Journal of Ophthalmic and Vision Research
Volume:9 Issue: 3, Jul-Sep 2014

To compare the outcomes of surgical procedures in the treatment of inferior oblique muscle overaction (IOOA) as a common disorder of ocular motility. 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. 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. We conclude that all these three procedures are effective for treatment of primary or secondary IOOA with minimum side‑effects.

To assess the agreement among ultrasonic pachymetry, the Galilei dual Scheimpflug analyzer, and Orbscan II for central and peripheral (Galilei vs. Orbscan) corneal thickness (CCT and PCT) measurement in normal and keratoconic eyes. In this prospective study, CCT and PCT were measured in 88 eyes of 88 refractive surgery candidates and 128 eyes of 69 keratoconic patients with ultrasonic pachymetry, the Galilei, and Orbscan II. The readings by the three instruments were compared using one‑way analysis of normal variance. Agreement among the three devices was assessed using Pearson and intraclass correlation coefficients, and Bland– Altman plots. The same analyses were employed to evaluate agreement between Galilei and Orbscan II for PCT measurement. In the normal group, mean CCT was 551.0±39.4, 566.9±33.5, and 565.5±40.9 μm measured by ultrasonic pachymetry, the Galilei, and Orbscan II, respectively (P<0.001). The corresponding figures in the keratoconus group were 492.0±61.7, 502.0±42.1, and 470.6±56.9 μm, respectively (P<0.001). Mean PCT was 612.5±35.3 and 640.9±38.0 μm in the normal group (P<0.001) and 567.6±35.2 and 595.1±41.4 μm in the keratoconus group (P<0.001) by the Galilei and Orbscan II, respectively. CCT and PCT measurements obtained by different devices were significantly correlated in both groups. To measure CCT, the Galilei and Orbscan II can be used interchangeably in normal eyes, but not in keratoconic eyes. For PCT, there is a systematic error between measurements obtained by the Galilei and Orbscan II. However, it is possible to change optical pachymeter readings into those obtained by ultrasonic pachymetry using a constant.

To compare the visual, refractive, and keratometric outcomes of single‑segment conventional and severe keratoconus (SK) types of Intacs for correction of inferior keratoconus (KCN). A total number of 41 consecutive eyes of 23 patients with a diagnosis of inferior KCN underwent Intacs implantation. Eight eyes were excluded due to postoperative complications (4 eyes) and loss to follow‑up (4 eyes) and finally 33 eyes underwent statistical analysis. Two groups were created according to Intacs type insertion; conventional group (17 eyes) and SK groups (16 eyes). Intracorneal ring segments (ICRS) implantation was indicated in keratoconic patients with contact‑lens intolerance or reduced best spectacle‑corrected visual acuity (BSCVA). In the conventional group, mean uncorrected distance visual acuity (UCDVA) improved from 0.45 ± 0.41 preoperatively to 0.69 ± 0.39 six months after surgery representing a gain of 2 Snellen lines, and in the SK group mean UCDVA changed from 0.40 ± 0.35 preoperatively to 0.58 ± 0.48 equivalent to two Snellen lines improvement 6 months after operation (P = 0.48). Mean preoperative BSCVA in the conventional group improved from 0.72 ± 0.41 to 0.86 ± 0.39 (2 lines improvement) postoperatively and in the SK group improved from 0.71 ± 0.69 to 0.75 ± 0.45 (0.50 line improvement) (P = 0.29). Mean preoperative spherical equivalent (SE) decreased from −4.86 ± 2.26 D to −3.57 ± 2.21 D (conventional group) and from −4.20 ± 1.82 D to −3.60 ± 1.89 D (P = 0.34), mean astigmatism (AST) decreased from −5.20 ± 2.07 D and −4.50 ± 2.26 D to −4.02 ± 2.57 D and − 3.18 ± 2.14 D in the conventional and SK groups, respectively (P = 0.68). Finally, mean K min decreased from 47.11 ± 2.51 D to 45.40 ± 3.30 D in the conventional group and from 45.05 ± 2.59 D to 44 ± 3.88 D in the SK group (P = 0.63) and mean K max was decreased from 52.82 ± 3.23 D to 50.52 ± 3.57 D and from 49.72 ± 3.17 D to 48.55 ± 4.50 D, respectively (P = 0.48). Single‑segment implantation of conventional and SK Intacs improved UCDVA and BSCVA, decreased corneal AST and keratometry in both groups with comparable outcomes.

