Central toxic keratopathy leading to epithelial ingrowth following femtosecond LASIK.

We report a case of a woman in her 30s who underwent femtosecond LASIK (laser-assisted in situ keratomileusis) in both eyes to correct her simple myopic astigmatism. After the surgery, both eyes developed diffuse lamellar keratitis, and intensive topical steroids were initiated to control the same. Subsequently, central toxic keratopathy (CTK) developed bilaterally. Three weeks after the surgery, the right eye showed signs of progressive epithelial ingrowth involving the pupillary area. Surgical intervention in the form of flap relift followed by debridement of the epithelial cells and an alcohol interface wash were performed to treat the same. This is the first report of an epithelial ingrowth following CTK after femtosecond LASIK.

Investigation of mechanical strength and structure of corneal graft-host junction.

Dehiscence is a common complication of corneal transplant surgery involving separating the graft from the host eye. The present article aims to investigate fundamental insights into the mechanical and structural aspects of the graft-host junction (GHJ) of a graft that survived in a patient for 13 years after penetrating keratoplasty (PK). Additionally, it adopts the sutur retention strength (SRS) test procedure defined in ISO:7198-2016 and aims to provide a comprehensive test protocol to study the biomechanics of the GHJ in extracted PK buttons. A 9 mm corneal button with GHJ was extracted from a 46-year-old patient who underwent PK 13 years back. The strength of the GHJ was quantified using the SRS test. Corresponding control results were obtained from the SRS tests of a corneoscleral button with no history of any refractive procedure. Birefringence, histological, and scanning electron microscopy (SEM) imaging were used to visualize the microstructural details of the GHJ. The strength of the GHJ was observed to be ten times lower than the native cornea. Histopathological features, such as fragmented Bowman's layer, and fibrosis with a clear demarcation line between host and graft tissue, were observed at the GHJ, suggesting a weak bond across the GHJ. The low strength of the GHJ in PK indicates the high susceptibility of the GHJ towards wound dehiscence.

Teleophthalmology at a primary and tertiary eye care network from India: environmental and economic impact.

OBJECTIVE: To evaluate the environmental and economic impact of teleophthalmological services provided by a primary (rural) and tertiary (urban) eyecare network in India. METHODS: This prospective study utilised a random sampling method, and administered an environmental and economic impact assessment questionnaire. The study included 324 (primary: 173; tertiary: 151) patients who received teleconsultations from July to September 2022. The primary network (rural) used a colour-coded triage system (Green: eye conditions managed by teleconsult alone; yellow: semi-urgent referral within 1 week to a month, red: urgent referral within a day to a week). The tertiary network (urban) included new and follow-up patients. The environmental impact was assessed by estimating the potential CO2 emissions saved by avoiding travel for various transport modes. Economic impact measured by the potential cost savings from direct (travel) and indirect (food and wages lost) expenses spent by yellow and red referrals (primary) and the first-visit expenses of follow-up (tertiary) patients. RESULTS: The primary rural network saved 2.89 kg CO2/person and 80 km/person. The tertiary urban network saved 176.6 kg CO2/person and 1666 km/person. The potential cost savings on travel expenses were INR 19,970 (USD 250) for the primary (average: INR 370 (USD 4.6) per patient) and INR 758,870 (USD 9486) for the tertiary network (average: INR 8339 (USD 104) per patient). Indirect cost savings (food and wages) were of INR 29,100 (USD 364) for the primary and INR 347,800 (USD 4347) for the tertiary network. CONCLUSION: Teleophthalmology offers substantial environmental and economic benefits in rural and urban eyecare systems.

Prevailing practice patterns in keratoconus among Indian ophthalmologists.

