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Changes in Eye Movement Amplitude after Conjunctivo-Limbal Autograft in Patients with Recurrent Pterygium, Ocular Motility Restriction
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Aim: To evaluate prospectively the effect of pterygium excision on visual acuity and contrast sensitivity before and after surgery. Material & method: A prospective observational study where in 63 eyes of 63 patients with primary pterygia were studied before and after surgery. Examination was done in which contrast sensitivity was measured with pellirobson chart pre-operatively and one month postoperatively following pterygium excision with Conjunctival Limbal Auto Graft. Result: As the grade of pterygium increases, decrement in contrast sensitivity occurs. The visual acuity significantly increased after the surgery. Mean contrast sensitivity following pterygium surgery improved from 1.49±0.21 to 1.70±0.20 (p value <0.001). Conclusion: Visual acuity and contrast sensitivity improved significantly following pterygium excision surgery.
Purpose
To compare the long-term outcomes of recurrent pterygium surgery between three different techniques.
Methods
We performed a 15-year follow-up study of a randomized controlled study on surgical management of recurrent pterygium. Group 1 received limbal conjunctival autograft (LCAU); group 2 received intraoperative mitomycin C (MMC) 0.02% for 5 min; and group 3 received combined LCAU + MMC 0.02% for 5 min. Consecutive patients enrolled in the original study (from April 2001 to March 2003) were invited back for a detailed clinical examination to document the long-term outcomes. The main outcome measures included the recurrence rate, residual conjunctival bed status, and complications from any of the surgical methods.
Results
Sixty-two patients were recruited in the original study. Eight patients had passed away and 12 patients were uncontactable or not responded. One patient who had bilateral operations refused to return for follow-up and one eye had insufficient data for analysis. Finally, 40 eyes of 40 patients were included for analyses. One eye developed a recurrence over 15 years and none required a tertiary pterygium operation. The patient received LCAU for a temporal recurrent pterygium developed a 2.2-mm recurrence.
Conclusions
All three techniques yielded favorable outcomes for patients with recurrent pterygium. The use of LCAU was associated with better cosmetic outcome.
Purpose:
To evaluate the efficacy and safety of pterygium excision using a large conjunctival autograft for the treatment of recurrent pterygium.
Methods:
The medical records of 120 patients (126 eyes) with recurrent pterygium were reviewed. For each affected eye, pterygium excision with a large conjunctival autograft was performed. The graft was harvested from the superior bulbar area and measured more than 8 × 10 mm in size. Only patients who completed at least six months of follow-up were included. Postoperative clinical outcomes, recurrence rate, and complications were analyzed. Patients with any evidence of recurrence after surgery received a subconjunctival bevacizumab injection.
Results:
The average patient age was 56.5 ± 10.2 years, and 45 out of 120 patients were male. The mean study follow-up period was 17.7 ± 17.6 months. Most patients were satisfied with the cosmetic outcome. Postoperative visual acuity improved from 0.69 to 0.75 (p < 0.05). Postoperative refractive astigmatism and corneal astigmatism decreased by 0.55 and 2.73 diopters, respectively (p < 0.05). The postoperative recurrence rate was 4.0%, and the average recurrence period was 7.4 ± 0.6 weeks. A subconjunctival injection of 5 mg bevacizumab was performed in cases of recurrence; no progression of the pterygium was observed following the injection. Postoperative complications included 2 cases of conjunctival graft edema in 2 eyes, 5 donor site scars in 5 eyes, 13 pyogenic granulomas in 13 eyes, and a conjunctival epithelial inclusion cyst in 7 eyes.
Conclusions:
Pterygium excision with a large conjunctival autograft for the treatment of recurrent pterygium produced an excellent cosmetic outcome, a low recurrence rate, and minimal complications. A subconjunctival bevacizumab injection given in cases of recurrence following surgery might be effective in preventing progression of the pterygium.
Purpose:
This study compared the outcomes of a limbal conjunctival autograft (LCAG) with those of an amniotic membrane graft (AMG) followed by intraoperative 0.02 % mitomycin C (MMC) to treat recurrent pterygium.
Methods:
In this randomized controlled trial, ninety-six eyes with recurrent pterygium were enrolled and randomly allocated into two groups using a computer-generated random number table. Pterygium removal was followed by intraoperative 0.02 % MMC for 3 min and then either LCAG or AMG transplantation. The major outcomes were recurrence rate, conjunctival inflammation grade, healing time of the corneal epithelial defect, eye-movement amplitude (EMA), uncorrected distance visual acuity (UDVA), and complications.
Results:
A follow-up of 12 months was conducted for 93 eyes of 82 patients. Grade D (recurrence) presented in one eye of the LCAG group and five eyes of the AMG group, with no between-group difference (p = 0.196). However, Grades A, B, and C presented in 46, zero and zero eyes of the LCAG group respectively, and in 37, two and two eyes of the AMG group respectively, with the surgical bed generally showing a better appearance in the LCAG group than in the AMG group (p = 0.008). Compared with baseline values, the postoperative EMA improved significantly in both groups (p < 0.001 for the LCAG group; p = 0.001 for the AMG group), as did UDVA (p = 0.005 for the LCAG group; p = 0.012 for the AMG group). No between-group differences were found in terms of the healing time for epithelial defect, conjunctival inflammation grade, or the frequency of complications such as punctate epithelial keratitis, episcleral melting, corneal pannus, and delayed corneal epithelium healing.
