129 patients who had undergone corneal transplantation between 2006 and 2013 at different eye centers throughout Iran.ResultsThe most common indication for corneal transplantation was keratoconus (KCN, n = 21,350 eyes, 45.3%), followed by bullous keratopathy (BK, n = 8,566 eyes, 18.2%), corneal opacity and scar (COS, n = 7,158 eyes, 15.2%), graft failure (n = 3,252 eyes, 6.9%), corneal dystrophies (n = 2,553 eyes, 5.4%), and infectious keratitis (n = 2,238 eyes, 4.7%). Over the study period, there was a significant increase in the frequency of BK (P = 0.001) and graft failure (P = 0.025), and a significant decrease in the relative frequency of COS (P = 0.012). The prevalence of KCN (P = 0.172), infectious keratitis (P = 0.107), and corneal dystrophies (P = 0.836) remained unchanged. The most common technique of corneal transplantation was penetrating keratoplasty (PKP, n = 33,476 eyes, 71.0%), followed by deep anterior lamellar keratoplasty (DALK, n = 8,363 eyes, 17.7%), Descemet's stripping automated endothelial keratoplasty (DSAEK, n = 3,516 eyes, 7.5%), tectonic (n = 1752, 3.7%), and keratolimbal allograft (KLAL, n = 19 eyes, 0.1%). Regarding the shift in surgical techniques, a significant increase was observed in DSAEK (PConclusionKCN was the most common indication and PKP was the most prevalent technique used for corneal transplantation. Significant changes in surgical techniques were observed over the past 8 years; DSAEK demonstrated an increasing trend while PKP showed a decrease.Keywords: Corneal Transplantation, Keratoconus, Surgical Technique, Trends
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Page 153PurposeTo investigate the correlations between clinical findings and histopathologic changes in eyes with pterygium.MethodsThis prospective study included 70 eyes with primary pterygia undergoing surgical excision. Prior to surgery, clinical features of the pterygia including extension over the cornea, redness, fleshiness (based on obscuration of the underlying episcleral vessels), and obliteration of the plica semilunaris were determined. Postoperatively, pterygium specimens were examined by hematoxylin-eosin and trichrome staining to evaluate histopathologic characteristics including vascular density, leukocytic infiltration, stromal elastosis, stromal fibrosis and subepithelial fibrosis. Correlations between clinical findings and histopathologic changes were then investigated.ResultsThere was a marginally significant correlation between the redness and the fleshiness of pterygium (P = 0.06). Both redness and fleshiness of the pterygium had significant positive correlation with dimensions of the lesion over the cornea. Moreover, larger pterygia were associated with obliteration of the plica semilunaris. Pterygium redness showed a significant correlation with vascular density (P = 0.04), and pterygium fleshiness had a significant correlation with stromal fibrosis (P = 0.04). Pterygium dimensions over the cornea demonstrated a positive correlation with vascular density and a negative correlation with stromal elastosis.ConclusionRedness and fleshiness of pterygium were only marginally correlated with each other, and each one showed a correlation with different histopathologic features. Larger pterygia were associated with more significant changes at the clinical and histopathologic levels.Keywords: Elastosis, Fibrosis, Pterygium, Vascular Density
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Page 159Purpose
To report findings that could suggest an elliptical shape of the capsular bag.
MethodsFive eyes of three patients with axial length greater than 24 mm underwent phacoemulsification cataract surgery with plate-haptic multifocal toric intraocular lens (IOL) implantation oriented in the vertical meridian.
ResultsIn all cases, correct orientation of the IOLs was verified 30 minutes after surgery. After 24 hours, all eyes demonstrated unwanted rotation of the IOLs ranging from 15 to 45 degrees. The IOLs remained stable in the new position in all cases until adhesion of the capsular bag took place.
ConclusionThese observations could suggest that the perimeter of the capsular bag has an elliptical shape. Therefore, the IOL tends to become fixated in a meridian of the capsular bag that best fits the diagonal diameter of the IOL.
