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Namrata Sharma

Publications and source records attributed to Namrata Sharma.

At least 19 recordsLinked to original sources
PubMed2026

"Tissue-specific mitochondrial dysfunction in keratoconus: An integrated structural, genomic, and functional analysis".

PURPOSE: Keratoconus (KC) is a progressive corneal ectasia characterized by stromal thinning, conical protrusion, and irregular astigmatism, leading to visual impairment. Although oxidative stress is implicated in KC, the role of mitochondrial dysfunction remains unclear. We evaluated mitochondrial structural, genomic, and functional abnormalities in corneal tissues and blood from KC patients. METHODS: This prospective study enrolled 110&#x202f;KC patients and 55 controls. Transmission electron microscopy (TEM) and immunohistochemistry (IHC) were performed on epithelial and stromal tissues from 10&#x202f;KC to 5 control corneas assessing mitochondrial morphology, oxidative phosphorylation (OXPHOS) complexes and pro-apoptotic protein NOXA. Whole mitochondrial DNA (mtDNA) sequencing and relative mtDNA copy number analysis were performed on paired blood and corneal tissues from 50&#x202f;KC patients and 35 controls including both epithelial and stromal samples. Gene expression of mitochondrial biogenesis and oxidative stress-related genes was analysed by qRT-PCR in corneal epithelium from independent 50&#x202f;KC patients and 15 controls. RESULTS: TEM revealed cristolysis, membrane disruption, and reduced mitochondrial density in KC corneas. IHC showed reduced expression of OXPHOS complexes and increased NOXA expression (p&#x202f;<&#x202f;0.05). Sequencing identified 1107 mtDNA variants, with more variants in corneal tissues than matched blood (929 vs. 576; p&#x202f;=&#x202f;0.0002). Recurrent likely pathogenic variants were enriched in complex I-encoding genes (ND4, ND5). KC corneas showed reduced mtDNA copy number, downregulated POLRMT, upregulated NOX4, and significant downregulation of multiple antioxidant genes (p&#x202f;<&#x202f;0.0001). CONCLUSION: KC patients exhibit tissue-specific mitochondrial abnormalities and impaired oxidative stress regulation, supporting a role for mitochondrial dysfunction in disease pathogenesis and highlighting potential therapeutic targets.

Corneal pathology↗
PubMed2006

Hyeropic shift after LASIK induced diffuse lamellar keratitis.

BACKGROUND: Diffuse lamellar keratitis (DLK) is a relatively new syndrome that is increasingly being reported after LASIK. We have observed that a hyperopic shift may be associated with the occurrence of this diffuse lamellar keratitis. CASE PRESENTATION: A 26 year old man developed bilateral diffuse lamellar keratitis (DLK) following myopic LASIK. The residual refractive error was +0.5D OD and +0.25D OS at the end of the first week. The sterile infiltrates resolved over a period of 4-6 weeks on topical steroid therapy. A progressive hyperopic shift was noted in the right eye with an error +4.25Dsph/+0.25Dcyl 20 at the final follow up 6 months post surgery. CONCLUSION: Diffuse lamellar keratitis after LASIK may be associated with a significant hyperopic shift.

Adult↗
PubMed2006

Severe ocular injury resulting from chuna packets.

OBJECTIVE: To describe a mechanism of severe ocular alkali burns occurring as a result of bursting of chuna packets (edible calcium hydroxide paste), a popular additive to chewing tobacco in India. DESIGN: Retrospective case series. PARTICIPANTS: Twenty-one patients (25 eyes) who experienced ocular burns as a result of bursting of chuna packets. INTERVENTION: Patients were treated medically or with 1 or more of the following surgeries: symblepharon release, amniotic membrane grafting, allograft or autograft stem cell transplantation, or both, and large diameter lamellar keratoplasty. MAIN OUTCOME MEASURES: The main outcome measures were time interval between the injury and presentation, presenting visual acuity, grade of injury, management (medical therapy or surgical intervention), and final visual outcome at the last follow-up. RESULTS: The average age at time of injury was 8.4+/-5.5 years. The median visual acuity at presentation was light perception with projection. The ocular burns were grade 4 in 23 eyes. Eight of 25 eyes were treated medically, and the rest underwent 1 or more surgeries in the form of symblepharon release (n = 6), amniotic membrane grafting (n = 3), allograft or autograft stem cell transplantation (n = 6), and large diameter lamellar keratoplasty (n = 6). At the final follow-up (mean, 637+/-592 days), median visual acuity was 1/60. CONCLUSIONS: Bursting of chuna packets can cause severe ocular alkali burns in children. These patients carry a poor visual prognosis with both medical and surgical therapy.