Conclusions:
LCAG transplantation with intraoperative 0.02 % MMC is as efficacious in treating recurrent pterygium as AMG transplantation with MMC. The former procedure results in an attractive cosmetic appearance but might result in limbal damage in some eyes. The surgeon's familiarity with these procedures should determine the method of treatment.
Background: Pterygium is a wing shaped fibrovascular growth of subconjunctival tissue encroaching upon the cornea from the either side within the interpalpebral fissure area inducing significant astigmatism. Surgical intervention for excision of pterygium leads to reduction in astigmatism which significantly improves vision.
Aim: To study changes in corneal astigmatism before and after pterygium excision surgery.
Material and Methods: The study was carried out on 100 eyes of 95 patients who had primary pterygium and were admitted in Department of Ophthalmology, P. D. U. Govt. Medical College, Rajkot and underwent pterygium surgery during period of October 2012 to April 2013. All patients underwent preoperative assessment for visual acuity, anterior segment examination, posterior segment examination, auto refraction and auto keratometry. After pterygium surgery, patients were assessed for visual acuity, auto refraction and auto keratometry on 1st, 7th and 45th post operative day and the results were analysed.
Results: Mean astigmatism preoperatively was found to be 6.20 ± 3.58 Diopters (D) which subsequently decreased to 1.20 ± 1.27 D on 45th post operative day-showing 5.09 ± 3.32 D of change in astigmatism which was statistically significant(paired t-test, p
To assess and compare the recurrence rate of pterygium after limbal stem cell transplantation versus amniotic membrane transplantation (AMT) as ocular surface reconstructing measures in recurrent pterygium, also evaluation of the use of antimetabolite drugs as adjunctive therapy for AMT.
Prospective randomized comparative study included 60 eyes of 48 patients with recurrent pterygia. Informed consents were taken from all patients. Primary pterygium excision was performed 6-15 months ago; the cases were divided randomly into three equal groups: Group 1: included 20 eyes with excision of the pterygium and application of limbal stem cell transplantation with conjunctival autograft, group 2: included 20 eyes with excision of the pterygium followed by AMT and group 3: included 20 eyes in which surgical excision of pterygium was followed by intra-operative application of low-dose of MMC (0.05%) for 3 min then using AMT.
The study included 36 males and 12 females of age ranged from 28 to 52 years. The recurrence rate was 2 eyes in group 1 (10%) (limbal stem cell transplantation + conjunctival autograft), 6 eyes in group 2 (30%) (AMT) and 4 eyes (20%) in group 3 (MMC + AMT). The rate of recurrence was significantly different between the three groups (P < 0.001).
Limbal stem cell transplantation together with conjunctival autografting proved to be more effective in prevention of pterygium recurrence and in rapid restoration of normal epithelial morphology. MMC in addition to AMT decreases the incidence of recurrence.
To evaluate the effectiveness of Mitomycin C used as a combined therapy along with limbal-conjunctival autograft for primary pterygium.
Purpose: To evaluate the efficacy of conjunctivo-limbal autograft after wide excision of primary and recurrent pterygia. Methods: Twenty-one eyes of 18 patients with primary pterygium and 18 eyes of 18 patients with recurrent pteygium underwent conjunctivo-limbal autograft after wide excision of pterygium. All patients underwent follow-up for more than six months. Recurrence rates and complications were evaluated. Results: With a minimum of six months of follow-up, fibrovascular tissue in the excised area, not invading the cornea, was noted in one eye (5.6%) in the recurrent pterygium group but no further surgical interventions for the cosmetic problem were needed. One eye (4.8%) showed wound dehiscence, three eyes (14.3%) showed subgraft hemorrhage, and one eye (4.8%) showed subconjunctival fibrosis at the donor site in the primary pterygium group, while two eyes (11.1%) showed subgraft hemorrhage, and one eye (5.6%) showed Tenon's Capsule granuloma at the donor site in the recurrent pterygium group. Conclusions: Conjunctivo-limbal autograft after wide excision of pterygium can be considered an effective treatment with low recurrence rates for both primary and recurrent pterygia.
To determine the power vector and aberrations before and after surgery for pterygium using a corneal topographer and a wavefront aberrometer.
Pterygium is an ocular surface disease of humans attributed to chronic ultraviolet-B exposure. Clinically, the condition involves invasive centripetal growth with associated inflammation and neovascularisation. Previous clinical studies focused primarily on the clinical characteristics and surgical management of pterygia and, because of this, the pathogenesis of pterygia remains incompletely understood. However, considerable progress in this area has been achieved, providing additional insight into this complex disease. This recent evidence implicates antiapoptotic mechanisms, immunological mechanisms, cytokines, growth factors, extracellular matrix modulators, genetic factors, viral infections and other possible causative factors. Limited investigation regarding differences in pathogenesis of primary and recurrent pterygia has been performed. We summarise many of these recent discoveries concerning the pathogenesis of pterygia and describe reported differences between primary and recurrent pterygia.
The study was designed to evaluate the long term results of intraoperative mitomycin C in patients with one recurrence of pterygium.
