Clinical presentation, risk factors and treatment outcomes of first allograft rejection after penetrating keratoplasty in early and late postoperative period.

PURPOSE: Corneal graft rejection is the most common reason for the failure of an allograft corneal transplant. We undertook this study to identify and compare risk factors and treatment outcomes for early and late corneal graft rejections after optical penetrating keratoplasty. METHODS: A retrospective case file analysis of 880 primary penetrating keratoplasties was performed at a tertiary ophthalmic care centre. Patients were divided into early rejectors (rejection episode within 6 months postoperatively) and late rejectors (rejection episode after 6 months postoperatively). Main parameters evaluated were demographics, preoperative diagnosis and clinical signs, donor tissue details, surgical technique, details of rejection episode, treatment, and outcome information. RESULTS: A total of 156 patients with rejection episodes were identified. Of these, 42 (26.9%) patients experienced early rejection episodes and 114 (73.1%) patients experienced late rejection episodes. Preoperative donor and recipient characteristics, surgical technique, and clinical presentation of graft rejection were found to be similar between both groups after a Bonferroni correction was applied (P>0.005). Treatment outcomes of graft rejections were not significantly different (P=0.46) between early and late rejectors, with 83% of patients responding to rejection treatment (80% early rejectors; 85% late rejectors). CONCLUSION: Patients with early and late graft rejection have similar characteristics and both groups respond to treatment equally.

Trypan blue dye for anterior segment surgeries.

Use of vital dyes in ophthalmic surgery has gained increased importance in the past few years. Trypan blue (TB) has been a popular choice among anterior segment surgeons mainly due to its safety, ease of availability, and remarkable ability to enable an easy surgery in difficult situations mostly related to visibility of the targeted tissue. It is being used in cataract surgery since nearly a decade and its utilization has been extended to other anterior segment surgeries like trabeculectomy and corneal transplantation. This review will discuss the techniques and outcome of TB dye-assisted anterior segment surgeries.

Correlation of proteinase production with amphotericin B resistance in fungi from mycotic keratitis.

Two hundred fungal isolates (Aspergillus and Fusarium species) from mycotic keratitis were tested for in vitro susceptibilities to amphotericin B and proteinase production. Geometric mean MICs for all fungal species increased fourfold with thousandfold increase in the inoculum. The MIC(50) and MIC(90) values ranged between 3.12-6.25 and 3.12-12.5 microg/ml, respectively. Proteinase production was noted in 113 (56.5%) isolates. Ninety-eight (49%) showed MICs of > or =1.56 microg/ml that was above the criteria of > or =1 microg/ml for amphotericin B resistance (CLSI). Seventy-three (74.5%) of these 98 isolates were proteinase producers, whereas only 40 (39.2%) of the remaining 102 with low MICs (<1.56 microg/ml) were proteinase producers (p < 0.001). Proteinase seems to be an important virulence marker of filamentous fungi in mycotic keratitis, correlating significantly with amphotericin B resistance.

Microbiological and clinical profiles of patients with microbial keratitis residing in nursing homes.

AIM: To study the microbiological and clinical profile of patients with microbial keratitis living in nursing homes. METHODS: A retrospective analysis of hospital records from 1996 to 2006 of patients who had microbial keratitis, and were living in nursing homes, was undertaken. The main parameters evaluated were clinical and microbiological profile and final visual outcome. RESULTS: Of 66 patients included in this study, 39 were female and 27 were male, with mean age of 81(SD 11) (range 46-97) years. The major ocular and systemic factors associated with the occurrence of microbial keratitis were the presence of dry eyes (26%) and rheumatoid arthritis (81%), respectively. A positive bacterial culture was obtained in 54 (82%) cases with Staphylococcus being the most prevalent isolate (48%). Seven patients had positive culture for herpes virus. Surgical intervention had to be performed in 31(47%) of cases mainly in the form of botox injection for induction of ptosis (n = 9, 27%), keratoplasty (n = 8, 24%), tarsorrhaphy (n = 5, 15%) or glue (n = 3, 9%). The mean pre-treatment and post-treatment visual acuity was counting fingers and 6/60 respectively. CONCLUSIONS: Microbial keratitis in patients living in nursing homes is usually caused by Staphylococcus and is associated with dry eyes and ocular surface disease. Surgical intervention is required in majority of cases with poor visual outcome.

Intravenous dexamethasone vs methylprednisolone pulse therapy in the treatment of acute endothelial graft rejection.

