Vitamin D and tear fluid cytokines in predicting outcomes in viral conjunctivitis - A new outlook.

PURPOSE: To determine the association between systemic vitamin D (VD) and immunoglobulin E (IgE) levels with severity and ocular surface inflammatory profile in patients with epidemic keratoconjunctivitis (EKC). METHODS: 210 eyes of 105 patients who were clinically diagnosed with EKC were included in the study. The levels of serum VD and serum IgE were measured. Schirmer's strip-based tear fluid (TF) was used to determine levels of IL-1ß, IL-6, IL-10, IL-17A, TNFα, MMP9, sICAM1, and VEGF-A in a subset of patients. RESULTS: Levels of VD were significantly ( P < 0.05) lower and levels of IgE were significantly higher in patients with severe forms of conjunctivitis compared to those with nonsevere forms. Majority of the patients with severe forms of the disease exhibited VD deficiency and/or abnormally high IgE. A negative correlation (r = -0.682; P < 0.0001) was observed between VD and IgE levels. TF levels of IL-1ß, IL-6, TNFα, and sICAM1 were significantly higher in eyes with severe forms of conjunctivitis compared to those with nonsevere forms and controls. These factors showed a positive correlation ( P < 0.05) with IgE levels and a negative correlation ( P < 0.05) with VD levels. CONCLUSION: Patients with severe forms of EKC exhibited VD deficiency and higher levels of IgE. Increased TF inflammatory factors demonstrated a disease causal relationship with VD and IgE. Hence, restoring the altered levels of VD and IgE to normal range would be pivotal in the prevention and management of severe conjunctivitis.

Topographic changes in contralateral eye of a case of Terrien's marginal degeneration.

A woman in her late twenties presented with blurring of vision in the right eye for 6 years. Retinoscopy showed a scissoring reflex in the right eye with best spectacle-corrected visual acuity of 20/40 in the right eye and 20/20 in the left eye. Slit-lamp examination of the right eye showed superior crescentic thinning with conjunctivalisation and lipid deposition while the left eye was normal. Corneal topography of the right eye showed inverse crab-claw pattern suggestive of Terrien's marginal degeneration (TMD) and the left eye showed inferior steepening with posterior elevation and thinning suggestive of keratoconus-like topography. This case shows that evaluation of the other apparently normal eye with 20/20 vision might show changes on topography in cases of unilateral TMD and needs follow-up to assess any further progression.

A case of acute endothelial corneal transplant rejection following immunization with ChAdOx1 nCoV-19 coronavirus vaccine.

A 28-year-old female who underwent an uneventful femtosecond laser enabled keratoplasty (FLEK) in her left eye presented with pain, redness, and blurring of vision in the operated eye two weeks after getting immunized with COVID-19 vector vaccine (ChAdOx1 nCoV19 Vaccine Recombinant COVISHIELD, AstraZeneca). Slit-lamp examination showed donor stromal edema with Descemet's membrane folds and Khodadoust line (KP's on endothelium) with anterior chamber cells and flare. The patient was diagnosed with acute corneal graft rejection and advised hourly topical steroids with cycloplegics and oral steroids. The patient responded to treatment and there was progressive reversal of graft rejection with the patient achieving best spectacle-corrected visual acuity (BSCVA) of 20/30 after five weeks of treatment. Our case highlights possible immune corneal graft rejection after COVID19 vaccination and the need to step up topical steroids before vaccination.

Effect of post crosslinking haze on the repeatability of Scheimpflug-based and slit-scanning imaging devices.