Keywords: Capsular Bag, Cataract Surgery, Intraocular Lens, Phacoemulsification Surgery -
Page 162PurposeTo compare the safety and efficacy of three methods for correcting pre-existing astigmatism during phacoemulsification.MethodsThis prospective, comparative, non-randomized study was conducted from March 2010 to January 2011, and included patients with keratometric astigmatism ≥1.25 D undergoing cataract surgery. Astigmatism was corrected using the following approaches: limbal relaxing incisions (LRI) on the steep meridian, extension and suturing of the phaco incision created at the steep meridian (extended-on-axis incision, EOAI), and toric intraocular lens (tIOL) implantation. Keratometric and refractive astigmatism were evaluated 1, 8, and 24 weeks postoperatively.ResultsEighty-three eyes of 72 patients (35 male and 37 female) with mean age of 62.4 ± 14.3 (range, 41-86) years were enrolled. The astigmatism was corrected by using the LRI, EOAI and tIOL implantation methods in 17, 33 and 33 eyes, respectively. Postoperative uncorrected distance visual acuity (UDVA) was significantly improved in all three groups. The difference in postoperative UDVA was not statistically significant among the study groups throughout follow-up except at week 24, when UCVA was significantly better in the tIOL group as compared to the EOAI group (P = 0.024). There is no statistically significant difference of correction index and index of success between three groups at week 24 (P = 0.085 and P = 0.085 respectively).ConclusionThere was no significant difference in astigmatism reduction among the three methods of astigmatism correction during phacoemulsification. Each of these methods can be used at the discretion of the surgeon.Keywords: Astigmatism Correction, Extended?on?axis Incision, Limbal Relaxing Incision, Phacoemulsification, Toric Intraocular Lens
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Page 168PurposeTo report the indications, anatomical outcomes, functional outcomes and limitations of descemetopexy with intracameral injection of isoexpansile perfluoropropane (14% C3F8) in eyes with Descemets membrane (DM) detachment after cataract surgery.MethodsThis retrospective non‑comparative interventional case series included 67 eyes of 67 patients who underwent descemetopexy at a tertiary eye hospital. The procedure consisted of descemets membrane reattachment by injecting isoexpansile perfluoropropane (14% C3F8) intracamerally. Outcome measures were reattachment of DM, improvement in visual acuity, resolution of corneal edema, causes for failure of DM reattachment and complications.ResultsSixty‑seven eyes of 74 patients were analyzed. Phacoemulsification (56.71%) had the highest DM detachment as compared to manual SICS in 19 (28.36%) and ECCE in 10 (14.93%) eyes. Descemetopexy with 14% C3F8 resulted in anatomical reattachment of DM in 71.64% and functional improvement in visual acuity in 74.63% of treated eyes. The location and the extent of DM detachment did not influence DM reattachment. Complete reattachment of DM occurred in all 26 eyes (100%) with planar type detachments, whereas with non‑planar type detachments only 22 eyes (53.7%) achieved complete reattachment.ConclusionDescemetopexy with isoexpansile perfluoropropane offers good surgical outcomes regarding visual acuity and resolution of corneal edema.Keywords: Descemet's Membrane Detachment, Descemetopexy, Isoexpansile Perfluoropropane
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Page 174PurposeIn this experimental study, the effects of systemic memantine administration on the retinal ultrastructure of experimentally induced glaucomatous rats were investigated.MethodsTwenty‑four Wistar albino rats were included in this study. Glaucoma was induced by injecting sodium hyaluronate into the anterior chamber of the rats for a period of three weeks. As a control, 8 rats were sham treated (Group C). Glaucoma induced animals were divided into two groups; Group M (n = 8) received a single daily dose of 10 mg/kg memantine, and Group G received the same volume of saline (n = 8), via intraperitoneal route for a period of six weeks, starting with the induction of glaucoma. Then, all rats were sacrificed and the retinas were prepared for electron microscopic examination. Electron microscopic damage findings were graded between 0 and 4 and mean damage scores for each cell or layer was calculated for each group. Statistical comparison was made between group G and group M.ResultsIncluding the photoreceptor cells, marked ultrastructural changes were observed in the retinas of the animals in group G. The ultrastructural changes in group M were modest and there was no significant cell death. Statistical findings indicated these results.ConclusionResults of the present study suggest that memantine treatment, when started in the early phase of glaucomatous process, may help to preserve the retinal ultrastructure and thus prevent neuronal injury in experimentally induced glaucoma.Keywords: Electron Microscopy, Glaucoma, Memantine, Neuroprotection, Rat
