Zunaina Embong

Specific detection of fungal pathogens by 18S rRNA gene PCR in microbial keratitis

BackgroundThe sensitivity and specificity of 18S rRNA polymerase chain reaction (PCR) in the detection of fungal aetiology of microbial keratitis was determined in thirty patients with clinical diagnosis of microbial keratitis.MethodsCorneal scrapings from patients were used for Gram stain, culture and PCR analysis. PCR was performed with primer pairs targeted to the 18S rRNA gene. The result of the PCR was compared with conventional culture and Gram staining method. The PCR positive samples were identified by DNA sequencing of the internal transcribed spacer (ITS) region of the rRNA gene. Main outcome measures were sensitivity and specificity of PCR in the detection of fungus in corneal keratitis.ResultsCombination of microscopy and culture gave a positive result in 11 of 30 samples of microbial keratitis. PCR detected 10 of 11 samples that were positive by conventional method. One of the 19 samples that was negative by conventional method was positive by PCR. Statistical analysis revealed that the PCR to have a sensitivity of 90.9% and specificity of 94.7% in the detection of a fungal aetiology in microbial keratitis.ConclusionPCR is a rapid, sensitive and useful method to detect fungal aetiology in microbial keratitis.

Syphilitic uveitis: report of 3 cases.

AIM To evaluate the clinical manifestations and visual outcome of syphilitic uveitis patients. METHODS Case series of three patients with syphilitic uveitis who were managed in Hospital USM. RESULTS Three patients were diagnosed to have uveitis secondary to Syphilis. All three patients were not known to have syphilis prior to presentation but have positive history of sexual promiscuity. All patients presented with progressive blurring of vision for average of one-month duration. Two of them have association with fever, ocular pain and floaters. Visual acuity at presentation ranges from 6/12 to hand movement. Mild anterior uveitis (non-granulomatous), vitritis and papillitis were presence in all the patients. First patient has multifocal chorioretinitis with exudative retinal detachment. The second patient presented with exudative retinal detachment while the third patient has chorioretinitis only. All the patients were treated with intramuscular benzyl-penicillin 2.4 MU weekly for 4 weeks and two of them received oral doxycycline 200mg twice daily for 3 months. The uveitis responded well to the treatment and two of them showed dramatic visual improvement from 6/120 to 6/21 and 6/12 to 6/6. The one with worse outcome was confirmed to have positive retroviral. CONCLUSION Ocular syphilis presented here as non-granulomatous inflammation associated with exudative retinal detachment. Final visual outcome is generally good despite slow improvement after treatment.

Optic perineuritis secondary to tuberculosis: A rare case presentation

Abstract A 58-year-old Malay lady, presented with gradual loss of vision in the right eye for 1 month duration. It was associated with right sided headache, nausea and vomiting. Patient had a history of contact with tuberculosis patient. On examination, visual acuity in right eye was no perception of light with presence of relative afferent pupillary defect. The left eye visual acuity was 6.0/7.5. There was a total restriction of extraocular movement in all direction (frozen eye) in the right eye. Both anterior segments were unremarkable. Fundoscopy in both eyes showed normal appearance of optic disc and retinal vessels. Other cranial nerves were normal. Lungs were clear and had no lymphadenopathy. Chest radiograph was normal. Erythrocyte sedimentation rate was elevated by 35 mm/h and Mantoux test was positive (20 mm). MRI of brain and orbit demonstrated thickening and irregularity of the right optic nerve on axial view with doughnut sign on coronal view. Patient was diagnosed to have optic perineuritis secondary to tuberculosis. She was treated with anti-TB drugs. Systemic corticosteroid was commenced after 2 weeks. The visual acuity was improved to hand motion after 1 month with almost complete resolution of extraocular movement.

Prediction error and accuracy of intraocular lens power calculation in pediatric patient comparing SRK II and Pediatric IOL Calculator

