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AIM:To compare the differences of ocular biometric parameters of age-related cataract between Tibetan and Han ethnic groups, and to analyze the distribution characteristics of ocular biometric parameters in Tibetan cataract patients.METHODS:Retrospective cohort study. A total of 661 patients(1 030 eyes)with age-related cataract confirmed in the hospital between January 2019 and December 2020 were enrolled. The parameters of axial length, anterior chamber depth, keratometry, corneal astigmatism and astigmatic axis were measured by IOL Master 500 in 483 cases(739 eyes)of Tibetan age-related cataract patients and 178 cases(291 eyes)of Han patients.RESULTS:The axial length, anterior chamber depth and corneal astigmatism of the Tibetan patients with age-related cataract were 23.33(22.81, 23.86)mm, 3.04(2.79, 3.30)mm and 0.73(0.47, 1.07)D. The mean keratometry was 43.89±1.35 D. The results indicated that Tibetan cataract patients had shorter axial lengths and smaller keratometry compared to Han patients(all P<0.05). Age in Tibetan patients was negatively correlated with axial length and anterior chamber depth, and positively correlated with keratometry(all P<0.05). Tibetan male patients had longer axial lengths, deeper anterior chambers, and flatter corneas compared to female patients(all P<0.05).CONCLUSION:There were differences in ocular biometric parameters between age-related cataract patients of Tibetan and Han ethnicities. The distribution of ocular biometric parameters in Tibetan cataract patients varied across different age groups and gender groups.
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AIM: To compare the anterior and posterior corneal astigmatism and total refractive astigmatism before and after MyoRing implantation in keratoconus(KCN)patients.METHODS: In this historical cohort study, the preoperative and postoperative total refractive, anterior and posterior corneal astigmatism of KCN patients implanted with a 360-degree full-ring implant(MyoRing)were compared before and after four consecutive follow-up sessions at 3, 6, 9, and 12 mo after surgery.RESULTS: The study encompassed 79 KCN patients(85 eyes), comprising 43 males and 36 females. The mean age of the patients was 29±7.41 years, ranging from 17 to 48 years. Throughout the follow-up sessions, a gradual decrease was observed in the trend of changes for total refractive astigmatism, anterior corneal astigmatism, and posterior corneal astigmatism. Postoperatively, total refractive astigmatism measurements exhibited a significant decrease of 2.09 D at 12 mo after MyoRing implantation(4.27±3.15 vs 2.18±1.63 D, P<0.001). Additionally, post-operative measurements revealed an enhancement of approximately 3.20 D and 0.59 D for anterior and posterior corneal astigmatism, respectively [6.40±1.90 vs 3.20±1.75 D for anterior corneal astigmatism(P<0.001)and 1.30±0.55 vs 0.71±0.35 D for posterior corneal astigmatism(P<0.001)].CONCLUSION: MyoRing implantation demonstrates significant improvements in astigmatism parameters, encompassing total refractive astigmatism as well as anterior and posterior corneal astigmatism.
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AIM: To evaluate the convenience and accuracy of a novel smartphone-assisted “any-point two-step method” for finding the target axial position in cataract phacoemulsification combined with intraocular lens(IOL)implantation.METHODS: Prospective observational study. A total of 62 cases(62 eyes)of patients with age-related cataracts who underwent cataract phacoemulsification combined with IOL implantation in our hospital from October 2021 to April 2022 were selected. They were randomly divided into two groups: 31 cases(31 eyes)in the control group were applied with the “traditional two-step method” using slit lamp to mark the target axial position of the IOL, and 31 cases(31 eyes)in the experimental group were applied with the smartphone-assisted “two-step method” to mark the target axial position of the IOL. The Callisto eye navigation system was used as a standard reference, and the deviation of the reference marking point(deviation-1), the deviation of the target axial marking point(deviation-total), and the deviation of the angle from the reference marking point to the target axial marking point(deviation-2)were calculated and recorded as the preoperative axial marking time.RESULTS:Both deviation-1 and deviation-total values were lower in the experimental group than those in the control group(1.06°±1.39° vs 2.48°±2.23°, 1.77°±1.54° vs 2.81°±1.58°, all P<0.01), but there was no significant difference in the deviation-2 values between the two groups(1.35°±1.40° vs 1.48°±1.79°, P>0.05). The preoperative axial marking took shorter time in the experimental group than in the control group(1.77±1.70 min vs 2.88±3.20 min, P<0.01).CONCLUSION: The smartphone-assisted “any-point two-step method” for finding the target axial position in cataract phacoemulsification combined with IOL implantation is simple, time-saving, and accurate compared with the “traditional two-step method”.