In 45 white patients with one recurrence of pterygium the 'bare sclera technique' was performed and a sterile sponge soaked in a 0.2 mg/ml (0.02%) mitomycin C solution was placed intraoperatively on the sclera for 3 minutes. The control group underwent surgical excision only. Recurrences were analysed by the chi 2 test and the method of Kaplan-Meier (life table analysis); the difference between survival curves was tested by the log rank test. The chi 2 test with Yates's correction or Fisher's exact test were used to analyse the difference in complications and side effects between the two groups.
After a mean postoperative follow up of 34.55 (SD 13.70) months, 6 recurrences (12.5%) were observed in the mitomycin C treated patients and 16 (35.6%) in the control patients (p = 0.027). The 24 and 48 month life table success rates were 89% and 83% in the mitomycin C treated group and 66% and 63% in the control group, respectively (p = 0.022). No severe side effects appeared during follow up. Superficial punctate keratitis appeared in the early postoperative period in only seven mitomycin C treated eyes (15.5%) (p = 0.018).
This study confirms the efficacy of intraoperative mitomycin C in improving the success rate after recurrent pterygium surgical excision.
Saccades are rapid eye movements that redirect the fovea from one object to another. A great deal has been learned about the anatomy and physiology of saccades, making them an ideal system for studying the neural control of movement. Basic research on normal eye movements has greatly increased our understanding of saccadic performance, anatomy and physiology, and led to a large number of control system models. These models simulate normal saccades well, but are challenged by clinical disorders because they often do not incorporate the specific anatomical and physiological substrates needed to model clinically important abnormalities. Historically, studies of saccadic abnormalities in patients have played a critical role in understanding the neural control of saccades because they provide information that complements basic research and thus restricts hypotheses to those that are biologically plausible. This review presents four examples of clinical disorders (slow saccades, interrupted saccades, high-frequency saccadic oscillations and macrosaccadic oscillations) that have provided insights into the neurobiology of saccades, have driven the development of new models, and have suggested an explanation or treatment for these disorders. We raise general questions for both scientists and clinicians that will assist in their efforts to understand the neural control of movement, improve diagnostic criteria and develop new treatments.
To determine the higher order aberrations at the corneal first surface before and after surgery for pterygium.
Data were drawn from a longitudinal study of patients undergoing pterygium excision at Royal Victoria Infirmary, Newcastle upon Tyne, England between September 1998 and May 2004. Corneal topography was taken with the TMS-2 Topographic Modeling System (Computed Anatomy Corp) prior to and 6 months after surgery, exported to VOLPro software v7.08 (Sarver & Associates), and wavefront aberrations were derived for a 5.0-mm pupil using a 10th order Zernike polynomial expansion. Pre- to postoperative changes were assessed for significance using analyses of variance, and the relative risk of significant postoperative aberrations by pterygium size was determined.
Satisfactory corneal topography was available on 67 eyes (mean age 53.8 +/- 16.7 years [range: 25-86 years]). The root-mean-square (RMS) fit error in preoperative eyes was 0.15 +/- 0.10 microm. Preoperatively, the total higher order RMS wavefront aberration was 0.94 +/- 0.83 microm. All Zernike modes were elevated, with trefoil being the major contributor 0.52 +/- 0.50 microm. Pterygium excision significantly reduced wavefront aberrations across all modes and orders (F(1, 129) = 6.7 to 22.6, P < .01): total higher order RMSpostop 0.45 +/- 0.35 microm. Cases with visually significant postoperative aberrations occurred and were more likely with larger pterygia: relative risk compared to pterygia 1.0 to 1.9 mm was 1.3 for 2.0 to 2.9 mm, 8.5 for 3.0 to 3.9 mm, 13.3 for 4.0 to 4.9 mm, and 10.2 for 5.0 to 5.9 mm.
Zernike polynomial fitting well describes wavefront aberrations in eyes with pterygia. Pterygia are associated with wavefront aberrations, especially trefoil, but these were largely eliminated by surgery. Earlier excision of pterygia reduces the likelihood of significant residual aberrations.
Purpose:
To evaluate the impact of race and ethnicity, surgical technique, and level of surgeon training on recurrence rates after primary pterygium excision.
Methods:
A retrospective review of patients who underwent primary pterygium excision at our academic institution was performed. The surgical technique-conjunctival autografting (CAG) or amniotic membrane grafting (AMG)-was chosen at the attending surgeon's discretion, and all surgeries were performed by surgeons in training. The primary outcome measure was pterygium recurrence, defined as regrowth of fibrovascular tissue onto a clear cornea in the region of previous pterygium removal.
Results:
There was a significant difference in age at presentation between white (64.3 ± 11.4), Hispanic (50.0 ± 13.5), black (64.8 ± 14.5), and Asian (59.3 ± 9.2) patients (P < 0.001). Average time to recurrence was 4.4 ± 3.0 months and was similar between races (P = 0.98). There was a significant difference in recurrence rates between the white (13%), Hispanic (28%), black (33%), and Asian (0%) patients (P = 0.049). Over 12 months, a significant difference in cumulative proportion with recurrence after AMG versus CAG was observed in Hispanic (75% vs. 30%; P = 0.002) and black (100% vs. 42%; P = 0.001) patients. Sex, method of graft fixation (glue, suture, or both), and level of surgeon training showed no difference in pterygium recurrence (P > 0.05).
