Contact lenses in dry eye disease and associated ocular surface disorders.

Dry eye disease (DED) is prevalent in all age groups and is known to cause chronic ocular discomfort and pain, and greatly affects the quality of life. Patients with ocular surface disease (OSD) may also have reduced tear secretion due to lacrimal gland damage, thus leading to aqueous deficient DED. Even with conventional management modalities such as lubricating eyedrops, topical corticosteroids, autologous serum eyedrops, or punctal plugs, many patients continue to suffer from debilitating symptoms. Contact lenses are increasingly being used in OSD providing surface hydration, protection from environmental insults, mechanical damage from abnormal lids, and as a modality for constant drug delivery to the ocular surface. This review describes the role of soft lenses and rigid gas-permeable scleral lenses in the management of DED associated with OSD. The efficacy of contact lenses, lens selection, and optimal lens fit are reviewed for specific indications.

Development of a Smart Scaffold for Sequential Cancer Chemotherapy and Tissue Engineering.

The fabrication of a dual-functional drug-containing porous polymeric scaffold by layer-by-layer surface modification involving citrate-stabilized gold nanoparticles and cisplatin molecules is being reported. These scaffolds were characterized by electron microscopy and X-ray photoelectron spectroscopy. The capability of the scaffolds to release hydrated cisplatin in a slow and sustained manner over two days is established. Most importantly, the scaffolds turn nontoxic and cell-friendly after drug release, thus allowing the noncancerous fibroblast cells to adhere and proliferate (from 5000 cells to 16,000 cells in 6 days), becoming a potential solution toward an effective drug-carrying scaffold for volume-filling applications. The scaffold-mediated cancer cell killing and fibroblast cell proliferation were confirmed by fluorescence microscopy imaging, flow cytometry, and cell proliferation assays. We surmise that such a dual-purpose (drug-delivery and volume-filler) scaffold could help avoid the multiple surgical interventions needed for tumor surgery and cosmetic corrections. To the best of our knowledge, this is the first example of scaffolds with such a dual functionality which gets manifested in a sequential manner.

Long-term results of cornea collagen cross-linking with riboflavin for keratoconus.

Corneal collagen cross-linking with riboflavin and UVA light (CXL) is the only method designed to arrest the progression of keratoconus. Visual improvement generally starts 3 months after treatment. Reduction is coma seen on aberrometry in early postoperative phase is also responsible for the improvement in visual acuity. In the light of currently available data we can thus say that CXL is a safe procedure that is successful in arresting keratoconus.

Characteristics of keratoconus patients at a tertiary eye center in India.

PURPOSE: To evaluate the presentation and characteristics of patients with keratoconus at a tertiary eye care center in Mumbai, India. METHODS: This single center, non-comparative, retrospective cohort analysis was performed on patients with keratoconus who presented to the Clear Vision Eye Center clinic from April 2007 to March 2009. Data was collected to characterize correlations among visual acuity, corneal biomicroscopic findings, and refractive and topographic findings in keratoconus. RESULTS: Records of 274 patients including 189 male and 85 female subjects with mean age of 20.1±3.5 (range, 13 to 29) years at the time of diagnosis were assessed. There was history of skin allergy in 73 (26.6%), symptomatic ocular allergy in 67 (24.45%) and asthma in 31 (11.31%) patients. The most frequent corneal sign was Fleischer's ring which was observed in 81% of cases. Corneal topography revealed mean simK (simulated keratometry) of 53.3±6.1 (range, 41.2 to 69.0) diopters. Corneal topography analysis with the Cone Location Magnitude Index disclosed the presence of inferior cones in 93% of patients. CONCLUSION: This group of patients had younger age at presentation and more severe keratoconus as compared to western populations; contact lenses were used only in a minority of patients.

Validation of scoring system for preoperative stratification of intra-operative risks of complications during cataract surgery: Indian multi-centric study.

