Philippe Chastang - Academia.edu (original) (raw)
Papers by Philippe Chastang
Journal Français d'Ophtalmologie, 2009
Implant diffractif et chirurgie de la cataracte : résultats à un an d'un nouveau type d'implant. ... more Implant diffractif et chirurgie de la cataracte : résultats à un an d'un nouveau type d'implant. A new sort of diffractive IOL in cataract surgery: one year results.
Journal francais d'ophtalmologie
Femtosecond laser technology in ophthalmology is not only used for refractive surgery (LASIK flap... more Femtosecond laser technology in ophthalmology is not only used for refractive surgery (LASIK flaps), but also now for lamellar and penetrating keratoplasties. This is not surprising when one knows that femtosecond lasers can cut corneal tissue in all directions with micrometric accuracy. Lamellar dissection of the cornea is very facilitated with femtosecond laser because it is quicker and more reproducible. However, predescemet dissection is not yet possible, and although the interfaces are smooth, the visual benefits of this technology has still to be proven. Another field of application of femtosecond lasers is their use to perform the cut for penetrating keratoplasties. Different shapes of non vertical cuts are currently assessed in order to reduce the incidence of complications such as induced astigmatism and wound dehiscence, and to improve the visual outcome.
Journal Français d Ophtalmologie
To study the correlation between subjective refraction and corneal topography. To compare the top... more To study the correlation between subjective refraction and corneal topography. To compare the topographic analysis of surgically induced astigmatism (cataract and penetrating keratoplasty) with that of idiopathic astigmatism. Subjective astigmatism, subjective spherical equivalent, best spectacle-corrected visual acuity (LogMAR units), and videokeratoscopy using the EyeSys 2000((R)) device (axial, tangential, and refractive power) were recorded in 100 eyes with idiopathic astigmatism, 100 eyes after cataract surgery, and 100 eyes after penetrating keratoplasty. Topographies were classified according to pattern (Bogan classification) and asphericity (shape factor: prolate or oblate). The asphericity shape distribution was significantly different between the 3 groups (p<0.001). The shape of idiopathic astigmatism was almost always prolate (90%) whereas the oblate shape was more frequent in the penetrating keratoplasty group (75%). There was no significant difference in topographic pattern distribution between the 3 groups (p=0.11). The asymmetric bow tie pattern was the most common topographic pattern. Topography pattern classification was significantly correlated with the subjective astigmatic cylinder. (r(s)=0.60, p<0.001). Unlike the round and oval patterns, the bow tie pattern was associated with the high subjective cylinder. Correlation between the subjective cylinder, the refractive power cylinder, and the axial power cylinder was strong (r(s)=0.92 p<0.001), but it was weak for the tangential power cylinder (r(s)=0.72 p<0.001). The correlation between the subjective spherical equivalent and central cornea power was poor (r(s)<0.37, p<0.001). Subjective astigmatic cylinder showed the strongest correlation with best spectacle-corrected visual acuity (r(s)=0.70, p<0.001), whereas the predicted corneal acuity, corneal uniformity index, asphericity, and refractive power symmetry index were poorly correlated with it (r(s)<0.54, p<0.001). Despite the difference in the asphericity shape, the topographic pattern was similar in the 3 groups. The pattern type was significantly correlated with the subjective astigmatic cylinder. Topographic indices failed to predict visual acuity, while the subjective cylinder showed a strong correlation with visual acuity.
