Chintan Malhotra

Human amniotic membrane transplantation: Different modalities of its use in ophthalmology

The amniotic membrane (AM) is the inner layer of the fetal membranes and consist of 3 different layers: the epithelium, basement membrane and stroma which further consists of three contiguous but distinct layers: the inner compact layer, middle fibroblast layer and the outermost spongy layer. The AM has been shown to have anti-inflammatory, anti-fibrotic, anti-angiogenic as well as anti-microbial properties. Also because of its transparent structure, lack of immunogenicity and the ability to provide an excellent substrate for growth, migration and adhesion of epithelial corneal and conjunctival cells, it is being used increasingly for ocular surface reconstruction in a variety of ocular pathologies including corneal disorders associated with limbal stem cell deficiency, surgeries for conjunctival reconstruction, as a carrier for ex vivo expansion of limbal epithelial cells, glaucoma surgeries and sceral melts and perforations. However indiscriminate use of human AM needs to be discouraged as complications though infrequent can occur. These include risk of transmission of bacterial, viral or fungal infections to the recipient if the donors are not adequately screened for communicable diseases, if the membrane is not processed under sterile conditions or if storage is improper. Optimal outcomes can be achieved only with meticulous case selection. This review explores the ever expanding ophthalmological indications for the use of human AM.

Effect of oral omega-3 Fatty Acid supplementation on contrast sensitivity in patients with moderate meibomian gland dysfunction: a prospective placebo-controlled study.

Purpose: To evaluate the effect of oral supplementation with omega-3 (&ohgr;-3) fatty acids (FAs) in improving contrast sensitivity (CS) of patients with moderate meibomian gland dysfunction (MGD). Methods: In this prospective study, 60 patients with moderate MGD were allocated alternately to treatment and control groups. Both groups received warm compresses, lid massage, and artificial tear substitutes. The treatment group also received oral supplements of 1.2 g &ohgr;-3 FAs per day. All parameters were recorded at baseline and at 12 weeks and included Ocular Surface Disease Index scores, CS testing at 3, 6, 12, and 18 cycles per degree (cpd), tear break-up time, Schirmer test I without anesthesia, corneal and conjunctival staining scores, and meibum quality and expressibility. Results: At the end of 12 weeks, significant improvement in CS was seen in the treatment group in 7 of the 8 testing conditions (3, 6, 12, and 18 cpd photopic and 6, 12, and 18 cpd mesopic), whereas in the placebo group, significant improvement was seen only in 3 of the 8 testing conditions (3 cpd photopic, 6 and 18 cpd mesopic). Ocular Surface Disease Index, tear break-up time, ocular surface staining, and meibum quality and expressibility improved significantly in both groups, but more so in the treatment group. Schirmer scores showed no significant improvement in either group. Conclusions: Oral supplementation with &ohgr;-3 FAs significantly improved CS under both photopic and mesopic testing conditions in patients with moderate MGD. Tear film stability also improved significantly, whereas no effect was seen on aqueous tear production.

Characteristics of Pre-Descemet Membrane Corneal Dystrophy by Three Different Imaging Modalities-In Vivo Confocal Microscopy, Anterior Segment Optical Coherence Tomography, and Scheimpflug Corneal Densitometry Analysis.