PURPOSE: The aim of this study was to analyze the effect of postcollagen crosslinking (CXL) haze on the measurement and repeatability of pachymetry and mean keratometry (Km) of four corneal topographers. MATERIALS AND METHODS: Sixty eyes of sixty patients with progressive keratoconus who had undergone accelerated CXL (ACXL) underwent imaging with a scanning slit imaging device (Orbscan II) and three Scheimpflug imaging devices (Pentacam HR, Sirius, and Galilei). Post-ACXL haze was measured using the densitometry software on the Pentacam HR. Readings of the thinnest corneal thickness (TCT) and Km from three scans of each device were analyzed. Effect of haze on the repeatability of TCT and Km measurements was evaluated using regression models. Repeatability was assessed by coefficient of variation. RESULTS: Corneal densitometry in different zones affected the repeatability of TCT measurement of Orbscan (P < 0.05) significantly but not the repeatability of TCT with Pentacam HR and Sirius (P = 0.03 and 0.05, respectively). Km values were affected by haze when measured with the Pentacam HR (P < 0.05). The repeatability of Km readings for all devices was unaffected by haze. In the anterior 0-2 mm and 2-6 mm zone, TCT (P = 0.43 and 0.45, respectively), Km values (P = 0.4 and 0.6, respectively), repeatability of TCT (P = 0.1 in both zones), and Km (P = 0.5 and 0.1, respectively) with Galilei were found to be the most reliable. CONCLUSION: Galilei measurements appear to be least affected by post-ACXL haze when compared with other devices. Hence, topography measurements in the presence of haze need to be interpreted with caution.

Laser Vision Correction with Q Factor Modification for Keratoconus Management.

PURPOSE: To evaluate the outcomes of corneal laser ablation with Q factor modification for vision correction in patients with progressive keratoconus. METHODS: In this prospective study, 50 eyes of 50 patients were divided into two groups based on Q factor (>-1 in Group I and ≤-1 in Group II). All patients underwent a detailed ophthalmic examination including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), subjective acceptance and corneal topography using the Pentacam. The topolyzer was used to measure the corneal asphericity (Q). Ablation was performed based on the preoperative Q values and thinnest pachymetry to obtain a target of near normal Q. This was followed by corneal collagen crosslinking to stabilize the progression. RESULTS: Statistically significant improvement (p ≤ 0.05) was noticed in refractive, topographic, and Q values posttreatment in both groups. The improvement in higher-order aberrations and total aberrations were statistically significant in both groups; however, the spherical aberration showed statistically significant improvement only in Group II. CONCLUSION: Ablation based on the preoperative Q and pachymetry for a near normal postoperative Q value appears to be an effective method to improve the visual acuity and quality in patients with keratoconus.

Lower Vitamin D Level and Distinct Tear Cytokine Profile Were Observed in Patients with Mild Dry Eye Signs but Exaggerated Symptoms.

PURPOSE: Dry eye is associated with inflammation, pain, and discomfort. Vitamin D is known to modulate immune responses and pain. This study investigates the level of serum vitamin D and tear-inflammatory proteins with relation to exaggerated symptoms in patients with mild dry eye. METHODS: Patients with mild dry eye signs (Dry Eye Workshop [DEWS] severity grade 1) but with exaggerated symptoms and healthy controls (n = 19, each) were recruited for this cross-sectional study. Schirmer's Test I (mm), tear film break-up time (TBUT; secs), and ocular surface disease index (OSDI) score were recorded. Serum vitamin D level and tear cytokine levels were measured. RESULTS: The mean OSDI score in the patient cohort (46 ± 3) was significantly higher than controls (8.4 ± 1.6). TBUT was lower (7.6 ± 0.3 secs) in patients compared with controls (11.0 ± 0.9 secs). Mean Schirmer's Test I value in patients (19.3 ± 1.4 mm) was lower than in controls (30.6 ± 1.9 mm). An inverse correlation was observed between serum vitamin D levels and OSDI score (r = -0.569; P = 0.01). Significantly higher levels of interleukin (IL)-17A/F, interferon (IFN)-γ, monocyte chemotactic protein (MCP)-1, intercellular adhesion molecule (ICAM)-1, IL-4, IL-10, and decreased IL-2 concentrations was observed in the tears of patients compared with controls (P < 0.05). CONCLUSION: Decreased serum vitamin D was associated with exaggerated symptoms in dry eye patients with mild dry eye signs. In addition, altered tear cytokine profile was also observed in these patients. TRANSLATIONAL RELEVANCE: Vitamin D measurements would aid in the diagnosis and management of dry eye.