AIM: To validate a system that uniformly and objectively assesses the risk of complications of cataract surgery performed with phacoemulsification technique in individual patients preoperatively. MATERIALS AND METHODS: Outcome analysis of patient data entered into a standardized protocol. The data sheet was analyzed at a single center in terms of the risk assessed preoperatively and the incidence of surgical complications. This study did not assess the final visual outcome of eyes with complications. Each patient was categorized into a risk group according to the number of points scored. Group 1 (no added risk) 0 points, Group 2 (low risk) 1-2 points, Group 3 (moderate risk) 3-5 points, Group 4 (high risk) 6 points or more. RESULTS: The number of eyes in each risk group was 2894 in Group 1 (44.1%), 1881 in Group 2 (28.6%), 1575 in Group 3 (23.9%), and 214 in Group 4 (3.3%). A total of 6564 eyes were assessed, of these 3669 eyes (55.9%) had a minimum of one risk factor and were thus not "routine". The group-specific events of complications were Group 1, 46 (1.6%), Group 2, 108 (5.7%), Group 3, 168 (10.7%), and Group 4, 69 (32.2%). The total incidence of complications was 5.7%. The group-specific rate of intraoperative complications increased through the risk groups ( P < 0.001). CONCLUSION: The study validates a scoring system that is predictive of intraoperative complications. This system uses information that is readily available from the preoperative history and assessment of the patient.

Corneal collagen cross-linking with riboflavin and ultraviolet - a light for keratoconus: results in Indian eyes.

AIM: To assess the results of corneal collagen cross-linking with riboflavin using ultraviolet - A light for keratoconus at one year in Indian eyes. MATERIALS AND METHODS: Sixty-eight eyes of 41 patients with progressive keratoconus were included in this retrospective study. All eyes completed was 12 months of follow-up and 37 eyes had a one-year follow-up. The maximum follow-up was 16 months. Ocular examinations including refraction, best corrected visual acuity (BCVA), corneal topography, were recorded at each visit. RESULTS: The mean age was 16.9 +/- 3.5 years (range 12-39 years) and the mean follow-up was 10.05 +/- 3.55 months (range six to 16 months). Thirty seven eyes with a follow-up of at least 12 months were analyzed. The preoperative values on the day of treatment were compared with postoperative values of the 12-month examination. This showed that BCVA improved at least one line in 54% (20/37) of eyes and remained stable in 28% (10/37) of eyes ( P =0.006). Astigmatism decreased by a mean of 1.20 diopter (D) in 47% (17/37) of eyes ( P =0.005) and remained stable (within +/- 0.50 D) in 42% (15/37) of eyes. The K value of the apex decreased by a mean of 2.73 D in 66% (24/37) of eyes ( P =0.004) and remained stable (within +/- 0.50 D) in 22% (8/37) of eyes. The maximum K value decreased by a mean of 2.47 D in 54% (20/37) of eyes ( P =0.004) and remained stable (within +/- 0.50 D) in 38% (14/37) of eyes. Corneal Wavefront analysis revealed that spherical and higher-order aberrations did not show significant variations in the follow-up period. The coma component showed a very significant reduction at six months after treatment and persisted throughout the follow-up period ( P =0.003) CONCLUSION: The results show a stabilization and improvement in keratoconus after collagen cross-linking in Indian eyes. This suggests that it is an effective treatment for progressive keratoconus.

Comparison of the mouse foot pad test with a Buddemeyer type radiorespirometric assay in detecting viable Mycobacterium leprae in human lesional biopsies.