Purpose: To evaluate the characteristics of pre-Descemet membrane corneal dystrophy by 3 different imaging modalities: in vivo confocal microscopy (IVCM), anterior segment optical coherence tomography (ASOCT), and Scheimpflug corneal densitometry analysis. Methods: A 32-year-old male patient with pre-Descemet membrane corneal dystrophy was subjected to imaging by IVCM, ASOCT, and Scheimpflug tomography. Results: Slit-lamp biomicroscopy showed the presence of tiny pleomorphic opacities in the posterior stroma, immediately anterior to Descemet membrane bilaterally. On IVCM, pleomorphic, hyperreflective punctate particles were seen both intracellularly and extracellularly in the anterior and mid stroma with increased reflectivity of some keratocytes that, however, were of normal size. These changes increased in severity from the anterior to mid stroma. The posterior stroma had grossly enlarged hyperreflective keratocytes with prominent processes. The hyperreflective particles were also seen scattered on the endothelium. ASOCT revealed a well-delineated homogenous band of increased reflectivity of approximately 70 &mgr;m width in the posterior stroma of both eyes with a normal-appearing anterior and mid stroma. Corneal densitometry measured by Scheimpflug optical analysis revealed a higher amount of backscattered light from the posterior stroma with a posterior to anterior ratio of 0.8. Conclusions: In pre-Descemet membrane corneal dystrophy, although the structural changes seem to be limited to the posterior stroma as seen clinically and on ASOCT, IVCM demonstrates that the pathology is more extensive involving the entire corneal stroma and endothelium.

Phenotypic heterogeneity of corneal endothelium in iridocorneal endothelial syndrome by in vivo confocal microscopy.

Purpose: To present a case of iridocorneal endothelial (ICE) syndrome showing phenotypic heterogeneity of endothelial morphology between the 2 eyes of a patient as visualized by in vivo confocal microscopy (IVCM). Methods: Confocal microscopy using the Heidelberg Retina Tomograph (HRT)-3 with Rostock Cornea Module was performed bilaterally during routine follow-up on a 60-year-old lady being managed as a case of ICE syndrome with secondary glaucoma in the right eye. Results: IVCM revealed endothelial changes in both eyes, which however varied in morphology. Endothelium of the right eye showed a “total ICE” pattern with “ICE-type of cells,” that is, diffuse involvement with enlarged, pleomorphic “epithelioid” cells having hyper-reflective nuclei and no intervening areas of the normal endothelium. The left endothelium had broad areas of normal hexagonal endothelial mosaic interspersed with different types of ICE cells showing nipple-shaped evaginations, light dark reversal and central craters with hyper-reflective rims. Conclusions: This report with the help of IVCM demonstrates that though ICE syndrome is a clinical entity which classically has been considered predominantly unilateral, the endothelial changes can be bilateral and heterogeneous. The apparent heterogeneity in the present case may represent 2 different stages of the disease process at the level of the corneal endothelium-advanced disease OD and presymptomatic disease OS.

Limbal Pseudoepitheliomatous Hyperplasia Mimicking Ocular Surface Squamous Neoplasia in Palpebral Vernal Keratoconjunctivitis

Purpose. Pseudoepitheliomatous hyperplasia at the limbus can mimic an ocular surface squamous neoplasia. It is an uncommon manifestation of vernal keratoconjunctivitis and has been reported previously in limbal VKC. It, however, has not been reported as a manifestation in the palpebral form of the disease and needs to be kept in the differential diagnosis of a limbal mass lesion in vernal keratoconjunctivitis. Case Report. We report the case of a 24 year old male patient having palpebral VKC and presenting with a papillomatous limbal mass with focal areas of keratinization mimicking an ocular surface squamous neoplasia. An excision biopsy was performed, and the specimen sent for histopathologywhich revealed features of pseudoepitheliomatous hyperplasia with no evidence of dysplasia or malignant transformation. The subepithelium revealed a dense plasma-rich inflammation. Discussion. We report this relatively uncommon presentation of limbal pseudoepitheliomatous hyperplasia mimicking an ocular surface squamous neoplasia in palpebral vernal keratoconjunctivitis. Wide excision as is required for an ocular surface neoplasia may thus be avoided if this entity is recognized in vernal keratoconjunctivitis.

Oral Omega-3 Fatty Acid Supplementation for Laser In Situ Keratomileusis-Associated Dry Eye.