Ocular toxicity by seeds of Annona squamosa (custard apple).

Custard apple seeds have been used in native medicine from time immemorial for the management of head lice and skin exfoliation. We report six consecutive patients who developed toxic keratoconjunctivitis within 6-12 h of ocular exposure to custard apple seeds. The use of topical steroid worsens the toxicity and predisposes to the development of microbial keratitis in such cases. Patients showed a good response to primary treatment with topical fortified antibiotics and lubricants. This case series highlights the need to educate the patients regarding the potential toxic effects of the custard seeds and the treating physicians about possible deleterious effects on using topical steroid.

Evaluation of Corneas from Donors With Septicemia for Use in Corneal Transplant.

PURPOSE: To evaluate if donor corneas obtained from deaths occurring because of septicemia can be used for corneal transplantation. STUDY DESIGN: Prospective study. METHODS: Eleven septicemic donor corneas were used in the study and 10 donor corneas from deaths because of causes other than septicemia were used as controls. Blood culture reports of all patients who had donated eyes were collected, and the pathogenic organisms causing septicemia were noted. On obtaining the eyeballs, aqueous and vitreous samples were sent for polymerase chain reaction to analyze for eubacterial and panfungal genomes. Corneal and scleral tissues (3 × 3 mm) were sent for culture in brain heart infusion media. Growth from each of the samples was checked to ascertain if the same organism was isolated in all. RESULTS: One corneal and 3 scleral culture reports in the sepsis group and 1 corneal and 1 scleral culture report in the control group showed positive growth. Normal conjunctival/eyelid commensal organisms were isolated from all culture-positive samples and did not correlate with the pathogenic organism causing the septicemia. Three aqueous and vitreous samples in the sepsis group and 4 samples of aqueous and vitreous in the control group that tested positive for eubacterial genome showed no corresponding growth in the culture report of cornea and sclera. CONCLUSIONS: Corneal tissues harvested from septicemic donors do not necessarily harbor the pathogenic organisms causing the septicemia, suggesting that such corneas may be suitable for transplantation.

Corneal Densitometry: Repeatability in Eyes With Keratoconus and Postcollagen Cross-Linking.

PURPOSE: To assess the repeatability of densitometry, a measure of corneal haze, in the control (group I), keratoconic (group II), and postcollagen cross-linking (CXL, group III) eyes as measured on Scheimpflug imaging. METHODS: Densitometry values for 160 eyes of 160 patients (50 eyes of 50 patients in group I, 50 eyes of 50 patients in group II, and 60 eyes of 60 patients in group III) were obtained for the 0- to 2-mm, 2- to 6-mm, and 6- to 10-mm zones of the anterior (up to 120 µm), posterior (posterior 60 µm), and central (between the anterior and posterior) cornea. The repeatability of these values was assessed by within-subject standard deviation, coefficient of repeatability, and coefficient of variation. RESULTS: Range of within-subject standard deviation and coefficient of variation in the control group (0.2%-0.5% and 2%-4%, respectively) was significantly better (less variable) than those in the keratoconus group (0.4%-0.6% and 3%-5%). The same parameters in the post-CXL group (0.8%-3.8% and 7%-15%) were significantly worse (more variable) than that in the other 2 groups. The repeatability measures of densitometry were significantly worse in the central 0- to 2-mm zone compared with the other 2 zones and for the anterior region compared with the central and posterior regions of cornea in all the 3 groups. CONCLUSIONS: Consequent to the low repeatability in post-CXL eyes, densitometry should be used with caution to gauge response to treatment and visual outcomes in treated keratoconus eyes.

An In Vivo Confocal Microscopic Study of Corneal Nerve Morphology in Unilateral Keratoconus.