Adolescent↗
PubMed2006

Efficacy of trypan blue in posterior capsulorhexis with optic capture in pediatric cataracts [ISRCTN48221688].

BACKGROUND: To evaluate the efficacy of trypan blue (0.06%) in posterior capsulorhexis with optic capture in pediatric cataracts. METHODS: In this prospective randomized controlled study, trypan blue dye assisted posterior capsulorhexis with optic capture was performed in 18 eyes (group 1) and no dye was used for posterior capsulorhexis (group 2) in 17 eyes. RESULTS: The mean size of the posterior capsulorhexis was 4.6 +/-1.77 mm and 4.0 +/- 0.93 mm in the group 1 and 2 respectively. Optic capture was possible in 17 eyes in the group 1 and 11 eyes in the group 2. CONCLUSION: Trypan blue facilitates posterior capsulorhexis with optic capture of AcrySof IOL in cases of pediatric cataracts.

Acrylates↗
PubMed2006

Contact lens rehabilitation following repaired corneal perforations.

BACKGROUND: Visual outcome following repair of post-traumatic corneal perforation may not be optimal due to presence of irregular keratometric astigmatism. We performed a study to evaluate and compare rigid gas permeable contact lens and spectacles in visual rehabilitation following perforating corneal injuries. METHOD: Eyes that had undergone repair for corneal perforating injuries with or without lens aspiration were fitted rigid gas permeable contact lenses. The fitting pattern and the improvement in visual acuity by contact lens over spectacle correction were noted. RESULTS: Forty eyes of 40 patients that had undergone surgical repair of posttraumatic corneal perforations were fitted rigid gas permeable contact lenses for visual rehabilitation. Twenty-four eyes (60%) required aphakic contact lenses. The best corrected visual acuity (BCVA) of > or = 6/18 in the snellen's acuity chart was seen in 10 (25%) eyes with spectacle correction and 37 (92.5%) eyes with the use of contact lens (p < 0.001). The best-corrected visual acuity with spectacles was 0.20 +/- 0.13 while the same with contact lens was 0.58 +/- 0.26. All the patients showed an improvement of > or = 2 lines over spectacles in the snellen's acuity chart with contact lens. CONCLUSION: Rigid gas permeable contact lenses are better means of rehabilitation in eyes that have an irregular cornea due to scars caused by perforating corneal injuries.

Adolescent↗
PubMed2006

Pseudomonas keratitis after laser in situ keratomileusis.

We report a 32-year-old woman who presented with infectious keratitis in the right eye 3 weeks after laser in situ keratomileusis (LASIK). On microbiological investigations, the microorganism isolated was Pseudomonas aeruginosa that was sensitive to ciprofloxacin. To our knowledge, this is the only case report in the literature of post-LASIK infectious keratitis caused by P aeruginosa.

Adult↗
PubMed2006

Effect of laser in situ keratomileusis and laser-assisted subepithelial keratectomy on retinal nerve fiber layer thickness.