Journal Français d Ophtalmologie
To compare the accuracy and reproducibility of the Eye Sys videokeratoscope algorithms for analyz... more To compare the accuracy and reproducibility of the Eye Sys videokeratoscope algorithms for analyzing idiopathic and surgery-induced astigmatism analysis. Refractive astigmatism, videokeratoscopy (axial, tangential and refractive power), autorefractometry, autokeratometry, and keratometry were recorded in 20 patients with idiopathic astigmatism, 40 patients who had undergone cataract surgery and 40 patients who had undergone penetrating keratoplasty. For each eye, 2 successive videokeratoscopy were recorded. Both cylinder and axis provided by the tangential algorithm are significantly less reproducible than the cylinder and axis provided by the axial and refractive algorithms (P < 0.001). Cylinders provided by the axial and refractive algorithms showed a stronger correlation with subjective cylinder (rs > 0.89; p < 0.001) than the cylinder provided by the tangential algorithm (rs = 0.66; p < 0.001). Both keratometric axis and autokeratometric axis showed the strongest correlation with subjective axis (rs > 0.92; p < 0.001). The accuracy and reproducibility were higher for the topographic "bow tie" patterns than for the other topographic patterns. The axial and refractive algorithms of the Eye Sys videokeratoscope are more accurate and reproducible than the tangential algorithm for analyzing idiopathic or surgery-induced astigmatism.
Journal Français d Ophtalmologie
Ophthalmology, 2003
To report a case of a 50-year-old man who was initially seen with a corneal perforation in his ri... more To report a case of a 50-year-old man who was initially seen with a corneal perforation in his right eye 2 months after a photorefractive keratectomy (PRK) procedure and to discuss the roles of topical diclofenac and matrix metalloproteinases (MMPs). Case report with tissue analysis. Ocular examination, diagnostic workup, surgical treatment, and histologic, immunofluorescent, zymography, and real time-polymerase chain reaction studies on corneal button. Slit-lamp examination of the right eye revealed a 4-mm diameter area of central corneal thinning with a 2-mm diameter perforation at its center. Predisposing factors included prolonged postoperative topical diclofenac therapy for more than 2 months and a 10-year history of well-controlled diabetes mellitus. An extensive diagnostic workup ruled out a systemic autoimmune disease. A penetrating keratoplasty was performed. Results of immunohistochemical studies of the corneal button showed stromal accumulation of temporary type III and IV collagens, MMP-3, and MMP-9 in the anterior wounded stroma and MMP-9 in the basal corneal epithelial cells of the leading edge. Differential activity and expression of MMP-2 and MMP-9 were found between the central and peripheral corneal buttons. Prolonged use of diclofenac and diabetes mellitus might be responsible for the corneal perforation after PRK in our patient. MMP-9 and MMP-3 might be involved in delayed wound closure and corneal melting.
Journal Français d Ophtalmologie
To compare the accuracy and reproducibility of the orbscan pachymetry and ultrasonic pachymetry i... more To compare the accuracy and reproducibility of the orbscan pachymetry and ultrasonic pachymetry in the normal eye and in the penetrating keratoplasty eye. Pachymetric measurements were assessed in 50 eyes of 25 normal patients and 50 eyes of 48 patients who had undergone penetrating keratoplasty using both Orbscan II and ultrasonic pachymetry (Tomey SP-2000). For each eye, 2 successive measures were recorded with both instruments. For both devices, the default setting was used. Orbscan pachymetry maps were divided into 5 groups using a modification of Liu's classification. Orbscan pachymetry strongly correlated with ultrasonic pachymetry (rs = 0.91; p < 0.001). Ultrasonic pachymetry values and Orbscan pachymetry values showed no significant differences in the normal group (respectively, 557 microns +/- 36 and 555 microns +/- 34; p > 0.05). Ultrasonic pachymetry values and orbscan pachymetry values were significantly different in the penetrating keratoplasty group (respectively, 571 microns +/- 52 and 550 microns +/- 54; p < 0.001). The best value for the acoustic factor for Orbscan pachymetry in the penetrating keratoplasty group was 0.89. Ultrasonic pachymetry reproducibility and Orbscan pachymetry reproducibility were not significantly different (0.86% +/- 0.61 v. 0.67% +/- 0.63; p = 0.13 in the normal group; 1.22% +/- 0.81 v. 1.23% +/- 1.13; p = 0.92, in the penetrating keratoplasty group). Both pachymetry methods showed less reproducibility in the penetrating keratoplasty group than in the normal group (p < 0.02). Thinnest point localization was significantly different in both groups (p < 0.001). In 66% of the normal group, the thinnest point of the cornea was located in inferotemporal quadrant. This point was located at an average of 0.63 +/- 0.25 mm from the visual axis in the normal group and 1.60 +/- 0.81 mm in the penetrating keratoplasty group (p < 0.001). Whereas "Centered round" (40%) and "centered oval" (34%) were the most common patterns in the normal group, "decentered oval" (40%) and "irregular" (30%) were more frequent in the penetrating keratoplasty group (p < 0.001). Orbscan pachymetry strongly correlated with ultrasonic pachymetry. Reproducibility of both methods is excellent and not significantly different. Thinnest point localization and pachymetric map classification are significantly different in normal eyes and in penetrating keratoplasty eyes.