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Purpose: To evaluate whether the toric intra?ocular lens (IOL) power calculation based on total corneal astigmatism (TCA) in eyes with high posterior corneal astigmatism (PCA) could result in a systematic over?correction or under?correction after operation. Methods: The present study included a mono?centric retrospective study design. The data were collected from 62 consecutive eyes during uncomplicated cataract surgery by a single surgeon with a measured PCA of 0.50 diopters (D) or higher. Toric IOL calculations were made using TCA measurements. The eyes were grouped as either “with?the?rule” (WTR) or “against?the?rule” (ATR) on the basis of the steep anterior corneal meridian. The post?operative refractive astigmatic prediction error was analyzed 1 month post?operatively using the vector analysis by the Alpins method and double?angle plots method. Results: The correction indexes were 1.14 ± 0.29 in the ATR eyes and 1.25 ± 0.18 for the WTR eyes, indicating a tendency toward over?correction. The mean over?correction was 0.22 ± 0.52D in the ATR group and 0.65 ± 0.60D in the WTR group. The magnitude of error (ME) values were significantly different from the ideal value of zero in both groups (ATR: P = 0.03; WTR: P = 0.00). No significant difference in mean absolute error (MAE) in predicted residual astigmatism was found between ATR and WTR groups (0.61 ± 0.42 D versus 0.64 ± 0.39 D; P = 0.54). The ATR group yielded better results, with 48% <0.50D prediction error in the main analysis. Conclusions: The results suggested that in cases of high PCA, the toric IOL calculation, which was performed using TCA, may cause a potential over?correction in the ATR and WTR eyes. For ATR eyes, over?correction led to slight disruption of post?operative visual quality because of the “with?the?rule” residual astigmatism after operation. Therefore, we suggested using TCA for toric IOL calculation in ATR eyes.
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Purpose: To evaluate the clinical outcomes of preloaded toric intraocular lens (IOLs) implantation in eyes undergoing phacoemulsification. Methods: This prospective study included 51 eyes of 51 patients with visually significant cataracts and corneal astigmatism ranging between 0.75 and 5.50 D. All patients underwent phacoemulsification with SupraPhob toric intraocular lens implantation under topical anesthesia. The main outcome measures were uncorrected distance visual acuity (UDVA), residual refractive cylinder, spherical equivalent, and IOL stability at 3 months follow?up. Results: At 3 months, 49% (25/51) of patients had UDVA equal to or better than 20/25 with 100% of eyes achieving better than 20/40. Mean logMAR UDVA improved from 1.02 ± 0.39, preoperatively to 0.11 ± 0.10 at 3 months follow?up (P < 0.001, Wilcoxon signed?rank test). The mean refractive cylinder improved from ? 1.56 ± 1.25 D preoperatively to ? 0.12 ± 0.31 D at 3 months follow?up (P < 0.001) while the mean spherical equivalent value changed from ? 1.93 ± 3.71D preoperatively to ? 0.16 ± 0.27D (P = 0.0013). The mean root mean square value for higher order aberrations was 0.30 ± 0.18 ?m while the average contrast sensitivity value (Pelli?Robson chart) was 1.56 ± 0.10 log unit, at the final follow?up. The mean IOL rotation at 3 weeks was 1.7 ± 1.61 degrees, which did not change significantly at 3 months (P = 0.988) follow?up. There were no intraoperative or postoperative complications. Conclusion: SupraPhob toric IOL implantation is an effective method for addressing preexisting corneal astigmatism in eyes undergoing phacoemulsification with good rotational stability