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Page 183PurposeTo determine the efficacy of an intravitreal dexamethasone implant (IDI) for diabetic macular edema (DME) in vitrectomized eyes.MethodsThis interventional retrospective consecutive case series included vitrectomized eyes undergoing IDI placement for treatment of recalcitrant DME between June 2011 and June 2014. All patients had previously received anti‑VEGF therapy (ranibizumab or bevacizumab). Primary endpoints were changes in visual acuity (VA) and central retinal thickness (CRT) from baseline values one month after device implantation. Secondary endpoints were VA and CRT changes at 3 months.ResultsA total of 8 eyes of 8 patients met the inclusion criteria. One month after IDI placement, there was a significant (p = 0.01) improvement in VA from 0.79 ± 0.52 logMAR (20/123 Snellen equivalent) to 0.64 ± 0.55 logMAR (20/88), meanwhile CRT improved from 455.75 ± 123.19 to 295.00 ± 90.39 μm (p = 0.02). These findings persisted at 3 months.ConclusionIn vitrectomized eyes previously treated with anti‑VEGF agents for recalcitrant DME, implantation of the IDI appears to be efficacious in improving VA and CRT at 1‑month with the observed benefits persisting for at least for 3 months.Keywords: Diabetic Macular Edema, Dexamethasone, Ozurdex, Vitrectomy
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Page 188PurposeTo assess quality of life (QOL) in children undergoing strabismus surgery.MethodsThis prospective cohort study included 87 children (including 41 boys, 47.1%) with mean age of 8.7 ± 4.1 years at three academic eye hospitals in Tehran. A modified version of the RAND Health Insurance Study QOL questionnaire was filled based on interviews with parents before and three months after surgery. The questionnaire consisted of 36 Likert scale items ranging in score from 0 to 100, with higher scores representing better function. Relevant items were averaged together and categorized into 11 distinct QOL dimensions.ResultsThe majority of QOL dimensions improved after strabismus surgery including functional limitation (92.36 ± 16.78 vs. 82.15 ± 20.92, PConclusionStrabismus surgery positively impacts physical and psychosocial function in children. Children with a greater amount of correction experienced more QOL improvement after surgery.Keywords: Quality of Life, Strabismus, Surgery
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Page 193PurposeFornix contracture is an obstacle for fitting a prosthesis in blind or enucleated patients, and may lead to disfigurement and psychological issues. This study evaluates the efficacy of amniotic membrane transplantation (AMT) for fornix reconstruction with the aim of better retention of the ocular prosthesis.MethodsThis non‑comparative interventional case series includes eighteen blind eyes with fornix deformity in which a cosmetic prosthesis could not be retained. Various causative factors included symblepharon, cyst formation and fornix shortening after enucleation. AMT was performed along with correction of symblepharon, cicatrix release, and excision of the cyst with or without anchoring sutures to reform the fornix.ResultsMean fornix depth pre‑ and post‑operation were 3.72 ± 0.69 and 7.13 ± 0.81 mm, respectively. Fornix deepening was achieved successfully in 15 cases (83.33%). Partial success was achieved in 1 case (5.66%); the remaining two cases (11.11%) were considered as failure despite repeat surgery. Both of these patients suffered from extensive symblepharon formation. Satisfactory results, i.e. formation of a deep fornix to hold the ocular prosthesis, could be achieved in 16 (89.99%) cases. There were no serious complications such as infection or graft rejection.ConclusionAMT can be a viable option for fornix reconstruction. It has a high success rate in subjects with blind eyes and moderate fornix shortening who are unable to retain an ocular prosthesis.Keywords: Amniotic Membrane Transplantation, Fornix Reconstruction, Prosthesis, Shallow Fornix, Symblepharon
