Refractive surprise: twice the SMILE

A 35-year-old man presented with decreased vision in his left eye following small incision lenticule extraction (SMILE) surgery. The refractive error after surgery was nearly twice his preoperative refractive error in the left eye. The patient was diagnosed as having a retained lenticule after SMILE surgery, which was folded on itself and was successfully managed by conversion to a flap. Postoperatively, the patient maintained good uncorrected visual acuity and a low refractive error, with the best spectacle corrected acuity of 20/20.

Self-medication complicating pseudo membranous conjunctivitis

We aim to highlight the prevalence of using local medications for curing eye ailments in a rural population and the harmful consequence of resultant disease, ranging from something as mild as conjunctivitis to sight-threatening conditions. This case report will address one such incidence where in a local village, the doctor known as a registered medical practitioner) in the rural community, uses local remedies for his conjunctivitis and ends up in a condition where he cannot see anything beyond perceiving light. The membrane removal and treatment with topical antibiotic cured his infection, restoring complete recovery of vision. This incidence inspired the local village doctor to become an eye health educator. He was motivated to spread awareness about the ill effects of self-medication on eye health. He is also determined to bring all blind people and others who need eye care from his remote village to our centre.

Optimising the surgical outcome in a case of post-traumatic cataract using ultrasound biomicroscopy

A 12-year-old boy was brought with the chief complaint of diminution of vision in his left eye for the past 1 month. History revealed a blunt trauma to his left eye with a wooden stick 6 weeks ago.Visual acuity was 20/20 and hand movement close to face in right and left eye, respectively, without any relative afferent pupillarydefect. Slit-lamp examination showed a total cataractous lens with signs suggestive of suspected posterior capsular (PC) defect. The PC defect was screened initially using B-scan ultrasound of the posterior segment, followed by confirmation of the same using ultrasound biomicroscopy. Left eye lens aspiration along with limited anterior vitrectomy followed by placement of multipiece intraocular lens in the sulcus was performed. Best-corrected visual acuity at 6 months of follow-up was 20/20.

Anterior segment optical coherence tomography angle and vault analysis after toric and non-toric implantable collamer lens V4c implantation in patients with high myopia

OBJECTIVE

To assess anterior segment changes, including iridocorneal angle and vault, after toric and non-toric implantable collamer lens (ICL) V4c (STAAR Surgical AG) implantation under different lighting conditions.

METHODS

Longitudinal, prospective, case series. Patients with high myopia (>6 dioptres) underwent toric and non-toric ICL V4c implantation. Optical coherence tomography measurements were taken under different lighting conditions preoperatively and at 1 week and 1, 6 and 12 months of follow-up.

RESULTS

Seventy-six eyes of 42 patients underwent ICL V4c implantation. Mean age was 27.4 years (±5.14 years, range 20 to 39 years). The average iridocorneal angle showed a statistically significant decrease (p<0.05) in all mesopic, scotopic and photopic conditions after 1 week of surgery compared with the preoperative measurements; in mesopic conditions, it decreased 14.1°, in photopic conditions 14.8° and scotopic conditions 13.2°. The angle measurement had a statistically significant change only in mesopic conditions (p=0.01) over the 1-year follow-up. The average vault under mesopic conditions was 0.661±0.21 mm at week 1. The vault measurement change was statistically significant over the 1-year follow-up in mesopic conditions (p=0.01). Refractive results showed a significant improvement in both uncorrected and corrected distance visual acuity (p<0.001).

CONCLUSION

There is a significant reduction in the iridocorneal angle after ICL V4c implantation. Furthermore, there is a change under mesopic conditions in both the iridocorneal angle and vault during long-term follow-up.

Reversible Corneal Toxicity of Retained Intracameral Perfluoro-n-octane

A 58-year-old female presented with intracameral retained perfluoro-n-octane (PFO) following previous retinal reattachment surgery. After 4 years of follow-up without related sequelae, the patient complained of a gradual decrease in vision secondary to corneal edema with whitish corneal precipitate inferiorly corresponding to the area of retained PFO. Three weeks after anterior chamber washout, corneal edema resolved and the patient obtained 20/40 visual acuity. Even though PFO considered to have a relatively good safety profile, early anterior chamber washout may prevent corneal toxicity and avoid later persistent corneal decompensation.