PURPOSE: To study the outcome of therapy for acute endothelial graft rejection with an intravenous (i.v.) pulse of dexamethasone vs methylprednisolone, in addition to topical corticosteroids. METHODS: Records of 98 eyes of 99 patients treated for endothelial graft rejection with a single i.v. pulse of dexamethasone or methylprednisolone in addition to topical steroids, between January 1999 and June 2004, were retrospectively reviewed. Baseline characteristics such as surgery-rejection interval, time taken to consult after onset of symptoms, history of failed grafts, extent of stromal vascularization, best-corrected visual acuity (BCVA) and corneal thickness at the time of presentation were noted. Main outcome measures following treatment for rejection included improvement in BCVA, change in corneal thickness, and reversal of graft rejection. RESULTS: Fifty-one patients were treated with i.v. methylprednisolone and 47 with i.v. dexamethasone, in addition to topical steroids. Both groups were found to be comparable with respect to baseline parameters, that is, time taken to present, history of failed grafts, extent of stromal vascularization, BCVA, and graft thickness. Graft rejection could be successfully reversed in 72.3% cases in the dexamethasone group and 49% in the methylprednisolone group (P=0.018). A significant improvement in visual acuity was recorded following treatment in both groups, with a better outcome in the dexamethasone group (P=0.012). Post-treatment pachymetry values were lower than pretreatment values in both groups, with significantly lower final pachymetry in the dexamethasone group (P=0.017). No adverse effects were observed. CONCLUSION: I.v. pulse therapy with dexamethasone may be used as an effective alternative to methylprednisolone in reversing acute endothelial graft rejection.

Comparative evaluation of 'flap on' and 'flap off' techniques of Epi-LASIK in low-to-moderate myopia.

PURPOSE: Comparative evaluation of 'flap on' and 'flap off' techniques of Epi-LASIK in low-to-moderate myopia. METHODS: Sixteen eyes of eight consecutive patients with myopia < or = 6 D were selected for this prospective, randomized, comparative, interventional case series. Epi-LASIK surgery was performed in all eyes. In one eye of each patient, the epithelial flap was retained after excimer laser ablation (flap on). In the fellow eye, the epithelial flap was discarded (flap off) after ablation. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), spherical equivalent (SEQ), postoperative pain score, time to epithelization, and corneal haze were recorded on postoperative visits. RESULTS: The mean preoperative SEQ in the two groups was -3.61+/-1.32 D (flap on) and -3.49+/-1.86 D (flap off; P=0.752). The mean follow-up period was 8.5+/-4.9 months. The mean pain score was comparable on all postoperative days except the second postoperative day when the group with flap off had a lesser mean pain score (P=0.053).Time for epithelial healing was 3.63+/-0.52 days in cases with flap off and 4.13+/-0.64 days in cases with flap on (P=0.113). Eyes with flap off had a better UCVA on the first postoperative day (0.19+/-0.11 logMAR) compared with eyes with flap on (0.41+/-0.28 logMAR; P=0.032). There was no significant difference in UCVA, BSCVA, SEQ, contrast sensitivity, corneal haze, and higher order aberrations at any other postoperative visit. CONCLUSIONS: There is no difference between flap on and flap off techniques of Epi-LASIK with regards to overall outcome of surgery.

Resuturing following penetrating keratoplasty: a retrospective analysis.

AIM: To examine the clinical profile of cases requiring resuturing following penetrating keratoplasty (PKP) at a tertiary care eye hospital. METHODS: The medical records of 947 consecutive patients who had undergone PKP between 1998 and 2006 were reviewed retrospectively and cases that were resutured during this period were analysed. The main parameters studied were indications for PKP, suturing techniques, causes of resuturing, visual acuity outcome and post-resuturing complications. RESULTS: The incidence of resuturing was 5.4% (51 eyes). The number of cases requiring resuturing was higher in corneal grafts performed for microbial keratitis (12%) than those for keratoconus (10%) and corneal endothelial decompensation (2.5%; p = 0.08). Wound dehiscence was the leading cause for resuturing (43%), followed by loose or broken sutures (37.3%). The most common complications after resuturing were occurrence of microbial keratitis (7.8%) and graft failure (5.9%). DISCUSSION: Resuturing may have to be performed more commonly for corneal transplantation surgery done for microbial keratitis and keratoconus. The major indications for resuturing are wound dehiscence and loose/broken sutures.

"Tuck In" Lamellar Keratoplasty (TILK) for corneal ectasias involving corneal periphery.

AIMS: Evaluation of a new surgical technique for the management of corneal ectasia with peripheral corneal involvement. METHODS: Twelve eyes of 12 patients with corneal ectasias and peripheral corneal thinning requiring surgical intervention, including eight patients with combined keratoconus and PMD and four patients of keratoglobus, were enrolled for the study in a tertiary care hospital. All patients were contact lens intolerant and had a best corrected visual acuity (BCVA) /=20/60, and all patients had BCVA >/=20/80. The mean keratometry decreased from 57.54 (SD 6.89) D preoperatively to 46.36 (2.39) D (p = 0.003), and the mean spherical equivalent (SEQ) refractive error decreased from -7.8 (4.6) D preoperatively to 1.23 (1.88) D (p = 0.007). A significant decrease was also seen in mean refractive astigmatism which decreased from 5.93 (3.06) D preoperatively to 3.23 (1.14) D (p = 0.037). CONCLUSION: Our technique of TILK is an effective surgical modality for the management of ectatic corneal dystrophies with peripheral corneal thinning.

