Comparative evaluation of biomechanical changes and aberration profile following accelerated collagen cross-linking using hypo-osmolar and iso-osmolar riboflavin: A prospective study.

PURPOSE: To compare the changes encountered in corneal biomechanics and aberration profile following accelerated corneal collagen cross-linking (CXL) using hypo-osmolar and iso-osmolar riboflavin in corneal thicknesses of <400 and >400 microns, respectively. METHODS: This is a prospective, interventional, comparative study involving 100 eyes of 75 patients with progressive keratoconus. Eyes were divided into two groups based on corneal thickness: group 1 included eyes with a corneal thickness of <400 microns who underwent hypo-osmolar CXL, and group 2 included eyes with a corneal thickness of >400 microns who underwent iso-osmolar CXL. Corneal biomechanical and aberration profiles were evaluated and compared between groups. RESULTS: In group 1, all higher-order aberrations (HOA) except secondary astigmatism significantly decreased from baseline; however, in group 2, only coma and trefoil decreased. The corneal resistance factor and corneal hysteresis significantly improved in both groups, which was significantly greater in group 2 than in group 1. The change in inverse radius, deformation amplitude, and tomographic biomechanical index was significantly improved in group 2 as compared to group 1. CONCLUSION: Improvement in corrected distance visual acuity and decrease in HOA were significantly better in the hypo-osmolar CXL group; however, the improvement in biomechanical strength of the cornea was significantly better in the iso-osmolar group.

Outcomes of preloaded toric intraocular lens implantation in eyes undergoing phacoemulsification.

Purpose: To evaluate the clinical outcomes of preloaded toric intraocular lens (IOLs) implantation in eyes undergoing phacoemulsification. Methods: This prospective study included 51 eyes of 51 patients with visually significant cataracts and corneal astigmatism ranging between 0.75 and 5.50 D. All patients underwent phacoemulsification with SupraPhob toric intraocular lens implantation under topical anesthesia. The main outcome measures were uncorrected distance visual acuity (UDVA), residual refractive cylinder, spherical equivalent, and IOL stability at 3 months follow-up. Results: At 3 months, 49% (25/51) of patients had UDVA equal to or better than 20/25 with 100% of eyes achieving better than 20/40. Mean logMAR UDVA improved from 1.02 ± 0.39, preoperatively to 0.11 ± 0.10 at 3 months follow-up (P < 0.001, Wilcoxon signed-rank test). The mean refractive cylinder improved from - 1.56 ± 1.25 D preoperatively to - 0.12 ± 0.31 D at 3 months follow-up (P < 0.001) while the mean spherical equivalent value changed from - 1.93 ± 3.71D preoperatively to - 0.16 ± 0.27D (P = 0.0013). The mean root mean square value for higher order aberrations was 0.30 ± 0.18 µm while the average contrast sensitivity value (Pelli-Robson chart) was 1.56 ± 0.10 log unit, at the final follow-up. The mean IOL rotation at 3 weeks was 1.7 ± 1.61 degrees, which did not change significantly at 3 months (P = 0.988) follow-up. There were no intraoperative or postoperative complications. Conclusion: SupraPhob toric IOL implantation is an effective method for addressing preexisting corneal astigmatism in eyes undergoing phacoemulsification with good rotational stability.

30G needle aspiration - A modified technique of capsulorhexis in pediatric cataract with high intra-lenticular pressure.

This surgical technique describes a modification of the continuous curvilinear capsulorhexis (CCC) to achieve an adequate-sized capsulorhexis in pediatric cataracts with high intralenticular pressure. Performing CCC in pediatric cataracts is challenging, especially when the intralenticular pressure is high. This technique involves 30 G needle decompression of the lens to reduce positive intralenticular pressure and subsequent flattening of the anterior capsule. This minimizes the chances of extension of CCC without using any special equipment. This technique was used in two eyes of two patients (age 8 and 10 years) with unilateral developmental cataracts. Both surgeries were performed by a single surgeon (PKM). In both eyes, a well-centered CCC was achieved with no extension, and a posterior chamber intraocular lens (IOL) was placed in the capsular bag. Thus, our technique of 30 G needle aspiration could be extremely useful to achieve an adequately sized CCC in pediatric cataracts with high intralenticular pressure, especially for beginner surgeons.

Immunopathogenesis of corneal graft rejection.

The most common cause of corneal graft failure is corneal graft rejection (CGR). Although cornea is one of the immune-privileged sites, it can still get a rejection episode due to a breach in its natural protective mechanism. Both anatomical and structural properties of cornea and anterior chamber contribute toward its immune tolerance. Clinically, every layer of the transplanted cornea can get a rejection episode. A proper understanding of immunopathogenesis will help in understanding the various mechanism of CGR and the development of newer strategies for the prevention and management of such cases.

