Inverse relationship between age and severity and sequelae of acute corneal hydrops associated with keratoconus

Identification of risk factors for persistent corneal edema associated with acute corneal hydrops in keratoconus

PURPOSE

The aim of this study was to investigate the clinical characteristics of acute corneal hydrops (ACH) in patients with keratoconus and to examine the risk factors for persistent corneal edema.

STUDY DESIGN

Retrospective observational study.

METHODS

The study included 98 patients (106 eyes) diagnosed with ACH between February 2009 and August 2023 at Kyoto Prefectural University of Medicine. Seventy-seven eyes with clear data on both onset and resolution were analyzed for the risk factors for persistent corneal edema. Clinical characteristics, duration of corneal edema, and associated risk factors such as seasonal variations, edema area, allergic diseases, eye rubbing, and neurodevelopmental disorders (including Down syndrome) were collected and analyzed.

RESULTS

The study included 90 male (91.8%) and 8 female (8.2%) patients. The mean (SD) age at ACH onset was 33.3 (13.8) years (range, 14-80). ACH occurred most prevalently during the spring season (n = 39, 36.8%). Allergic diseases were present in 59 eyes (55.7%); eye rubbing, in 58 eyes (54.7%); and neurodevelopmental disorders, in 9 eyes (8.5%). Corneal edema resolved within 3 months in 55 eyes (71.4%), whereas it persisted for over 3 months in 22 eyes (28.6%). Multivariate analysis showed that a large edema area, ≥50%, was a significant risk factor for persistent corneal edema of more than 3 months in ACH patients (odds ratio, 7.41; 95% CI, 1.95-33.02; P = .005).

CONCLUSION

Large corneal edema at ACH onset carries a high risk of persistent corneal edema. These patients should be managed more carefully to resolve the corneal edema earlier.

Deep Anterior Lamellar Keratoplasty-Treated Keratoconic Eyes With Descemet Membrane Rupture

PURPOSE

The aim of this study was to evaluate the outcomes of deep anterior lamellar keratoplasty (DALK) and compare it with penetrating keratoplasty (PKP) in keratoconic eyes with Descemet membrane (DM) rupture.

METHODS

In this comparative retrospective case series, 33 keratoconic eyes with a history of hydrops underwent DALK and 27 received PKP. Baseline and postoperative visual acuity, corneal astigmatism, mean keratometry, endothelial cell density, and complication rates were measured.

RESULTS

The median follow-up of patients who underwent DALK was 45 months (range, 4-76 months) and that of patients who underwent PKP was 84 months (range, 4-136 months). Both procedures had comparable postoperative visual acuity, astigmatism, and mean keratometry. Significantly higher endothelial cell densities were observed in DALK than in PKP at 2, 3, and 5 years postsurgery (2043 ± 767 vs. 1165 ± 683 cell/mm 2 , P = 0.007, n = 12 in both groups at 2 years). Intra-DALK, 15 perforations occurred (44.12%) and 1 (2.94%) was converted to PKP. Graft rejection was diagnosed in 1 (3.03%) DALK procedure versus 8 (29.63%) PKP ( P = 0.008), and other long-term complication rates were equivalent. Kaplan-Meier survival analysis also revealed a higher rejection-free survival rate for the DALK group ( P = 0.012). Subgroup analysis within both groups based on the severity of preoperative DM rupture revealed no significant difference in any major 2-year outcomes.

CONCLUSIONS

DALK showed similar beneficial visual outcome and safety but significantly better endothelial protection over PKP in eyes with keratoconus and previous hydrops. Therefore, DALK is recommended in posthydrops cases irrespective of the DM rupture severity.

Corneal Collagen Cross-Linking for Progressive Keratoconus in Pediatric Patients: Up to 14 Years of Follow-up

PURPOSE

To assess the long-term outcomes of corneal collagen cross-linking according to the Dresden protocol (S-CXL) in progressive pediatric keratoconus (KC).

DESIGN

Retrospective, single-center noncomparative interventional study.

METHODS

Patients aged <18 years who underwent S-CXL from June 2007 to January 2011 in Humanitas Clinical and Research Center, Rozzano, Milan, Italy, and completed at least 10 years of follow-up were included. Corrected distance visual acuity (CDVA), refraction, and tomography were evaluated at baseline and ≥10 years after S-CXL. Meeting 2 of the following 3 criteria indicated reprogression: progression above 95% CI for post-CXL population of A or B values or a decrease in minimal thickness C evaluated with the ABCD display.