Objective: The past few years have seen a rapid advancement in the management of keratoconus (KC). However, there is no prescribed standard of care for the management of KC. This study evaluated the prevailing practice patterns among Indian ophthalmologists in the diagnosis and treatment of KC via an online survey. Methods: This was a survey-based cross-sectional study in which a questionnaire (Supplement 1) was created. Questions pertaining to the practicing experience, setting of practice, and training background were asked in addition to the investigations done and decision making in KC management. Responses were collected via Survey Monkey (Survey Monkey, Palo Alto, California, USA) and statistical analysis performed using R software (4.1.3). Results: The survey was answered by 273 ophthalmologists. Pentacam was the most used topographer (195 users), followed by Orbscan (41 users), Sirius (34 users), and Galilei (3 users). The lowest limit of pachymetry for performing collagen crosslinking (CXL) was 400µ for most practitioners. More than half the respondents (50.55%) did not perform photorefractive keratectomy (PRK) or intracorneal ring segment (ICRS) implantation in a suitable patient. Accelerated 10-minute protocol (9 mW/cm2 for 10 minutes) was the most commonly (54.21%) used for CXL, followed by Dresden protocol (3 mW/cm2 for 30 minutes) (36.63%). When a patient was unsuitable for CXL, 55.31% surgeons advise contact lens (CL) trial, 35.16% surgeons advise keratoplasty, 26.74% surgeons perform stromal augmentation, and 7.69% surgeons advise spectacle correction. Corneal scar was the most common indication (49.45%) for performing keratoplasty. Conclusion: Topography remains the most used diagnostic modality for initial diagnosis. Optical coherence tomography and epithelial mapping are increasingly being used for early diagnosis of KC. Not all ophthalmologists were comfortable performing ICRS or PRK. When patients are unsuitable for CXL, CL trial remains the most frequently advised option followed by keratoplasty.

Suprathreshold contrast perception of resolvable high spatial frequencies remain intact in keratoconus.

Contrast detection thresholds are elevated with optical quality loss in keratoconus. This study hypothesized that suprathreshold contrast perception is also impaired in keratoconus, with the impairment being predictable from the pattern of loss in threshold-level performance. Contrast detection thresholds were determined across a range of spatial frequencies in 12 cases with mild to severe keratoconus and 12 age-similar controls. These values were used to predict the contrast needed to achieve perceptual matches between reference and test spatial frequency pairs (peak of CSF Vs. 0.3x, 0.5x, 2x or 3x spatial frequency from the peak) for stimuli at 10% and 50% suprathreshold contrast. Contrast thresholds predicted a 1.5 to 6.7-fold increase in the test pattern's contrast to obtain a perceptual match with the reference pattern in keratoconus, relative to controls. Contrary to predictions, the empirical data of contrast matches between test and reference patterns were similar for higher than peak spatial frequencies at both contrast levels. However, as predicted, test patterns required higher contrast than the reference pattern for a perceptual match for lower than peak spatial frequencies. These results were similar to controls and invariant of disease severity, interocular asymmetry and short-term changes in optical quality. Unlike thresholds, suprathreshold contrast perception of resolvable high spatial frequencies appears immune to optical quality losses in keratoconus. These results are discussed in the context of the prevailing models of contrast constancy in healthy humans. Breakdown of contrast constancy at lower than peak spatial frequencies may reflect the properties of the testing paradigm employed here.

Interocular Contrast Balancing Partially Improves Stereoacuity in Keratoconus.

SIGNIFICANCE: Partial improvement in stereoacuity may be achieved by balancing the contrast input to the two eyes of patients with bilaterally asymmetric keratoconus. PURPOSE: Interocular differences in image quality, characterized by dissimilar contrast loss and phase shifts, are implicated in stereoacuity loss in keratoconus. This study determined whether contrast balancing improves stereoacuity in this disease condition and, if so, whether it is dependent on the baseline interocular contrast imbalance. METHODS: Interocular contrast imbalance and stereoacuity of 43 subjects (16 to 33 years) with bilaterally asymmetric keratoconus were tested with spectacle correction as baseline using a binocular rivalry paradigm and random-dot stereograms, respectively. Stereoacuity measurements were repeated in a subset of 33 subjects at their contrast balance point (i.e., contrast level in stronger eye allowing balanced rivalry with 100% contrast in weaker eye) and with contrast levels biased in favor of stronger or weaker eye, all conditions in randomized order. RESULTS: Contrast imbalance level was significantly correlated with the subject's stereoacuity at baseline ( r = -0.47, P = .002). The median (25th to 75th interquartile range) stereoacuity improved by 34.6% (19.0 to 65.1%) from baseline (748.8 arc sec [261.3 to 1257.3 arc sec]) to the contrast balanced condition (419.0 arc sec [86.6 to 868.9 arc sec]) ( P < .001), independent of their baseline stereoacuity or contrast imbalance levels ( r < 0.2, P > .26 for both). Contrast bias in favor of the weaker eye (881.3 arc sec [239.6 to 1707.6 arc sec]) worsened stereoacuity more than a bias toward the stronger eye (502.6 arc sec [181.9 to 1161.4 arc sec]), both relative to the contrast balanced condition ( P < .002). CONCLUSIONS: Interocular contrast balancing partially improves stereoacuity in bilaterally asymmetric keratoconus, independent of their baseline contrast imbalance level. Cyclopean viewing may be inherently biased toward the input from the stronger eye in keratoconus.