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AIM: To investigate the effects of small incision extracapsular excision and phacoemulsification on the number of corneal endothelial cells, macular thickness and surgically induced corneal astigmatism in cataract patients.METHODS: Retrospective research. A total of 296 age-related cataract patients(296 eyes)admitted to our hospital from May 2019 to February 2023 were selected. They were divided into a small incision extracapsular excision group(144 eyes)and a phacoemulsification group(152 eyes)according to surgical method. The uncorrected visual acuity, best corrected visual acuity, numbers of corneal endothelial cells, macular thickness, surgically induced corneal astigmatism and postoperative complications between the two groups of patients at 7d, 1 and 3mo after surgery were compared.RESULTS: The uncorrected visual acuity and best corrected visual acuity of patients in the small incision extracapsular excision group after 7d of surgery were better than those of the phacoemulsification group, the number of corneal endothelial cells after 7d and 1, 3mo of surgery were higher than that of the phacoemulsification group, the macular thickness after 7d and 1mo of surgery was lower than that of the phacoemulsification group, and the incidence rate of postoperative corneal edema and incidence rate of total complications were lower than those of the phacoemulsification group(all P<0.05). Furthermore, there was no statistical significance in the values of surgically induced corneal astigmatism after 1, 7d and 1, 3mo of surgery compared with phacoemulsification group(P>0.05).CONCLUSION: Compared with phacoemulsification, the changes in the number of corneal endothelial cells and thickness of the macular area after small incision extracapsular excision are relatively small, visual recovery is faster, and the complications reduced.
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AIM: To investigate the effect of phacoemulsification with steep meridian transparent corneal incision on visual function, corneal astigmatism and tear film changes.METHODS: A total of 106 cataract patients(106 eyes)who underwent phacoemulsification in our hospital from January 2019 to December 2020 were selected as research objects, and they were divided into observation group and control group according to the operation mode: with 51 patients in the observation group who were treated with steep meridian transparent corneal incision, and 55 patients in the control group who were treated with transnasal transparent corneal incision. The changes of visual function, corneal astigmatism and tear film between the two groups were compared before operation and at 1wk, 1 and 3mo after operation.RESULTS: There was no statistical difference between the operation of two groups(all P&#x003E;0.05). The visual acuity was significantly improved at 1wk, 1 and 3mo after operation, and it was better in the observation group than that in the control group. Mean defect(MD)of visual field was significantly lower, and it was significantly lower in the control group(all P&#x003C;0.05); The corneal astigmatism AKP(+0)of the two groups was significantly lower at 3mo after operation, and the observation group was significantly lower than the control group(P&#x003C;0.05). There was no statistical difference in corneal astigmatism AKP(+45)(P&#x003E;0.05); Schirmer Ⅰ test(SⅠt)value increased first and then decreased, and the valley value was at 1wk after operation; Tear film break-up time(BUT)decreased first and then increased, and the valley value was at 1wk after operation. SⅠt in the observation group was lower than that in the control group at each time point(all P&#x003C;0.05), while BUT in the observation group was higher than that in the control group at each time point(all P&#x003C;0.05).CONCLUSION: Steep meridian transparent corneal incision phacoemulsification surgery is beneficial to improve the postoperative visual function of patients, reduce postoperative corneal astigmatism, reduce the damage to the patient's tear film function, and promote its recovery.
