Taym Darwish - Academia.edu (original) (raw)
Papers by Taym Darwish
BMC Ophthalmology, May 18, 2022
Aim: To investigate the application of anterior and posterior corneal higher order aberrations (H... more Aim: To investigate the application of anterior and posterior corneal higher order aberrations (HOAs) in detecting keratoconus (KC) and suspect keratoconus (SKC). Method: This is a retrospective, case-control study which evaluated non-ectatic (normal) eyes, SKC eyes, and KC eyes. The Sirius Scheimpfug (CSO, Italy) analyzer was used to measure HOAs of the anterior and posterior corneal surfaces. Sensitivity, specificity and area under receiver operating characteristic curve (AUC) were calculated. Results: Two-hundred and twenty eyes were included in the analysis (normal n = 108, SKC n= 42, KC n= 70). Receiver operating characteristic (ROC) curve analysis revealed a high predictive ability for anterior corneal HOAs parameters: Root mean square (RMS) total corneal HOAs, RMS trefoil and RMS coma to detect keratoconus (AUC > 0.9 for all). RMS Coma (3, ±1) derived from the anterior corneal surface was the parameter with the highest ability to discriminate between suspect keratoconus an...
Purpose: to compare the root mean square (RMS) of anterior corneal higher-order aberrations (HOAs... more Purpose: to compare the root mean square (RMS) of anterior corneal higher-order aberrations (HOAs) in patients with refractive errors.Methods: This retrospective observational study was conducted at Department of Ophthalmology, Tishreen University Hospital, Latakia, Syria. The eyes were divided into four groups based on refractive error: mild-to-moderate myopia, hypermetropia, myopic astigmatism, and emmetropic eyes as controls. The following anterior corneal HOAs were evaluated using the Scheimpflug-Placido Sirius (CSO, Italy) topographer over 6 mm pupil: Root mean square (RMS) total corneal HOAs, RMS trefoil, RMS coma and RMS spherical aberrations. Results: RMS values of total HOAs, trefoil and coma showed a statistically significant difference in all four groups (P < 0.05, all). They were lowest in the control group (0.18± 0.09, 011± 0.08 and 0.09± 0.08 μm, respectively) and highest in the myopic astigmatism group (0.31± 0.16, 0.15± 0.12, 0.17± 0.14 μm, respectively). RMS sphe...
Journal of Ophthalmology
Aim. To determine the prevalence and associations of keratoconus (KC) in a university student pop... more Aim. To determine the prevalence and associations of keratoconus (KC) in a university student population in Syria. Methods. A prospective multicentre cross-sectional cohort study was conducted at two universities in Syria. Student volunteers were recruited from Tishreen University (Latakia governorate) and Damascus University (Damascus governorate). All participants underwent a comprehensive ocular examination. Placido/Scheimpflug-based corneal imaging using the Sirius (CSO, Florence. Italy), and a questionnaire to evaluate the baseline characteristics and medical history, as well as to highlight possible risk factors of KC. Univariate and bivariate analyses were performed. Results. The estimated prevalence of KC among all subjects was 1.43% (n = 12). A strong association between eye rubbing and keratoconus was found (OR 9.33, 95% CI 2.94–29.63, P < 0.001 ). Damascus University participants had a higher prevalence of KC than Tishreen University. However, the difference was not st...
Tishreen University Journal -Medical Sciences Series, Jul 6, 2021
Tishreen University Journal -Medical Sciences Series, Oct 1, 2020
Aim: To evaluate changes in corneal higher-order aberrations (HOAs) after accelerated corneal cro... more Aim: To evaluate changes in corneal higher-order aberrations (HOAs) after accelerated corneal cross-linking (A-CXL) and the effect of change in HOAs on visual acuity between baseline and one year after A-CXL.Methods: In this retrospective case-series, 32 eyes of 24 patients with keratoconus (KC) underwent accelerated corneal cross-linking. The following anterior corneal HOAs: total corneal HOAs, trefoil, secondary trefoil, coma, secondary coma, secondary astigmatism and spherical aberrations were measured and analysed using the Scheimpfug-Placido Sirius (CSO, Italy) topographer at baseline and 12 months after CXL. Multivariate analysis was used to evaluate the independent effect of HOA subtypes on changes in uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA). Results: At one year post CXL, UDVA and CDVA were significantly improved, -0.13 ± 0.19 LogMar (P = 0.0005) and -0.08 ±.0.11 LogMar (P = 0.0003), respectively. The mean preoperative trefoil, se...