Impact of teleconsultation on visual and refractive outcomes in patients undergoing laser refractive surgery during COVID-19.

Purpose: To assess the role of remote teleconsultation (TC) follow-up care following a successful and uneventful laser vision correction. Methods: The study is a retrospective, comparative analysis of patients undergoing laser vision correction at tertiary care eye hospital in Southern India. The patients were divided into two groups. The first group included patients operated on before the coronavirus disease (COVID-19) pandemic and were followed up with physical consultations during their follow-up visit (Group 1). The second group comprised patients operated on during the pandemic and had at least one remote TC during their post-operative follow-up (Group 2). Results: A total of 1088 eyes of 564 patients and 717 eyes of 372 patients were included in Group 1 and 2, respectively. The mean number of visits for the patients from Group 2 during the COVID period (2.56 +/- 0.74 days) was significantly lesser (P < 0.0001) than that of Group 1 in the pre-COVID period (3.53 +/- 1.07 days). Close to 90% of the eyes achieved an uncorrected distance visual acuity (UDVA) of 20/20 in both groups (P = 0.925). 96.50% of the eyes in Group 1 and 98.18% of the eyes in Group 2 achieved UCVA 20/25 or better (P = 0.049). Eight eyes (0.73%) in Group 1 and one eye (0.14%) in Group 2 reported a loss of 2 or more lines. However, the results were not statistically significant (P = 0.156). None of the groups had any patients who had a sight-threatening complication. Conclusion: Remote TC following refractive surgery is safe and can be effectively integrated into routine refractive practice to reduce travel to the hospital for a physical consult.

Feasibility study for measuring patients' visual acuity at home by their caregivers.

Purpose: To assess the feasibility of measuring patients' visual acuity (VA) in their homes by their caregivers. Methods: Patients consulting in a tertiary eye care institute were prospectively enrolled with informed consent. All underwent standard COMPlog distance VA testing. Patients and caregivers were oriented to test distance VA using the Peek Acuity app. The app was installed on the caregiver's or patient's smartphone. The patient's VA was measured by the caregiver in the clinic (baseline value) under supervision. After 1 week, the caregivers recorded the patient's VA with the Peek Acuity app at their home and reported the value in a telephone consultation. A questionnaire to assess the ease of using the app was administered at both the baseline visit and 1 week later. Results: A total of 100 patients (age group: 13 to 76 years) and 100 caregivers (age group: 17 to 65 years) participated. VA measurements with the Peek Acuity app were comparable with COMPlog (P > 0.1) both during the baseline and after 1-week measurement, regardless of the underlying ocular condition or educational level of the caregivers/patients. Most caregivers (95%) felt the app was easy to use. Conclusion: Though the Peek Acuity app was originally developed for health care workers to be used in field visits, we found that with proper orientation, the layperson can also use it. Such orientation can enable caregivers to effectively measure VA at home. Such a tool would enhance teleophthalmology consultations and can minimize the need for short follow-up visits.

Clinical Outcomes of Rose Bengal Mediated Photodynamic Antimicrobial Therapy on Fungal Keratitis with Their Microbiological and Pathological Correlation.