Conclusions:
Hispanic and black patients are more likely to experience pterygium recurrence after AMG than CAG. White patients are less likely than Hispanic or black patients to experience recurrence regardless of the surgical technique. To reduce the likelihood of recurrence, surgeons may consider race and ethnicity when selecting their operative technique.
Saccades are rapid eye movements that redirect the fovea from one object to another. A great deal has been learned about the anatomy and physiology of saccades, making them an ideal system for studying the neural control of movement. Basic research on normal eye movements has greatly increased our understanding of saccadic performance, anatomy and physiology, and led to a large number of control system models. These models simulate normal saccades well, but are challenged by clinical disorders because they often do not incorporate the specific anatomical and physiological substrates needed to model clinically important abnormalities. Historically, studies of saccadic abnormalities in patients have played a critical role in understanding the neural control of saccades because they provide information that complements basic research and thus restricts hypotheses to those that are biologically plausible. This review presents four examples of clinical disorders (slow saccades, interrupted saccades, high-frequency saccadic oscillations and macrosaccadic oscillations) that have provided insights into the neurobiology of saccades, have driven the development of new models, and have suggested an explanation or treatment for these disorders. We raise general questions for both scientists and clinicians that will assist in their efforts to understand the neural control of movement, improve diagnostic criteria and develop new treatments.
To compare the long-term outcome of pterygium surgery and the long-term effect on endothelial counts after mitomycin C (MMC) or limbal conjunctival autograft (LCAU) in pterygium surgery.
We performed a 10-year follow-up study of a randomized controlled trial.
A total of 115 eyes of 114 patients with primary pterygium were treated with intraoperative MMC (n = 63) or LCAU transplants (n = 52). A total of 76 patients completed the current 10-year long-term follow-up (47 in the MMC group, 29 in the LCAU group).
This is a follow-up study of a randomized controlled trial of a cohort of 114 patients in 2 groups that was performed at the Prince of Wales Hospital 10 years ago: group 1, intraoperative 0.02% MMC for 5 minutes; group 2, LCAU. Consecutive patients enrolled in the original study (recruitment began in February 2001) were invited back for a detailed clinical examination to document the long-term outcome of both surgical groups.
The main outcome measures included the recurrence rate, residual conjunctival bed status, complications, and corneal endothelial cell density (ECD) differences.
A total of 115 eyes of 114 patients were enrolled and randomized in our previous study. For the current study, 76 of the 114 patients (47 in the MMC group, 29 in the LCAU group) were contacted, whereas 18 patients were lost to follow-up and 20 patients had died. The mean follow-up period was 138±2 months in the MMC group and 137±2 months in the LCAU group. Twelve of 47 patients (25.5%) in the original MMC group and 2 of 29 patients (6.9%) in the LCAU group had recurrent pterygium (P = 0.021). The mean ECD was 2392±342 cells/mm(2) in the MMC group and 2390±388 cells/mm(2) in the LCAU group (P = 0.978). There was no significant difference in the ECD between the operated eyes and the fellow eyes in both groups (P = 0.926 MMC, P = 0.468 LCAU). No other significant ocular complications were observed in either group at the 10-year postoperative follow-up.
Limbal conjunctival autograft was more effective than intraoperative MMC in minimizing pterygium recurrence at the 10-year follow-up. Treatment with intraoperative MMC was not associated with long-term corneal endothelial cell loss.
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Objective:
The objective of this study is to present the 3 months results of pterygium excision with adjunctive amniotic membrane graft.
Materials and methods:
In a non-comparative case series study, the medical records of all patients who had pterygium excision with adjunctive amniotic membrane transplant on bare sclera from December 2009 to August 2010 were reviewed. All the patients were followed up for 3 months. The data collected were sex, age, occupation, type of pterygium (primary or recurrent), extent of pterygium, post-operative complications and recurrent pterygium growth.
Results:
Thirty eyes of 30 consecutive patients were operated on. There were 14 males and 16 females (M:F =1:1); age range 25 to 70 years (mean: 48.3 SD + 12.01). Twenty-six eyes had primary and 4 recurrent pterygia. Stage 3 pterygium accounted for most of the cases (53.3%) followed by stage 2 (36.7%) and stage 4 (10%). Nineteen patients (63.3%) had occupations with considerable exposure to actinic damage. Of these, manual laborers accounted for the highest number contributing 13 (43.3%) out of the 19 cases. Of the 30 patients 2 had a reoccurrence giving a recurrence rate of 6%. One patient developed dellen 1 week post-operatively with complete resolution following conservative large soft contact lens application.
Conclusion:
Short term results suggests that adjunctive amniotic membrane transplant with pterygium excision is effective and safe. A larger randomized clinical trial with a longer follow-up period is however recommended.
The recurrence of pterygium after surgery is high. A variety of adjunctive treatment approaches have been developed to improve the clinical efficacy and many related articles have been published. This study aimed to determine the risk for postoperative pterygium recurrence comparing autologous conjunctival transplantation (ACT) versus mitomycin C (MMC).