Purpose: To determine the effect of oral omega-3 fatty acid (&ohgr;3FA) supplementation in laser in situ keratomileusis (LASIK)-associated dry eye. Methods: In this prospective, open-label study, patients undergoing LASIK were randomized to receive either 1.2 g/d of a triglyceride formulation of oral &ohgr;3FA (treatment group) or 400 mg/d vitamin E (control group) for 1 week before and continued for 12 weeks after surgery. Ocular surface disease index, tear breakup time, ocular surface staining, and Schirmer scores were evaluated and compared preoperatively and at 3 months after LASIK. Results: The study included 30 patients in each group. All parameters were comparable at baseline. Ocular surface disease index scores increased comparably in both groups (1.9 ± 0.6 increase in the treatment group; 2.8 ± 0.5 in the control group) (P = 0.267). Compared with baseline levels, tear breakup time decreased significantly (P < 0.01) but comparably in both treatment (−2.3 ± 0.4 seconds decrease) and control (−3.5 ± 0.7 seconds decrease) groups (P = 0.105). More eyes in the control group (43.4%) had conjunctival staining with Lissamine green at 3 months compared with the treatment group (14%) (P = 0.009). The Schirmer score at 3 months was higher (P = 0.003) in the treatment group (30.5 ± 0.90 mm) than in the control group (25.7 ± 1.3 mm) with a increase of 5.9 ± 1.3 mm from baseline in the treatment group and a decrease of 1.5 ± 1.2 mm in the control group. Conclusions: Supplementation with &ohgr;3FA in patients undergoing LASIK had a positive influence on tear secretion, whereas tear film stability remained unaffected when compared with the control group.

Outcomes of topography-guided versus wavefront-optimized laser in situ keratomileusis for myopia in virgin eyes

Purpose To compare the outcomes of topography‐guided and wavefront‐optimized treatment in patients having laser in situ keratomileusis (LASIK) for myopia. Setting Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India. Design Prospective contralateral‐eye case study. Methods Patients had topography‐guided LASIK in 1 eye and wavefront‐optimized LASIK in the contralateral eye using the Customized Refractive Surgery Master software and Mel 80 excimer laser. Refractive (residual manifest refraction spherical equivalent [MRSE], higher‐order aberrations [HOAs]), and visual (uncorrected distance visual acuity [UDVA] and photopic and mesopic contrast sensitivity) outcomes were prospectively analyzed 6 months postoperatively. Results The study comprised 35 patients. The UDVA was 0.0 logMAR or better and the postoperative residual MRSE was ±0.50 diopter in 94.29% of eyes in the topography‐guided group and 85.71% of eyes in the wavefront‐optimized group (P = .09). More eyes in the topography‐guided group than in the wavefront‐optimized group had a UDVA of −0.1 logMAR or better (P = .04). Topography‐guided LASIK was associated with less deterioration of mesopic contrast sensitivity at higher spatial frequencies (12 cycles per degree [cpd] and 18 cpd) and lower amounts of induced coma (P = .04) and spherical aberration (P = .04). Less stromal tissue was ablated in the topography‐guided group (mean 61.57 &mgr;m ± 16.23 [SD]) than in the wavefront‐optimized group (mean 79.71 ± 14.81 &mgr;m) (P < .001). Conclusion Although topography‐guided LASIK and wavefront‐optimized LASIK gave excellent results, topography‐guided LASIK was associated with better contrast sensitivity, lower induction of HOAs, and a smaller amount of tissue ablation. Financial Disclosure None of the authors has a financial or proprietary interest in any material or method mentioned.

Higher Order Aberrations and Visual Outcomes in Wavefront-Optimized Sub-Bowman Keratomileusis: Flap Creation Using Femtosecond Laser Versus Mechanical Microkeratome.