جفاف العين التالي لقطع القرنية الضوئي الانكساري عبر الظهارة و الليزك تيم درويش الهدف: مقارنة جفاف... more جفاف العين التالي لقطع القرنية الضوئي الانكساري عبر الظهارة و الليزك تيم درويش الهدف: مقارنة جفاف العين التالي لقطع القرنية الضوئي الانكساري عبر الظهارة و الليزك. الطرق: شارك بالدراسة 50 مريض لديهم حسر مع أو بدون لا بؤرية. حيث تم إجراء قطع القرنية الضوئي الانكساري لـ 50 عين و ليزك لـ 50 عين. تم إجراء استبيان العين الجافة, اختبار زمن تحطم فيلم الدمع, اختبارشيرمر قبل الجراحة و بعد 1, 3, 6 أشهر من الجراحة. النتائج : تزايدت أعراض جفاف العين بشكل هام بالشهر الأول و الثالث بعد قطع القرنية الضوئي الانكساري عبر الظهارة و الليزك و اعتبارا من الشهر السادس لم يكن هناك فرق هام إحصائيا مقارنة بالأعراض قبل الجراحة كذلك لم يكن هناك فرق هام إحصائيا بين الليزك و قطع القرنية خلا ل جميع الزيارات. حدث تناقص غير هام احصائيا بقياس اختبار شيرمر بعد الجراحة و لم يكن هتاك فرق هام احصائيا بين كل من قطع القرنية الضوئي الانكساري عبر الظهارة و الليزك خلال كل الزيارات. بالنسبة لزمن تحطم فيلم الدمع فقد تناقص بعد الجراحة لكن هذا التناقص لم يكن هام إحصائيا مقارنة مع قبل الجراحة و كذلك لم يكن هناك فرق هام إحصائيا ...
European Journal of Ophthalmology, 2021
Aim To estimate the sensitivity and specificity of topographic and tomographic corneal parameters... more Aim To estimate the sensitivity and specificity of topographic and tomographic corneal parameters as determined by Sirius (CSO, Florence, Italy) in discriminating keratoconus (KC) and suspect keratoconus from normal cornea. Method In this retrospective case-series study, keratoconus screening indices were measured using Sirius tomographer. Receiver operating characteristics (ROC) curves were used to determine the test's overall predictive accuracy (area under the curve) and to identify optimal cut-off points to maximize sensitivity and specificity in differentiating keratoconus and suspect keratoconus from normal corneas. Results Receiver operating characteristics (ROC) curve analyses showed high predictive accuracy for Symmetry Index back (SIb), Keratoconus Vertex front (KVf), Symmetry Index front (SIf), Keratoconus Vertex back (KVb), Apex Keratometry (Curve-Apex) and Minimum corneal Thickness (ThkMin) to distinguish keratoconus from normal (area under the curve > 0.9, all)....