Comparison of Pre-Descemet Endothelial Keratoplasty and Descemet Membrane Endothelial Keratoplasty in Endothelial Decompensation.

PURPOSE: The purpose of this study was to compare the outcomes of pre-Descemet endothelial keratoplasty (PDEK) and Descemet membrane endothelial keratoplasty (DMEK) in cases of endothelial decompensation. METHODS: This was a prospective, randomized, interventional study conducted at a tertiary eye hospital in North India. Thirty eyes of 28 patients with corneal decompensation were randomly subjected to PDEK (n = 15 eyes) and DMEK (n = 15 eyes). Preoperative demographic details, surgical indications, uncorrected distance visual acuity, corrected distance visual acuity, contrast sensitivity, anterior and posterior segment details, intraocular pressure, central corneal thickness, endothelial cell count, and corneal aberrometry tracing on wavefront analysis were recorded. Patients were followed up for 6 months postsurgery. Visual and graft survival outcomes were assessed. RESULTS: Intraoperatively, a surgeon reported better ease of preparation and intracameral handling with PDEK grafts. Both groups showed comparable improvement in visual acuity, contrast, and high-order aberrations. A decrease in central corneal thickness was significantly higher in DMEK (196 ± 26 vs. 140 ± 14 µm) patients. DMEK grafts were significantly thinner than PDEK grafts at the 6-month follow-up (16 ± 2.17 vs. 27.2 ± 1.93 µm). Endothelial cell loss (35% in DMEK vs. 33.4% in PDEK, P = 0.48) and rise of intraocular pressure (from 15.33 ± 2.85 mm Hg to 15.53 ± 2.2 mm Hg in the DMEK group vs. from 14.6 ± 1.99 mm Hg to 16.2 ± 1.43 mm Hg in the PDEK group) were comparable. Rebubbling rates were higher in the DMEK group (3/15, 20%) compared with the PDEK group (1/15, 6.66%; P = 0.165). CONCLUSIONS: DMEK and PDEK were comparable for both quantitative and qualitative visual outcomes and anatomically for graft survival at the 6-month follow-up.

Impact of Topical Cyclosporine-A or Topical Chloroquine on Post-LASIK Ocular Surface Stability - A Randomized Controlled Trial.

PURPOSE: To compare effect of topical cyclosporine-A 0.05% (CsA) and chloroquine phosphate 0.03% (CHQ) as an adjunct to standard therapy in maintaining post-laser assisted in situ keratomileusis (LASIK) ocular surface stability. METHODS: Randomized controlled trial on 100 eyes undergoing femtosecond-LASIK randomized into three groups: 33 eyes in Group I (Standard Treatment group), 34 eyes in Group II (CsA group) and 33 eyes in Group III (CHQ group). Standard treatment included topical moxifloxacin, topical prednisolone and carboxymethyl cellulose. Group II received topical CsA 0.05% twice daily for three months and group III received topical CHQ 0.03% twice daily for three months in addition to standard treatment. Primary outcome measure was change in ocular surface disease index (OSDI) at 6 months. Secondary outcome measures were tear break up time (TBUT), Schirmer-I score, tear film osmolarity, tear film MMP-9 and visual acuity. Follow-up was performed at postoperative 1, 3 and 6 months. RESULTS: At 6 months, OSDI score, MMP-9, tear osmolarity, TBUT and Schirmer score were significantly better in both CsA and CHQ groups as compared with controls (p < 0.001). OSDI, Tear osmolarity, TBUT, MMP-9 levels were comparable in CsA and CHQ group (p > 0.05). In CsA group, tear film MMP-9 levels at 6 months were comparable to preoperative baseline (p = 0.09). There was no significant change in the Schirmer score from baseline in the CsA group; in addition, the Schirmer score was significantly better than the CHQ group at 6 months (p = 0.02). Visual acuity was comparable in all three groups. Adverse effects including burning sensation, stinging, pain and redness were reported by ten patients (CsA group- 3, CHQ group-7; p = 0.28). CONCLUSION: Both CsA and CHQ are useful adjuncts to standard therapy in maintaining ocular surface stability after refractive surgery. Cyclosporine A has more potent and sustained anti-inflammatory effect with less ocular irritative effects.

Early onset unilateral Terrien's marginal degeneration.