EX-PRESS® Implant Position and Function: Comparative Evaluation with Ultrasound Biomicroscopy and Optical Coherence Tomography

PURPOSE

This study evaluated the feasibility of anterior segment optical coherence tomography (OCT) and ultrasound biomicroscopy (UBM) for the imaging of EX-PRESS(®) implant.

MATERIALS AND METHODS

This nonrandomized comparative case series was performed at the Department of Ophthalmology of the University Hospital of Heraklion, Crete, Greece. The Ellex Eye Cubed (40 MHz) UBM and the Zeiss Visante OCT systems were used. The filtering bleb morphology (BL), aqueous outflow (AS), and tube position (TB) were evaluated by two independent observers using a quality scale of 1 (worst) to 4 (best). Data were also collected on corneal and iris clearance from the tip of the tube (CC and IC, respectively). Data from both the devices were statistically analyzed. P < 0.05 was considered as statistically significant.

RESULTS

Ten eyes of 10 patients (6 males) with EX-PRESS(®) implant were examined. TB, AS, and BL scores using UBM were 2.40 ± 0.39, 3.45 ± 0.72, and 2.45 ± 0.64, respectively. TB, AS, and BL scores for OCT were 3.35 ± 0.41, 1.55 ± 0.43, and 2.55 ± 0.55, respectively. AS was significantly higher with UBM whereas the opposite was true for TB. Differences in BL between OCT and UBM were not statistically significant (P > 0.05).

CONCLUSION

Imaging of the EX-PRESS(®) implant is feasible with both UBM and OCT. Both modalities allow visualization of the position of the implant tube in relation to the iris or cornea and delineate the internal structure of the filtering bleb.

Phakic Intraocular Lenses and their Special Indications

Phakic intraocular lenses revolutionize refractive surgery and continue to serve as an excellent option for vision correction in patients who are not ideal candidates for laser vision correction. This article will review special indications of phakic intraocular lenses in the clinical practice.

Cytochrome P450 1B1 and Primary Congenital Glaucoma

Cytochrome P450 1B1 (Cyp1b1) belongs to the CYP450 superfamily of heme-binding mono-oxygenases which catalyze oxidation of various endogenous and exogenous substrates. The expression of Cyp1b1 plays an important role in the modulation of development and functions of the trabecular meshwork (TM). Mutations in Cyp1b1 have been reported in patients with primary congenital glaucoma (PCG). Mice lacking Cyp1b1 also exhibit developmental defects in the TM similar to those reported in congenital glaucoma patients. However, how Cyp1b1 deficiency contributes to TM dysgenesis remains unknown. In the present review, we will address the significance of Cyp1b1 expression and/or its function in anterior segment development. Cyp1b1-deficient (Cyp1b1^−/−) mice are discussed as a promising model for an oxidative stress-induced model of PCG, in which Cyp1b1 activity is revealed as an important modulator of oxidative homeostasis contributing to the development and structural function of the TM. This conclusion suggests a possible clinical intervention for individuals who are genetically at high risk of developing PCG.

Nine years of retained perfluoro-n-octane in the anterior chamber after retinal detachment repair with no signs of ocular toxicity

Perfluoro-n-octane (PFO) is commonly used in vitreoretinal surgery. In this case report, we present a 35-year-old patient with retained PFO up to 9 years after par plana vitrectomy. Post-operatively, PFO bubbles occupied 15% of the anterior chamber (AC). Follow-up over 9 years, consistently showed a quiet AC, normal intraocular pressure and endothelial cell counts remained stable. Until date, the patient has been under observation and there have been no ocular symptoms or side-effects. Residual PFO that inadvertently remains in the AC can be well- tolerated, without side-effects for up to 9 years.

Anterior segment study with the Pentacam Scheimpflug camera in refractive surgery candidates

PURPOSE

The purpose of this study was to evaluate the anterior segment measurements according to refractive status in a sample of the Iranian population.

SETTING

Rassoul Akram Hospital, Tehran University of Medical Sciences.