'Layer by layer' phacoemulsification in posterior polar cataract with pre-existing posterior capsular rent.

PURPOSE: To evaluate a new technique of 'Layer by Layer' phacoemulsification in eyes with posterior polar cataract with pre-existing posterior capsular rent (PCR). METHODS: Layer by layer phacoemulsification was performed in eight eyes of eight patients of posterior polar cataract with pre-existing posterior capsular rent. All the patients had evidence of a posterior capsular defect showing presence of iridescent refractile lens particles in vitreous with onion skinning of central dense plaque. RESULTS: The mean age of the patients was 43.75+/-2.5 years and six patients were men. All the eyes had vertical posterior capsular defect irrespective of the site of entry of phaco probe. Vitrectomy was not required in any of the eyes. Single piece foldable acrylic intraocular lens was implanted in the bag in all the eyes. The mean preoperative best corrected visual acuity was 0.14+/-0.05, which improved to 0.77+/-0.27. CONCLUSION: Our technique of 'Layer by layer' phacoemulsification is an effective and safe technique for the management of posterior polar cataract with pre-existing PCR.

Risk factors for postoperative cylindrical prediction error after laser in situ keratomileusis for myopia and myopic astigmatism.

PURPOSE: To study the risk factors for the occurrence of cylindrical prediction error (PE) after laser in situkeratomileusis (LASIK) for myopia and myopic astigmatism. METHODS: The study was a nested case-control study. Five hundred eyes of 252 consecutive patients who underwent LASIK for myopia and myopic astigmatism on the Chiron Technolas 217C laser and completed 6 months of follow-up. There were 435 controls and 65 cases based on the postoperative refractive cylindrical PE. The probable risk factors studied included preoperative sphere and cylinder, keratometry, pachymetry, suction ring used, flap thickness, hinge centeration, optic zone, ablation depth, and intraoperative complications. RESULTS: By univariate analysis, the cylindrical PE was found to be associated with preoperative spherical equivalent higher than -6 D (chi(2)=10.83; P=0.001), preoperative sphere higher than -6 D (chi(2)=6.15, P=0.013), preoperative cylinder more than -0.75 D (chi(2)=6.61; P-value=0.010), and an optic zone less than 5.5 mm (chi(2)=19.3; P=0.001). Risk factors for postoperative astigmatism by stepwise multivariate logistic regression analysis were an optic zone of less than 5.5 mm with an odds ratio (OR) of 2.81 (95% confidence interval (CI)=1.62-4.86) and preoperative cylinder more than -0.75 D with an OR of 1.60 (95% CI=0.92-2.77). CONCLUSION: Postoperative astigmatism (as indicated by the cylindrical PE) is more likely to occur with an optic zone of less than 5.5 mm and a higher preoperative cylindrical error.

Phacoemulsification with nondominant hand.

PURPOSE: Evaluation of on axis phacoemulsification surgery through temporal incision using nondominant hand with surgeon sitting at the head end, inpatients with against-the-rule astigmatism. METHODS: Eighty eyes of 80 patients who underwent phacoemulsification through a temporal clear corneal tunnel for age-related cataract and against-the-rule astigmatism were enrolled and divided into four equal groups. In Group 1A, the surgeon was sitting at the head end for the left eye performing surgery with the left hand (nondominant hand). In group 1B, the surgeon was seated at the temporal side and surgery was performed in the left eye with dominant right hand. In group 2A, the surgeon was sitting at the head end for the right eye and performed surgery holding the phacoemulsification hand piece in his right hand. In group 2B, the surgeon sat on the temporal side of the right eye and performed phacoemulsification with his right hand. The patients were followed up on day 7, 1 month, and 3 months. Parameters evaluated included average phaco power, effective phaco time, uncorrected and best-corrected visual acuity, keratometry, intraocular pressure, surgically induced astigmatism, pachymetry, and endothelial cell counts. RESULTS: The phaco time and phaco power among the four groups were comparable (phaco time: P=0.368; phaco power: P=0.294). The four groups were also comparable on parameters like surgically induced astigmatism (P=0.674), change in postoperative keratometric astigmatism (P=0.584), endothelial cell loss (0.921), change in ultrasonic pachymetry (P=0.476), and intraocular pressure (P=0.942). No intraoperative or postoperative complications were observed in any of the groups. The mean uncorrected visual acuity at 3 months in group 1 was 0.723+/-0.21; in group 2 it was 0.756+/-0.21; in group 3 it was 0.748+/-0.22, and in group 4 it was 0.732+/-0.23. The best-corrected visual acuity was 0.96+/-0.10, 0.97+/-0.11, 0.95+/-0.13, and 0.96+/-0.10 in the four groups at 3 months. CONCLUSION: Phacoemulsification surgery can be successfully performed with nondominant hand with a good surgical outcome. The technique gives an alternative approach where surgeon does not have to shift the position to perform on-axis phacoemulsification.