PURPOSE: To report the clinical outcome of Photodynamic Antimicrobial Therapy (PDAT) with Rose Bengal (RB) used as an early adjuvant therapy in patients with fungal keratitis and their microbiological and pathological correlation. METHODS: Patients with microbiologically confirmed fungal keratitis underwent PDAT-RB along with topical natamycin 5% drops hourly and oral ketoconazole 200 mg twice a day. This was performed by applying rose bengal (0.1%) to the de-epithelialized cornea for 30 minutes, followed by irradiation with a 6 mW/cm2 custom-made green LED source for 15 minutes (5.4 J/cm2). The corresponding fungal isolates were tested in vitro using PDAT-RB and corneal buttons were evaluated for correlation. RESULTS: Following informed consent, seven patients (male-5, female-2, mean age 47.7 years) with fungal keratitis were recruited. There were 3 cases each of Fusarium and Aspergillus flavus and 1 case of Acremonium sp. The average vertical and horizontal diameters of the corneal infiltrate were 4.12 ± 0.55 and 3.99 ± 1.19 mm, respectively. The average depth of corneal involvement was 283 ± 75.27µ as measured by anterior segment OCT. The clinical resolution was achieved in the cases with Fusarium keratitis with an average time of 39 days. Three cases of A. flavus and a single patient with Acremonium keratitis worsened and needed therapeutic keratoplasty (TPK) for resolution. Post-TPK, the corneal tissues grew A. flavus in one out of three cases and Acremonium sp. in one case. In vitro PDAT-RB experiment was performed on the corresponding fungal isolates grown from the corneal scraping. PDAT-RB produced clear inhibition of Fusarium and Acremonium sp. with no effect on the growth of A. flavus. Histopathologically, 2 out of 4 (50%) corneal buttons showed fungal filaments. CONCLUSIONS: While the in vitro and in vivo results of PDAT-RB matched for Fusarium sp. and Aspergillus flavus keratitis being favourable in the former and non-favourable in the latter, these results were discrepant in Acremonium sp.

Descemet Membrane Endothelial Keratoplasty and Goniosynechialysis in Iridocorneal Endothelial Syndrome: Surgical Perspective and Long-Term Outcomes.

PURPOSE: The purpose of this study was to report the long-term outcomes of Descemet membrane endothelial keratoplasty (DMEK) with goniosynechialysis in eyes with iridocorneal endothelial syndrome with an emphasis on the surgical technique. METHODS: This was a retrospective series of 5 eyes of 5 patients undergoing a DMEK procedure at a tertiary eye care institute by a single surgeon. Modifications in the standard surgical technique, including the release of peripheral anterior synechiae, peripheral descemetorhexis, the release of adherent membranes, maneuvers in the anterior chamber with or without cataract extraction were logged. Long-term outcomes of the surgery in these patients are reported. RESULTS: Five DMEK procedures were performed in 5 eyes of 5 patients. The average age of the patients was 48.2 ± 10.8 years, and the donor was 55.2 ± 3.2 years with a mean endothelial cell density (ECD) of 2784.6 ± 231 cells/mm 2 . After a mean follow-up period of 29.6 months (24-41 mo), all the 5 grafts remained clear; the mean BCVA at the last follow-up was 0.18 ± 0.17 logarithm of the minimum angle of resolution with a mean ECD of 1086.2 ± 338 cells/mm 2 with a 61.1% reduction in ECD. intra ocular pressure was normal in all the cases. None of the patients had graft detachments that required rebubbling, and all eyes had a clear graft at the last follow-up. CONCLUSIONS: DMEK can be performed successfully in a case with iridocorneal endothelial syndrome with good visual outcomes with modifications to the surgical technique, including peripheral anterior synechiae release and minimizing surgical manipulation.

Biocompatibility and Comfort during Extended Wear of Mel4 Peptide-Coated Antimicrobial Contact Lenses.

(1) Purpose: This study aimed to investigate the effects of Mel4 antimicrobial contact lenses (MACL) on the ocular surface and comfort during extended wear. (2) Methods: A prospective, randomised, double-masked, contralateral clinical trial was conducted with 176 subjects to evaluate the biocompatibility of contralateral wear of MACL. The wearing modality was 14-day extended lens wear for three months. The participants were assessed at lens dispensing, after one night, two weeks, one month and three months of extended wear and one month after study completion. (3) Results: There were no significant differences (p > 0.05) in ocular redness or palpebral roughness between Mel4 and control eyes at any of the study visits. There was no significant difference (p > 0.05) in corneal staining between Mel4 and control eyes. There were no significant differences in front surface wettability or deposits or back surface debris (p > 0.05). No statistically significant differences (p > 0.05) were found in comfort, dryness, CLDEQ-8 scores lens or edge awareness. There was no evidence for delayed reactions on the ocular surface after cessation of lens wear. (4) Conclusion: The novel MACLs showed similar comfort to control lenses and were biocompatible during extended wear. Thus, these lenses were compatible with the ocular surface.