BackgroundDespite growing number of intraocular lens power calculation formulas, there is no evidence that these formulas have good predictive accuracy in pediatric, whose eyes are still undergoing rapid growth and refractive changes. This study is intended to compare the prediction error and the accuracy of predictability of intraocular lens power calculation in pediatric patients at 3 month post cataract surgery with primary implantation of an intraocular lens using SRK II versus Pediatric IOL Calculator for pediatric intraocular lens calculation. Pediatric IOL Calculator is a modification of SRK II using Holladay algorithm. This program attempts to predict the refraction of a pseudophakic child as he grows, using a Holladay algorithm model. This model is based on refraction measurements of pediatric aphakic eyes. Pediatric IOL Calculator uses computer software for intraocular lens calculation.MethodsThis comparative study consists of 31 eyes (24 patients) that successfully underwent cataract surgery and intraocular lens implantations. All patients were 12 years old and below (range: 4 months to 12 years old). Patients were randomized into 2 groups; SRK II group and Pediatric IOL Calculator group using envelope technique sampling procedure. Intraocular lens power calculations were made using either SRK II or Pediatric IOL Calculator for pediatric intraocular lens calculation based on the printed technique selected for every patient. Thirteen patients were assigned for SRK II group and another 11 patients for Pediatric IOL Calculator group. For SRK II group, the predicted postoperative refraction is based on the patients axial length and is aimed for emmetropic at the time of surgery. However for Pediatric IOL Calculator group, the predicted postoperative refraction is aimed for emmetropic spherical equivalent at age 2 years old. The postoperative refractive outcome was taken as the spherical equivalent of the refraction at 3 month postoperative follow-up. The data were analysed to compare the mean prediction error and the accuracy of predictability of intraocular lens power calculation between SRK II and Pediatric IOL Calculator.ResultsThere were 16 eyes in SRK II group and 15 eyes in Pediatric IOL Calculator group. The mean prediction error in the SRK II group was 1.03 D (SD, 0.69 D) while in Pediatric IOL Calculator group was 1.14 D (SD, 1.19 D). The SRK II group showed lower prediction error of 0.11 D compared to Pediatric IOL Calculator group, but this was not statistically significant (p = 0.74). There were 3 eyes (18.75%) in SRK II group achieved acccurate predictability where the refraction postoperatively was within ± 0.5 D from predicted refraction compared to 7 eyes (46.67%) in the Pediatric IOL Calculator group. However the difference of the accuracy of predictability of postoperative refraction between the two formulas was also not statistically significant (p = 0.097).ConclusionsThe prediction error and the accuracy of predictability of postoperative refraction in pediatric cataract surgery are comparable between SRK II and Pediatric IOL Calculator. The existence of the Pediatric IOL Calculator provides an alternative to the ophthalmologist for intraocular lens calculation in pediatric patients. Relatively small sample size and unequal distribution of patients especially the younger children (less than 3 years) with a short time follow-up (3 months), considering spherical equivalent only.

Intravitreal ranibizumab in treating extensive traumatic submacular hemorrhage

Herein, we report our experience in treating extensive traumatic submacular hemorrhage with a single dose of intravitreal ranibizumab. A 23-year-old healthy Malay man presented with a progressive reduction of central vision in the left eye of 2 days’ duration following a history of blunt trauma. Visual acuity was reduced to counting fingers. Examination revealed infero-temporal subconjunctival hemorrhage, traumatic anterior uveitis, and an extensive sub-macular hemorrhage with suspicion of a choroidal rupture in the affected eye. He was initially treated conservatively with topical prednisolone acetate 1%. The subconjunctival hemorrhage and anterior uveitis resolved but his vision remained poor with minimal resolution of the submacular hemorrhage at 1 week follow-up (day 12 post-trauma). In view of the poor resolution of submacular hemorrhage, he was treated with a single dose of 0.5 mg intravitreal ranibizumab at day 20 post-trauma. At 4 weeks post-intravitreal ranibizumab, there was an improvement in visual acuity (from counting fingers to 6/45) and complete resolution of the submacular hemorrhage with presence of a choroidal rupture scar temporal to the fovea, which was not seen clearly at presentation due to obscuration by blood. His visual acuity further improved to 6/18 at 3 months post-trauma. Although this single case had a favorable outcome, a large population cohort study is needed to establish the effectiveness of intravitreal ranibizumab in treating extensive traumatic submacular hemorrhage.

Orbital apex syndrome after tooth extraction in an immunocompromised patient.

A 60 year-old man presented with acute on set of left eye proptosis and ptosis. It was associated with poor vision, eye pain and restriction of eye movement of the same eye after 5 hours post left upper molar tooth extraction. The visual acuity in the left eye was hand movement. There was severe ptosis and proptosis of the left eye. The conjunctiva was chemotic with quite anterior chamber. The pupil was mid dilated and sluggished to light. The ocular movement was restricted in all directions. Fundoscopy of the left eye revealed features of central retinal artery occlusion with hyperaemic disc and subretinal exudates at posterior pole. The right eye appeared normal. Urgent MRI brain and orbit revealed severe left paranasal sinusitis with anterior displacement of the left globe and presence orbital abscess. Patient was managed with Otorhinolaryngology and Neurosurgery teams. He underwent emergency transnasal drainage of abscess. Histopathological examination of unhealthy sinus mucosa showed evidence of fungal infection. However, the culture and sensitivity result was inconclusive. Patient was treated with amphotericin B, ceftriaxone, amoxicillin clavulanate and metronidazole. Patient was detected to have high blood sugar level and was managed accordingly. The proptosis improved with treatment. However, his vision, ptosis and ophthalmoplegia remained static. Assessing the immunocompromised status is important for the management of patient presented as acute orbital apex syndrome to avoid fatal outcome.

Spontaneous Bilateral Anterior Lens Dislocation in an 8-Year-Old Girl

The authors describe recurrent lens dislocation into the anterior chamber in a young girl with homocystinuria. The patients 12-year-old sister died after a cerebrovascular accident caused by the same disease. This report highlights the importance of early dietary restrictions and treatment.