Journal Français d Ophtalmologie
High postkeratoplasty astigmatism is a common postoperative complication which can limit the fina... more High postkeratoplasty astigmatism is a common postoperative complication which can limit the final functional result. Arcuate incisions are a possible surgical treatment. They can be performed with the arcuate keratome which provides regular incisions. The aim of this study was to evaluate the results obtained with this device in the correction of high postkeratoplasty astigmatism. We retrospectively studied ten eyes operated for high postkeratoplasty astigmatism with the Hanna arcuate keratome. Arcuate keratomy procedures were performed on the graft button in all. Before surgery, mean uncorrected visual acuity was 0.07 +/- 0.05. Best spectacle-corrected visual acuity was 0.33 +/- 0.20 and mean subjective cylinder was 6.1 +/- 1.71 D. After one month postoperatively, the mean best spectacle-corrected visual acuity (0.45 +/- 0.20) was significantly improved (p < 5%) and mean subjective cylinder (2.85 +/- 1.29 D) was significantly decreased (p < 5%). Vector analysis showed a 5.59...
To assess the accuracy of pachymetric measurements using Orbscan (Bausch &amp;amp;amp;amp... more To assess the accuracy of pachymetric measurements using Orbscan (Bausch &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Lomb, Rochester, NY) after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). Prospective instrument validation study. Seventy-nine nonoperated normal eyes, 84 eyes after LASIK, and 50 eyes after PRK. Laser in situ keratomileusis or PRK. Central corneal thickness was measured using ultrasound and Orbscan II. The acoustic factor (AF) was adjusted, based on the results obtained in the normal eye group, to minimize the difference between ultrasound and Orbscan pachymetric values. Central corneal thickness as measured by Orbscan and ultrasound pachymeter. Using the adjusted AF, which was 0.946, the mean difference between Orbscan and ultrasonic pachymetric measurements was 0 +/- 17, 16 +/- 28, and 68 +/- 39 microm in the normal, LASIK, and PRK groups, respectively. The difference between all groups was statistically significant (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). Orbscan pachymetric values may be underestimated and less accurate after LASIK and PRK.
Ophthalmology, 2003
To report a case of a 50-year-old man who was initially seen with a corneal perforation in his ri... more To report a case of a 50-year-old man who was initially seen with a corneal perforation in his right eye 2 months after a photorefractive keratectomy (PRK) procedure and to discuss the roles of topical diclofenac and matrix metalloproteinases (MMPs). Case report with tissue analysis. Ocular examination, diagnostic workup, surgical treatment, and histologic, immunofluorescent, zymography, and real time-polymerase chain reaction studies on corneal button. Slit-lamp examination of the right eye revealed a 4-mm diameter area of central corneal thinning with a 2-mm diameter perforation at its center. Predisposing factors included prolonged postoperative topical diclofenac therapy for more than 2 months and a 10-year history of well-controlled diabetes mellitus. An extensive diagnostic workup ruled out a systemic autoimmune disease. A penetrating keratoplasty was performed. Results of immunohistochemical studies of the corneal button showed stromal accumulation of temporary type III and IV collagens, MMP-3, and MMP-9 in the anterior wounded stroma and MMP-9 in the basal corneal epithelial cells of the leading edge. Differential activity and expression of MMP-2 and MMP-9 were found between the central and peripheral corneal buttons. Prolonged use of diclofenac and diabetes mellitus might be responsible for the corneal perforation after PRK in our patient. MMP-9 and MMP-3 might be involved in delayed wound closure and corneal melting.