RESULTS

Thirty-eight eyes of 24 patients fulfilled inclusion criteria. At a mean of 11.6 years postoperation (maximum 14 years), the CDVA improved significantly (from 0.703 ± 0.33 decimal fraction to 0.887 ± 0.2, P < .001). Similarly, the A value significantly improved from 2.550 ± 1.7 to 1.627 ± 1.68 (P = .019). Thirteen eyes (34%) showed significant postoperative progression in 2 of the 3 parameters A, B, and C. Of these, only 3 eyes (7.9%) of 3 patients showed a statistically significant change in the A value.

CONCLUSIONS

S-CXL proved to be a safe treatment for progressive KC in pediatric patients with an anterior curvature progression rate of up to 7.9% at ≥10 years of follow-up.

Corneal Hydrops - Aetiology and Advanced Therapeutic Strategies

Acute hydrops refers to sudden corneal edema caused by rupture of Descemet's membrane (DM) - often in progressive keratectasia. It leads to a sudden decrease in visual acuity, pain, and foreign body sensation as well as an increased glare sensation. Acute hydrops usually heals with scarring within months, but complications such as corneal perforation, infectious keratitis, and corneal vascularization may occur. The prevalence in keratoconus patients is 2.6 to 2.8%. Risk factors include keratoconjunctivitis vernalis, atopic dermatitis, high keratometry, male gender, and eye rubbing. Keratoplasty should be avoided in the acute phase. The prognosis of the graft is reduced, and after scar healing of the hydrops, wearing contact lenses or glasses may be possible again. Conservative therapy alone with lubricants and hyperosmolar eye drops, prophylactic antibiotic eye drops to prevent superinfection, and topical steroids was long considered the only possible form of treatment. However, healing under conservative therapy takes an average of over 100 days. In the meantime, there are different surgical strategies that rapidly shorten the healing and thus the recovery phase of the patients to a few days. If the DM is detached without tension, a simple injection of gas into the anterior chamber can already lead to reattachment and thus to almost immediate deswelling of the cornea. If the DM is under tension, predescemetal sutures combined with a gas injection into the anterior chamber can flatten the cornea and reattach the DM. Mini-Descemet membrane endothelial keratoplasty (mini-DMEK) allows for sutureless closure of the DM defect by transplantation of a small (< 5 mm) graft. In cases of particularly large DM tears and very pronounced hydrops, suture loosening and relapse may occur after the placement of predescemetal sutures. Mini-DMEK can then lead to permanent healing, but in contrast to simple corneal sutures, it is usually performed under general anesthesia and by aid of intraoperative optical coherence tomography. The very good results with regard to the rapid healing prove that surgical therapy makes sense in the vast majority of patients with acute hydrops and should be initiated quickly.

Outcomes of accelerated collagen cross linking in progressive paediatric keratoconus

Purpose

To determine the efficacy and safety of pediatric accelerated cross linking (CXL).

Methods

A prospective study on progressive keratoconus (KC) cases under ≤18 years of age. Sixty four eyes of thirty nine cases underwent epithelium-off accelerated CXL protocol. Visual acuity (VA), slit-lamp examination, refraction, pentacam reading of keratometry (K), corneal thickness, and thinnest location pachymetry were noted. Cases were followed up on days 1, 5, and at 1^st, 3^rd, 6^th, and 12th-month post procedure.

Results

Statistically, significant improvement of the mean aided VA, K, and mean corneal astigmatism (p < 0.0001) was noted. Mean Kmax reading reduced from 55.5 ± 5.64 (47.4-70.4) diopter (D) preoperatively to 54.41 ± 5.51 (46-68.3) D at 12 months postaccelerated CXL. Two cases had progression. Complications encountered were sterile infiltrate and persistent haze.

Conclusion

Accelerated CXL is effective and efficacious in pediatric KC.

Long-term Safety and Efficacy of Corneal Collagen Crosslinking in a Pediatric Group With Progressive Keratoconus: A 7-year Follow-up

PURPOSE

To assess effectiveness and safety of corneal crosslinking (CXL) to reduce keratoconus (KC) progression and improve visual acuity among children with progressive KC and to analyze the use of 20% dextran-based (Dextran) and 1% hydroxypropyl methylcellulose-based (HPMC) riboflavin.