To evaluate the effect of silicone oil (SO) on the corneal endothelium in SO filled phakic and pseudophakic vitrectomizied eyes. This prospective comparative consecutive case‑control study evaluated the corneal endothelial characteristics of 64 SO filled vitrectomizied eyes (case group) as compared to 46 vitrectomizied eyes without SO injection (control group). Endothelial cell densities (ECD), coefficient of variation (CV), and percentage of hexagonal cells (hexagonality) at the corneal center were evaluated preoperatively, 1 month and 6 months after surgery using noncontact specular microscopy and were compared between the two groups. Exclusion criteria were previous vitreoretinal surgery, aphakia, any degree of anterior chamber inflammation, SO bubbles in the anterior chamber and increased intraocular pressure in the postoperative period. Six months after SO injection, mean ECD was 2,438.2±327.6 cell/mm2 in the case group and 2,462.6±361.7 cell/mm2 in the control group (P = 0.714) and mean hexagonality was 49.6 ± 6.8 and 54.6 ± 8.9, in the case and control groups, respectively (P = 0.004). Six months after operation, CV in the case group was 39.3 ± 5.6 and that in the control group was 35.7 ± 6.4 (P = 0.003). Although the presence of SO in the vitreous cavity of phakic and pseudophakic eyes causes slight reduction in the number of endothelial cells, however it leads to significant changes in endothelial cell morphology. Thus, removal of SO after reaching the desired tamponade effect is recommended.

To compare different preparation methods for a suitable amniotic membrane (AM) extract containing a given amount of growth factors. In this interventional case series, we dissected the AM from eight placentas within 24 hours after delivery, under clean conditions. After washing and mixing, AM extracts (AMEs) were prepared using pulverization and homogenization methods, and different processing and storing conditions. Main outcome measures were the amount of added protease inhibitor (PI), the relative centrifugal force (g), in‑process temperature, repeated extraction times, drying percentage, repeated pulverization times, and the effect of filtering with 0.2 μm filters. Extract samples were preserved at different temperature and time parameters, and analyzed for hepatic growth factor (HGF) and total protein using ELISA and calorimetric methods, respectively. The extracted HGF was 20% higher with pulverization as compared to homogenization, and increased by increasing the PI to 5.0 μl/g of dried AM. Repeating centrifugation up to 3 times almost doubled the extracted HGF and protein. Storing the AME at −170° for 6 months caused a 50% drop in the level of HGF and protein. Other studied parameters showed no significant effect on the extracted amount of HGF or total protein. Appropriate extraction methods with an adequate amount of PI increases the level of extractable components from harvested AMs. To achieve the maximal therapeutic effects of AMEs, it is necessary to consider the half‑life of its bioactive components.

To evaluate changes in the concentration of tear immunoglobulins in contact lens wearers. A total of 45 cases including 23 contact lens wearers (43 eyes) and 22 age and sex matched healthy controls having no ocular pathology were studied for immunoglobulins (IgA, IgG, IgM) in their tears by single radial immunodiffusion method. Most of the cases used soft (56.6%) and semi‑soft gas permeable (30.4%) contact lenses. Tear IgM was detected in only 17.4% and tear IgG in 43.6% of contact lens wearers, while in controls IgG was detected in 9.1% but none of the controls had IgM. There was a significant rise in total tear IgA 13.17 ± 4.44 mg/dl) in contact lens wearer as compared to controls (8.93 ± 3.79 mg/dl). Rise of tear IgA was more in symptomatic patients (15.38 ± 5.28 mg/dl) and in those wearing hard (19.73 ± 5.43 mg/dl) and semi‑soft contact lenses (13.31 ± 5.43 mg/dl). A significant increase in tear IgA was noticed in subjects wearing lenses for >3 years (15.69 ± 5.39 mg/dl). About 43.4% of lens wearers were symptomatic and 80% of their lenses showed deposits and/or haziness. All cases with IgM in tear were symptomatic. The relation of immunoglobulin concentration with increasing duration of wear and material of contact lens shows that tear immunoglobulin rise accrues due to mechanical stimulation, hence contact lenses should not be used for a long period and lenses of hard nature should be discouraged. The maintenance, cleaning and deproteinization of the lenses are of high importance to avoid immunostimulation.