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AIM: To investigate the differences in visual recovery, corneal astigmatism, and rotation stability of Toric intraocular lens(TIOL)implantation in cataract patients with different axial lengths.METHODS: Retrospective analysis. A total of 132 patients(132 eyes)with age-related cataract and corneal astigmatism who underwent phacoemulsification cataract extraction combined with TIOL implantation in our hospital's ophthalmology department from February 2021 to September 2022 were selected. They were divided into two groups based on the axial length: the group with axial length ≤24mm(79 cases, 79 eyes)and the group with axial length >24mm(53 cases, 53 eyes). Compare the best corrected distance visual acuity(BCDVA), corneal astigmatism, and TIOL rotation between the two groups of patients at 3mo after surgery.RESULT: After 3mo of surgery, both groups of patients had improved BCDVA and significantly decreased corneal astigmatism compared to those before surgery(P<0.001). However, there was no difference in BCDVA and corneal astigmatism between the two groups(P>0.05), and there was no significant difference in TIOL rotation between the two groups [(5.24±3.72)° vs.(6.36±4.21)°, P=0.110].CONCLUSION: There is no significant difference in visual recovery, corneal astigmatism, and TIOL rotational stability after TIOL implantation in cataract patients with different axial lengths.
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AIM:To compare the curative effect of different surgical methods combined with Toric intraocular lens(IOL)implantation on age-related hard nuclear cataract.METHODS:According to retrospective study, 104 patients(104 eyes)with age-related hard nuclear cataract confirmed in the hospital between January 2020 and December 2021 were enrolled. They were divided into phacoemulsification group(52 eyes, phacoemulsification combined with Toric IOL implantation)and small-incision group(52 eyes, small-incision split nuclear technique in horizontal space combined with Toric IOL implantation)according to different surgical methods. The best corrected distance visual acuity(BCDVA), corneal astigmatism, number of corneal endothelial cells, proportion of normal hexagonal cells, tear film function and complications were compared between the two groups.RESULTS:There was no significant difference in BCDVA(LogMAR)between the two groups before and at 3mo after surgery(all P>0.05), while BCDVA(LogMAR)was better in small-incision group than phacoemulsification group at 1wk after surgery(0.15±0.04 vs. 0.20±0.05, P<0.001). The corneal astigmatism of the patients in both groups was lower at 1wk and 3mo after surgery than that before surgery, and it was lower at 3mo than 1wk after surgery(all P<0.05), while there was no significant difference in corneal astigmatism between the two groups before and after surgery(all P>0.05). At 1wk and 3mo after surgery, number of corneal endothelial cells in small-incision group was more than that in phacoemulsification group(1wk after surgery: 2363.8±315.3 vs. 2231.4±326.4 cells/mm2, P<0.05; 3mo after surgery: 2414.6±245.7 vs. 2322.9±221.0 cells/mm2, P<0.05). Before and at 1wk after surgery, there was no significant difference in the proportion of normal hexagonal cells between the two groups(all P>0.05). At 3mo after surgery, proportion of normal hexagonal cells in small-incision group was higher than that in phacoemulsification group(21.77%±1.91% vs. 20.59%±1.65%, P<0.001). Before and at 3mo after surgery, there was no difference in break up time(BUT)or ocular surface disease index(OSDI)score between the two groups(P>0.05). At 1wk after surgery, BUT in small-incision group was longer than that in phacoemulsification group(6.8±0.8 vs. 5.9±1.0s, P<0.001)and OSDI score was lower than that in phacoemulsification group(17.62±5.47 vs. 20.34±6.18 points, P<0.05). The incidence of postoperative complications in small-incision group was lower than that in phacoemulsification group(3.9% vs. 17.3%, P<0.05).CONCLUSION: Small-incision split nuclear technique in horizontal space combined with Toric IOL implantation can significantly improve visual acuity and astigmatism in patients with age-related cataract, with slight damage to corneal endothelium and tear film function.