Purpose. To study the corneal nerve morphology and its importance in unilateral keratoconus. Materials and Methods. In this prospective cross-sectional study, 33 eyes of 33 patients with keratoconus in one eye (Group 3) were compared with the other normal eye of the same patients (Group 2) and 30 eyes of healthy patients (Group 1). All patients underwent detailed ophthalmic examination followed by topography with Pentacam HR and in vivo confocal microscopy (IVCM). Five images obtained with IVCM were analyzed using an automated CCmetrics software version 1.0 for changes in subbasal plexus of nerves. Results. Intergroup comparison showed statistically significant reduction in corneal nerve fiber density (CNFD) and length (CNFL) in Group 3 as compared to Group 1 (p < 0.001 and p = 0.001, resp.) and Group 2 (p = 0.01 and p = 0.02, resp.). Though corneal nerve fiber length, diameter, area, width, corneal nerve branch density, and corneal total branch density were found to be higher in decentered cones, only the corneal nerve branch density (CNBD) was found to be statistically significant (p < 0.01) as compared to centered cones. Conclusion. Quantitative changes in the corneal nerve morphology can be used as an imaging marker for the early diagnosis of keratoconus before the onset of refractive or topography changes.

Safety and Efficacy of Epi-Bowman Keratectomy in Photorefractive Keratectomy and Corneal Collagen Cross-Linking: A Pilot Study.

PURPOSE: The purpose of this study is to compare the efficacy and safety of Epi-Bowman Keratectomy (EBK) using Epi-clear™ epikeratome with a mechanical scraper for corneal epithelium debridement during photorefractive keratectomy (PRK) and corneal collagen cross-linking (CXL). METHODOLOGY: Sixty eyes of 30 patients undergoing PRK and 44 eyes of 44 patients undergoing CXL were included in this study. In the PRK group, one eye of each patient underwent EBK and the other eye epithelial debridement with a mechanical scraper. In the CXL group, 22 eyes of 22 patients underwent EBK and the other 22 eyes with a mechanical scraping to remove the epithelium. Intra-operative spectral domain optical coherence tomography (SD OCT; Bioptigen Inc, Durham, NC) was performed to evaluate the integrity of Bowman's membrane following epithelial removal. The time taken for epithelial removal, post-operative pain score using the Wong-Baker's pain scale, time for epithelial healing, and the epithelial profile using the Optovue (Optovue Inc. Fremont, CA) during the healing was observed and analyzed between the two groups and subgroups. RESULTS: Intra-operative SD OCT showed a smooth and undamaged Bowman's membrane when EBK was performed. Post-operative pain was significantly less (p < 0.01 in the PRK group and p < 0.001 in the CXL group) with faster epithelial healing (p < 0.001 in the PRK group and p < 0.0001 in the CXL group) in the EBK subgroup as compared with the mechanical scraper subgroup. Epithelial profiling during the healing phase showed an edematous epithelium in the initial 2 weeks in the mechanical scraper subgroup while the EBK subgroup showed minimal epithelial edema lasting up to a week with regularized and smooth corneal epithelium healing. CONCLUSION: Epi-Bowman Keratectomy appears to be an effective and safe method of corneal epithelial debridement with negligible damage to Bowman's membrane and the surrounding epithelium leading to early healing thereby reducing the post-operative pain and complications.

Current Protocols of Corneal Collagen Cross-Linking: Visual, Refractive, and Tomographic Outcomes.