Risk factors for perforation in microbial corneal ulcers in north India.

AIM: To identify predisposing factors leading to corneal perforation in patients with microbial keratitis. METHOD: Two groups of 60 patients each, with perforated corneal ulcers and healed/healing corneal ulcers, respectively, were recruited in a case-control study conducted in northern India. The cases and controls were matched by age and time of presentation. A standardised proforma was used to identify potential predisposing factors for demographic, social, medical, ocular, and treatment history. All participants underwent a detailed ocular examination. Corneal scrapings were performed where relevant. RESULTS: The characteristics associated with corneal perforation in microbial keratitis were outdoor occupation (p = 0.005), illiteracy (p = 0.02), excessive alcohol use (p = 0.03), history of "something falling into eye" (p = 0.003), trauma with vegetable matter (p = 0.008), vision less than counting fingers at referral (p<0.001), central location of ulcer (p<0.001), lack of corneal vascularisation (p<0.001), delay in starting initial treatment (p<0.001), failure to start fortified antibiotics (p<0.001), and monotherapy with fluoroquinolones (p = 0.002). The lack of corneal vascularisation (OR 6.4, 95% CI 4.2 to 13.5), delay in starting initial treatment (OR 35.6, 95% CI 6.9 to 68.2), and failure to start fortified antibiotics (OR 19.9, 95% CI 2.7 to 64.7) retained significance on a logistic regression model. CONCLUSIONS: This study characterises microbial keratitis cases at increased risk of corneal perforation and reinforces the need for standardised referral and treatment protocols for patients with corneal ulcer on their first contact at primary care level in the developing world.

Outcome of penetrating keratoplasty in patients with bilateral corneal blindness.

PURPOSE: To evaluate the outcome of penetrating keratoplasty in patients with bilateral corneal blindness. METHODS: Bilaterally blind patients who had undergone optical penetrating keratoplasty (PK) were evaluated on optical and refractive parameters and presence of complications if any. The results at 3 months, 6 months, and 1 year were compared with age-matched and indication-matched unilaterally blind controls. RESULTS: The most common indication for surgery in both the groups was the presence of a corneoiridic scar. Best corrected visual acuity of > or =6/18 was seen in five (16.66%) patients in the study group and in 11 (36.66%) patients in the control group (P = 0.14). In all, 15 (50%) grafts in the study group and six (20%) in the control group failed (P = 0.03). The most common cause of failure was graft infection (40%) in the study group and post-PK glaucoma (20%) in the control group. The percentage of graft rejection as a cause of graft failure was the same in both the groups. A composite socioeconomic status scale based on family literacy and income suggested that 70% of the cases in the study group and 30% in the control group belonged to the low socioeconomic group (P = 0.004). CONCLUSION: The outcome of optical penetrating keratoplasty in patients with bilaterally blinding corneal disease is poorer than those who are unilaterally blind. Low socioeconomic status may be a contributing factor for the poor outcome.

Evaluation of umbilical cord serum therapy for persistent corneal epithelial defects.

AIMS: To evaluate umbilical cord serum therapy as a means of promoting the healing of persistent corneal epithelial defects. METHODS: Umbilical cord serum or autologous serum drops were used to promote the healing of persistent epithelial defects. The study design was a prospective randomised controlled clinical trial. 60 eyes of 59 patients were divided into two groups, 31 in the cord serum group and 29 in the autologous serum control group. Epithelial defects measuring at least 2 mm in linear dimension resistant to conventional medical management were included. Serial measurements of the size of the epithelial defects-namely, two maximum linear dimensions perpendicular to each other, and the area and perimeter was done at start of therapy and follow up days 3, 7, 14, 21. Rate of healing of the epithelial defects were measured as percentage decrease from the baseline parameter at each subsequent follow up. The data were analysed by the non-parametric Wilcoxon rank sum test using STATA 7.0. RESULTS: The median percentage decrease in the size of the epithelial defect was significantly greater in the cord serum group at days 7, 14 and 21 (p<0.05) when measured in terms of the area and perimeter. A greater number of patients showed complete re-epithelialisation with umbilical cord serum (n = 18) than with autologous serum (n = 11) (Pearson chi = 0.19). None of the patients reported any side effects or discomfort with either treatment. CONCLUSIONS: Umbilical cord serum leads to faster healing of the persistent corneal epithelial defects refractory to all medical management compared to autologous serum.