AIM: This study assesses the utility of a Buddemeyer type radiorespirometric (RR) assay in detecting viable Mycobacterium leprae in clinical samples taking the mouse foot pad (MFP) test as gold standard. METHODS: A total of 131 skin biopsy specimens comprising of 56 untreated, smear-positive, borderline lepromatous and lepromatous leprosy (BL-LL) and 75 untreated, smear-negative, borderline tuberculoid and mid-borderline (BT-BB) specimens were processed by both the methods. The cut-off value (in counts per minute, cpm) for test samples in the RR assay was determined using nonleprous (normal) skin biopsy specimens. RESULTS: In the untreated BL-LL and BT-BB groups, 86 and 56% of the cases tested positive in the RR assay respectively, which was comparable to the results of the MFP test (80 and 45% respectively). The overall concordance between the two tests was 74.79%, whereas the sensitivity and specificity were 75 and 74.3% respectively. A Kappa value of 0.459 indicated a fairly good agreement between the two methods. There was no linear relationship observed between the bacteriological index (BI) and the morphological index (MI) with the counts per minute (cpm) output. CONCLUSION: The results indicate the ability of this RR assay to detect viability; however a comparison with another sensitive method would further validate the assay system.

Hypokalemia causing rhabdomyolysis resulting in life-threatening hyperkalemia.

Hyperkalemia is commonly associated with renal failure and is rare if renal function is normal. It is rarely caused by rhabdomyolysis and can be life threatening if unrecognized. Rhabdomyolysis is caused by many disorders, including hypokalemia. The available literature, both for human beings and experimental animals, contains evidence of hypokalemia causing rhabdomyolysis and rhabdomyolysis leading to hyperkalemia. Hypokalemia as a cause of rhabdomyolysis often goes unnoticed, because of the counteracting effect of rhabdomyolysis on serum potassium. There are no pediatric reports showing hypokalemia as a cause of rhabdomyolysis leading to life-threatening hyperkalemia. This case emphasizes the vigilance required toward the occurrence of rhabdomyolysis, which if not detected promptly may prove fatal.

Corneal epithelial wound healing.

One of the important functions of the cornea is to maintain normal vision by refracting light onto the lens and retina. This property is dependent in part on the ability of the corneal epithelium to undergo continuous renewal. Epithelial renewal is essential because it enables this tissue to act as a barrier that protects the corneal interior from becoming infected by noxious environmental agents. The renewal process also maintains the smooth optical surface of the cornea. This rate of renewal is closely maintained by an integrated balance between the processes of corneal epithelial proliferation, differentiation, and cell death. Attempts to understand this complex cascade make it evident that the appropriate integration and coordination of corneal epithelial renewal depends on the actions of a myriad of cytokines. We have attempted in this review to collate the receptor and cell signaling events and cytokine studies that are responsible for mediating corneal wound healing.

Peribulbar anaesthesia for penetrating keratoplasty. A case series.

PURPOSE: To prospectively analyse the efficacy and safety of peribulbar anaesthesia for penetrating keratoplasty through a noncomparative, consecutive series. METHODS: One hundred twenty-four (91.1%) of 136 patients undergoing penetrating keratoplasty (PK) from January 1997 to December 2001, were administered peribulbar anaesthesia. The anaesthetic mixture consisted 5 ml of lignocaine, bupivacaine, and hyaluronidase (to avoid evaluation bias) in the peribulbar space. A repeat injection of 3 ml was used if the primary injection was inadequate. Digital ocular compression was done for 10-15 minutes after the first injection. Each patient was analysed for degree of akinesia, subjective patient comfort, analgesia, subjective surgeon comfort, and types of surgical conditions. RESULTS: The age ranged from 19 to 86 years. Forty-nine of 124 patients (39.5%) received PK only and remaining 75 patients (60.5%) received additional procedures. A single injection was sufficient to achieve adequate akinesia (grade II and III) in 114 (92%) patients and 120 (97%) of patients were satisfied (graded pain as < or = grade II). During surgery, 6 (5%) phakic eyes developed episodes of positive intraocular pressure and 5 eyes (4%) developed chemosis. There were no other local or systemic adverse events. The surgeon level comfort was (grade II or more) 98% (122 of 124). CONCLUSION: One-point, low volume, peribulbar anaesthesia for penetrating keratoplasty is safe and efficacions.