To assess the refractive and visual outcomes following cataract surgery and implantation of the AcrySof IQ Toric SN6AT2 intraolcular lens (IOL) (Alcon Laboratories, Inc., Fort Worth, TX, USA) in patients with low corneal astigmatism. This study is a retrospective, consecutive, single surgeon series of 98 eyes of patients (with low preoperative corneal astigmatism) undergoing cataract surgery and implantation of the AcrySof IQ Toric SN6AT2 IOL. Postoperative measurements were obtained 1‑month postsurgery. Main outcome measures were monocular distance visual acuity and residual refractive astigmatism. Mean preoperative corneal astigmatic power vector (APV) was 0.38±0.09 D. Following surgery and implantation of the toric IOL, mean postoperative refractive APV was 0.13±0.10 D. Mean postoperative distance uncorrected visual acuity was 0.08±0.09 logMAR. Postoperative spherical equivalent refraction (SER) resulted in a mean of −0.23±0.22 D, with 96% of eyes falling within 0.50 D of the target SER. The AcrySof IQ Toric SN6AT2 IOL is a safe and effective option for eyes undergoing cataract surgery with low levels of preoperative corneal astigmatism.

To compare the effectiveness of topical and sub‑Tenon’s anesthesia in providing pain relief during phacoemulsification. This randomized controlled trial was carried out at a tertiary eye care hospital, Coimbatore, Tamil Nadu, India. Patients who underwent phacoemulsification through self‑sealing clear corneal incision with foldable intra‑ocular lens implantation were randomized into two groups. Group 1 (n = 100) received topical anesthesia with 0.5% proparacaine (Paracaine, Sunways India Pvt. Ltd., India) drops. Group 2 (n = 100) received sub‑Tenon’s infiltration with 2% lignocaine (Xylocaine, AstraZeneca Pharma India Pvt. Ltd., India). As per study criteria, patients graded the pain during administration of anesthesia, during surgery and after surgery on a visual analogue pain scale. The surgeon graded overall patient co‑operation. The complications were also noted. Data analysis was performed using Statistical Package for Social Sciences version 11. Student’s t‑test and Chi‑square test were used for comparison of variables between the groups. Sub‑Tenon’s anesthesia provided statistically significant better intra‑operative pain relief and patient satisfaction than topical anesthesiat. No statistically significant difference was noted between the two groups regarding pain during administration, postoperative pain, and surgeon satisfaction. Sub‑Tenon’s anesthesia provides better pain relief than topical anesthesia during phacoemulsification.

To evaluate fundus autofluorescence (FAF) changes in patients with chronic essential hypertension (HTN). In this case-control study, 35 eyes of 35 patients with chronic essential HTN (lasting >5 years) and 31 eyes of 31 volunteers without history of HTN were included. FAF pictures were taken from right eyes of all cases with the Heidelberg retina angiography and then were assessed by two masked retinal specialists. In total, FAF images including 35 images of hypertensive patients and 31 pictures of volunteers, three apparently abnormal patterns were detected. A ring of hyper‑autofluorescence in the central macula (doughnut-shaped) was observed in 9 (25.7%) eyes of the hypertensive group but only in 2 (6.5%) eyes of the control group. This difference was statistically significant (P = 0.036) between two groups. Hypo‑ and/or hyper‑autofluorescence patches outside the fovea were the other sign found more in the hypertensive group (22.9%) than in the control group (6.5%); however, the difference was not statistically significant (P = 0.089). The third feature was hypo‑autofluorescence around the disk noticed in 11 (31.4%) eyes of hypertensive patients compared to 8 (25.8%) eyes of the controls (P = 0.615). A ring of hyper‑autofluorescence in the central macula forming a doughnut shaped feature may be a FAF sign in patients with chronic essential HTN.