Differences in Image Quality after Three Laser Keratorefractive Procedures for Myopia.

SIGNIFICANCE: Psychophysical estimates of spatial and depth vision have been shown to be better after bilateral ReLEx small-incision lenticule extraction (SMILE) refractive surgery for myopia, relative to photorefractive keratectomy (PRK) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK). The present study provides the optical basis for these findings using computational image quality analysis. PURPOSE: This study aimed to compare longitudinal changes in higher-order wavefront aberrations and image quality before and after bilateral PRK, FS-LASIK, and SMILE refractive procedures for correcting myopia. METHODS: Wavefront aberrations and image quality of both the eyes of 106 subjects (n = 40 for FS-LASIK and SMILE and n = 26 for PRK) were determined pre-operatively and at 1-week, 1-month, 3-month, and 6-month post-operative intervals using computational through-focus analysis for a 6-mm pupil diameter. Image quality was quantified in terms of its peak value and its interocular difference, residual defocus that was needed to achieve peak image quality (best focus), and the depth of focus. RESULTS: The increase in root mean squared deviations of higher-order aberrations post-operatively was lesser after SMILE (1-month visit median [25th to 75th interquartile range], 0.34 µm (0.28 to 0.39 µm]) than after PRK (0.80 µm [0.74 to 0.87 µm]) and FS-LASIK (0.74 µm [0.59 to 0.83 µm]; P ≤ .001), all relative to pre-operative values (0.20 µm [0.15 to 0.30 µm]). The peak image quality dropped and its interocular difference increased, best focus shifted myopically by 0.5 to 0.75 D, and depth of focus widened significantly after PRK and FS-LASIK surgeries, all relative to pre-operative values (P < .001). All these changes were negligible but statistically significant in a minority of instances after SMILE surgery (P ≥ .01). CONCLUSIONS: Although all three refractive surgeries correct myopia, the image quality and its similarity between eyes are better and closer to pre-operative values after SMILE, compared with FS-LASIK and PRK. These results can be explained from the underlying increase in higher-order wavefront aberrations experienced by the eye post-operatively.

Anterior segment imaging using a simple universal smartphone attachment for patients.

To assess the utility of a universal smartphone attachment to capture images of the anterior segment of the eye, we conducted a retrospective analysis of 344 images captured using a smartphone by the patients to identify factors affecting image quality, such as lack of perspective, lack of focus, improper illumination, and resolution. Based on this analysis, a universal smartphone attachment named GrabiTMLite and a protocol for anterior segment imaging were designed and validated in the first prospective arm of 60 patients. These images were then compared with the same eyes imaged on the gold standard slit-lamp photography. In the second prospective arm, nine patients were trained to use the GrabiTM Lite with the imaging protocol, and the images were assessed for utility in arriving at a diagnosis. A total of 178 images were analyzed using a questionnaire by masked observers. The images were evaluated based on their quality and suitability in clinical decision-making, risk stratification for triage for referral to a tertiary eye care centre. The quality of 344 images captured by patients using only their smartphone was rated as good 24 (7%), average 209 (60.8%), and poor in 111 (32.2%). Of these, 55 (16%) images were deemed suitable for clinical decision-making, and 224 (65.6%) images were adequate for risk stratification. Lack of perspective, focus, illumination, and resolution were seen in 167 (51.2%), 284 (87.1%), 226 (69.3%), and 126 (38.7%) images, respectively. These metrics improved in the next iteration of 178 images captured by patients using Grabi Lite + imaging protocol to good 103 (57%), average 58 (32.6%), and bad 17 (19.6%) (p < .001 using chi-square test). Images deemed suitable for clinical decision-making, and risk stratification for triage also improved to 80 (45%), 158 (88.8%) (p < .001 using chi-square test), respectively. Adherence to protocol was seen in 98 (55.5%) images, of which all were suitable for risk stratification, while of these images, 66 (67.3%) were eligible for clinical decision making. In comparison with slit-lamp photography, out of 120 responses by masked observers to images captured by GrabiTM Lite with the imaging protocol, 63 (52.85%) were suitable for clinical decision-making, and 68 (57%) were graded to be between 70 and 99% of the quality of the slit lamp photographs. The GrabiTM lite with imaging protocol training is an effective tool to improve anterior segment imaging, potentially allowing smartphone use for teleconsultations. This device may serve as a universal solution for all smartphones with the patient as the user and is of value in the future of tele-ophthalmology.