A young man in his first decade of life presented with insidious onset, gradually progressive diminution of vision in right eye since 2 months associated with foreign body sensation. Slit-lamp examination revealed superior arcuate band of corneal stromal thinning extending from 9-3 o' clock. There was associated corneal vascularisation and presence of lipid deposition at the leading edge of the furrow formation with intact epithelium without any apparent signs of inflammation. There was no previous history of ocular or systemic disease, trauma, ocular surgery, collagen vascular disease or contact lens wear. Serological tests for rheumatic diseases did not show any abnormalities. Scheimpflug imaging showed high against the rule astigmatism with a 'reverse crab claw' pattern. A provisional diagnosis of right eye Terrien's marginal corneal degeneration was made. On a 1-month follow-up visit, there was significant symptomatic relief with lubricants alone and with spectacles the visual acuity improved to 20/60 in the right eye.

Deep blue dot corneal degeneration: a rare corneal degeneration.

A female patient in the age group 55-60 years presented to us with blurring of vision in both eyes. On slit-lamp examination, numerous circular to oval fleck-like discrete blue opacities at the level of deep corneal stroma and Descemet's membrane was observed. These lesions were predominantly seen in the central two-thirds of the cornea. Considering the age of presentation and the clinical features, the probable diagnosis of 'deep blue dot corneal degeneration' was made.

Complications following implantation of posterior chamber phakic intraocular lens (pIOL).

A male patient in his 20s presented with right eye aphakic corneal decompensation and left eye intumescent cataract with phakic intraocular lens (pIOL) lenticular touch. He had a history of pIOL implantation in both eyes 6 months ago. On first postoperative day, uncorrected distance visual acuity was 20/400 and 20/20 in right and left eye, respectively. Postoperatively, a diagnosis of right eye toxic anterior segment syndrome (TASS) was made and pIOL was explanted. Subsequently, the patient developed intumescent cataract for which lens aspiration with posterior chamber intraocular lens (PCIOL) implantation was performed in the right eye. Ongoing uveitis with membrane formation warranted PCIOL explantation. The patient developed aphakic corneal decompensation in the right eye and underwent penetrating keratoplasty with intrascleral haptic fixation of an intraocular lens. Central pIOL-lenticular touch with intumescent cataract was diagnosed in the left eye for which pIOL explant with lens aspiration and PCIOL was done. TASS and post-pIOL cataract are rare but vision-threatening complications require judicious management for visual rehabilitation.

Microscope Integrated Optical Coherence Tomography Guided Descemet Stripping Automated Endothelial Keratoplasty in Congenital Hereditary Endothelial Dystrophy.

PURPOSE: To describe the outcomes of descemet stripping automated endothelial keratoplasty (DSAEK) in congenital hereditary endothelial dystrophy (CHED) and to evaluate the role of microscope integrated optical coherence tomography (Mi-OCT) during the surgery. DESIGN: Retrospective data analysis. METHODS: A retrospective study from the medical records of all those patients who were diagnosed with CHED and underwent DSAEK at our centre from 2015 were evaluated. All patients underwent Mi-OCT-guided standard DSAEK procedure. Intra-operative difficulties, visual outcomes and graft survival were recorded. RESULTS: A total of 48 eyes of 29 patients with a mean age of 9.87 ± 8.2 years and mean follow-up of 17.3 months were evaluated. Thirty-nine eyes underwent primary DSAEK and 9 eyes underwent PKP. Three eyes who underwent PKP had failed graft for which they underwent DSAEK. The mean preoperative Snellen's visual acuity was 1.71 ± 0.66 and the mean preoperative central corneal thickness was 1.10 ± 0.174 mm. Intraoperatively, all the grafts were attached which was confirmed using Mi-OCT. Graft detachment was seen in the immediate postoperative period in 10.4% (4 eyes) of primary DSAEK, out of which DM scoring was not performed in 2 eyes. Following DSAEK, cornea cleared at four-week follow-up in 89.7% eyes and in all the eyes the cornea cleared at six-week follow-up. CONCLUSION: Primary DSAEK could be a preferred option over PKP for CHED with early presentation and in those eyes with failed primary PKP. Mi-OCT is a very useful tool in these eyes for various intraoperative procedures, thereby improving the outcomes of the procedure.

Quantitative Analysis of Gap Between the Intraocular Lens and Posterior Capsule Using Microscope-Integrated Optical Coherence Tomography in Eyes Undergoing Phacoemulsification.