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Purpose: Functional recovery after cataract surgery depends on the anatomical recovery of the eye. This study compared the improvement in visual function parameters after uniocular manual small-incision cataract surgery (MSICS) and phacoemulsification cataract surgery. Methods: This study included 310 patients divided randomly into two groups: 155 who received MSICS (MSICS group) and 155 who underwent phacoemulsification (phaco group) for cataract treatment. Outcome measures assessed included vertical and horizontal keratometry reading. The mean corneal astigmatism tear function measured using Schirmer 1 test results were recorded preoperatively, and on postoperative day 1, day 7, and day 30. Optical coherence tomography (OCT) was done to record the average central macular thickness (?m) on day 7 and day 30. Results: The mean corneal astigmatism and anterior chamber inflammation were more in the MSICS group than in the phaco group immediately postoperatively. However, no statistically significant difference was found between the groups with respect to corneal sensation, mean corneal astigmatism, tear film function, and visual outcomes on postoperative day 30. Uncorrected visual acuity was better in the phacoemulsification group than in the manual SICS group on postoperative day 1, day 7, and day 30 (P < 0.001). Conclusion: Both phacoemulsification cataract surgery and manual small-incision sutureless cataract surgery (MSICS) are safe and effective for visual rehabilitation. Phacoemulsification is the preferred technique where resources are available with the advantages of less mean corneal astigmatism, less anterior chamber inflammation, and better uncorrected visual acuity (UCVA) in the immediate postoperative period
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Correcting astigmatism safely and effectively has become a crucial part of modern cataract surgery due to the transformation of the surgery into a refractive procedure. The increased predictability and enhanced safety of Toric intraocular lens(IOL)implantation has made it the preferred method of correcting corneal regular astigmatism above 0.75D in cataract surgery. Toric IOL needs to be implanted in a precise axis position to achieve good astigmatism correction. A major cause of toric misalignment is postoperative rotation, which typically occurs soon after surgery. However, large axis misalignment will eliminate the astigmatism corrective effect of Toric IOL, even cause astigmatism in a new axis position. The factors responsible for IOL postoperative rotation are diverse. As a result, profound understanding of the factors is crucial for clinicians to minimize the rotation. Repositioning procedure is generally selected in case of significant rotation and the timing of the procedure is vital. This paper reviewed the influencing factors of IOL rotation postoperatively and its principle of treatment.
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With the rapidly improvement of people's living standard and diversification life style, obtaining better visual quality has become a new goal of cataract surgery. Corneal astigmatism directly affects the selection of functional intraocular lens(IOL)in cataract surgery and the recovery of postoperative visual function. The types of corneal astigmatism are no longer limited to a single astigmatism value, but subdivided into anterior corneal astigmatism, posterior corneal astigmatism, total corneal astigmatism and corneal higher order astigmatism. The corresponding examination equipment and technology are also updated. According to the characteristics and application of different equipment, clinicians can select appropriate examination equipments to evaluate the preoperative corneal astigmatism, so as to provide reference for formulating more accurate refractive cataract surgery planning. It is important for the axis and power calculation of Toric IOL and the selection of multifocal IOL. This paper reviews the recent progress of corneal astigmatism examination before cataract surgery.
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@#AIM: To investigate the difference and consistency among iTrace, IOL Master 700 and Pentacam HR in measuring corneal astigmatism before cataract surgery.<p>METHODS: Across-sectional study. From May 2020 to May 2021, a total of 149 cataract patients(181 eyes)were collected in our hospital. Presurgery, steep keratometry(Ks), flat keratometry(Kf), mean keratometry(Km), astigmatism magnitude(Cyl), and steep astigmatic axis values measured by the three instruments of the iTrace, IOL Master 700 and the Pentacam HR. The difference and consistency of the measurement indexes of the three instruments were analyzed.<p>RESULTS: Statistical differences existed in Ks, Kf, Km among the three instruments(<i>F</i>=4.912, 3.514, 4.873, all <i>P</i><0.05)and there was no difference in Cyl and Axis(<i>F</i>=0.523, 0.128, all <i>P</i>>0.05). Bland-Altman analysis showed the outcomes revealed that the Ks and Kf measured by iTrace and the other two instruments have poor consistency, and the consistency of Cyl and Axis was good. But the difference of Axis is not clinically acceptable. There were no statistically differences between the iTrace and the other two devices among the low astigmatism(50 eyes), moderate astigmatism(34 eyes)and high astigmatism(18 eyes)groups(all <i>P</i>>0.05). <p>CONCLUSION: In the preoperative measurement of cataract patients except for the good consistency of astigmatism, the iTrace, IOL Master 700 and Pentacam HR showed different Ks and Kf, and the Axis difference exceeded the clinically acceptable range, especially in the highly astigmatism group. The measurement of corneal astigmatism before cataract surgery should be evaluated by multiple measurement methods and make comprehensive planning for the surgical plan.