Relevant literature published until December 2010 in Medline, Embase, Cochrane, Cochrane library, Science Citation Index, and Google Scholar were searched. Qualified random clinical trial (RCT) studies on the comparison of recurrence rate of pterygium after ACT and MMC treatment were included in this study.
Eight RCTs with 663 eyes entered the final analysis. The recurrent rate of pterygium was 8.7% (30/343) for ACT and 18.75% (60/320) for MMC. Using fixed-effect meta analysis, we found that the recurrence was significantly lower after ACT than MMC treatment (odds ratio (OR) = 0.40, 95% confidence index (CI), 0.25 - 0.63, P < 0.0001). In sensitivity analyses, we employed random-effects model and excluded studies of low quality or studies in which MMC was administrated after the operation. All the sensitivity analyses confirmed that ACT led to lower recurrence rates than MMC. Sub-group analysis revealed that the recurrence rate was 20.2% (20/99) and 27.65% (26/94) for conjunctival autograft (CA) and MMC respectively, and no significant difference in the recurrence rate was detected (OR = 0.65, 95%CI 0.33 - 1.28, P = 0.22). However, we found that conjunctival limbal autograft (CLA) had lower recurrence rate than MMC (OR = 0.26, 95%CI 0.14 - 0.48, P = 0.0001).
CLA has better therapy efficacy against the recurrence of pterygium than MMC.
To evaluate the safety and efficacy of using fibrin glue in cases of recurrent pterygium treated with pterygium excision and conjunctival autograft combined with mitomycin C.
Retrospective, interventional case series.
The charts of 28 patients with recurrent pterygium who had undergone pterygium excision and conjunctival autograft using fibrin glue to secure the graft combined with intraoperative mitomycin C at a corneal service in a university teaching hospital were reviewed. Inclusion criteria were recurrent pterygium that had undergone at least 1 previous surgical excision and patients who had completed a regular postoperative follow-up of at least 12 months. Outcome measures included mean best-corrected visual acuity (BCVA) and intraoperative and postoperative complications.
The mean age of the cohort was 49.7 years. There were no intraoperative complications. Early postoperative total graft dehiscence developed in 1 eye that underwent repositioning with glue and sutures. One eye had mild graft dehiscence and required no surgical intervention. One eye had a conjunctival cyst on the graft that did not require intervention. No significant change was observed in BCVA. At a mean follow-up of 26.5 months, there was 1 case of recurrence.
Pterygium excision and conjunctival autograft using fibrin glue to secure the graft combined with intraoperative mitomycin C seems to be a safe and effective surgical option for treating recurrent pterygium. However, a larger cohort with longer follow-up may be required to assess the recurrence rate of this method.
Surgical results can be assessed as a function of what was aimed for, what was done, and what was achieved. One of the aims of refractive surgery is to reduce astigmatism; the smaller the postoperative astigmatism the better the result. Determination of what was done--that is, the surgical effect, can be calculated from the preoperative and postoperative astigmatism. A simplified formulation is described which facilitates the calculation (magnitude and direction) of this surgical effect. In addition, an expression for surgical accuracy is described, as a function of what was aimed for and what was achieved.
Eighty patients (99 eyes) with primary pterygia were treated with excision, with or without additional therapy, and were followed up for three to eight years after treatment. Of 29 eyes that underwent excision and postoperative instillation of 0.02% mitomycin C, there were only two recurrences. The other eyes were treated with excision only, excision and radiation, or excision and 0.04% mitomycin C. Instillation of 0.02% mitomycin C reduced the recurrence rate significantly (P less than .01). Only one of the 29 eyes (3%) treated with excision and 0.02% mitomycin C had a complication, the lowest rate of all groups postoperatively. We found the postoperative instillation of 0.02% mitomycin C, twice a day for five days, to be effective and safe in the treatment of primary pterygium.
High-grade corneal astigmatism is considered to be an indication for pterygium surgery. However, no prospective studies have been carried out to determine whether a pterygium operation really reduces preoperative astigmatism. Therefore, we prospectively examined 23 patients who were operated on for pterygia at the University Eye Clinic in Freiburg in 1991. Pre- and postoperative corneal astigmatism was measured by ophthalmometry or retinoscopy. Preoperative astigmatism after pterygium surgery was reduced or unaltered in 19 patients. In 4 patients, the postoperative astigmatism was increased. The mean preoperative astigmatism was 2.41 D in the horizontal meridian, the postoperative astigmatism 1.29 D. The reduction was statistically significant (P < 0.0001, Wilcoxon test). The higher the preoperative astigmatism, the higher the difference between pre- and postoperative astigmatism (r2 = 0.88, P = 0.0001). Our technique of pterygium surgery (free conjunctival transplant after polishing the cornea, limbus, and sclera) reduces preoperative astigmatism. Thus, high-grade astigmatism can be regarded as an indication for pterygium surgery.
To define the amount of time necessary to follow patients after pterygium removal to identify a recurrence.
The authors reviewed patients who supposedly had a recurrence of their pterygium and analyzed the records to determine the duration of these recurrences.