Ocular microbiota and lens contamination following Mel4 peptide-coated antimicrobial contact lens (MACL) extended wear.

PURPOSE: The purpose of this study was to investigate the effect of Mel4 antimicrobial peptide-coated contact lenses (MACL) on the microbiota of the conjunctiva and lenses during three months of extended wear. METHODS: One hundred and seventy-six participants were recruited into a randomised, contralateral, double masked, biweekly extended wear MACL and uncoated control lens trial. At the one month and 3-month visit, the conjunctival microbiota was sampled using sterile cotton swabs and contact lenses were collected aseptically. Standard microbiological procedures were employed for culture of the swabs and contact lenses and identification of the isolated microorganisms. RESULTS: Gram-positive bacteria (predominantly coagulase-negative staphylococci) were the most frequently isolated microbes from both contact lenses and conjunctiva. There was no difference in the frequency of isolation of most bacteria or fungi from the conjunctival swabs of eyes wearing either MACL or control lenses. The only exception was a higher frequency of eyes harbouring Staphylococcus arlettae when wearing control lenses (5%) versus MACL (<1%) (p = 0.002). There was no significant difference in the frequency of microbes isolated from MACL or control contact lenses. There were also no differences between lens types in the frequency of isolation of >1 microbial type per sampling occasion for either conjunctiva swabs or contact lenses. CONCLUSION: MACL wear did not change the conjunctival microbiota during extended wear, and the types of microbes isolated from MACL were similar to those isolated from control lenses.

Effect of Antimicrobial Contact Lenses on Corneal Infiltrative Events: A Randomized Clinical Trial.

Purpose: To determine whether Mel4-coated antimicrobial contact lenses (MACLs) can reduce the incidence of corneal infiltrative events (CIEs) during extended wear. Methods: A prospective, randomized, double-masked, single-center, contralateral, extended contact lens wear clinical trial was conducted with 176 subjects. Each participant was randomly assigned to wear a MACL in one eye and an uncoated control contact lens in the contralateral eye or an extended-wear biweekly disposable modality for 3 months. The main outcome measures were the incidence of CIEs per 100 eye-months, identification of the microbial types colonizing the contact lenses or eyes at the time of the CIEs, and their susceptibility to Mel4. Results: Nine participants (5.1%) experienced unilateral CIEs; six participants had contact lens acute red eye, and three participants had infiltrative keratitis. The incidence rate for CIEs (0.4 events per 100 participant months; 1.7%) in the Mel4-coated lenses (test) was 69% less than that of the control lenses (1.3 events per 100 participant months; 3.4%; P = 0.29). All Gram-negative bacteria isolated from lenses and lids of participants with CIEs (Citrobacter diversus, Acinetobacter haemolyticus, and Acinetobacter lwoffii) were susceptible to Mel4 peptide; minimum inhibitory concentrations ranged from 15.6 to 62.5 µg/mL. Reduction of adhesion of these bacteria by Mel4-coated lenses ranged from 2.1 to 2.2 log10 colony-forming units/lens. Conclusions: MACLs had the capacity to reduce CIEs by at least 50% compared with uncoated control lenses during extended wear over 3 months; however, due to the relatively low rates of CIEs, the reduction was not statistically different compared with control lenses. Translational Relevance: This study provides evidence that antimicrobial contact lenses have the potential to reduce the incidence of corneal infiltrative events during extended wear.

Dye-based identification of the orientation of tissue for Descemet stripping automated endothelial keratoplasty: A laboratory-based study.