PurposeThe aim of this study was to compare the outcomes of wavefront-optimized sub-Bowman keratomileusis (SBK) performed using the 150 KHz IntraLase femtosecond (IFS) laser (Abbot Medical Optics) with those using the Moria Evo 3 One Use-Plus SBK mechanical microkeratome (Moria SA). DesignA prospective comparative clinical trial. MethodsFifty patients had bilateral wavefront-optimized SBK performed for myopia or myopic astigmatism. In 25 patients, the flap was created with the 150 KHz IFS laser (group 1) and in the other 25 with the Moria One Use-Plus SBK mechanical microkeratome (group 2). All other treatment parameters were the same. Results were reported for 1 eye per patient in each group (ie, 25 eyes in each group). ResultsEfficacy, refractive stability, predictability, and safety profiles were comparable between the 2 groups. Although higher order aberrations (HOAs) increased significantly in both groups after laser in situ keratomileusis, intergroup comparison revealed that group 1 was associated with a significantly higher induction of both total HOAs [mean root mean square (RMS), 0.63 ± 0.20 in group 1 vs 0.52 ± 0.14 in group 2; P = 0.031] and spherical aberrations (RMS, 0.37 ± 0.17 in group 1 vs 0.22 ± 0.09 in group 2; P < 0.001) as compared with group 2. ConclusionsFlaps created using the Moria Evo 3 One Use-Plus SBK mechanical microkeratome were associated with significantly lower induction of total HOAs and spherical aberrations as compared with 150 KHz IFS flaps at the end of 3 months follow-up.

Ocular Rosacea—a Review

O cular rosacea, a disease often associated with acne rosacea, can present with a variety of clinical features, which are often nonspecific. However, in about one-third of cases, it may occur as an isolated entity without skin involvement. Appropriate diagnosis and management is essential as potentially sight-threatening corneal involvement can occur in a significant number of patients if the condition remains unrecognized and untreated. Diagnosis remains mainly clinical and includes recognition of the commonly occurring signs of chronic blepharoconjunctivitis, lid margin telangiectasis,meibomian gland dysfunction, dry eyes, and corneal involvement in the form of vascularization, infiltration, and even perforation. Management depends on the severity of the disease, with milder forms being amenable to treatment with local measures like lid hygiene and topical lubricants, while more severe forms require treatment with systemic drugs including tetracyclines, azithromycin, erythromycin, or metronidazole and more aggressive local therapy with topical steroids and/or topical cyclosporine. Surgical treatment may be required to manage the sequelae of chronic ocular surface inflammation.

In vivo confocal microscopic characteristics of microsporidial keratoconjunctivitis in immunocompetent adults

Background/aims To describe in vivo confocal microscopy (IVCM) features of microsporidial keratoconjunctivitis in immunocompetent adult patients. Methods Patients suspected clinically to be suffering from microsporidial keratoconjunctivitis (ie, presence of unilateral follicular and/or papillary conjunctivitis in conjunction with multifocal, coarse corneal epitheliopathy) were subjected to IVCM with the Rostock Cornea Module of the Heidelberg Retinal Tomograph 3, and combined potassium hydroxide and calcofluor white (KOH+CFW) staining of the corneal scrapings, to detect the microsporidial spores. Detection of spores in corneal scrapings was considered as being confirmatory for microsporidial infection. Results Of a total of 10 patients screened, 8 patients (7 male, 1 female) demonstrated the presence of oval, non-budding microsporidial spores which fluoresced bluish white on combined KOH+CFW staining. IVCM in seven of these eight patients demonstrated multiple rosette-like clusters/plaque of epithelial cells, within which hyper-reflective, pinpoint oval intracellular bodies (similar to the spores seen on microbiological staining) were present. One patient who had been on prolonged treatment with topical steroids showed the presence of the oval bright bodies scattered diffusely within the epithelial cells, without rosette formation. Conclusions In microsporidial keratoconjunctivitis, IVCM is able to detect presence of bright, ovoid spore-like structures in the epithelial layers. Epithelial rosette formation is another characteristic feature seen in a majority of these patients. These features may be used as a reliable screening tool for starting therapy, precluding the need for corneal scrapings in a majority of patients.