PURPOSE: To study the effect of different protocols of collagen cross-linking on visual, refractive, and tomographic parameters in patients with progressive keratoconus. DESIGN: Prospective randomized interventional study. METHODS: In this study, 138 eyes of 138 patients with progressive keratoconus underwent corneal collagen cross-linking (CXL). Following detailed preoperative examination, Group I underwent conventional cross-linking (36 patients, 3 mW/cm(2) for 30 min); Group II (36 patients, 9 mW/cm(2) for 10 min), Group III (33 patients, 18 mW/cm(2) for 5 min), and Group IV (33 patients, 30 mW/cm(2) for 3 min) underwent accelerated cross-linking. Changes in corrected distance visual acuity (CDVA), spherical equivalent (SE), flat keratometry, steep keratometry, thinnest pachymetry, specular microscopy, and demarcation line were studied at 6 and 12 months. RESULTS: Improvement in the mean CDVA and SE were statistically significant in all groups except Group IV (P = .15 at 6 months, P = .17 at 12 months), with Group III (P = .01 at 6 and 12 months) showing the best results. Flattening of steep and flat keratometry was significant in Groups I (P = .01) and II (P = .01) as compared to the other groups. There was no significant difference in the pachymetry or specular microscopy in any of the groups. Groups I and II demonstrated a good demarcation line when compared to other groups. CONCLUSION: Conventional CXL (Group I) and accelerated CXL with irradiations of 9 mW/cm(2) (Group II) and 18 mW/cm(2) (Group III) showed better visual, refractive, and tomographic improvements at the end of 12 months.

Current review and a simplified "five-point management algorithm" for keratoconus.

Keratoconus is a slowly progressive, noninflammatory ectatic corneal disease characterized by changes in corneal collagen structure and organization. Though the etiology remains unknown, novel techniques are continuously emerging for the diagnosis and management of the disease. Demographical parameters are known to affect the rate of progression of the disease. Common methods of vision correction for keratoconus range from spectacles and rigid gas-permeable contact lenses to other specialized lenses such as piggyback, Rose-K or Boston scleral lenses. Corneal collagen cross-linking is effective in stabilizing the progression of the disease. Intra-corneal ring segments can improve vision by flattening the cornea in patients with mild to moderate keratoconus. Topography-guided custom ablation treatment betters the quality of vision by correcting the refractive error and improving the contact lens fit. In advanced keratoconus with corneal scarring, lamellar or full thickness penetrating keratoplasty will be the treatment of choice. With such a wide spectrum of alternatives available, it is necessary to choose the best possible treatment option for each patient. Based on a brief review of the literature and our own studies we have designed a five-point management algorithm for the treatment of keratoconus.

Sutureless femtosecond anterior lamellar keratoplasty: a 1-year follow-up study.

AIM: To study the safety and efficacy of sutureless femtosecond anterior lamellar keratoplasty (FALK) in patients with corneal stromal opacities. MATERIALS AND METHODS: Eleven eyes of 11 consecutive patients with corneal stromal opacities involving < 250 µ due to various pathologies were included in the study. Preoperatively, all underwent anterior segment imaging with spectral domain optical coherence tomography (SD-OCT) (Bioptigen Inc., Durham, North Carolina, USA) to measure the depth of the stromal opacity. All patients underwent FALK, and bandage contact lens was placed for a period of 2 weeks. Postoperatively, uncorrected visual acuity, best corrected visual acuity (BCVA), and SD-OCT evaluation were performed. RESULTS: All patients showed significant improvement in BCVA. The mean postoperative BCVA (in decimals) improved from 0.11 ± 0.06 preoperatively to 0.59 ± 0.08. There were no intraoperative or significant postoperative complications that were noticed. CONCLUSION: FALK is a safe and effective alternative to deep anterior lamellar keratoplasty or penetrating keratoplasty in the treatment of anterior stromal opacities.

Accelerated corneal collagen cross-linking in pediatric patients: two-year follow-up results.

PURPOSE: To evaluate the effectiveness and safety of accelerated corneal collagen cross-linking (ACXL) in patients below 14 years of age with progressive keratoconus. MATERIALS AND METHODS: Thirty eyes of 18 patients with established progressive keratoconus underwent preoperative and postoperative visual acuity assessment, topography, and specular microscopy prior to ACXL and were followed up for 24 months. RESULTS: Mean age of the patients was 12.7 years with ten males and eight females. There was an improvement in the mean postoperative uncorrected distant visual acuity (from 0.76±0.26 to 0.61±0.25; P=0.005), mean corrected distant visual acuity (from 0.24±0.19 to 0.12±0.12; P<0.001), mean spherical refraction (from -3.04 DS±3.60 to -2.38 DS±3.37; P=0.28), mean cylinder (from -3.63 DC±1.82 to -2.80 DC±1.48; P=0.008), and spherical equivalent (from -4.70 D±3.86 to -3.75 D±3.49; P=0.15). Three eyes of two patients with vernal keratoconjunctivitis (VKC) showed progression. There were no intra- or postoperative complications. CONCLUSION: In pediatric patients ACXL is an effective and safe procedure for the management of keratoconus. Optimal management of VKC is important to arrest the progression of keratoconus.