To evaluate the malondialdehyde (MDA) and total thiol (sulfhydryl, SH) levels in rat corneas after intraperitoneal injection of amantadine sulfate. A total of 12 Wistar albino rats were divided into two groups: control group (n = 6) and amantadine group (n = 6). Balanced salt solution (1 mL, 0.9% NaCl, twice/day) was injected into rats in control group. Amantadine sulfate (2 mg/1 mL, twice/day) was injected into rats in amantadine group. In each group, two rats were injected for 1 week, two received injections for 1 month, and two rats received injections for 3 months. The corneas were homogenized and MDA and SH levels were measured spectroflourometrically. In control group, median MDA and SH levels were 2.37 (range, 0.92-3.60) and 25.35 (range, 6.30-54.0) nmol/mg, respectively. In amantadine group, median MDA and SH levels were 3.57 (range, 1.25-5.92) and 32.65 (range, 3.30-48.3) nmol/mg, respectively. The difference between this two groups regarding MDA (P = 0.14) and SH (P = 1.0) levels was statistically insignificant. Systemically administered amantadine sulfate seems not to cause MDA and SH imbalance in rat corneas.

To evaluate the demographics and management outcomes of strabismus surgery in patients with third cranial nerve palsy. This retrospective study includes subjects with third cranial nerve palsy. We evaluated age, sex, laterality, severity of involvement, etiology, frequency of clinical findings, and types and results of treatments. 52 patients including 29 male and 23 female subjects with mean age of 21.1±15.5 years were studied between January 1999 and January 2009. Etiologies of third nerve palsy included congenital in 16 (30.8%), trauma in 26 (50%) and other causes in 10 (19.2%) patients. In 24 patients (46.2%), the palsy was complete. The most common type of strabismus was exotropia associated with hypotropia (40%). Medical treatment was used in 25 (48%) and surgical treatment in 46 (88.4%) subjects. One time strabismus surgery was performed in 30 (65.2%), 2 times in 11 (24%) and 3 times in 5 (10.8%) subjects. The most common operation was large horizontal recession and resection in 78.2% of cases. Mean horizontal deviation in primary position was 66±29 prism diopters (PD) before surgery decreasing to 21±19, 13±12 and 6±8 PD after first, second and third surgery, respectively. Corresponding figures for mean vertical deviation were 13±15, 7±12, 4±6 and 1±2 PD, respectively. Abnormal head posture was 10-30° in 11 (21.1%) cases before treatment which completely resolved after surgery. Surgical management of strabismus in patients with third nerve palsy is difficult and challenging, however the majority of patients achieve ideal results with appropriate and stepwise surgical plans.

Birdshot retinochoroidopathy (BSRC) is an uncommon, but well‑characterized chronic, bilateral posterior uveitis, which is uniquely associated with the human leukocyte antigen‑A29 phenotype. The disease presents predominantly in middle‑aged Caucasian females who complain of blurred vision, floaters, photopsias, paracentral scotomas and nyctalopia. While autoimmune mechanisms are thought to play an important role in the pathogenesis of BSRC, its etiology remains unknown. Important questions remain in our understanding of BSRC with respect to its pathogenesis, epidemiology, optimal treatment, and prognosis, including the determinants of remission and relapse, as well as the best strategy for monitoring disease activity, progression and response to therapy with electroretinographic and psychophysical testing, established and emerging imaging modalities, and peripheral cytokines profiles.