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Page 198PurposeTo assess the reliability of school teachers for vision screening of younger school children and to study the pattern of vision problems.MethodsIn this cross‑sectional study, trained school teachers screened 5,938 school children aged 3 to 8 years for vision and ocular disorders. Children were cross screened by professionals to assess the reliability of the teachers in vision screening and detecting ocular disorders in these children. The pattern of visual acuity, ametropia and ocular disorders was studied.ResultsSensitivity and specificity of the vision screening by school teachers was 69.2% 95% CI: 66.8‑71.5%) and 95.3% (95% CI: 94.5‑95.8%), respectively. The positive predictive value was 83.5% (95% CI: 81.4‑85.6%) and negative predictive value was 89.8% (95% CI: 88.8‑90.6%). The kappa statistic was 0.68 (95% CI: 0.66‑0.7).ConclusionSchool teachers could effectively screen younger school children for vision assessment and ocular disorders.Keywords: Ametropia, Vision Screening, Visual Acuity, Younger School Children
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Page 204Normal tension glaucoma (NTG) is labelled when typical glaucomatous disc changes, visual field defects and open anterior chamber angles are associated with intraocular pressure (IOP) constantly below 21 mmHg. Chronic low vascular perfusion, Raynaud`s phenomenon, migraine, nocturnal systemic hypotension and over‑treated systemic hypertension are the main causes of normal tension glaucoma. Goldmann applanation tonometry, gonioscopy, slit lamp biomicroscopy, optical coherence tomography and visual field analysis are the main tools of investigation for the diagnosis of NTG. Management follows the same principles of treatment for other chronic glaucomas: To reduce IOP by a substantial amount, sufficient to prevent disabling visual loss. Treatment is generally aimed to lower IOP by 30% from pre‑existing levels to 12‑14 mmHg. Betaxolol, brimonidine, prostaglandin analogues, trabeculectomy (in refractory cases), systemic calcium channel blockers (such as nifedipine) and 24‑hour monitoring of blood pressure are considered in the management of NTG. The present review summarises risk factors, causes, pathogenesis, diagnosis and management of NTG.Keywords: Normal Tension Glaucoma, Ocular Hypoperfusion, Vasospasm
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Page 209Glaucoma is a degenerative optic neuropathy characterized by retinal ganglion cell (RGC) loss and visual field defects. It is known that in some glaucoma patients, death of RGCs continues despite intraocular pressure (IOP) reduction. Neuroprotection in the field of glaucoma is defined as any treatment, independent of IOP reduction, which prevents RGC death. Glutamate antagonists, ginkgo biloba extract, neurotrophic factors, antioxidants, calcium channel blockers, brimonidine, glaucoma medications with blood regulatory effect and nitric oxide synthase inhibitors are among compounds with possible neuroprotective activity in preclinical studies. A few agents (such as brimonidine or memantine) with neuroprotective effects in experimental studies have advanced to clinical trials; however the results of clinical trials for these agents have not been conclusive. Nevertheless, lack of compelling clinical evidence has not prevented the off‑label use of some of these compounds in glaucoma practice. Stem cell transplantation has been reported to halt experimental neurodegenerative disease processes in the absence of cell replacement. It has been hypothesized that transplantation of some types of stem cells activates multiple neuroprotective pathways via secretion of various factors. The advantage of this approach is a prolonged and targeted effect. Important concerns in this field include the secretion of unwanted harmful mediators, graft survival issues and tumorigenesis. Neuroprotection in glaucoma, pharmacologically or by stem cell transplantation, is an interesting subject waiting for broad and multidisciplinary collaborative studies to better clarify its role in clinical practice.Keywords: Brimonidine, Ginkgo Biloba Extract, Glaucoma, Memantine, Neuroprotection, Stem Cell Transplantation
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Page 221PurposeScleritis is a rare presentation of herpes zoster ophthalmicus, complicated most commonly by iridocyclitis and raised intraocular pressure. These complications can recur in subsequent years, therefore they should be managed well.