PURPOSE: To quantitatively analyze the dimensions of the gap between the intraocular lens (IOL) and the posterior capsule using microscope-integrated optical coherence tomography (MIOCT). SETTING: Institutional. DESIGN: Prospective, interventional. METHODS: A total of 105 eyes of 105 consecutive patients planned for phacoemulsification with IOL implantation were enrolled. At the end of surgery, the gap between the IOL and the posterior capsule (IOL-PC gap) was measured using MIOCT (RESCAN). The same gap was reassessed at 1 week follow-up visit using the Visante-OCT system. The cases were sub-grouped based on the grade of cataract, IOL material, size and design and were analyzed to look for any difference in the IOL-PC gap both intraoperatively and postoperatively. RESULTS: The IOL-PC gap could be successfully measured intra-operatively in all cases, using the RESCAN. The mean gap at the end of phacoemulsification was 385.08±264.58 µm, and at one week follow up this was 120.83± 95.13 µm. CONCLUSION: MIOCT may be successfully used to quantify the dimensions of the gap between the IOL and the posterior capsule. It can be used as a potential tool to further understand the dynamics of the IOL-PC space and to assess the impact of various IOL and non-IOL parameters implicated in the causation of posterior capsule opacification.

Role of Microscope-Intraoperative Optical Coherence Tomography in Pediatric Keratoplasty: AComparative Study.

PURPOSE: We evaluate the role of microscope-integrated intraoperative optical coherence tomography (i-OCT) in pediatric keratoplasty. DESIGN: Combined prospective and retrospective, comparative, interventional study conducted at the Dr Rajendra Prasad Center for Ophthalmic Sciences in New Dehli, India. METHODS: Seventy-five children ≤16 years of age undergoing planned keratoplasty were divided into 2 groups and compared regarding intraoperative course and postoperative outcome. In group 1 (prospective group, n = 56), preoperative anterior segment visualization was performed clinically, with ultrasound biomicroscopy (UBM) and i-OCT and keratoplasty was commenced under i-OCT microscope. In group 2 (retrospective group, n = 19), a conventional microscope was used during keratoplasty. RESULTS: In group 1, i-OCT, UBM, and clinical examination detected retrocorneal membrane in 10%, 7.5%, and 5% (P = .005), iris adhesions in 62.5%, 57.5%, and 20% (P = .02), iris stump in aniridia 15%, 10%, and 0% (P = .001), shallow central anterior chamber in 22.5%, 22.5%, and 7.5% (P = .003), and shallow peripheral anterior chamber in 65%, 60%, and 17.5% (P = .004) of children, respectively. The use of i-OCT affected intraoperative surgeon decision making in 45% and 33% of cases of anterior and posterior lamellar keratoplasty, respectively. During penetrating keratoplasty, concomitant intraoperative procedures were higher in group 1 than in group 2, namely synechiolysis (19/40 vs 2/15; P = .1), pupilloplasty (4/40 vs 0/15; P = .02), lens extraction (4/40 vs 1/15; P = .5), and anterior vitrectomy (2/40 vs 1/15; P = .4). Postoperative secondary interventions were lower (P = .04) in group 1 (48.21% vs 94.74%). CONCLUSIONS: Anterior segment imaging with i-OCT and UBM immediately before surgery improves the surgical planning of children with corneal opacities. In addition, the use of i-OCT refines intraoperative steps, thereby optimizing the postoperative outcome of pediatric keratoplasty.

Role of combined immunomodulator therapy in severe steroid intolerant vernal keratoconjunctivitis.

PURPOSE: To describe the role of combined topical cyclosporine (CsA) 0.1% and tacrolimus 0.03% in cases with severe steroid intolerant vernal keratoconjunctivitis (VKC). METHODS: Medical records of patients with acute exacerbation of VKC and steroid intolerance referred from glaucoma to cornea clinic were reviewed from March 2017 to December 2018. Eleven patients (22 eyes), (nine with steroid-induced glaucoma, two with steroid-induced cataract and glaucoma) were found. All were started on topical CsA 0.1% QID. Due to suboptimal response at 2 weeks, topical tacrolimus 0.03% BD was also included. RESULTS: The mean total subjective score at presentation was 13 ± 1.4, which reduced to 11.2 ± 1.3 at 2 weeks of topical CsA therapy and further reduced to 5 ± 0 at 2 weeks of combination therapy (p < 0.001). The mean total objective score at presentation was 9.4 ± 1.4 that reduced to 8.0 ± 1.3 at 2 weeks of topical CsA therapy and further reduced to 4.3 ± 1.6 at 2 weeks of combination therapy (p < 0.001). Similar results were obtained in a sub-group analysis including the worse eye or right eye of the cases only. The absolute change in the total subjective and objective score was much more with combination therapy. Photophobia and conjunctival hyperemia resolved within 4 weeks of combined therapy. No recurrence was observed till 6 months follow-up. CONCLUSIONS: Combined use of cyclosporine and tacrolimus may lead to rapid resolution of symptoms and reduced recurrence rate in cases with severe VKC where steroid has to be avoided.