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@#AIM:To analyze the effects of corneal surface morphology and tear-film with different incisions guided by corneal topography after phacoemulsification.<p>METHODS: Retrospective study. Totally 56 patients(60 eyes)were selected and divided into clear corneal incision group and angle scleral margin incision group who were treated by phacoemulsification in our hospital from June 2019 to December 2020. Best corrected visual acuity(BCVA), ocular surface disease index(OSDI)questionnaire, tear film break-up time(TBUT), corneal surface regularity index(SRI), corneal surface asymmetry index(SAI)and corneal surface astigmatism(CYL)were measured preoperatively and postoperatively, the results were statistically analyzed.<p>RESULTS: BCVA in both groups increased after operation(<i>P</i><0.01). The OSDI score of the two groups increased significantly after surgery(<i>P</i><0.01). TBUT was shortened to varying degrees after surgery(<i>P</i><0.05). SAI and SRI increased to varying degrees in both groups after surgery, and SAI value of angle scleral margin incision group in 1wk and 1mo postoperatively was significantly lower than that in clear corneal incision group(<i>P</i><0.05). The corneal astigmatism at 1wk postoperatively was significant increased in both groups(<i>P</i><0.05). The astigmatism increase of clear corneal incision group at 3mo postoperatively was still higher than that before surgery.<p>CONCLUSION: Angle scleral margin incision has less effect on stability of tear film and corneal surface morphology, which is reliable on phacoemulsification.
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@#AIM: To analyze the influence of limbal conjunctival autograft and amniotic membrane transplantation on vision, corneal astigmatism(CAD)and tear film function in patients undergo pterygium surgery.<p>METHODS: Totally 96 patients(96 eyes)who had undergone pterygium surgery in the Department of Ophthalmology at Pengzhou People's Hospital were enrolled in this retrospective study between August 2018 and March 2020. According to random number table method, the patients were divided into observation group(48 patients with 48 eyes treated with pterygium excision combined with limbal conjunctival autograft)and control group(48 patients with 48 eyes treated with pterygium excision combined with amniotic membrane transplantation). General surgical indicators, uncorrected visual acuity(UCVA), tear film function \〖break-up time(BUT), SⅠt\〗, CAD, ocular surface disease index(OSDI), recurrence rate and incidence of complications were compared between the two groups.<p>RESULTS: The surgical time of observation group was longer than that of the control group, and the corneal epithelial healing time was shorter than that of the control group(<i>P</i><0.001). There was no significant difference in hospital stay or conjunctival hyperemia and edema remission time between the two groups(<i>P</i> >0.05). The UCVA of the two groups increased at 1, 3 and 6mo after surgery(<i>P</i><0.05), without statistically significant difference between groups(<i>P</i> >0.05). Compared with pre-operation, the BUT and SⅠt of both groups also increased, while CAD and OSDI scores decreased at 1, 3 and 6mo after surgery(<i>P</i><0.05). Besides, the BUT and SⅠt of observation group at 1mo after surgery were shorter/lower than control group, which were longer/higher than control group at 3 and 6mo after surgery(<i>P</i><0.05). However, there was no significant difference in CAD between the two groups(<i>P</i> >0.05). OSDI scores of the observation group were lower than those of the control group at 1, 3 and 6mo after surgery(<i>P</i><0.05). The recurrence rate of observation group within 6mo after surgery was lower than that of control group(<i>P</i><0.05), but the difference in incidence of complications was not significant(<i>P</i>>0.05).<p>CONCLUSION: Compared with amniotic membrane transplantation, limbal conjunctival autograft combined with pterygium excision applied in treatment of patients with pterygium can significantly shorten the corneal epithelial healing time, and reduce the influence on tear film function and recurrence rate, without affecting vision and corneal astigmatism. It is also safe and reliable.