DESIGN

Prospective, clinical cohort study METHODS: Standard CXL (SCXL) was performed in 74 eyes (58 patients, 45 males, mean age 13.0 ± 2.1 years): 53 eyes with HPMC and 21 with Dextran. Examinations were performed at baseline, 3 and 6 months, and 1, 2, 3, 4, 5, and 7 years of follow-up, including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), a complete ophthalmologic examination, anterior segment ocular coherence tomography, Scheimpflug corneal tomography, and specular microscopy.

RESULTS

UDVA and CDVA improved at all periods with statistically significant differences in CDVA at 1, 2, and 3 years. Compared with baseline, maximum K (Max K) reduced throughout the 7-year follow-up. Mean thinnest pachymetry (Th Pachy) decreased significantly at 3 months and remained low; in the Dextran group, the Th Pachy mean value returned to baseline 6 months postoperatively. After CXL, 1.5 diopter progression in max K was 1.4% to 14.6% of eyes; worsening was found at 4 to 7 years postoperatively.

CONCLUSION

SCXL reduced KC progression in children up to 7 years of follow-up and revealed improvement and stability of UDVA and CDVA in 82% of eyes. For visual acuity and KC stability, no statistically significant difference was observed between Dextran-HPMC. The HPMC group showed persistent cornea thinning, raising concerns about its use in SCXL.

The ABCD Keratoconus Grading System-A Useful Tool to Estimate Keratoconus Progression in the Pediatric Population

PURPOSE

To evaluate the ABCD grading system in pediatric keratoconus.

METHODS

A retrospective cohort analysis of all children with keratoconus followed up at the Shamir medical center between 2010 and 2017. A recommendation by the treating physician to undergo corneal crosslinking (CXL) was used as an estimate for clinically significant disease progression. The ABCD grading was not available to the treating physician and was computed post hoc. The ABCD grading was compared between patients who required CXL with those who did not. A single eye of each patient was included.

RESULTS

Fifty eyes of 50 children were analyzed. The mean age at presentation was 15.56 ± 1.36 years. In 23 eyes, progression of keratoconus was recorded and CXL was performed (CXL-group). On presentation, the stable and CXL groups did not differ significantly in their clinical parameters. In the CXL-group, a statistically significant increase was seen in the ABCD staging (P < 0.001). In the stable group, the ABCD staging did not change significantly in parallel visits (P = 0.87). An increase of 1 point in the sum of the ABCD staging showed a 5-fold risk for undergoing CXL (odds ratio = 5.28; 95% CI, 1.82-15.34). There was no significant change in the Amsler-Krumeich classification in the CXL group.

CONCLUSIONS

Among a cohort of pediatric patients with keratoconus, worsening in the ABCD grading was associated with disease progression, whereas no significant change was demonstrated in the Amsler-Krumeich classification The ABCD grading system is a useful tool for initial assessment of disease progression in the pediatric population, in which early recognition is of paramount importance.

Tomographic and aberrometric assessment of first-time diagnosed paediatric keratoconus based on age ranges: a multicentre study

PURPOSE

To describe paediatric keratoconus (KC) patients by tomographic and aberrometric characteristics at first diagnosis, in a multicentre study.

METHODS

We included 278 eyes from 139 paediatric patients, with a first tomographic diagnosis (Pentacam^® ) of KC prior to 18 years old. KC classification was based on the KC Index (≥ 1.07) and Topographic Keratoconus Classification (TKC ≥ 1). Patients were divided based on age ranges (14 and under and over 14 years) and gender. Statistical analysis was performed with SPSS statistics 25.0. ANOVA factor was carried out comparing to compare groups.

RESULTS

278 eyes were screened, and 230 eyes were diagnosed with paediatric KC. Mean age was 15.48 ± 2.33 (6 to 18) years. We found differences in terms of TKC (2.08 ± 0.89 and 2.38 ± 0.82, p < 0.05) and spherical aberration (-0.71 ± 0.97 and -1.07 ± 1.36, p < 0.05) among the 14 years old or under and above 14 years old groups, respectively. Overall, female paediatric KC patients presented a more severe TKC, Belin Ambrosio Display, maximum keratometry, asphericity and primary and secondary coma aberrations compared to male KC patients. We observed a correlation between CDVA and asphericity (r = 0.71, p < 0.01), as well as between CDVA and spherical aberration (r = 0.69, p < 0.01).