Journal of Ophthalmology, 2021
Aim. To assess the efficacy and safety of accelerated corneal cross-linking in the treatment of p... more Aim. To assess the efficacy and safety of accelerated corneal cross-linking in the treatment of pediatric keratoconus. Method. In this retrospective case series, 29 eyes of 20 pediatric patients with keratoconus underwent accelerated corneal cross-linking. Treatment was delivered at 10 mW/cm2 for 9 minutes with a total dose of 5.4 J/cm2. Clinical evaluation included visual acuities and refractive and Scheimpflug corneal tomography assessments. All patients with a minimum follow-up duration of 24 months were included in the study. Results. Mean ± standard deviation age was 15.41 ± 2.13 years (range: 8 to 18 years). Uncorrected distance visual acuity improved significantly from 0.56 ± 0.28 to 0.42 ± 0.29 logMAR P = 0.0003 , and corrected distance visual acuity improved significantly from 0.34 ± 0.23 to 0.28 ± 0.22 logMAR P = 0.014 . The mean manifest refraction spherical equivalent value was significantly reduced (−0.59 ± 0.95 D, P = 0.0024 ). While mean flat keratometry and steep ker...
Journal of Ophthalmic and Vision Research, 2021
Purpose: To compare the outcomes of accelerated versus standard corneal cross-linking for the tre... more Purpose: To compare the outcomes of accelerated versus standard corneal cross-linking for the treatment of progressive keratoconus. Methods: In this retrospective comparative study, 63 eyes of 40 patients with progressive keratoconus were divided into two groups; 27 eyes in group one were treated with an accelerated protocol (10 mW/cm2, 9 min) and 36 eyes in group two were treated with the standard method (3 mW/cm2, 30 min). Visual acuity, refraction, corneal topography, corneal tomography, and anterior and posterior corneal higher-order aberrations (HOAs) were assessed preoperatively and 18–30 months postoperatively. Results: The LogMAR uncorrected and corrected distance visual acuity values were improved in both groups postoperatively. However, the improvement was significantly higher in group one (P < 0.05, all). The flattening in the anterior keratometry readings, flat K, steep K, and average K were significantly higher in group two (P < 0.001, all). The maximum anterior k...
European Journal of Ophthalmology, 2021
Aim To evaluate the long-term outcomes of corneal cross-linking (CXL) in patients with progressiv... more Aim To evaluate the long-term outcomes of corneal cross-linking (CXL) in patients with progressive keratoconus. Method In this retrospective non-comparative study, forty-five eyes of 31 patients with progressive keratoconus were treated with 30 min “epi-off” corneal cross-linking. The visual, refractive, topographic and tomographic outcomes were evaluated preoperatively and at least 10 years after cross-linking. Results Ten years post-corneal cross-linking, the mean anterior maximum keratometry decreased (−2.10 ± 3.25 D, P = 0.0001). Conversely, the posterior maximum keratometry increased (6.38 ± 9.79 D, P = 0.065). Both uncorrected and corrected distance visual acuity improved (LogMAR −0.08 ± 0.30) and (LogMAR −0.05 ± 0.21), respectively (P > 0.05, both). A statistically significant hyperopic shift was observed postoperatively (0.70 ± 1.31 D, P = 0.0009). The anterior topographic cylinder values revealed no change (−0.17 ± 1.31 D, P = 0.3), whereas the mean posterior cylinder va...
Background: Laser in situ keratomileusis (LASIK) is increasingly used worldwide to correct a wide... more Background: Laser in situ keratomileusis (LASIK) is increasingly used worldwide to correct a wide range of refractive errors. Toxic anterior segment syndrome (TASS), a noninfectious inflammatory disease with symptoms and signs that resemble bacterial infection, is a rare complication of LASIK. Case presentation: We report a case of TASS in a 42-year-old male patient after LASIK surgery in both eyes for hyperopia. Diagnosed clinically. Discussion and conclusion: Little information about complications after LASIK is available. TASS is a general term used to describe acute, sterile postoperative anterior segment reactions. Patients with TASS will often experience blurry vision with or without pain within 12 to 48 hours after surgery. Steroids have shown to be effective in resolving the inflammatory response, reducing the pain and recovering the vision.