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@#AIM: To compare the differences of corneal curvature and astigmatism measured by Pentacam, IOL Master and iTrace of cataract patients.<p>METHODS:In this prospective clinical trial,68 cataract patients(82 eyes)received treatment at the ophthalmology department of our hospital. In the treatment process, used the IOL Master, Pentacam and iTrace to measure the patient's corneal curvature(K1, K2, Km)and astigmatism(J0, J45). The difference, correlation and consistence among three instruments were analysed. <p>RESULTS: Differences analysis showed that in the measurement of K1, K2, Km, there was no difference among Pentacam, IOL Master and iTrace(<i>P</i>>0.05). Pearson correlation analysis showed that K1, K2, Km were highly correlated among three instruments(|<i>r</i>|>0.5, <i>P</i><0.01). J0, J45 were moderately correlated between IOL Master and Pentacam, so as IOL Master and iTrace(0.3<|<i>r</i>|<0.5, <i>P</i><0.01). J0, J45 were weakly correlated between Pentacam and iTrace(0.1<|<i>r</i>|<0.3, <i>P</i><0.05). The Bland-Altman showed that the corneal curvature and astigmatism vectors examined by these three devices had non-comparable results.<p>CONCLUSION: K1, K2, Km, J0, J45 were correlated among the three devices, but the three devices all cannot directly interchanged, targeted selection is required for the measuring the corneal curvature and astigmatism by these three different instruments in the actual clinical process.
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@#AIM: To investigate dynamic changes of posterior corneal power and astigmatism after cataract surgery based on Pentacam three-dimensional anterior eye segment analyzer.<p>METHODS: Totally 96 elderly patients(116 eyes)with cataract underwent phacoemulsification combined with intraocular lens implantation in our hospital from January 2019 to January 2020 were selected. Parameters including anterior corneal power, posterior corneal power, flat keratometry, steep keratometry, mean keratometry, anterior corneal astigmatism, posterior corneal astigmatism, and total corneal astigmatism were obtained using Pentacam three-dimensional anterior eye segment analyzer system at postoperative 1wk, 1mo and 3mo. Spearan correlation analysis was performed on the anterior segment. <p>RESULTS: The anterior corneal power(flat keratometry, steep keratometry, mean keratometry)was lower at postoperative 1wk than that before operation, and began to return to the preoperative level at postoperative 1mo and 3mo. The posterior corneal power and total corneal power(flat keratometry, steep keratometry, mean keratometry)were higher at postoperative 1wk than before operation, and began to stabilize at postoperative 3mo. The anterior corneal astigmatism, posterior corneal astigmatism, and total corneal astigmatism were also higher at postoperative 1wk than before operation, and began to decrease and stabilize at postoperative 3mo. The anterior corneal power was significantly positively correlated with total corneal power; The posterior corneal power was significantly negatively correlated with the total corneal power, and was significantly positively correlated with its absolute value(<i>P</i><0.05). The total corneal astigmatism before operation and at postoperative 1wk and 3mo was significantly positively correlated with anterior corneal astigmatism at corresponding time points(<i>P</i><0.01), while showed no significant correlation with posterior corneal astigmatism.<p>CONCLUSION: Changes of posterior corneal power and astigmatism can be observed with 3mo of cataract surgery, and Pentacam three-dimensional anterior eye segment analyzer system can accurately assess the dynamic changes of anterior and posterior corneal power and astigmatism before and after operation, which is of great clinical value.