Ophthalmology, 2003
To assess the accuracy of pachymetric measurements using Orbscan (Bausch &amp;amp;amp;amp... more To assess the accuracy of pachymetric measurements using Orbscan (Bausch &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Lomb, Rochester, NY) after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). Prospective instrument validation study. Seventy-nine nonoperated normal eyes, 84 eyes after LASIK, and 50 eyes after PRK. Laser in situ keratomileusis or PRK. Central corneal thickness was measured using ultrasound and Orbscan II. The acoustic factor (AF) was adjusted, based on the results obtained in the normal eye group, to minimize the difference between ultrasound and Orbscan pachymetric values. Central corneal thickness as measured by Orbscan and ultrasound pachymeter. Using the adjusted AF, which was 0.946, the mean difference between Orbscan and ultrasonic pachymetric measurements was 0 +/- 17, 16 +/- 28, and 68 +/- 39 microm in the normal, LASIK, and PRK groups, respectively. The difference between all groups was statistically significant (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). Orbscan pachymetric values may be underestimated and less accurate after LASIK and PRK.
Journal of Cataract & Refractive Surgery, 2000
To evaluate the effectiveness of indices derived from the EyeSys System 2000 in detecting keratoc... more To evaluate the effectiveness of indices derived from the EyeSys System 2000 in detecting keratoconic corneas.
Journal of Cataract & Refractive Surgery, 2003
Journal of Cataract & Refractive Surgery, 1999
To report the results of arcuate keratotomy performed with the Hanna arcitome in patients with po... more To report the results of arcuate keratotomy performed with the Hanna arcitome in patients with postkeratoplasty astigmatism. Department of Ophthalmology, Saint-Antoine Hospital, Paris VI University, Paris, France. This retrospective study comprised 22 eyes (22 patients) with postkeratoplasty astigmatism. Paired symmetrical arcuate keratotomy was performed with the Hanna arcitome. Outcome measures included refraction, videokeratography, and keratometry. At 6.6 months +/- 8.9 (SD) after surgery, the mean increase in best spectacle-corrected visual acuity (BSCVA) was 2.1 +/- 2.4 lines. Thirteen eyes gained 2 lines or more of BSCVA, and 15 gained 3 lines or more of uncorrected visual acuity. Two patients had a decrease in BSCVA: 1 had lens opacification unrelated to arcuate keratotomy and 1, increased corneal irregularity. Mean refractive astigmatism was 6.94 +/- 2.11 diopters (D) preoperatively and 3.85 +/- 1.95 D postoperatively (P < .01). Mean change in keratometric astigmatism was -51 +/- 36%. Astigmatism decreased in 21 eyes as measured by manifest refraction, keratometry, and videokeratography; it increased in 1 cornea with a microperforation. The results of arcuate keratotomy performed with the Hanna arcitome were comparable to those with freehand relaxing incisions. The instrument made safer and more uniform arcuate incisions than a freehand technique.
Journal Français d'Ophtalmologie, 2008
Journal Français d'Ophtalmologie, 2008
ABSTRACT Après les applications réfractives, se développent actuellement les applications thérape... more ABSTRACT Après les applications réfractives, se développent actuellement les applications thérapeutiques du laser femtoseconde, dont les kératoplasties lamellaires et transfixiantes. L’utilisation de cet outil dans ces domaines semble logique, puisqu’il permet de réaliser des dissections dans toutes les directions de l’espace avec une précision de l’ordre de quelques microns. Il facilite les découpes lamellaires, et garantit une qualité anatomique satisfaisante sauf en cas de dissection profonde, les dissections prédescemétiques demeurant impossibles. L’amélioration des résultats fonctionnels reste à démontrer. Il permet également la réalisation de profils de découpes transfixiantes à bords non verticaux dans le but de diminuer la fréquence et/ou l’importance des complications habituelles (astigmatisme, récupération fonctionnelle lente, déhiscence de la cicatrice). Cette application est débutante, mais prometteuse. Cependant, seule l’expérience permettra de définir plus précisément la place du laser femtoseconde dans ce champ d’application
Journal Français d'Ophtalmologie, 2009
Implant diffractif et chirurgie de la cataracte : résultats à un an d'un nouveau type d'implant. ... more Implant diffractif et chirurgie de la cataracte : résultats à un an d'un nouveau type d'implant. A new sort of diffractive IOL in cataract surgery: one year results.