CONCLUSION

Our findings revealed that the debut of KC is usually in a moderate to advanced stage in the paediatric population at first diagnosis, particularly in female patients. Corneal tomography should be systematically performed in children with recent onset of corneal astigmatism.

Treatment strategies for the management of acute hydrops

Acute corneal hydrops is a condition characterized by marked stromal edema attributable to leakage of aqueous humor through a rupture in Descemet's membrane. In addition to the clinical examination, imaging options include ultrasound biomicroscopy, anterior segment optical coherence tomography and in vivo confocal microscopy. While it is a self-limiting condition, the duration of acute hydrops is an important factor linked to complications such as neovascularization. Therapeutic options may relieve symptoms and/or reduce healing time; these include conservative, medical and/or surgical therapies. Several new medical and surgical management options have been reported in the past few years and will be discussed in this article.

Two-Year Follow-up of Intracorneal Ring Segments Implantation in Adolescent Patients With Keratoconus

PURPOSE

To evaluate the visual, refractive, topographic, and aberrometric outcomes after intracorneal ring segments (ICRS) implantation in adolescent patients with keratoconus.

METHODS

A retrospective longitudinal study was undertaken with a total of 61 eyes from 47 patients with keratoconus, aged between 13 and 18 years, implanted with a Ferrara-type ICRS. Topography (flattest keratometry, steepest keratometry, and asphericity), uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error (sphere and cylinder), and aberrometric measurements (spherical aberration and vertical coma) were evaluated before surgery and at 1 month, 6 months, 1 year, and 2 years after surgery.

RESULTS

UDVA exhibited a statistically significant increase at all times from 1 month to 2 years postoperatively (P < .001), whereas CDVA showed a statistically significant improvement at 1 month, 6 months, and 2 years (P < .002), but dropped in significance at 1 year postoperatively (P = .097). The refractive error analysis showed no variation in statistical significance in the sphere (P = .712) after 2 years. The cylinder presented a statistically significant decrease in diopters at all times from preoperatively to 2 years postoperatively (P < .007). Steepest keratometry manifested a statistically significant decrease in steepness at all times after surgery (P < .001), whereas flattest keratometry lost significance at 1 year (P = .298) and 2 years (P = .053) postoperatively. There was no statistically significant change in the spherical aberration at any of the measured times. The vertical coma was only significantly different at 2 years postoperatively (P = .001).

CONCLUSIONS

ICRS implantation is a safe and effective treatment for improving visual and corneal morphological parameters as shown at 2 years of follow-up in adolescent patients with keratoconus. It is a good option to flatten and regularize the cornea and to temporarily improve the quality of life of young patients and delay the need for keratoplasty. [J Refract Surg. 2021;37(2):91-97.].

Penetrating Keratoplasty Versus Deep Anterior Lamellar Keratoplasty in Children and Adolescents With Keratoconus

PURPOSE

To compare the outcomes of penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) for pediatric keratoconus.

DESIGN

Retrospective comparative interventional case series.

METHODS

This study included consecutive pediatric keratoconus cases (≤18 years of age) who received PK (n=45) or DALK (n=54) in 2 different time periods. Postoperative best spectacle-corrected visual acuity (BSCVA), refraction, and complications were compared between the study groups.

RESULTS

The mean follow-up was 83.3±46.1 and 63.3±45.6 months in the PK and DALK groups, respectively (P = .10). Postoperatively, BSCVA was 0.20±0.19 logMAR in the PK group and 0.26±0.19 logMAR in the DALK group (P = .11), with a BSCVA of ≥20/40 in 91.1% and 83.3% of eyes, respectively (P = .25). Two groups were comparable regarding postoperative refractive outcomes. Graft epitheliopathy and suture-associated complications were more commonly encountered after DALK, which was attributable to the effect of low-quality grafts on the clinical outcomes of DALK. Ten PK eyes (22.2%) and 9 DALK eyes (16.7%) experienced at least 1 episode of graft rejection within 5 years of corneal transplantation (P = .49). Rejection was reversible in 93.1% and 100% of episodes in the PK and DALK groups, respectively (P = .63). At the postoperative year 5, 95.6% of grafts in the PK group and 98.2% in the DALK group remained clear (P = .45).