Case Report: We describe a female patient who developed scleritis, complicated cataract and secondary glaucoma 2 years after being diagnosed by HZO. Secondary glaucoma was managed medically, and the patient underwent extracapsular cataract extraction for the complicated cataract. Final visual acuity was 6/6 and IOP was 22.4 mm Hg. This is a rare report describing favorable long‑term (>20 years) prognosis for surgical management of cataract associated with HZO together with scleritis, secondary glaucoma and post‑herpetic neuralgia.ConclusionA favorable outcome may be attained with surgery for complicated cataract associated with HZO if the condition is managed optimally and intraocular inflammation is well controlled.Keywords: Complicated Cataract, Herpes Zoster Ophthalmicus, Post‑herpetic Neuralgia, Scleritis, Secondary Glaucoma -
Page 225PurposeTo report hydrophilic acylic intraocular lens (IOL) opacification after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) in an eye with multiple prior intraocular surgeries and iatrogenic aniridia.
Case Report: A 34‑year‑old woman with history of penetrating keratoplasty (PKP) for advanced keratoconus and subsequent Urrets‑Zavalia Syndrome (UZS) underwent phacoemulsification and hydrophilic acrylic IOL implantation for her cataract. In order to control post‑PKP glaucoma, multiple glaucoma surgeries including two glaucoma drainage implants were performed. As the original corneal graft failed, the patient subsequently underwent re‑PKP. Four years later, she underwent DSAEK for treatment of the second graft failure. Ten months after DSAEK, a double semi‑circular pattern of IOL opacification was observed on the anterior surface of the IOL. The patient did not report any complaints and we decided not to exchange the IOL.ConclusionIn an eye with UZS and iatrogenic aniridia, IOL opacification may result from direct contact between the IOL surface and exogenous air. Aniridia can be a risk factor for development of IOL opacification after DSAEK. Further studies are required to confirm this hypothesis.Keywords: Descemet Stripping Automated Endothelial Keratoplasty, Hydrophilic Intraocular lens, Intracameral Air, Opacification -
Page 228PurposeTo describe a case of bilateral presumed tuberculous choroiditis which resolved promptly with a short course of antituberculous therapy.
Case Report: A 44‑year‑old lady presented with bilateral visual loss of 8 monthsduration. Considering the presence of pan‑uveitis, severe macular edema, multifocal leakage on fluorescein angiography, positive tuberculin skin test, and after excluding other diseases, she underwent anti‑tuberculous therapy (ATT) for disseminated choroiditis due to presumed ocular tuberculosis. She improved promptly and completely. There were no signs of relapse 18 months after completion of the treatment course. In a young patient with disseminated choroiditis and relatively short duration of symptoms, a course of ATT for 6 months may effectively treat the disease preventing relapse for a considerable period of time.ConclusionIn Presumed Tuberculous chroiditis early diagnosis is crucial for prompt and complete improvement.Keywords: Pan, uveitis, Presumed Ocular Tuberculosis, Tuberculous Choroiditis -
Page 231PurposeTo describe an unusual retinal manifestation of dengue fever in an endemic region.
Case Report: A 35 year old male presenting with acute onset decreased vision in his right eye, was found to have a massive retinal pigment epithelial detachment (PED) extending up to the vascular arcades. He had been diagnosed with acute hypokalemic quadriparesis in dengue fever in the preceding week, which had resolved following treatment. The patient was managed conservatively. At three months follow up, there was spontaneous flattening of the PEDs with improvement in visual acuity.ConclusionDengue fever complicated by acute hypokalemic quadriparesis can be associated with PED, which can be large. The condition resolves spontaneously and bears a good prognosis.Keywords: Dengue Fever, Flaccid Quadriparesis, Hypokalemia, Pigment Epithelial Detachment