Journal francais d'ophtalmologie
Femtosecond laser technology in ophthalmology is not only used for refractive surgery (LASIK flap... more Femtosecond laser technology in ophthalmology is not only used for refractive surgery (LASIK flaps), but also now for lamellar and penetrating keratoplasties. This is not surprising when one knows that femtosecond lasers can cut corneal tissue in all directions with micrometric accuracy. Lamellar dissection of the cornea is very facilitated with femtosecond laser because it is quicker and more reproducible. However, predescemet dissection is not yet possible, and although the interfaces are smooth, the visual benefits of this technology has still to be proven. Another field of application of femtosecond lasers is their use to perform the cut for penetrating keratoplasties. Different shapes of non vertical cuts are currently assessed in order to reduce the incidence of complications such as induced astigmatism and wound dehiscence, and to improve the visual outcome.
Journal Français d Ophtalmologie
To study the correlation between subjective refraction and corneal topography. To compare the top... more To study the correlation between subjective refraction and corneal topography. To compare the topographic analysis of surgically induced astigmatism (cataract and penetrating keratoplasty) with that of idiopathic astigmatism. Subjective astigmatism, subjective spherical equivalent, best spectacle-corrected visual acuity (LogMAR units), and videokeratoscopy using the EyeSys 2000((R)) device (axial, tangential, and refractive power) were recorded in 100 eyes with idiopathic astigmatism, 100 eyes after cataract surgery, and 100 eyes after penetrating keratoplasty. Topographies were classified according to pattern (Bogan classification) and asphericity (shape factor: prolate or oblate). The asphericity shape distribution was significantly different between the 3 groups (p<0.001). The shape of idiopathic astigmatism was almost always prolate (90%) whereas the oblate shape was more frequent in the penetrating keratoplasty group (75%). There was no significant difference in topographic pattern distribution between the 3 groups (p=0.11). The asymmetric bow tie pattern was the most common topographic pattern. Topography pattern classification was significantly correlated with the subjective astigmatic cylinder. (r(s)=0.60, p<0.001). Unlike the round and oval patterns, the bow tie pattern was associated with the high subjective cylinder. Correlation between the subjective cylinder, the refractive power cylinder, and the axial power cylinder was strong (r(s)=0.92 p<0.001), but it was weak for the tangential power cylinder (r(s)=0.72 p<0.001). The correlation between the subjective spherical equivalent and central cornea power was poor (r(s)<0.37, p<0.001). Subjective astigmatic cylinder showed the strongest correlation with best spectacle-corrected visual acuity (r(s)=0.70, p<0.001), whereas the predicted corneal acuity, corneal uniformity index, asphericity, and refractive power symmetry index were poorly correlated with it (r(s)<0.54, p<0.001). Despite the difference in the asphericity shape, the topographic pattern was similar in the 3 groups. The pattern type was significantly correlated with the subjective astigmatic cylinder. Topographic indices failed to predict visual acuity, while the subjective cylinder showed a strong correlation with visual acuity.
Journal Français d Ophtalmologie
To compare the accuracy and reproducibility of the Eye Sys videokeratoscope algorithms for analyz... more To compare the accuracy and reproducibility of the Eye Sys videokeratoscope algorithms for analyzing idiopathic and surgery-induced astigmatism analysis. Refractive astigmatism, videokeratoscopy (axial, tangential and refractive power), autorefractometry, autokeratometry, and keratometry were recorded in 20 patients with idiopathic astigmatism, 40 patients who had undergone cataract surgery and 40 patients who had undergone penetrating keratoplasty. For each eye, 2 successive videokeratoscopy were recorded. Both cylinder and axis provided by the tangential algorithm are significantly less reproducible than the cylinder and axis provided by the axial and refractive algorithms (P < 0.001). Cylinders provided by the axial and refractive algorithms showed a stronger correlation with subjective cylinder (rs > 0.89; p < 0.001) than the cylinder provided by the tangential algorithm (rs = 0.66; p < 0.001). Both keratometric axis and autokeratometric axis showed the strongest correlation with subjective axis (rs > 0.92; p < 0.001). The accuracy and reproducibility were higher for the topographic "bow tie" patterns than for the other topographic patterns. The axial and refractive algorithms of the Eye Sys videokeratoscope are more accurate and reproducible than the tangential algorithm for analyzing idiopathic or surgery-induced astigmatism.