CONCLUSION

No significant difference was observed in the outcomes between PK and DALK in pediatric keratoconus. Low-quality donor tissues in DALK increased the incidence of graft epithelial problems and suture-related complications as compared to PK.

Three-Dimensional Morphogeometric and Volumetric Characterization of Cornea in Pediatric Patients With Early Keratoconus

PURPOSE

To present morphogeometric and volumetric characteristics of the cornea and its diagnostic value in pediatric patients with keratoconus (KC) using 3-dimensional (3-D) corneal modeling.

DESIGN

Cross-sectional study.

METHODS

This single-center (VISSUM Innovation, Alicante, Spain) study comprised 49 eyes of 49 pediatric patients (age ≤16 years) with KC and 31 eyes of 31 healthy pediatric controls. Eyes were graded as early (n = 21) and mild KC (n = 28) based on the RETICS (Thematic Network for Co-Operative Research in Health) classification system. The 3-D corneal model was generated using raw topographic data. Deviation of anterior (D_apexant) and posterior (D_apexpost) apex and minimum thickness points (D_mctant, D_mctpost), D_apexant-D_apexpost difference, total corneal volume (V_total), volumetric distribution (VOL_AAP, VOL_PAP, and VOL_MCT), and percentage of relative volume increase (VOL_AAPrel, VOL_PAPrel, and VOL_MCTrel) between 2 consecutive radii centered to anterior/posterior apex and thinnest point were evaluated.

RESULTS

D_apexpost and D_apexant-D_apexpost difference were higher in the early and mild KC groups compared to the control group (P < .05). Eyes with early and mild KC had decreased V_total compared with the control group (P < .05). D_apexpost, D_apexant-D_apexpost difference, and VOL_MCTrel between 1.0 and 1.4 mm diameters had area under receiver operating characteristics curve (AUROC) values over 0.93 in discrimination of early KC from normal.

CONCLUSIONS

This is the first study presenting morphogeometric and volumetric characterization of cornea in pediatric patients with early and mild KC using a 3-D corneal model. Integration of the morphogeometric and volumetric parameters to topography software can add value in early detection of KC in pediatric patients.

Intracorneal Ring Segment Implantation for the Management of Keratoconus in Children

The short-term safety and efficacy of intracorneal ring segment (ICRS) implantation in keratoconus eyes of children are investigated in this study. A retrospective interventional case series study including a total of 33 keratoconus eyes (age 8 to 17 years) that had undergone ICRS (Keraring segments, Mediphacos) implantation was conducted. Information about visual, refractive, pachymetric, corneal topographic and aberrometric, and corneal endothelial changes during a 3-month follow-up were extracted and analysed. A significant improvement was observed in logMAR corrected distance visual acuity (p = 0.005), combined with a statistically significant reduction in keratometric readings (p < 0.001). A reduction in the magnitude of corneal astigmatism of ≥1 D was observed in 52.8% of eyes. No significant changes were observed in corneal endothelial density (p = 0.317). Significant changes were found in the anterior vertical coma component (p = 0.002) as well as in the spherical aberration of the posterior corneal surface (p = 0.004). Only two relevant complications were described: one corneal microperforation with penetration of the ring segment into the anterior chamber (1 eye, 2.8%), and a case of ring extrusion (1 eye, 2.8%). ICRS implantation in children keratoconus eyes allows a reduction of corneal astigmatism, irregularity, and aberrations, leading to a significant visual improvement.

Three-year follow-up of accelerated transepithelial corneal cross-linking for progressive paediatric keratoconus

Purpose

To investigate the long-term safety and efficacy of accelerated transepithelial cornealcross-linking (ATE-CXL) in children with progressive keratoconus.

Methods

Fifty-three eyes of 41 paediatric patients (34 boys, 7 girls; mean age 14.81±1.96 years) undergoing ATE-CXL were enrolled in the study. Corrected distance visual acuity (CDVA) and manifest refraction were assessed preoperatively and 36 months postoperatively. Corneal keratometry, corneal thickness and posterior elevation were measured using Pentacam preoperatively and 1, 6, 12 and 36 months postoperatively. Pachymetry and epithelial thicknesses were measured using optical coherence tomography preoperatively and 6, 12, and 36 months postoperatively.