Incidentally detected primary corneal squamous neoplasia in an elderly man presenting with cataract.

Primary corneal neoplasia (PCN) is a rare cancerous lesion of cornea usually encountered in elderly. The clinical symptoms are generally non-specific, with ocular irritation, redness, cosmetic disfigurement and varying degrees of visual disturbances depending on visual axis involvement. Corneal neoplasia is usually associated with surrounding conjunctival lesions and incidentally detected PCN is rarely encountered in clinical practice. Presently, we report a case of isolated unilateral PCN diagnosed incidentally in an elderly man presenting with cataract. In vivo confocal microscopy aided in its diagnosis after impression cytology was repeatedly negative. Cataract surgery was deferred and the patient was administered three cycles of mitomycin C 0.04% 4 times/day. The tumour margins receded as evident on clinical examination and on anterior segment optical coherence tomography. We discuss the role of various corneal imaging modalities in diagnosis and management of PCN besides highlighting importance of comprehensive slit-lamp examination in patients planned for cataract surgery.

Tuck-In Tenon Patch Graft in Corneal Perforation.

PURPOSE: To describe the outcomes of tuck-in tenon patch graft (TPG) in the management of corneal perforation up to 5-mm size. METHODS: Thirty-one cases of sterile corneal perforation (3-5 mm) underwent autologous TPG. The technique included, freshening of the edges, measuring the size of defect, creating a 360-degree stromal pocket around the perforation margin, harvesting the tenon graft followed by tucking into the stromal pocket, and application of cyanoacrylate glue or suturing the graft using 10-0 monofilament nylon suture. The main outcome measure was rate of healing (percentage of cases healed). RESULTS: The mean age was 52.3 ± 8.9 years with 22 male and 9 female patients. The various etiologies of corneal perforation included trauma (n = 10), neurotrophic keratitis (n = 11), and peripheral ulcerative keratitis (n = 10). The mean size of corneal perforation was 4.2 ± 0.6 mm (range 3-5 mm). The mean duration of epithelial healing was 25.7 ± 6.7 days. Best-corrected visual acuity improved from 1.8 ± 0.4 to 1.2 ± 0.4 logarithm of the minimum angle of resolution units at 4 weeks after surgery (P ≤ 0.01). Twenty-seven (87.1%) cases healed with formation of a leucomatous scar at 16.9 ± 2.7 weeks, whereas 4 cases had a flat anterior chamber. In three-fourths of the cases, a corneal graft was performed. In one case, graft resuturing was performed for post-op aqueous leak, which healed with the formation of a corneo-iridic scar. CONCLUSIONS: TPG is a safe, simple, inexpensive, and an effective technique for the management of corneal perforations. The advantages include the autologous nature of the graft, cost effectiveness, and easy availability.

Microbial Keratitis in Stevens-Johnson Syndrome: A Prospective Study.

PURPOSE: To evaluate the microbiological profile and outcome in cases with infective keratitis in Stevens-Johnson syndrome (SJS). METHODS: Eighty-three eyes of 68 patients with SJS presenting with microbial keratitis were recruited and managed with standard antimicrobial therapy. RESULTS: Microbial keratitis developed in 34% of patients with SJS (83 eyes, 68 patients) over a period of 5 years. Four eyes (4.8%) had a history of concurrent topical steroid use at the onset of keratitis. Mean baseline best-corrected visual acuity was 1.8 ± 0.9 logMAR units. The site of corneal ulceration was central in 52 eyes (62.6%), paracentral in 17 eyes (20.5%), and peripheral in 14 eyes (16.8%). The mean ulcer area was 3.9 ± 2.7 mm. Approximately 15 of 24 (62.5%) culture-positive eyes had bacterial infection, most of which (80%) were caused by Gram-positive bacteria. Polymicrobial infection was noted in 7 of 24 eyes (29.1%). Although 57 of 83 (68.6%) eyes healed with medical therapy, 26 of 83 (31.3%) eyes had corneal perforation and were managed with cyanoacrylate glue application (30.7%) or therapeutic keratoplasty (69.3%). Systemic infection as an inciting factor of SJS and an early presentation for keratitis were the major risk factors associated with corneal perforation. Large mean ulcer size, paracentral ulcers, and punctal involvement were associated with a good visual outcome. CONCLUSIONS: Infective keratitis in SJS is common, and unlike routine cases, surgical intervention is often required. However, the antibiotic sensitivity pattern suggests that resistance is not that high.