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Background: A pterygium is a wing-shaped growth of conjunctiva and fibrovascular tissue on the superficial cornea. The pathogenesis of pterygia is strongly correlated with UV light exposure and environmental factors. The prevalence of pterygia increases steadily with proximity to the equator, and the condition is more common in men than women. It is well established fact that before entering the optical zone pterygium causes flattening of the cornea in horizontal meridian with the more normal side of the cornea usually temporally, resulting in with-the-rule astigmatism.Methods: The study included 80 patients of primary pterygium who underwent pterygium excision with conjunctival autograft adhered by autologous blood surgery. After performing routine ocular examination which includes visual acuity without and with pinhole and pre-operative keratomery was assessed by autokeratorefractometer. Repeat examination was performed after 6 weeks of surgery. Patients with recurrent pterygium, pseudo-pterygium, and history of previous ocular surgery were excluded.Results: The pre‑ and postoperative corneal astigmatism were compared after 6 weeks of surgery. The changes in corneal astigmatism were statistically significant p value <0.001. The preoperative mean corneal astigmatism of 3.41 D was reduced to 1.59 D (p value <0.001) 6 weeks after surgery, but maximum change in astigmatism was seen in Grade IV >Grade III >Grade II >Grade I.Conclusions: Primary pterygium of all grades treated with well accepted technique pterygium excision with conjunctival autograft with autologous blood gives promising results in terms of improvement in corneal astigmatism and hence visual acuity as well.
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@#AIM: To observe the clinical effect of Toric intraocular lens(Toric IOL)implantation in the correction of corneal astigmatism, and vector analysis of residual astigmatism and corneal astigmatism.<p>METHODS: A retrospective case observation study. A total of 63 patients with 77 eyes who underwent phacoemulsification combined with Toric IOL implantation in our hospital from September 2018 to October 2019 were selected. LogMAR uncorrected distance visual acuity(UCDVA), best corrected distance visual acuity(BCDVA), residual astigmatism of subjective refraction were observed after operation in 1wk, 1mo, and 3mo. And after dilated pupil, the Toric IOL axis position was measured by OPD-scanⅢ, and compared with the target axis position(LAD).<p>RESULTS: The median(interquartile range)of UCDVA at 1wk, 1mo, and 3mo after operation were 0.22(0.15, 0.40), 0.30(0.15,0.40),and 0.30(0.15, 0.40), which were better than those of UCDVA \〖0.82(0.60, 1.22)\〗 and BCDVA \〖0.52(0.30, 0.70)\〗 before operation(<i>P</i><0.008). The residual astigmatism was 0.75(0.50, 1.00), 0.75(0.38, 1.00), 0.50(0.25, 1.00)D, respectively, which was significantly lower than that of preoperative corneal astigmatism \〖2.19(1.73, 2.69)D\〗(<i>P</i><0.008). At 3mo after surgery, the proportion of UCDVA(LogMAR)≤0.301 was 69%; the proportion of residual astigmatism ≤0.75D was 73%. The median LAD at 1wk, 1mo, and 3mo after surgery were 2.0°, 2.0°, and 3.0°; 81%, 82%, 77% were less than 5°. The maximum LAD value is 11°. Astigmatism vector analysis: preoperative corneal astigmatism was 2.31±0.80D, centroid value was 1.44D@177°±1.99D; Predicted postoperative residual astigmatism was 0.14±0.17D, centroid value was 0.02D@58°±0.22D; residual astigmatism at 3mo after operation was 0.69±0.53D, centroid value was 0.05D@142°±0.88D.<p>CONCLUSION: Toric IOL can effectively correct corneal astigmatism in patients with cataract and has good rotational stability. Astigmatism vector analysis can directly show the difference between predicting postoperative astigmatism and actual residual astigmatism, which is helpful to analyze and optimize the measurement of corneal astigmatism, calculation of IOL degree, surgical design, postoperative observation.
ABSTRACT
Correction of astigmatism is an important part of refractive cataract surgery.Currently,methods of combined corneal astigmatism correction in cataract surgery mainly include keratotomy and Toric intraocular lens (IOL) implantation.Whether it is a scalpel or femtosecond laser keratotomy,the effects of astigmatism correction is related to the position,shape,length and depth of the incisions,configuration,and distance between incisions and optic axis.Moreover,the pattern and material of Toric IOL can affect its rotation stability and effects of astigmatism correction.This article reviewed recent progress of correcting corneal astigmatism in cataract surgery,which provided reference for ophthalmologists in clinical.