Results

Thirty-six months postoperatively, CDVA improved from 0.32±0.28 to 0.26±0.25 in logarithm of the minimum angle resolution (p=0.025). Maximum keratometry was 58.73±9.70 D preoperatively and 59.20±10.24, 58.28±9.33, 57.88±9.99 and 58.98±10.79 D at 1, 6, 12 and 36 months postoperatively throughout the 36-month follow-up period (p>0.05). Similarly, corneal central thickness, which was 492.42±33.83 µm postoperatively, also remained stable during the 36-month follow-up (p>0.05). Both posterior central elevation and posterior highest elevation were stable at 12 months after ATE-CXL (p>0.05), but increased at 36 months postprocedure (p<0.05). Corneal pachymetry and epithelial thicknesses remained stable throughout the follow-up period (p>0.05).

Conclusions

ATE-CXL is a safe and effective treatment in paediatric progressive keratoconus patients, leading to stable keratometry and corneal thickness throughout the 36-month follow-up.

Outcomes of big-bubble deep anterior lamellar keratoplasty for pediatric keratoconus

PURPOSE

To evaluate the outcomes and complications of deep anterior lamellar keratoplasty (DALK) performed for pediatric keratoconus.

METHODS

This retrospective study enrolled 44 consecutive eyes of 39 keratoconus-affected children (≤ 18 years of age). All patients underwent big-bubble DALK from March 2004 to June 2016. The outcome measures included postoperative best spectacle-corrected visual acuity (BSCVA), manifest refraction, keratometry readings, and complications.

RESULTS

The mean participant age was 16.8 ± 1.4 years, and the mean follow-up period was 68.5 ± 39.9 months. Successful big bubble was achieved in 33 eyes (75.0%), while the surgical technique was predescemetic DALK in 11 (25.0%). The mean BSCVA changed from 1.34 ± 0.49 LogMAR preoperatively to 0.24 ± 0.10 LogMAR postoperatively (P < 0.001). The mean keratometry decreased from 59.54 ± 5.17 D preoperatively to 46.23 ± 2.17 D postoperatively (P < 0.001). The complications encountered during the study period were intraoperative Descemet's membrane perforation (n = 5, 11.4%), the Urrets Zavalia syndrome (n = 1, 2.3%), graft epithelial problems (n = 3, 6.8%), subepithelial graft rejection (n = 5, 11.4%), high intraocular pressure (n = 8, 18.2%), and traumatic wound dehiscence (n = 2, 4.6%). Suture-related complications included premature loosening (n = 13, 29.6%), broken sutures (n = 12, 27.3%), suture-tract vascularization (n = 6, 13.6%), suture-associated abscesses (n = 5, 11.4%), and suture cheese wiring (n = 2, 4.6%). A clear graft was found in 40 eyes (90.9%) at the last follow-up examination.

CONCLUSION

This study showed promising results with big-bubble DALK in keratoconus-affected children. A frequent and close follow-up with dedicated parental involvement is essential for the early recognition and management of postoperative complications.

The Effect of Age on Corneal Topographic Indices, Keratometry and Visual Acuity After Combined Intrastromal Corneal Ring Segment (ICRS) Implantation and Corneal Crosslinking

We aimed to assess age-related changes in corneal topographic indices, keratometry and visual acuity after sequential intracorneal ring segment implantation (ICRS) and crosslinking (CXL). This was a retrospective matched case-control series including 26 eyes of patients ≤18 years as cases and 26 eyes of adult patients as controls. All eyes received ICRS+CXL for progressive keratoconus. Eyes were matched regarding the keratoconus parameters and the treatment (type, number and thickness of ICRS). Data was analyzed for refractive and topographic values (uncorrected and corrected distance visual acuity (UDVA; CDVA) sphere; cylinder; spherical equivalent; maximum keratometry (Kmax); flat keratometry (Kflat); steep keratometry (Ksteep); all 7 pentacam topographic indices) preoperatively and one year postoperatively. Preoperatively, there was no significant difference for any refractive, clinical or topographic parameters between the groups except for index of vertical asymmetry. After one year, children had a significantly higher improvement in Ksteep (3.05D) than adults (2.10D; P=0.036) and a trend to significance for Kflat (2.7D compared to 1.78D, respectively; P=0.081). UDVA improved by 4.3 ETDRS lines in children compared to 3.3 ETDRS lines in adults and CDVA improved by 1.7 ETDRS lines in children compared to 1.2 ETDRS lines in adults, but with no statistical significance. The effects on keratometry indicated that corneal response after ICRS and CXL for keratoconus is more pronounced in young patients than adults. This assumption is also supported by functional improvement and by the fact that a few eyes (5) of some very young patients (<13years) showed highly remarkable improvements after surgery (higher than any adult eye).