One hundred sixty-one known pterygium recurrences were identified from records. Those patients with frequent follow-up in whom recurrence could be determined to within 1 month were in group A, and those in whom the time of recurrence was indefinite were in group B. For patients in group A, there was an average time to the first recurrence of 123 +/- 113 days, with second and third recurrences at 97 +/- 58 and 67 +/- 47 days, respectively. Survival curve analysis showed that there was a 50% chance that there would be a recurrence within the first 120 days, and there was a 97% chance there would be a recurrence within 12 months of its removal.
This suggests that a 1-year follow-up time is likely to identify a recurrence.
The purpose of the study is to determine whether amniotic membrane can be used as an alternative to conjunctival autograft after pterygium excision.
A prospective study of amniotic membrane grafts (group A) and primary closure (group B) was compared retrospectively with conjunctival autografts (group C) in patients with pterygia.
Group A included 46 eyes with primary pterygia and 8 eyes with recurrent pterygia, group B had 20 eyes with primary pterygia, and group C consisted of 78 eyes with primary and 44 eyes with recurrent pterygia.
For the above three different surgeries, the amount of tissue removed was estimated from histopathologic analysis, and the result was evaluated by clinical examination.
Recurrence, survival analysis, and final appearance were compared.
In group A, the recurrence rate was 10.9%, 37.5%, and 14.8% for primary, recurrent, and all pterygia, respectively (mean follow-up, 11 months). These three rates were significantly higher than 2.6%, 9.1%, and 4.9% noted in group C (mean follow-up, 23 months) (P < 0.001, 0.018, and 0.01, respectively). However, the latter recurrence rate was significantly lower than 45% (mean follow-up, 5.2 months) in group B for primary pterygia (P < 0.001). The onset of recurrence was delayed significantly in group C as compared with that of groups A and B.
The relatively low recurrence rate for primary pterygia allows one to use amniotic membrane transplantation as an alternative first choice, especially for advanced cases with bilateral heads or those who might need glaucoma surgery later.
Before invasion of the visual axis, pterygia typically induce with-the-rule astigmatism, which can be visually significant. In this study, we attempted to assess the quantitative relation between pterygium size and induced corneal astigmatism using corneal topography and digital imaging.
Thirty-three eyes of 25 patients with primary pterygia were evaluated using corneal topography (TMS), slit-lamp photography, and digital imaging to correlate parameters of pterygium size with induced corneal astigmatism at the 3- and 6-mm optical zones.
Pterygia induce asymmetric with-the-rule astigmatism. Lesions extending >45% of the corneal radius or within 3.2 mm of the visual axis produce increasing degrees of induced astigmatism.
Once pterygia reach a critical size, they induce visually significant central with-the-rule astigmatic changes that may not be apparent by subjective refraction. This finding helps to identify those patients who may benefit from surgical intervention.
Treatment of recurrent pterygium associated with symblepharon requires both suppression of fibrosis and reconstruction of limbal barrier. To achieve this, human amniotic membrane was transplanted and limbal autografts performed.
Four patients with severe symblepharon resulting from multiple surgeries for pterygium were treated. Human amniotic membrane was obtained at caesarean section and preserved until surgery. After excision of the fibrous tissues, the amniotic membrane was placed on the sclera, and a limbal autograft transplantation was performed using limbal tissues taken from the affected eye.
Recurrence of symblepharon was not observed in any of the patients and significant suppression of the subconjunctival fibrosis was achieved. Ocular movement improved in all cases. Complete remission of pterygium regrowth occurred in three cases, and a slight (about 1 mm) recurrence occurred in one case. The limbal donor site showed the presence of mild depressions without the formation of pseudopterygium.
Transplantation of human amniotic membrane with a limbal autograft appears to be a promising surgical treatment for reconstructing the ocular surface in patients with recurrent pterygium associated with symblepharon.
The treatment of pterygium is still quite controversial, with various treatments being advocated in the scientific literature. Unfortunately, there are very few well-conducted controlled clinical trials of treatments. However, years of anecdotal and noncontrolled studies have confirmed that some methods, such as bare scleral closure, are no longer acceptable in the treatment of pterygium and that other methods are likely to be more useful. In the future it will be important to develop a grading system, and surgeons will need to be conservative in the treatment of pterygium until such time as a single treatment provides a lower recurrence rate and complication rate.
To compare the recurrence rate following treatment of recurrent pterygia using one of two techniques-limbal conjunctival autograft transplantation versus low-dose intraoperative mitomycin C (0.2 mg/ml) combined with conjunctival flap closure.
Randomized clinical trial.
Eighty-one patients with recurrent pterygia treated by limbal conjunctival autograft transplantation (n= 41) or mitomycin C combined with conjunctival flap (n= 40) participated.
Limbal conjunctival autograft transplantation or low-dose intraoperative mitomycin C application with conjunctival flap technique was performed on recurrent pterygium cases.
Recurrence of pterygium and postoperative complications.
During mean follow-up periods of 16+/-1.9 and 15.5+/-1.5 months, six recurrences (14.6%) in the limbal conjunctival autograft transplantation group and five recurrences (12.5%) in the mitomycin C group were observed (P=0.77). The difference between the mean ages of recurrent (26.4+/-8.0 years) and nonrecurrent (35.8+/-11.9 years) cases for all patients was statistically significant (P=0.014). Technically, limbal conjunctival autograft transplantation seemed to be more difficult. The most frequent complication in limbal conjunctival autograft transplantation was graft edema, whereas that in the mitomycin C group was superficial keratitis.