Journal of Refractive Surgery, 2007
To determine the relationship between the degree of subbasal nerve regeneration and corneal sensa... more To determine the relationship between the degree of subbasal nerve regeneration and corneal sensation and tear film functions after LASEK using corneal confocal microscopy. This prospective, observational, and longitudinal study included 35 LASEK patients who underwent tear breakup time assessment, phenol red thread test, corneal esthesiometry, and confocal microscopy preoperatively and 1, 3, and 6 months postoperatively. Subbasal nerve images were analyzed to assess nerve regeneration. Postoperatively, tear breakup time decreased significantly and had not returned to the preoperative level by 6 months after surgery. There were no significant differences in the phenol red thread test results before and after LASEK. Central corneal sensation decreased significantly 1 month after LASEK and returned to normal levels 3 months after surgery. Nerve fiber density, nerve branch density, and nerve fiber length and width decreased significantly after LASEK and had not returned to preoperative levels 6 months after surgery. Subbasal nerve fibers retained their vertical orientation after LASEK. There were no significant correlations between the length and density of subbasal nerve fibers and central corneal sensitivity, tear volume, or breakup time after surgery. Subbasal nerves were injured by LASEK and had not returned to preoperative levels 6 months after surgery. Corneal sensitivity was reduced after LASEK and returned to normal levels 3 months after surgery.
Journal of Cataract and Refractive Surgery, 2007
To evaluate recovery of the corneal subbasal nerve plexus and corneal sensitivity after myopic la... more To evaluate recovery of the corneal subbasal nerve plexus and corneal sensitivity after myopic laser in situ keratomileusis (LASIK) and laser-assisted subepithelial keratectomy (LASEK). Manchester Centre for Vision, Royal Eye Hospital, Manchester, United Kingdom. Thirty LASEK patients and 20 LASIK patients had slit-scanning confocal microscopy and noncontact corneal esthesiometry preoperatively and 1, 3, and 6 months after surgery. Images of the subbasal nerve plexus were analyzed using customized software to evaluate nerve regeneration. Central corneal sensitivity decreased significantly 1 month after LASEK and LASIK and returned to normal levels after 3 months. Corneal subbasal nerve fiber density, nerve branch density, nerve fiber length, and nerve fiber width decreased significantly 1 month after LASIK and had not returned to the preoperative levels by 6 months. Nerve fiber tortuosity decreased significantly 1 month after LASEK and returned to the preoperative levels 3 months after surgery. There were no significant differences in nerve fiber tortuosity before and after LASIK. Neither corneal sensitivity nor nerve fiber morphology was different between the 2 groups at any postoperative visit. Corneal sensitivity and subbasal nerve morphology were adversely affected by LASEK and LASIK. Corneal sensitivity recovered 3 months after the procedure, but subbasal nerves were still abnormal after 6 months. Despite the different forms of surgical trauma to corneal nerves with LASIK and LASEK, there was no apparent difference in the time course of recovery of corneal structure and function.
Cornea, 2007
Methods: Twenty keratoplasty patients were assessed before and 1, 3, 6, and 12 months after penet... more Methods: Twenty keratoplasty patients were assessed before and 1, 3, 6, and 12 months after penetrating keratoplasty by using noncontact corneal esthesiometry, tear breakup time measurement, the phenol red thread test, and confocal microscopy. Ten healthy control subjects were also assessed by using these techniques on 1 occasion. Subbasal nerve images were analyzed by using customized software to evaluate nerve regeneration. Results: Before surgery, the subbasal nerve plexus could be imaged only in 11 patients because of the existence of pathology. Significant deficits in nerve morphology were apparent in these patients compared with control subjects. No subbasal nerves were detected over the 12-month postoperative period. Central corneal sensitivity decreased significantly after surgery and returned to near normal levels after 12 months. Tear breakup time was significantly shorter at 3 and 12 months after keratoplasty. There were no significant differences in the phenol red thread test results before and after surgery. Conclusions: There is no direct association between subbasal nerve fiber regeneration, central corneal sensitivity, and tear film stability and volume. The apparent recovery of corneal sensitivity to normal levels 12 months postoperatively, in the absence of clinically observable subbasal nerves, may be a methodologic phenomenon related to the inability of current-generation confocal microscopes to image fine regenerating nerves that mediate corneal sensibility.