Journal Français d Ophtalmologie
Ophthalmology, 2003
To report a case of a 50-year-old man who was initially seen with a corneal perforation in his ri... more To report a case of a 50-year-old man who was initially seen with a corneal perforation in his right eye 2 months after a photorefractive keratectomy (PRK) procedure and to discuss the roles of topical diclofenac and matrix metalloproteinases (MMPs). Case report with tissue analysis. Ocular examination, diagnostic workup, surgical treatment, and histologic, immunofluorescent, zymography, and real time-polymerase chain reaction studies on corneal button. Slit-lamp examination of the right eye revealed a 4-mm diameter area of central corneal thinning with a 2-mm diameter perforation at its center. Predisposing factors included prolonged postoperative topical diclofenac therapy for more than 2 months and a 10-year history of well-controlled diabetes mellitus. An extensive diagnostic workup ruled out a systemic autoimmune disease. A penetrating keratoplasty was performed. Results of immunohistochemical studies of the corneal button showed stromal accumulation of temporary type III and IV collagens, MMP-3, and MMP-9 in the anterior wounded stroma and MMP-9 in the basal corneal epithelial cells of the leading edge. Differential activity and expression of MMP-2 and MMP-9 were found between the central and peripheral corneal buttons. Prolonged use of diclofenac and diabetes mellitus might be responsible for the corneal perforation after PRK in our patient. MMP-9 and MMP-3 might be involved in delayed wound closure and corneal melting.
Journal Français d Ophtalmologie
To compare the accuracy and reproducibility of the orbscan pachymetry and ultrasonic pachymetry i... more To compare the accuracy and reproducibility of the orbscan pachymetry and ultrasonic pachymetry in the normal eye and in the penetrating keratoplasty eye. Pachymetric measurements were assessed in 50 eyes of 25 normal patients and 50 eyes of 48 patients who had undergone penetrating keratoplasty using both Orbscan II and ultrasonic pachymetry (Tomey SP-2000). For each eye, 2 successive measures were recorded with both instruments. For both devices, the default setting was used. Orbscan pachymetry maps were divided into 5 groups using a modification of Liu's classification. Orbscan pachymetry strongly correlated with ultrasonic pachymetry (rs = 0.91; p < 0.001). Ultrasonic pachymetry values and Orbscan pachymetry values showed no significant differences in the normal group (respectively, 557 microns +/- 36 and 555 microns +/- 34; p > 0.05). Ultrasonic pachymetry values and orbscan pachymetry values were significantly different in the penetrating keratoplasty group (respectively, 571 microns +/- 52 and 550 microns +/- 54; p < 0.001). The best value for the acoustic factor for Orbscan pachymetry in the penetrating keratoplasty group was 0.89. Ultrasonic pachymetry reproducibility and Orbscan pachymetry reproducibility were not significantly different (0.86% +/- 0.61 v. 0.67% +/- 0.63; p = 0.13 in the normal group; 1.22% +/- 0.81 v. 1.23% +/- 1.13; p = 0.92, in the penetrating keratoplasty group). Both pachymetry methods showed less reproducibility in the penetrating keratoplasty group than in the normal group (p < 0.02). Thinnest point localization was significantly different in both groups (p < 0.001). In 66% of the normal group, the thinnest point of the cornea was located in inferotemporal quadrant. This point was located at an average of 0.63 +/- 0.25 mm from the visual axis in the normal group and 1.60 +/- 0.81 mm in the penetrating keratoplasty group (p < 0.001). Whereas "Centered round" (40%) and "centered oval" (34%) were the most common patterns in the normal group, "decentered oval" (40%) and "irregular" (30%) were more frequent in the penetrating keratoplasty group (p < 0.001). Orbscan pachymetry strongly correlated with ultrasonic pachymetry. Reproducibility of both methods is excellent and not significantly different. Thinnest point localization and pachymetric map classification are significantly different in normal eyes and in penetrating keratoplasty eyes.