MATERIAL AND METHODS

IN THIS STUDY, REFRACTIVE SURGERY CANDIDATES WERE ASSIGNED ACCORDING TO THE REFRACTIVE ERROR TO ONE OF THREE GROUPS : emmetropia, myopia, and hyperopia. Myopic eyes were further divided to four subgroups : simple myopic group, simple myopic astigmatism group, high myopic group, and high myopia with astigmatism group. Anterior segment measurements with the Pentacam Scheimpflug system were performed in the right eye of all subjects.

RESULTS

The study sample was comprised of 283 subjects with a mean age of 29.1 ± 7.5 (standard deviation) years. Mean keratometry reading, Anterior chamber depth (ACD) and volume measurements were significantly higher in the myopic group and mean keratometry reading and anterior chamber angle measurements were significantly lower in the hyperopic group (P < 0.05, all comparisons). Maximum anterior elevation (AEmax) and maximum posterior elevation (PEmax), Q value, progression index, minimum corneal thickness, and corneal volume measurements were similar for all groups (P > 0.05, all comparisons). In the myopic subgroups, AEmax and PEmax and maximum keratometry (Kmax) were significantly higher, and ACD was lower in the astigmatic groups (P < 0.05, all comparisons). The Q value was less negative in low myopia (P < 0.05).

CONCLUSIONS

Myopic eyes had steeper corneas than hyperopic eyes and anterior chamber measurements were significantly higher in the myopic eyes. In myopic eyes, AEmax and PEmax and Kmax measurements were higher, and ACD measurements were lower in the astigmatic groups.

Comparison of corneal curvature and anterior chamber depth measurements using the manual keratometer, Lenstar LS 900 and the Pentacam

Purpose:

The purpose of this study was to compare keratometry and anterior chamber depth (ACD) measurements from the Lenstar LS 900 (Haag-Streit AG, Switzerland) and the Pentacam (Oculus, Weltzar, Germany), and compare the keratometry readings of these two systems to a manual keratometer (MK), (Haag-Streit, Switzerland).

Materials and Methods:

In this prospective study, keratometry and ACD measurements were obtained in 50 eyes of 50 normal subjects with the Lenstar and the Pentacam. Keratometry was also measured using a MK. Correlation, comparison, and interdevice agreement was evaluated using intraclass correlation analysis, Wilcoxon test, and Bland-Altman plots.

Results:

The keratometry and ACD measurements obtained from the Lenstar and the Pentacam showed excellent correlation. The mean interdevice differences in mean keratometry (Km) for the Lenstar and the Pentacam, the Lenstar and the MK, and the Pentacam and the MK were 0.39 D, 0.10 D, and 0.30 D respectively; and the 95% limits of agreement (LoA) for Km were 0.04-0.82 D; −1.90-2.10 D; and −2.30-1.70 D, respectively. The mean interdevice difference in ACD for the Lenstar versus the Pentacam was 0.09 mm, with 95% LoA of 0.23-0.05 mm.

Conclusions:

The ACD measurements obtained using the Lenstar and the Pentacam seem to be interchangeable, whereas, the keratometry measurements obtained using the Lenstar, Pentacam, and MK differ considerably, and are not interchangeable.

In vitro-induced cell-mediated immune deviation to encephalitogenic antigens

The injection of antigens into the Anterior Chamber (AC) of the eye induces Anterior Chamber Associated Immune Deviation (ACAID), which is a potent form of immune deviation that is largely attributed to the effect of TGFβ2 in the aqueous humor on ocular antigen-presenting cells (APCs). ACAID antigen presentation via APCs and B cells leads to the generation of antigen-specific T regulatory cells. The encephalitogenic antigens Myelin oligodendrocyte glycoprotein (MOG) and Myelin basic protein (MBP) have an obvious clinical relevance. We hypothesized that the intravenous injection of in vitro-generated ACAID APCs or in vitro-generated ACAID B cells specific to the encephalitogenic antigens MOG35-55/MBP induces specific peripheral tolerance in recipient BALB/c mice. We examined the suppression of MOG35-55-specific/MBP-specific inflammatory responses using delayed-type hypersensitivity (DTH) assays and Local Adoptive Transfer (LAT) assays. Results indicated that MOG35-55-specific/MBP-specific tolerance was generated after the intravenous injections of MOG35-55-specific/MBP-specific ACAID APCs, MOG35-55-specific/MBP-specific ACAID B cells, and MOG35-55-specific/MBP-specific ACAID T regulatory cells. The specific immune deviation was in vitro-induced, cell-mediated, and specific to the encephalitogenic antigens MOG35-55/MBP. This in vitro-mediated approach for the generation of MOG35-55/MBP-specific tolerance opens up avenues for the application of ACAID as a tool for the therapy of Multiple Sclerosis, Schizophrenia, and other diseases.