BMC Ophthalmology, May 18, 2022
Aim: To investigate the application of anterior and posterior corneal higher order aberrations (H... more Aim: To investigate the application of anterior and posterior corneal higher order aberrations (HOAs) in detecting keratoconus (KC) and suspect keratoconus (SKC). Method: This is a retrospective, case-control study which evaluated non-ectatic (normal) eyes, SKC eyes, and KC eyes. The Sirius Scheimpfug (CSO, Italy) analyzer was used to measure HOAs of the anterior and posterior corneal surfaces. Sensitivity, specificity and area under receiver operating characteristic curve (AUC) were calculated. Results: Two-hundred and twenty eyes were included in the analysis (normal n = 108, SKC n= 42, KC n= 70). Receiver operating characteristic (ROC) curve analysis revealed a high predictive ability for anterior corneal HOAs parameters: Root mean square (RMS) total corneal HOAs, RMS trefoil and RMS coma to detect keratoconus (AUC > 0.9 for all). RMS Coma (3, ±1) derived from the anterior corneal surface was the parameter with the highest ability to discriminate between suspect keratoconus an...
Purpose: to compare the root mean square (RMS) of anterior corneal higher-order aberrations (HOAs... more Purpose: to compare the root mean square (RMS) of anterior corneal higher-order aberrations (HOAs) in patients with refractive errors.Methods: This retrospective observational study was conducted at Department of Ophthalmology, Tishreen University Hospital, Latakia, Syria. The eyes were divided into four groups based on refractive error: mild-to-moderate myopia, hypermetropia, myopic astigmatism, and emmetropic eyes as controls. The following anterior corneal HOAs were evaluated using the Scheimpflug-Placido Sirius (CSO, Italy) topographer over 6 mm pupil: Root mean square (RMS) total corneal HOAs, RMS trefoil, RMS coma and RMS spherical aberrations. Results: RMS values of total HOAs, trefoil and coma showed a statistically significant difference in all four groups (P < 0.05, all). They were lowest in the control group (0.18± 0.09, 011± 0.08 and 0.09± 0.08 μm, respectively) and highest in the myopic astigmatism group (0.31± 0.16, 0.15± 0.12, 0.17± 0.14 μm, respectively). RMS sphe...
Journal of Ophthalmology
Aim. To determine the prevalence and associations of keratoconus (KC) in a university student pop... more Aim. To determine the prevalence and associations of keratoconus (KC) in a university student population in Syria. Methods. A prospective multicentre cross-sectional cohort study was conducted at two universities in Syria. Student volunteers were recruited from Tishreen University (Latakia governorate) and Damascus University (Damascus governorate). All participants underwent a comprehensive ocular examination. Placido/Scheimpflug-based corneal imaging using the Sirius (CSO, Florence. Italy), and a questionnaire to evaluate the baseline characteristics and medical history, as well as to highlight possible risk factors of KC. Univariate and bivariate analyses were performed. Results. The estimated prevalence of KC among all subjects was 1.43% (n = 12). A strong association between eye rubbing and keratoconus was found (OR 9.33, 95% CI 2.94–29.63, P < 0.001 ). Damascus University participants had a higher prevalence of KC than Tishreen University. However, the difference was not st...
Tishreen University Journal -Medical Sciences Series, Jul 6, 2021
Tishreen University Journal -Medical Sciences Series, Oct 1, 2020
Aim: To evaluate changes in corneal higher-order aberrations (HOAs) after accelerated corneal cro... more Aim: To evaluate changes in corneal higher-order aberrations (HOAs) after accelerated corneal cross-linking (A-CXL) and the effect of change in HOAs on visual acuity between baseline and one year after A-CXL.Methods: In this retrospective case-series, 32 eyes of 24 patients with keratoconus (KC) underwent accelerated corneal cross-linking. The following anterior corneal HOAs: total corneal HOAs, trefoil, secondary trefoil, coma, secondary coma, secondary astigmatism and spherical aberrations were measured and analysed using the Scheimpfug-Placido Sirius (CSO, Italy) topographer at baseline and 12 months after CXL. Multivariate analysis was used to evaluate the independent effect of HOA subtypes on changes in uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA). Results: At one year post CXL, UDVA and CDVA were significantly improved, -0.13 ± 0.19 LogMar (P = 0.0005) and -0.08 ±.0.11 LogMar (P = 0.0003), respectively. The mean preoperative trefoil, se...