Both techniques showed similar recurrence rates in the treatment of recurrent pterygia. Although technically easier to perform, further follow-up is necessary to determine the long-term safety of low-dose intraoperative mitomycin C with conjunctival flap closure. The surgeon's familiarity with either procedure should determine the method of choice.
The aim of this prospective randomized clinical study was to evaluate the effect of pterygium surgery on the corneal topography using a computerized corneal topography system.
Computerized corneal topography was performed on 27 patients with primary pterygium before and after pterygium excision surgery. The topographical changes that occurred following surgery were evaluated using paired and unpaired two-tailed t-test and Pearson coefficient of correlation analyses. Simulated keratometric astigmatism at the central 3 mm and the total mean refractive powers of the whole cornea were measured before and after surgery. Following surgery, flattened or steepened corneal areas were determined.
Simulated keratometric astigmatism at 3 mm was found to be 2.30 +/- 2.08 D (0.2 - 7.63) preoperatively and 0.82 +/- 0.74 D (0.06 - 2.79) postoperatively. The difference between these two values was statistically significant (t = -3.46, P = 0.002). Total mean refractive power of the whole cornea was found to be 42.26 +/- 0.63 (40.80 - 43.64) preoperatively and 43.69 +/- 0.88 (41.50 - 44.90) postoperatively and the difference was 1.42 +/- 0.87. There was a statistically significant high difference (t = 28.36, P < 0.001). When preoperative and postoperative corneal topographies were compared, the whole cornea was found steeper at the postoperative period except a little region in the superior nasal quadrant.
We believe that corneal topographical changes caused by the pterygium are almost reversible after surgical treatment, and postoperatively the cornea becomes steeper.
To evaluate the postoperative outcome and the recurrence rate after extensive removal of primary and recurrent pterygia combined with amniotic membrane transplantation.
A noncomparative interventional case series.
Fifty-four eyes in 54 subjects with either primary (n = 33) or recurrent (n = 21) pterygia operated on by one surgeon (SCGT).
All subjects were operated on for pterygia with an extensive excision of the lesion followed by amniotic membrane transplantation and intraoperative injection of a depot corticosteroid.
Cumulative rates of conjunctival (grade 3) and corneal (grade 4) recurrence and incidence of complications.
The mean follow-up was 12.8 +/- 4.3 months for primary and 14.3 +/- 4.9 months for recurrent pterygia. The true recurrence rate (grade 4) was 3.0%, 9.5%, and 5.6% for primary, recurrent, and all pterygia, respectively. The cumulative proportion of recurrence-free eyes at 12 months was 0.90 +/- 0.06 for primary and 0.69 +/- 0.11 for recurrent pterygia (P = 0.047, log-rank test). Removal of the semilunar fold was associated with longer survival times (P = 0.063) and decreased failure rate (P = 0.046). A similar success rate was achieved in double-head pterygia (1 recurrence in 11 eyes).
Amniotic membrane transplantation is an effective and safe procedure for pterygium surgery, with a relatively low recurrence rate for both primary and recurrent pterygia. It can be a useful alternative to conjunctival autograft when a large conjunctival defect has to be covered, such as in primary double-head pterygia and in large recurrent pterygia.
The treatment of pterygium is still quite controversial, with various treatments being advocated in the scientific literature. Unfortunately, there are very few well-conducted controlled clinical trials of treatments. However, years of anecdotal and noncontrolled studies have confirmed that some methods, such as bare scleral closure, are no longer acceptable in the treatment of pterygium and that other methods are likely to be more useful. In the future it will be important to develop a grading system, and surgeons will need to be conservative in the treatment of pterygium until such time as a single treatment provides a lower recurrence rate and complication rate.
To investigate the effects of fibrovascular traction and the pooling of tears at the pterygium apex on the corneal topographic changes induced by pterygium.
A total of 16 eyes of 14 cases with primary pterygium were included in the study. A computerized corneal topography system was used for corneal topography examinations. Baseline keratographs were taken two times at straight gaze. A repeat corneoscope photograph was immediately obtained in temporal gaze. Then the tears at the pterygium apex were dried with a cellulose sponge, and a new corneoscope photograph was immediately obtained without allowing one to blink. Corneal topographic maps (numeric maps) were divided into 301 fields in 24 meridians. One colour was allocated to each field, representing its mean refractive power for all groups. In all eyes, keratometric astigmatism at the 3 mm central cornea and total mean corneal refractive power were found. Data were compared using paired-samples two-tailed t-tests.
Keratometric astigmatism at the 3 mm central cornea was significantly reduced at the temporal gaze (3.10+/-2.34 D, t=3.40, P=0.027) and dried eyes (2.12+/-1.01 D, t=4.74, P=0.001) according to the first baseline measurement (4.31+/-1.91 D) of the total mean corneal refractive power was found to be 43.45+/-1.28 D (39.29-45.87) at the first baseline measurement. There was no change at the temporal gaze (43.54+/-1.06 D, P>0.05). However, the total corneal refractive power was significantly higher in dried eyes (44.26+/-0.93 D, t=34.92, P<0.001). The steepest region of corneal topography was a superior quadrant, and the flattest area was a nasal quadrant at the baseline. At the temporal gaze, the cornea was significantly flatter in the superior and inferior sides of the pterygium meridian. After dried pooling of tears, topographic abnormalities returned, and the cornea became more uniform and symmetric.