Genotype-phenotype analysis of SNPs associated with primary angle closure glaucoma (rs1015213, rs3753841 and rs11024102) and ocular biometry in the EPIC-Norfolk Eye Study

AIMS

To investigate if the single nucleotide polymorphisms rs3753841, rs1015213 and rs11024102, recently implicated in the development of acute primary angle closure or primary angle closure glaucoma, are associated with ocular biometric characteristics of British adults in the European Prospective Investigation of Cancer-Norfolk eye study.

METHODS

Genotyping data on rs1015213 (between PCMTD1 and ST18), rs11024102 (at PLEKHA7) and rs3753841 (at COL11A1) were available on 3268 participants. Direct genotypic data was available for rs1015213 and rs3753841. Data was imputed for rs11024102. Ocular biometric data was available on 1137 participants who attended the third European Prospective Investigation of Cancer health examination and 988 (87%) of these participants had no previous cataract surgery either eye. Axial length (AL), anterior chamber depth (ACD) and corneal keratometry were measured by using the Zeiss IOLMaster.

RESULTS

Presence of at least one A allele (AG or AA genotype) for rs1015213 was associated with a shallower ACD (-0.07 mm, 95% CI -0.01 to -0.14 mm, p=0.028) after adjusting for age and sex (both p≤0.001). There was no association with AL or corneal keratometry for rs1015213 genotypes. AL, ACD and keratometry were not associated with rs3753841 or rs11024102 genotypes including after adjusting for age and sex.

CONCLUSIONS

This study suggests that primary angle closure glaucoma susceptibility at the PCMTD1-ST18 locus may be partly explained by an association between rs1015213 and ACD in European populations. This effect is equivalent to almost 20% of the SD of the mean ACD of phakic individuals in this cohort. We were not able to identify any association between rs3753841 or rs11024102 and ocular biometry.

Dirofilaria in the anterior chamber: a rare occurrence

Dirofilariasis is a parasitic infection of the carvivores that may present as a zoonotic infestation in humans. Systemic involvement in man is subcutaneous, pulmonary, or ocular. We report a rare occurrence of ocular dirofilariasis in a 25-year-old male patient who presented with pain and redness in the eye. A live, white, coiled, and highly motile worm was present in the anterior chamber. The worm, however, could not be detected in the anterior chamber, posterior segment, or the angle of the anterior chamber when the patient was taken to the operating room for surgical removal of the worm. The patient was made to lie prone till the worm reappeared in the anterior chamber and was removed by paracentesis. The worm was identified as Dirofilaria repens on the basis of microscopic and histopathological examination.

Vitreous asteroid hyalosis prolapse into the anterior chamber simulating iris metastasis

Two asymptomatic elderly women who underwent cataract extraction 7 or more years previously and with intraocular lens placement presented with a linear bead-like white multinodular mass in the inferior angle simulating iris metastasis versus large inflammatory precipitates. There was no iris infiltration. In the first case, the posterior lens capsule was intact and there was no evidence of gelatinous vitreous in the anterior chamber, whereas in the second case, the capsule was open and there was gelatinous vitreous prolapse. In both cases, there was asteroid hyalosis in the vitreous. Both patients were diagnosed with prolapsed vitreous asteroid hyalosis into the anterior chamber and managed with observation. Vitreous asteroid hyalosis can prolapse into the anterior chamber of pseudophakic elderly patients with or without capsular opening and can simulate an intraocular tumor.