جفاف العين التالي لقطع القرنية الضوئي الانكساري عبر الظهارة و الليزك تيم درويش الهدف: مقارنة جفاف... more جفاف العين التالي لقطع القرنية الضوئي الانكساري عبر الظهارة و الليزك تيم درويش الهدف: مقارنة جفاف العين التالي لقطع القرنية الضوئي الانكساري عبر الظهارة و الليزك. الطرق: شارك بالدراسة 50 مريض لديهم حسر مع أو بدون لا بؤرية. حيث تم إجراء قطع القرنية الضوئي الانكساري لـ 50 عين و ليزك لـ 50 عين. تم إجراء استبيان العين الجافة, اختبار زمن تحطم فيلم الدمع, اختبارشيرمر قبل الجراحة و بعد 1, 3, 6 أشهر من الجراحة. النتائج : تزايدت أعراض جفاف العين بشكل هام بالشهر الأول و الثالث بعد قطع القرنية الضوئي الانكساري عبر الظهارة و الليزك و اعتبارا من الشهر السادس لم يكن هناك فرق هام إحصائيا مقارنة بالأعراض قبل الجراحة كذلك لم يكن هناك فرق هام إحصائيا بين الليزك و قطع القرنية خلا ل جميع الزيارات. حدث تناقص غير هام احصائيا بقياس اختبار شيرمر بعد الجراحة و لم يكن هتاك فرق هام احصائيا بين كل من قطع القرنية الضوئي الانكساري عبر الظهارة و الليزك خلال كل الزيارات. بالنسبة لزمن تحطم فيلم الدمع فقد تناقص بعد الجراحة لكن هذا التناقص لم يكن هام إحصائيا مقارنة مع قبل الجراحة و كذلك لم يكن هناك فرق هام إحصائيا ...
European Journal of Ophthalmology, 2021
Aim To estimate the sensitivity and specificity of topographic and tomographic corneal parameters... more Aim To estimate the sensitivity and specificity of topographic and tomographic corneal parameters as determined by Sirius (CSO, Florence, Italy) in discriminating keratoconus (KC) and suspect keratoconus from normal cornea. Method In this retrospective case-series study, keratoconus screening indices were measured using Sirius tomographer. Receiver operating characteristics (ROC) curves were used to determine the test's overall predictive accuracy (area under the curve) and to identify optimal cut-off points to maximize sensitivity and specificity in differentiating keratoconus and suspect keratoconus from normal corneas. Results Receiver operating characteristics (ROC) curve analyses showed high predictive accuracy for Symmetry Index back (SIb), Keratoconus Vertex front (KVf), Symmetry Index front (SIf), Keratoconus Vertex back (KVb), Apex Keratometry (Curve-Apex) and Minimum corneal Thickness (ThkMin) to distinguish keratoconus from normal (area under the curve > 0.9, all)....
Journal of Ophthalmology, 2021
Aim. To assess the efficacy and safety of accelerated corneal cross-linking in the treatment of p... more Aim. To assess the efficacy and safety of accelerated corneal cross-linking in the treatment of pediatric keratoconus. Method. In this retrospective case series, 29 eyes of 20 pediatric patients with keratoconus underwent accelerated corneal cross-linking. Treatment was delivered at 10 mW/cm2 for 9 minutes with a total dose of 5.4 J/cm2. Clinical evaluation included visual acuities and refractive and Scheimpflug corneal tomography assessments. All patients with a minimum follow-up duration of 24 months were included in the study. Results. Mean ± standard deviation age was 15.41 ± 2.13 years (range: 8 to 18 years). Uncorrected distance visual acuity improved significantly from 0.56 ± 0.28 to 0.42 ± 0.29 logMAR P = 0.0003 , and corrected distance visual acuity improved significantly from 0.34 ± 0.23 to 0.28 ± 0.22 logMAR P = 0.014 . The mean manifest refraction spherical equivalent value was significantly reduced (−0.59 ± 0.95 D, P = 0.0024 ). While mean flat keratometry and steep ker...