PURPOSE: To evaluate and compare the influence of laser in situ keratomileusis (LASIK) and laser-assisted subepithelial keratectomy (LASEK) on the peripapillary retinal nerve fiber layer (RNFL) thickness. SETTING: Observational case series. METHODS: Twenty nonglaucomatous patients with mild to moderate myopia were included. One eye in each patient was randomly selected to have LASIK (Group 1, n = 20), and LASEK was performed in the fellow eye (Group 2, n = 20). The RNFL thickness measurements were performed using optical coherence tomography (OCT) preoperatively and 1 day and 1 month postoperatively. The RNFL thickness parameters were compared using repeated-measures 1-way analysis of variance (ANOVA) followed by multiple comparison tests in both groups. The main outcome parameter was RNFL thickness as determined by OCT before and after LASIK and LASEK. RESULTS: The mean age of the patients was 21 years +/- 3.2 (SD). The mean preoperative spherical equivalent was -4.23 +/- 1.71 diopters (D) in Group 1 and -4.16 +/- 1.68 D in Group 2. The mean ablation depth was 73.35 +/- 27.85 microm and 66.35 +/- 23.64 microm in groups 1 and 2, respectively. In Group 1, the mean average RNFL thickness, inferior average, superior average, temporal average, and nasal average were 98.2 +/- 5.6 microm, 128.6 +/- 11.9 microm, 120.38 +/- 10.2 microm, 65. 8+/- 7.1 microm, and 80.5 +/- 18.8 microm, respectively. None of the RNFL thickness parameters or RNFL ratios were found to have a significant change after surgery. In Group 2, the average RNFL thickness, inferior average, superior average, temporal average, and nasal average were 98.47 +/- 5.9 microm, 128.38 +/- 14.3 microm, 125.1 +/- 8.8 microm, 66.4 +/- 8.2 microm, 73.6 +/- 15.8 microm, respectively. No significant change was observed in any of the parameters following surgery. No significant alterations were noted in the RNFL parameters following LASIK or LASEK. CONCLUSIONS: Laser in situ keratomileusis and LASEK did not significantly affect the RNFL thickness parameters postoperatively.

Adult↗
PubMed2006

Penetrating keratoplasty for perforated corneal ulcers: preservation of iris by corneal debulking.

PURPOSE: This study was designed to study an alternative technique of lamellar separation of corneal layers for therapeutic keratoplasty in place of an en bloc removal of host corneal button in eyes with perforated corneal ulcers with pseudocornea. METHODS: Twelve eyes with perforated corneal ulcers with pseudocornea in which therapeutic keratoplasty was planned were included in the study. A new technique was used in which the host corneal tissue was removed in layers by lamellar dissection started peripherally and proceeding centripetally with care taken to prevent perforation at the site of iris incarceration. After injection of viscoelastic into the anterior chamber with a 26-gauge needle entered tangentially, the deeper layer of the cornea was then gently dissected and peeled away from the iris tissue, with care not to avulse the fragile iris and the overlying fibrotic membrane. Adjunctive procedures were performed, and the donor tissue was secured over the host bed. RESULTS: A complete separation of the iris tissue from corneal button and the fibrous membrane was achieved in 9 eyes. In 3 eyes, iris was partly trimmed along with the fibrous membrane, because the membrane was totally adherent to the iris tissue. Eight patients required pupilloplasty. Apart from minimal bleeding, no other complication was encountered. At the end of 3 months, 9 of 12 grafts remained clear. CONCLUSIONS: Debulking and layer-by-layer removal of host corneal tissue is effective in preservation of iris while performing therapeutic keratoplasty in eyes with perforated corneal ulcers with pseudocornea.

Adult↗
PubMed2006

Modification in descemet-stripping automated endothelial keratoplasty: "Hitch suture" technique.

PURPOSE: To describe a new modification in Descemet-stripping automated endothelial keratoplasty, using a "hitch suture" to unfold the donor lenticule inside the recipient's eye. METHODS: The technique was used in 2 eyes of 2 patients with bullous keratopathy after complicated cataract surgery. A hitch suture was created in both the donor lenticules before inserting the folded graft in the recipient's anterior chamber. The hitch suture was pulled through a limbal stab incision to unfold the donor lenticule in both cases. RESULTS: No intraoperative problems were encountered. The grafts were well centered with corneal edema. The central part of the graft cleared over a period of 10 to 14 days. CONCLUSION: The technique of using a hitch suture to unfold the graft eliminates the problems associated with this difficult step of the surgery. The hitch loop can be easily made at the edge of the graft and can be pulled using a Sinskey hook through 1 of the stab incisions. We believe that this simple modification in this surgery would help simplify the learning curve of the procedure and increase its chances of success.

Corneal Diseases↗
PubMed2006

Presumed herpetic endotheliitis following phacoemulsification surgery.