Journal Français d Ophtalmologie
High postkeratoplasty astigmatism is a common postoperative complication which can limit the fina... more High postkeratoplasty astigmatism is a common postoperative complication which can limit the final functional result. Arcuate incisions are a possible surgical treatment. They can be performed with the arcuate keratome which provides regular incisions. The aim of this study was to evaluate the results obtained with this device in the correction of high postkeratoplasty astigmatism. We retrospectively studied ten eyes operated for high postkeratoplasty astigmatism with the Hanna arcuate keratome. Arcuate keratomy procedures were performed on the graft button in all. Before surgery, mean uncorrected visual acuity was 0.07 +/- 0.05. Best spectacle-corrected visual acuity was 0.33 +/- 0.20 and mean subjective cylinder was 6.1 +/- 1.71 D. After one month postoperatively, the mean best spectacle-corrected visual acuity (0.45 +/- 0.20) was significantly improved (p < 5%) and mean subjective cylinder (2.85 +/- 1.29 D) was significantly decreased (p < 5%). Vector analysis showed a 5.59...
To assess the accuracy of pachymetric measurements using Orbscan (Bausch &amp;amp;amp;amp... more To assess the accuracy of pachymetric measurements using Orbscan (Bausch &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Lomb, Rochester, NY) after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). Prospective instrument validation study. Seventy-nine nonoperated normal eyes, 84 eyes after LASIK, and 50 eyes after PRK. Laser in situ keratomileusis or PRK. Central corneal thickness was measured using ultrasound and Orbscan II. The acoustic factor (AF) was adjusted, based on the results obtained in the normal eye group, to minimize the difference between ultrasound and Orbscan pachymetric values. Central corneal thickness as measured by Orbscan and ultrasound pachymeter. Using the adjusted AF, which was 0.946, the mean difference between Orbscan and ultrasonic pachymetric measurements was 0 +/- 17, 16 +/- 28, and 68 +/- 39 microm in the normal, LASIK, and PRK groups, respectively. The difference between all groups was statistically significant (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). Orbscan pachymetric values may be underestimated and less accurate after LASIK and PRK.
Ophthalmology, 2003
To report a case of a 50-year-old man who was initially seen with a corneal perforation in his ri... more To report a case of a 50-year-old man who was initially seen with a corneal perforation in his right eye 2 months after a photorefractive keratectomy (PRK) procedure and to discuss the roles of topical diclofenac and matrix metalloproteinases (MMPs). Case report with tissue analysis. Ocular examination, diagnostic workup, surgical treatment, and histologic, immunofluorescent, zymography, and real time-polymerase chain reaction studies on corneal button. Slit-lamp examination of the right eye revealed a 4-mm diameter area of central corneal thinning with a 2-mm diameter perforation at its center. Predisposing factors included prolonged postoperative topical diclofenac therapy for more than 2 months and a 10-year history of well-controlled diabetes mellitus. An extensive diagnostic workup ruled out a systemic autoimmune disease. A penetrating keratoplasty was performed. Results of immunohistochemical studies of the corneal button showed stromal accumulation of temporary type III and IV collagens, MMP-3, and MMP-9 in the anterior wounded stroma and MMP-9 in the basal corneal epithelial cells of the leading edge. Differential activity and expression of MMP-2 and MMP-9 were found between the central and peripheral corneal buttons. Prolonged use of diclofenac and diabetes mellitus might be responsible for the corneal perforation after PRK in our patient. MMP-9 and MMP-3 might be involved in delayed wound closure and corneal melting.