Journal of Ophthalmic and Vision Research, 2021
Purpose: To compare the outcomes of accelerated versus standard corneal cross-linking for the tre... more Purpose: To compare the outcomes of accelerated versus standard corneal cross-linking for the treatment of progressive keratoconus. Methods: In this retrospective comparative study, 63 eyes of 40 patients with progressive keratoconus were divided into two groups; 27 eyes in group one were treated with an accelerated protocol (10 mW/cm2, 9 min) and 36 eyes in group two were treated with the standard method (3 mW/cm2, 30 min). Visual acuity, refraction, corneal topography, corneal tomography, and anterior and posterior corneal higher-order aberrations (HOAs) were assessed preoperatively and 18–30 months postoperatively. Results: The LogMAR uncorrected and corrected distance visual acuity values were improved in both groups postoperatively. However, the improvement was significantly higher in group one (P < 0.05, all). The flattening in the anterior keratometry readings, flat K, steep K, and average K were significantly higher in group two (P < 0.001, all). The maximum anterior k...
European Journal of Ophthalmology, 2021
Aim To evaluate the long-term outcomes of corneal cross-linking (CXL) in patients with progressiv... more Aim To evaluate the long-term outcomes of corneal cross-linking (CXL) in patients with progressive keratoconus. Method In this retrospective non-comparative study, forty-five eyes of 31 patients with progressive keratoconus were treated with 30 min “epi-off” corneal cross-linking. The visual, refractive, topographic and tomographic outcomes were evaluated preoperatively and at least 10 years after cross-linking. Results Ten years post-corneal cross-linking, the mean anterior maximum keratometry decreased (−2.10 ± 3.25 D, P = 0.0001). Conversely, the posterior maximum keratometry increased (6.38 ± 9.79 D, P = 0.065). Both uncorrected and corrected distance visual acuity improved (LogMAR −0.08 ± 0.30) and (LogMAR −0.05 ± 0.21), respectively (P > 0.05, both). A statistically significant hyperopic shift was observed postoperatively (0.70 ± 1.31 D, P = 0.0009). The anterior topographic cylinder values revealed no change (−0.17 ± 1.31 D, P = 0.3), whereas the mean posterior cylinder va...
Background: Laser in situ keratomileusis (LASIK) is increasingly used worldwide to correct a wide... more Background: Laser in situ keratomileusis (LASIK) is increasingly used worldwide to correct a wide range of refractive errors. Toxic anterior segment syndrome (TASS), a noninfectious inflammatory disease with symptoms and signs that resemble bacterial infection, is a rare complication of LASIK. Case presentation: We report a case of TASS in a 42-year-old male patient after LASIK surgery in both eyes for hyperopia. Diagnosed clinically. Discussion and conclusion: Little information about complications after LASIK is available. TASS is a general term used to describe acute, sterile postoperative anterior segment reactions. Patients with TASS will often experience blurry vision with or without pain within 12 to 48 hours after surgery. Steroids have shown to be effective in resolving the inflammatory response, reducing the pain and recovering the vision.