Purpose: To describe the features enabling the identification of the orientation of Descemet stripping automated endothelial keratoplasty (DSAEK) lenticule with the assistance of vital dyes. Methods: This is a blinded experimental lab-based study, including 30 microkeratome prepared precut DSAEK lenticules. The lenticules were divided into control and study arms which included 10 unstained and 20 stained lenticules, respectively. In the study arm, vital dyes like trypan blue (TB), brilliant blue (BB), indocyanine green (ICG) and fluorescein stain (FS) were used to stain 5 lenticules each. They were examined by experienced (group 1) and novice surgeons (group 2) to identify the correct orientation of the lenticule. The results were tabulated and analyzed. Results: Of the 30 lenticules examined, the average of total scores obtained by each observer was higher (78%) in group 1 as compared to group 2 (65.3%) which was statistically significant (P < 0.005). In group 1, the accuracy of identifying the correct orientation of unstained lenticules was 70% which improved to 82% on staining. The accuracy in group 2 was 58% with unstained lenticules which improved to 69% on staining. Within the study arm, irrespective of surgical experience, the accuracy was highest with BB (86%), followed by TB (82%), ICG (72%) and FS (62%). Conclusion: This study found that the accuracy of identifying the orientation of DSAEK lenticules increased with experience and with the assistance of staining using vital dyes. This accuracy improved with blue dyes like brilliant blue and trypan blue, irrespective of the level of experience.

Corneal oedema with in situ implantable collamer lens: a challenging scenario for descemet membrane endothelial keratoplasty.

A 27-year-old woman had foggy vision and photophobia since 10 months after implantation of implantable collamer lens (ICL STAAR Surgical AG, Nidau, Switzerland) with evidence of corneal decompensation and no cataract formation. Descemet membrane endothelial keratoplasty in phakic eyes is challenging, considering presence of posterior chamber phakic intraocular lens (IOL), decreasing the space available in anterior chamber to manoeuvre the graft. Need of inferior peripheral iridotomy in presence of central hole technology in ICL depends on the dynamics of full chamber air bubble. At 8 months, vision had improved to 20/20 and normal IOP with well-attached graft, stable phakic IOL and clear lens.

Evaluation of safety and efficacy of different protocols of collagen cross linking for keratoconus.

Introduction: Collagen cross-linking is a well-established modality that could stop the keratoconus from progressing. Off late, newer protocols have been suggested for progressive keratoconus, which include the use of hypoosmolar riboflavin for thinner corneas and the use of accelerated CXL protocol to reduce the effective treatment time. Objective: To assess the safety and efficacy of different protocols of conventional CXL, hypoosmolar CXL and accelerated CXL in patients with keratoconus. Materials & methods: It was a prospective, interventional study with minimum of 12 months follow-up. Patients were divided into 3 groups; conventional CXL, CXL using hypotonic riboflavin and accelerated CXL group. Primary outcome measures - For efficacy, Sim Kmax and Sim Kmin (Progression (Kmax > +1 D), stabilization (Kmax +1 D to -1 D) and regression (Kmax > -1 D). For safety - endothelial count evaluation (decrease >10% amounted to compromise the safety of the procedure). Secondary outcome measures - BCVA and adverse events. Results: 32 eyes underwent isotonic CXL treatment. Pre-treatment and post-treatment BCVA were 0.16 +/- 0.15 and 0.10 +/- 0.11 log MAR; specular counts 2782.81 +/- 307.25 (cells/ mm2) and 2708.5 +/- 263.27 (cells/ mm2) (p=0.05); KMax values 55.31 +/- 4.12 D and 53.9 +/- 3.77 D (p=0.0001). 16 eyes underwent hypotonic CXL treatment. Pre-treatment and post-treatment BCVA were 0.15 +/- 0.13 log MAR and 0.14 +/- 0.14; specular count 2701.19 +/- 243.25 (cells/ mm2) and 2713.5 +/- 369 (cells/ mm2) (p= 1) and KMax values 54.74 +/- 7.44 D and 52.74 +/- 6.76 D (p = 0.002). 15 eyes underwent accelerated CXL treatment. Pre-treatment and post-treatment BCVA were 0.16 +/- 0.15 and 0.10 +/- 0.12 log MAR; specular counts 2967.53 +/- 356.48 and 2893.07 +/- 336.55 (cells/ mm2) (p = 0.78) and KMax values 55.19 +/- 5.46 D and 54.24 +/- 5.33 D (p = 0.337). Conclusion: All three protocols appeared safe and efficacious as therapeutic regimen for progressive keratoconus.