Diabetes predominantly affects the microvascular circulation of the retina resulting in a range of structural changes unique to this tissue. These changes ultimately lead to altered permeability, hyperproliferation of endothelial cells and edema, and abnormal vascularization of the retina with resulting loss of vision. Enhanced production of inflammatory mediators and oxidative stress are primary insults with significant contribution to the pathogenesis of diabetic retinopathy (DR). We have determined the identity of the retinal vascular cells affected by hyperglycemia, and have delineated the cell autonomous impact of high glucose on function of these cells. We discuss some of the high glucose specific changes in retinal vascular cells and their contribution to retinal vascular dysfunction. This knowledge provides novel insight into the molecular and cellular defects contributing to the development and progression of diabetic retinopathy, and will aid in the development of innovative, as well as target specific therapeutic approaches for prevention and treatment of DR.

Optogenetics is the use of genetic methods combined with optical technology to achieve gain or loss of function within neuronal circuits. The field of optogenetics has been rapidly expanding in efforts to restore visual function to blinding diseases such as retinitis pigmentosa (RP). Most work in the field includes a group of light‑sensitive retinaldehyde‑binding proteins known as opsins. Opsins couple photon absorption to molecular signaling chains that control cellular ion currents. Targeting of opsin genes to surviving retinal cells is fundamental to the success of optogenetic therapy. Viral delivery, primarily adeno‑associated virus, using intravitreal injection for inner retinal cells and subretinal injection for outer retinal cells, has proven successful in many models. Challenges in bioengineering remain for optogenetics including relative insensitivity of opsins to physiologic light levels of stimulation and difficulty with viral delivery in primate models. However, targeting optogenetic therapy may present an even greater challenge. Neural and glial remodeling seen in advanced stages of RP result in reorganization of remaining neural retina, and optogenetic therapy may not yield functional results. Remodeling also poses a challenge to the selection of cellular targets, with bipolar, amacrine and ganglion cells all playing distinct physiologic roles, and affected by remodeling differently. Although optogenetics has drawn closer to clinical utility, advances in opsin engineering, therapeutic targeting and ultimately in molecular inhibition of remodeling will play critical roles in the continued clinical advancement of optogenetic therapy.

We report three cases of Stenotrophomonas maltophilia endophthalmitis after uneventful extracapsular cataract extraction with intraocular lens implantation‑related to surgical equipment contamination.Case report: All patients developed acute, culture‑positive endophthalmitis in a period ranging from 2 to 13 days. Cultures from vitreous tap, as well as those obtained from the hand‑piece of the irrigation‑aspiration system, revealed S. maltophilia as the causing infectious agent. All patients received intravitreal antibiotic treatment as initial therapy, nevertheless, visual disturbance continued to be present, hence pars plana vitrectomy was required. Contamination of surgical‑reusable equipment should be considered in addition to the well‑known risk factors associated with development of endophthalmitis by S. maltophilia.

To report a case of adult retinoblastoma with a wrong diagnosis of melanoma. Case report: Herein, we present an adult retinoblastoma case who was misdiagnosed as melanoma in fine‑needle aspiration biopsy with intravitreal hemorrhage and later neovascular glaucoma after biopsy. The diagnosis of retinoblastoma was confirmed after enucleation. Retinoblastoma should be considered in the differential diagnosis of an intraocular mass in adults, especially when media haziness precludes adequate ophthalmoscopic visualization.

The authors report the long-term results of combined conjunctival autograft and overlay amniotic membrane transplantation (AMT) for treatment of pterygium as a new surgical technique. Nineteen patients including 12 male and 7 female subjects with pterygium (primary, 14 cases; recurrent, 5 cases) underwent combined conjunctival autograft and overlay AMT and were followed from 10 to 26 months. Mean age was 44.21±12.49 (range, 29.0-73.0) years. In one patient with grade T3 primary pterygium, the lesion recurred (5.2%, recurrence rate). No intra-and postoperative complication developed. This procedure seems a safe and effective surgical technique for pterygium treatment. Protection of the ocular surface during the early postoperative period reduces the friction-induced inflammation and might be helpful to prevent the recurrence.