Journal of Refractive Surgery, 2007
To determine the relationship between the degree of subbasal nerve regeneration and corneal sensa... more To determine the relationship between the degree of subbasal nerve regeneration and corneal sensation and tear film functions after LASEK using corneal confocal microscopy. This prospective, observational, and longitudinal study included 35 LASEK patients who underwent tear breakup time assessment, phenol red thread test, corneal esthesiometry, and confocal microscopy preoperatively and 1, 3, and 6 months postoperatively. Subbasal nerve images were analyzed to assess nerve regeneration. Postoperatively, tear breakup time decreased significantly and had not returned to the preoperative level by 6 months after surgery. There were no significant differences in the phenol red thread test results before and after LASEK. Central corneal sensation decreased significantly 1 month after LASEK and returned to normal levels 3 months after surgery. Nerve fiber density, nerve branch density, and nerve fiber length and width decreased significantly after LASEK and had not returned to preoperative levels 6 months after surgery. Subbasal nerve fibers retained their vertical orientation after LASEK. There were no significant correlations between the length and density of subbasal nerve fibers and central corneal sensitivity, tear volume, or breakup time after surgery. Subbasal nerves were injured by LASEK and had not returned to preoperative levels 6 months after surgery. Corneal sensitivity was reduced after LASEK and returned to normal levels 3 months after surgery.
Journal of Cataract and Refractive Surgery, 2007
To evaluate recovery of the corneal subbasal nerve plexus and corneal sensitivity after myopic la... more To evaluate recovery of the corneal subbasal nerve plexus and corneal sensitivity after myopic laser in situ keratomileusis (LASIK) and laser-assisted subepithelial keratectomy (LASEK). Manchester Centre for Vision, Royal Eye Hospital, Manchester, United Kingdom. Thirty LASEK patients and 20 LASIK patients had slit-scanning confocal microscopy and noncontact corneal esthesiometry preoperatively and 1, 3, and 6 months after surgery. Images of the subbasal nerve plexus were analyzed using customized software to evaluate nerve regeneration. Central corneal sensitivity decreased significantly 1 month after LASEK and LASIK and returned to normal levels after 3 months. Corneal subbasal nerve fiber density, nerve branch density, nerve fiber length, and nerve fiber width decreased significantly 1 month after LASIK and had not returned to the preoperative levels by 6 months. Nerve fiber tortuosity decreased significantly 1 month after LASEK and returned to the preoperative levels 3 months after surgery. There were no significant differences in nerve fiber tortuosity before and after LASIK. Neither corneal sensitivity nor nerve fiber morphology was different between the 2 groups at any postoperative visit. Corneal sensitivity and subbasal nerve morphology were adversely affected by LASEK and LASIK. Corneal sensitivity recovered 3 months after the procedure, but subbasal nerves were still abnormal after 6 months. Despite the different forms of surgical trauma to corneal nerves with LASIK and LASEK, there was no apparent difference in the time course of recovery of corneal structure and function.
Cornea, 2007
Methods: Twenty keratoplasty patients were assessed before and 1, 3, 6, and 12 months after penet... more Methods: Twenty keratoplasty patients were assessed before and 1, 3, 6, and 12 months after penetrating keratoplasty by using noncontact corneal esthesiometry, tear breakup time measurement, the phenol red thread test, and confocal microscopy. Ten healthy control subjects were also assessed by using these techniques on 1 occasion. Subbasal nerve images were analyzed by using customized software to evaluate nerve regeneration. Results: Before surgery, the subbasal nerve plexus could be imaged only in 11 patients because of the existence of pathology. Significant deficits in nerve morphology were apparent in these patients compared with control subjects. No subbasal nerves were detected over the 12-month postoperative period. Central corneal sensitivity decreased significantly after surgery and returned to near normal levels after 12 months. Tear breakup time was significantly shorter at 3 and 12 months after keratoplasty. There were no significant differences in the phenol red thread test results before and after surgery. Conclusions: There is no direct association between subbasal nerve fiber regeneration, central corneal sensitivity, and tear film stability and volume. The apparent recovery of corneal sensitivity to normal levels 12 months postoperatively, in the absence of clinically observable subbasal nerves, may be a methodologic phenomenon related to the inability of current-generation confocal microscopes to image fine regenerating nerves that mediate corneal sensibility.