Corneal Parameters in Healthy Subjects Assessed by Corvis ST

Purpose: To evaluate corneal biomechanics using Corvis ST in healthy eyes from Iranian keratorefractive surgery candidates. Methods: In this prospective consecutive observational case series, the intraocular pressure (IOP), central corneal thickness (CCT), and biomechanical properties of 1,304 eyes from 652 patients were evaluated using Corvis ST. Keratometric readings and manifest refraction were also recorded. Results: The mean (±SD) age of participants was 28 ± 5 years, and 31.7% were male. The mean spherical equivalent refraction was –3.50 ± 1.57 diopters (D), the mean IOP was 16.8 ± 2.9 mmHg, and the mean CCT was 531 ± 31 μm for the right eye. The respective means (±SD) corneal biomechanical parameters of the right eye were as follows: first applanation time: 7.36 ± 0.39 milliseconds (ms); first applanation length: 1.82 ± 0.22 mm; velocity in: 0.12 ± 0.04 m/s; second applanation time: 20.13 ± 0.48 ms; second applanation length: 1.34 ± 0.55 mm; velocity out: –0.67 ± 0.17 m/s; total time: 16.84 ± 0.64 ms; deformation amplitude: 1.05 ± 0.10 mm; peak distance: 4.60 ± 1.01 mm; and concave radius of curvature: 7.35 ± 1.39 mm. In the linear regression analysis, IOP exhibited a statistically significant association with the first and second applanation times, total time, velocity in, peak distance, deformation amplitude, and concave radius of curvature. Conclusion: Our study results can be used as a reference for the interpretation of Corvis ST parameters in healthy refractive surgery candidates in the Iranian population. Our results confirmed that IOP is a major determinant of Corvis parameters

Inferior Spear-like Lens Opacity as a Sign of Keratoconus

Purpose: To report 21 cases of typical inferior feather-shape lens opacity associated with keratoconus. Methods: In this cross-sectional study, we evaluated the association of keratoconus with inferior feather-shape lens opacity in refractive surgery candidates. Visual acuity, demographic, refractive, and topographic characteristics of 26 eyes of 21 patients with inferior feather-shape lens opacity were evaluated in detail. Pedigree analysis was also performed to assess possible inheritance. Results: Overall, 2122 out of 33,368 cases (6.4%) without lens opacity had keratoconus, while 20 out of 21 patients (95.2%) with peculiar lens opacity had definite keratoconus (P < 0.001). Lens opacity was bilateral in 5 cases (24%), and keratoconus was bilateral in all 20 patients with lens opacity. Nine eyes out of thirty-six with a complete data record (25%) had severe keratoconus and underwent deep lamellar keratoplasty, while 11 (31%) had forme fruste keratoconus. Pedigrees were drawn for eight patients, most families of whom suggested an X-linked recessive inheritance. Conclusion: The present study was the first to investigate patients with a peculiar inferior feather-shape lens opacity accompanied by bilateral keratoconus, which was observed in 95% of the patients. This finding should raise awareness as to the possibility of diagnosing keratoconus in the eyes of the patients with these characteristics

Acute Progressive Visual Loss in a Case of Acute Myeloid Leukemia: Challenges in the Utility of Molecular Tests in Early Diagnose of Cytomegalovirus Retinitis

Cytomegalovirus (CMV) retinitis is one of the rare but debilitating presentations of the CMV infection in children with leukemia. Herein, we report a 12-year-old boy with acute myeloid leukemia complicated by rapid progressive visual loss during relapse of leukemia. The definite diagnosis of CMV retinitis was made after vitreous aspiration. Despite prompt treatment and ophthalmologic intervention, he died because of AML relapse. Viral infections, especially cytomegalovirus infection, may present with vague clinical pictures during any time of chemotherapy, which may not be easily distinguishable from bacterial or fungal retinitis and also chemotherapy-induced retinopathies. Clinician should consider CMV retinitis in seropositive patients especially those without detectable viremia

Spectral domain optical coherent tomography demonstrates structural retinal changes in isolated cilioretinal artery occlusion

This report demonstrates the structural retinal changes observed in-vivo by spectral domain optical coherent tomography (SD-OCT) in a case of isolated cilioretinal artery occlusion.  A 32-year-old woman presented one week following acute sudden painless loss of vision.  Ophthalmoscopy revealed macular edema and a cherry red spot.  Fluorescein angiography one week post-infarction demonstrated a large patch of macular hypoflorescence in the distribution of the cilioretinal artery, with perfusion of the cilioretinal artery.  Within this same macular distribution, SD-OCT demonstrated increased reflectivity, with increased reflectivity of the inner nuclear, inner plexiform, and ganglion cell layers.  A sharp boundary was present between normal and infarcted macula on SD-OCT imaging.  SD-OCT is a useful tool for diagnosing and identifying the extent of retinal vascular occlusion

Changes in ocular biometry and anterior chamber parameters after pharmacologic mydriasis and peripheral iridotomy in primary angle closure suspects