Profile of microbial keratitis after corneal collagen cross-linking.

PURPOSE: To report the profile of microbial keratitis occurring after corneal collagen cross-linking (CXL) in keratoconus patients. METHODS: A retrospective analysis of 2350 patients (1715 conventional CXL, 310 transepithelial CXL, and 325 accelerated CXL) over 7 years (from January 2007 to January 2014) of progressive keratoconus, who underwent CXL at a tertiary eye care centre, was performed. Clinical findings, treatment, and course of disease of four eyes that developed postprocedural moxifloxacin resistant Staphylococcus aureus (MXRSA) infectious keratitis are highlighted. RESULTS: Four eyes that underwent CXL (0.0017%) had corneal infiltrates. All eyes that developed keratitis had conventional CXL. Corneal infiltrates were noted on the third postoperative day. Gram's stain as well as culture reported MXRSA as the causative agent in all cases. Polymerase chain reaction (PCR) in each case was positive for eubacterial genome. All patients were treated with fortified antibiotic eye drops, following which keratitis resolved over a 6-week period with scarring. All these patients were on long-term preoperative oral/topical steroids for chronic disorders (chronic vernal keratoconjunctivitis, bronchial asthma, and chronic eczema). CONCLUSION: The incidence of infectious keratitis after CXL is a rare complication (0.0017%). MXRSA is a potential organism for causing post-CXL keratitis and should be identified early and treated aggressively with fortified antibiotics.

Collagen crosslinking in the management of advanced non-resolving microbial keratitis.

AIM: To evaluate the efficacy and safety of corneal collagen crosslinking (CXL) in the management of culture proven microbial keratitis. METHODS: 15 eyes of 15 patients of microbial keratitis were included in the study. Nine patients had bacterial keratitis and six had fungal keratitis. All patients underwent microbiological evaluation to identify the causative organism. The depth of the infiltrate was determined clinically with slit lamp and measured manually using anterior segment optical coherence tomography. Patients were treated with antibiotics/antifungals and those who did not respond to at least 2 weeks of topical medications underwent CXL as per the standard protocol. The same preoperative topical medications were continued post-CXL. All patients were followed up every third day and observed for signs of resolution of microbial keratitis. RESULTS: Six of nine patients with bacterial keratitis and three of six patients with fungal keratitis resolved following CXL treatment. Patients with deep stromal keratitis or endothelial plaque failed to resolve. All patients had resolution of pain on the first postoperative day. There was an appearance of or increase in hypopyon in seven patients. No intraoperative or postoperative complications were noticed. CONCLUSIONS: CXL appears to be an effective procedure in the management of superficial microbial keratitis. It can be used as an adjunctive treatment in the management of non-resolving microbial keratitis.

Femtosecond laser enabled keratoplasty for advanced keratoconus.

PURPOSE: To assess the efficacy and advantages of femtosecond laser enabled keratoplasty (FLEK) over conventional penetrating keratoplasty (PKP) in advanced keratoconus. MATERIALS AND METHODS: Detailed review of literature of published randomized controlled trials of operative techniques in PKP and FLEK. RESULTS: Fifteen studies were identified, analyzed, and compared with our outcome. FLEK was found to have better outcome in view of better and earlier stabilization uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and better refractive outcomes with low astigmatism as compared with conventional PKP. Wound healing also was noticed to be earlier, enabling early suture removal in FLEK. CONCLUSIONS: Studies relating to FLEK have shown better results than conventional PKP, however further studies are needed to assess the safety and intraoperative complications of the procedure.