Ophthalmology, 2003
To assess the accuracy of pachymetric measurements using Orbscan (Bausch &amp;amp;amp;amp... more To assess the accuracy of pachymetric measurements using Orbscan (Bausch &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Lomb, Rochester, NY) after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). Prospective instrument validation study. Seventy-nine nonoperated normal eyes, 84 eyes after LASIK, and 50 eyes after PRK. Laser in situ keratomileusis or PRK. Central corneal thickness was measured using ultrasound and Orbscan II. The acoustic factor (AF) was adjusted, based on the results obtained in the normal eye group, to minimize the difference between ultrasound and Orbscan pachymetric values. Central corneal thickness as measured by Orbscan and ultrasound pachymeter. Using the adjusted AF, which was 0.946, the mean difference between Orbscan and ultrasonic pachymetric measurements was 0 +/- 17, 16 +/- 28, and 68 +/- 39 microm in the normal, LASIK, and PRK groups, respectively. The difference between all groups was statistically significant (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). Orbscan pachymetric values may be underestimated and less accurate after LASIK and PRK.
Journal of Cataract & Refractive Surgery, 2000
To evaluate the effectiveness of indices derived from the EyeSys System 2000 in detecting keratoc... more To evaluate the effectiveness of indices derived from the EyeSys System 2000 in detecting keratoconic corneas.
Journal of Cataract & Refractive Surgery, 2003
Journal of Cataract & Refractive Surgery, 1999
To report the results of arcuate keratotomy performed with the Hanna arcitome in patients with po... more To report the results of arcuate keratotomy performed with the Hanna arcitome in patients with postkeratoplasty astigmatism. Department of Ophthalmology, Saint-Antoine Hospital, Paris VI University, Paris, France. This retrospective study comprised 22 eyes (22 patients) with postkeratoplasty astigmatism. Paired symmetrical arcuate keratotomy was performed with the Hanna arcitome. Outcome measures included refraction, videokeratography, and keratometry. At 6.6 months +/- 8.9 (SD) after surgery, the mean increase in best spectacle-corrected visual acuity (BSCVA) was 2.1 +/- 2.4 lines. Thirteen eyes gained 2 lines or more of BSCVA, and 15 gained 3 lines or more of uncorrected visual acuity. Two patients had a decrease in BSCVA: 1 had lens opacification unrelated to arcuate keratotomy and 1, increased corneal irregularity. Mean refractive astigmatism was 6.94 +/- 2.11 diopters (D) preoperatively and 3.85 +/- 1.95 D postoperatively (P < .01). Mean change in keratometric astigmatism was -51 +/- 36%. Astigmatism decreased in 21 eyes as measured by manifest refraction, keratometry, and videokeratography; it increased in 1 cornea with a microperforation. The results of arcuate keratotomy performed with the Hanna arcitome were comparable to those with freehand relaxing incisions. The instrument made safer and more uniform arcuate incisions than a freehand technique.
Journal Français d'Ophtalmologie, 2008
Journal Français d'Ophtalmologie, 2008
ABSTRACT Après les applications réfractives, se développent actuellement les applications thérape... more ABSTRACT Après les applications réfractives, se développent actuellement les applications thérapeutiques du laser femtoseconde, dont les kératoplasties lamellaires et transfixiantes. L’utilisation de cet outil dans ces domaines semble logique, puisqu’il permet de réaliser des dissections dans toutes les directions de l’espace avec une précision de l’ordre de quelques microns. Il facilite les découpes lamellaires, et garantit une qualité anatomique satisfaisante sauf en cas de dissection profonde, les dissections prédescemétiques demeurant impossibles. L’amélioration des résultats fonctionnels reste à démontrer. Il permet également la réalisation de profils de découpes transfixiantes à bords non verticaux dans le but de diminuer la fréquence et/ou l’importance des complications habituelles (astigmatisme, récupération fonctionnelle lente, déhiscence de la cicatrice). Cette application est débutante, mais prometteuse. Cependant, seule l’expérience permettra de définir plus précisément la place du laser femtoseconde dans ce champ d’application