Purpose: The aim of this study was to evaluate the effects of pharmacologic mydriasis and Peripheral Iridotomy (PI) on ocular biometry and anterior chamber parameters in primary angle closure suspects. Methods: In this prospective interventional case series, 21 primary angle closure suspects were enrolled. Intraocular pressure, refraction, ocular biometry (Lenstar, LS900), and anterior chamber parameters (Pentacam HR) were measured at four occasions: before PI (before and after mydriasis with phenylephrine) and two weeks after PI (before and after mydriasis). The study was conducted on both eyes and only one eye per patient, in random, was included in the analysis. Results: The mean age of the participants was 60 ± 7 years and 17 (81%) were female. There were no significant differences in intraocular pressure, refraction, keratometry, biometric and anterior chamber parameters between groups, except for anterior chamber volume, which showed increments with PI and mydriasis. The corresponding values for anterior chamber volume were as follows: 88.2 ± 13.7 mm3 before PI, undilated; 106.3 ± 18.8 before PI, dilated; 99.0 ± 14.6 after PI, undilated, and 107.4 ± 16.5 after PI, dilated (P < 0.001). Conclusions: This study showed no change in the ocular biometric and anterior chamber parameters including iridocorneal angle after PI and/or pharmacologic mydriasis except for increments in anterior chamber volume. This factor has the potential to be used as a numerical proxy for iris position in evaluating and monitoring patients with primary angle closure suspects after PI

Author’s Reply to Prevalence of Visual Impairment in School Children

This is a Reply Letter and does not have an abstract

Water drinking test: Intraocular pressure changes after tube surgery and trabeculectomy

Purpose: To study the effects of filtration surgeries (tube and trabeculectomy) on changes in intraocular pressure after a water-drinking test. Methods: In this prospective, non-randomized, comparative clinical study, 30 patients who had tube surgery and 30 age- and sex-matched trabeculectomy patients underwent a water-drinking test. Only one eye of each patient was included. The baseline intraocular pressure was ≤21 mmHg in all enrolled eyes with or without adjunctive topical medications. After the water-drinking test, the intraocular pressure was measured and recorded at 15, 30, 45, and 60 minutes and the results were compared between the two groups. Results: In both groups, intraocular pressure significantly increased from baseline at all measured time-points (P < 0.001). In the trabeculectomy group, the average intraocular pressure increased from 14.8 ± 2.9 to 18.8 ± 4.7 mmHg at 30 minutes, but decreased at 60 min (18.0 ± 5.2 mmHg). In the Tube group, intraocular pressure increased incrementally until the last measurement (14.2 ± 3.9, 18.8 ± 5.6, and 19.7 ± 6.0 mmHg at baseline, 30, and 60 minutes, respectively). The end-pressure difference (intraocular pressure at 60 minutes vs. baseline) was significantly greater in the tube group (5.6 ± 3.6 mmHg; 41% change) than in the trabeculectomy group (3.2 ± 4.7; 23% change; P = 0.03). Conclusion: Intraocular pressure significantly increased after the water-drinking test in both the groups. Intraocular pressure started to decline 30 minutes after the water-drinking test in the trabeculectomy group, while it continued to increase up to 60 minutes in the Tube group. This finding may have implications regarding the efficacy or safety of the procedures in advanced glaucoma patients

Botulinum toxin injection for treatment of acute traumatic superior oblique muscle palsy

Purpose: To evaluate the outcomes of botulinum toxin injection into the inferior oblique (IO) muscle for management of unilateral acute traumatic superior oblique (SO) palsy. Methods: In this prospective case series, 10-20 units of botulinum toxin A (Dysport, Ipsen, Biopharm Ltd., Wrexham, UK) was injected into the ipsilateral IO muscle of 13 consecutive patients with unilateral acute traumatic SO palsy. All patients received injections within four weeks of the incident. Results: Mean age was 29 ± 15 years and 12 (92%) subjects were male. Mean amount of hypertropia (in primary position) was decreased from 10.0 ± 3.9Δ at baseline to 4.6 ± 8.9Δ, one month after the injection, and to 1.5 ± 2.7Δ at final follow-up (P = 0.001). IO overaction improved from 2.7 ± 0.6 to 1.0 ± 1.2 and 0.6 ± 0.9 (P ≤ 0.001), and subjective torsion from 5.3 ± 3.9 to 3.2 ± 3.4 and 1.6 ± 2.5 degrees (P ≤ 0.001), at the same time intervals respectively. One month after the injection as well as at final follow-up, 10 (77%) patients were diplopia-free in primary and reading positions. Subgroup analysis showed that patients who recovered had less baseline hypertropia as compared to those who failed (8.3Δ vs. 15.7Δ, respectively; P = 0.01). All patients with a favorable outcome had baseline hypertropia of 10Δ or less. Conclusion: A single injection of BTA into the IO muscle can rapidly and safely resolve symptomatic diplopia in patients with acute traumatic SO palsy, while waiting for spontaneous recovery

Corneal wasp sting: A case report and review of literature

Purpose: To report severe immunologic and toxic reaction due to corneal wasp sting that may cause catastrophic sight-threatening outcomes. Methods: A 45-year-old man referred to the emergency room with corneal wasp sting of Vespa Orientalis. The authors review previous Medline literature about this topic. Results: In our case, the response to frequent topical corticosteroid was dramatic, and at the seventh day after injury, all inflammatory responses in the anterior segment of the eye had been resolved. Conclusion: Corneal wasp injury with Vespa Orientalis can cause severe inflammation of the cornea and the anterior segment. Topical corticosteroids are the mainstay of treatment. Keywords: Wasp, Sting, Corne