The authors present an observational case series. Three cases of presumed herpetic endotheliitis presented as cases of pseudophakic bullous keratopathy many years after successful phacoemulsification surgery. All patients had reduction of vision in the involved eye, corneal oedema and secondary glaucoma. The patients were treated with medical therapy consisting of topical corticosteroids, antiviral and antiglaucoma drugs. Resolution of corneal oedema, control of glaucoma and restoration of visual acuity were achieved in all cases. Specular microscopy performed thereafter demonstrated relatively normal endothelial cell counts. The authors conclude that pseudophakic bullous keratopathy occurring after phacoemulsification surgery may be caused by herpetic endotheliitis.

Aged↗
PubMed2006

Automated lamellar therapeutic keratoplasty (ALTK) in the treatment of anterior to mid-stromal corneal pathologies.

PURPOSE: To evaluate the efficacy of automated lamellar therapeutic keratoplasty (ALTK) in the treatment of anterior to mid-stromal corneal pathologies. METHODS: A prospective clinical study was undertaken in 15 eyes of 15 patients who underwent ALTK using the ALTK System (Moria/Microtek Inc., Doylestown, Pennsylvania, USA). The parameters evaluated were uncorrected and best corrected visual acuity (BCVA), keratometry, pachymetry, contrast sensitivity, glare acuity, intraoperative surgical time and complications, postoperative time to epithelialization, graft clarity and postoperative complications. RESULTS: The mean surgical time was 46 +/- 9 mins. The BCVA, contrast sensitivity and glare acuity significantly improved at 6 months postoperatively. The mean decimal BCVA was 0.08 +/- 0.03 preoperatively, which improved to 0.33 +/- 0.30 at 6 months, when 11 eyes had BCVA > or = 6/18. The median epithelialization time was 3 days (range 1-10 days). CONCLUSIONS: Automated lamellar therapeutic keratoplasty appears to be safe and effective for diseases affecting the anterior to mid-stroma of the cornea.

Adult↗
PubMed2006

Retreatment of LASIK.

PURPOSE: To review the indications, techniques, and results of retreatment LASIK. METHODS: Review of the literature and the authors' experience. RESULTS: Patient selection is the key to successful LASIK enhancement. The enhancement procedure should generally be undertaken 3 months after the initial LASIK procedure. Relifting of the flap may be done easily within 1 year of previous LASIK surgery. A new LASIK flap is required in cases with previously complicated LASIK. LASIK retreatment by lifting the flap is an effective and safe procedure. Overall improvement is seen in uncorrected visual acuity (> or = 20/20 and > or = 20/40) and postoperative spherical equivalent refraction within +/- 0.5 D and +/- 1.0 D. CONCLUSIONS: LASIK retreatment is an effective modality to treat regressions and residual refractive errors.

Humans↗
PubMed2005

Indications and outcome of repeat penetrating keratoplasty in India.

BACKGROUND: Repeat penetrating keratoplasty is quite often required as there is high chance of failure of the primary graft particularly in the developing world. We planned a study to analyze the indications and outcome of repeat penetrating keratoplasty in a tertiary care centre in India. METHODS: A retrospective analysis of all the patients who underwent repeat penetrating keratoplasty, between January 1999 and December 2001 was performed. The parameters evaluated were indication for the primary penetrating keratoplasty, causes of failure of the previous graft, and final visual outcome and clarity of the repeat corneal grafts. RESULTS: Of fifty-three eyes of 50 patients with repeat penetrating keratoplasty (three patients underwent bilateral corneal regrafts), 37 eyes had undergone one regraft each, 14 eyes two regrafts and two eyes had three regrafts. The follow-up of the patients ranged from one to three years. The most common primary etiologic diagnosis was vascularized corneal scars (66%), of which the scars related to infection were most common (68.5%). Twenty-eight regrafts (52.8%) remained clear at a mean follow-up of 1.54 +/- 0.68 years, of which 25 were single regrafts (89.3%). The commonest cause of failure of regraft was infection to the corneal graft (recurrence of herpetic infection in 9 eyes and perforated graft ulcers in 3 eyes). Three (18.6%) of the 16 eyes with multiple corneal regrafts achieved a BCVA of 6/60. Overall, only five eyes (all with single regraft) achieved a BCVA of 6/18 or better at the end of follow-up. CONCLUSION: Graft infection is the leading cause of failure of repeat keratoplasty in this part of the world. Prognosis for visual recovery and graft survival is worse in eyes undergoing multiple regrafts.

Corneal Diseases↗