We conclude that the pooling of tears at the pterygium apex plays an important role, but fibrovascular traction has no effect on the corneal topographical changes induced by pterygium.
The aim of this study was to compare the corneal topographic changes at the early and late postoperative period after pterygium surgery.
Sixteen eyes of 15 patients with primary pterygium were included in the study. All of the pterygia were excised primarily. Computerized corneal topography measurements were taken before surgery and at the second week (postoperative early period) and third month (postoperative late period) after the operation. Keratometric astigmatism, total mean corneal refractive power, and flattened or steepened areas of the cornea were detected at each visit. The topographical changes were evaluated using the analysis of variance. Multiple comparison analyses were made with the Tukey HSD test.
Keratometric astigmatism was 2.58 +/- 2.33 diopters (D) at the preoperative period, 1.30 +/- 1.24 D at the postoperative early period, and 0.61 +/- 0.38 D at the postoperative late period (P < .001). The surgically induced corneal astigmatism was 3.23 +/- 2.33 D (range, 0.52 to 8.32 D) at the postoperative early period and 2.70 +/- 2.24 D (range, 0.47 to 7.72 D) at the postoperative late period (P = .287). Astigmatism was 81.25% with-the-rule at the preoperative period, 43.75% oblique and 37.50% against-the-rule at the postoperative early period, and 62.50% with-the-rule at the postoperative late period. Total mean corneal refractive power was 42.51 +/- 1.99 D at the preoperative period, 43.95 +/- 1.58 D at the postoperative early period, and 43.89 +/- 1.80 D at the postoperative late period (P = .014).
Corneal topographic changes induced by pterygium greatly improve at the postoperative early period. However, normal corneal topography patterns are formed at the postoperative late period.
To study the effect of pterygium on corneal topography, a retrospective analysis of 151 eyes with primary pterygia was done. All cases underwent videokeratography preoperatively and one month postoperatively. Statistical analysis of average corneal power (ACP), corneal astigmatism, surface regularity index (SRI) and surface asymmetry index (SAI) was done before and one month after surgery. Topographic indices were compared statistically for various grades of pterygia. Increase in the grade of pterygia had a significant effect on topographic indices. Corneal astigmatism reduced from 4.40+/-3.64 diopter (D) to 1.55+/-1.63D ( P value < 0.001) following surgery. The regularity of corneal surface improved and asymmetry of the cornea reduced one month after surgery. Pterygium leads to significant changes in corneal refractive status, which increase with the increase in the grade of pterygia and improve following pterygium excision.
To study the relationship between pterygium size (extension, width, total area) and corneal astigmatism in eyes with unilateral primary pterygium. Also to determine the critical size for surgery before the occurrence of a significant corneal astigmatism.
This study was conducted on 77 eyes of 77 patients with unilateral primary pterygium. The extension and width were measured and the total area was calculated. Automated keratometry was used to determine corneal astigmatism.
Pterygium extension ranged from 0.25 to 6.50 mm (mean, 2.0 +/- 1.2 mm), width ranged from 1.50 to 10.0 mm (mean, 4.19 +/- 1.5 mm), and total area ranged from 0.3 to 24.3 mm(2) (mean, 5.0 +/- 4.8 mm(2)). The mean value of corneal astigmatism was significantly (P < 0.0001) higher in pterygium-affected eyes (1.2 +/- 0.9 D) than control eyes (0.6 +/- 0.5 D). With-the-rule was the main type of pterygium-induced astigmatism (49.4%), followed by against-the-rule (36.4%) and oblique (14.3%). Pterygium extension had the best correlation (Pearson correlation coefficient r = 0.462, P < 0.001), followed by total area (r = 0.447, P < 0.002) and width (r = 0.348, P < 0.002). A stronger correlation was noted between pterygium size and the difference in corneal astigmatism between pterygium-affected eyes and control eyes. Pterygium induced 2 D of corneal astigmatism when its extension exceeded 2.2 mm, width exceeded 5 mm, or total area exceeded 6.25 mm(2).
Pterygium extension and total area have a stronger correlation with corneal astigmatism than does width. Surgical intervention is indicated when pterygium extension exceeded 2.2 mm, width exceeded 5 mm, or total area exceeded 6.25 mm(2).
Immunohistochemical study of PCNA
- J B Min
- Y S Choi
- J Y Kim
Min JB, Choi YS, Kim JY. Immunohistochemical study of PCNA
The clinical results of limbal conjunctival autograft transplantation with intraoperative mitomycin C application for recurrent pterygia
- D G Ahn
- S J Auh
- Y S Choi
Ahn DG, Auh SJ, Choi YS. The clinical results of limbal conjunctival autograft transplantation with intraoperative mitomycin
C application for recurrent pterygia. J Korean Ophthalmol Soc
1999;40:2443-9.
The effect of pterygium surgery on corneal topography
- A Cinal
- T Yasar
- A Demirok
- H Topaz
Cinal A, Yasar T, Demirok A, Topaz H. The effect of pterygium surgery on corneal topography. Ophthalmic Surg Laser 2001;32:35-40.