Optimal management of pediatric keratoconus: challenges and solutions

Keratoconus (KC) shows several distinctive features in clinical appearance, disease progression, and treatment in children compared with adults. Therefore, diagnostic, clinical care, and therapeutic approaches are different. However, pediatric keratoconus is often undiagnosed and thus untreated in many cases. Once diagnosis has been made, compliance with treatment recommendations is often poor. Pediatric keratoconus also tends to have more rapid progression than in adults; therefore, early detection and treatment are paramount to prevent serious vision impairment, which can affect the child's development. This review of pediatric keratoconus discusses important issues such as worldwide epidemiology, clinical features in children compared to adults, and challenges in diagnosis and treatment and focuses on the most appropriate management strategies based on the best available current evidence.

Distribution of Keratoconus Indices in Normal Children 6 to 12 Years of Age

OBJECTIVES

To determine the distribution of keratoconus indices in normal children 6 to 12 years of age.

METHODS

This cross-sectional study was conducted in children living in urban and rural areas of Shahroud, northeast Iran in 2015. After careful optometric examinations, the Pentacam was used for corneal imaging and measurement of keratoconus indices.

RESULTS

Of 5,620 students who participated in the study, the data of the right eye of 4,947 children were analyzed after applying the exclusion criteria. The mean age of all children was 9.23±1.71 years (range: 6-12 years). The mean and 95% confidence intervals (in the parentheses) of index of surface variance (ISV), index of vertical asymmetry, keratoconus index (KI), central keratoconus index (CKI), index of height asymmetry, index of height decentration (IHD), and average pachymetric progression index (PPIAve) was 17.770 (17.610-17.930), 0.137 (0.135-0.139), 1.022 (1.022-1.023), 1.010 (1.010-1.010), 3.299 (3.230-3.368), 0.007 (0.007-0.008), and 0.948 (0.943-0.952), respectively. The results of multilevel mixed-effects linear regression analysis showed that ISV, KI, CKI, IHD, and PPIAve were significantly higher in girls. Index of surface variance and CKI were higher in urban students, and PPIAve was higher in rural students. Except for PPIAve, which was increased with increasing age, the mean values of other keratoconus indices were significantly lower in 12-year-old students compared with 6-year-old ones.

CONCLUSION

The results provide valuable information about normal distribution of keratoconus indices in children aged 6 to 12 years. These findings can be used in future research and detection of abnormal cases in the clinical setting.

Pediatric keratoconus: a review of the literature

PURPOSE

To describe the epidemiology and prevalence, rates of progression, difference between adult and pediatric populations, and therapeutic approaches to pediatric keratoconus from documented literature.

METHODS

A literature search was done on PubMed using key words including pediatric keratoconus, children with keratoconus, adult keratoconus, penetrating keratoplasty, corneal cross-linking and intracorneal ring segments. The literature was reviewed and reported to explore the key epidemiological differences between the pediatric and adult population with regards to presentation and treatment options.

RESULTS

Pediatric keratoconus is more aggressive than adult keratoconus, which has been explained by structural differences in the cornea between both populations. High rates of progression were documented in pediatric populations. While corneal collagen cross-linking, intracorneal ring segments and penetrating keratoplasties have been used as therapies in the pediatric population, the literature overwhelmingly shows higher rates of failure and progression despite these measures as compared to adults.

CONCLUSION

Pediatric keratoconus is more aggressive than adult keratoconus, and current therapies used in adults may not be sufficient for the pediatric population.

Corneal Collagen Cross-Linking With Riboflavin and Ultraviolet A Light for Pediatric Keratoconus: Ten-Year Results

PURPOSE

To assess the 10-year follow-up efficacy and safety of riboflavin ultraviolet A-induced cross-linking (CXL) in a population of pediatric patients aged 18 years and younger with progressive keratoconus (KC).

METHODS

The prospective longitudinal cohort study included 62 eyes of 47 keratoconic patients undergoing epithelium-off CXL who completed 10-year follow-up. The surgical procedure was performed in all patients according to the Siena (Dresden modified) protocol. Evaluation included uncorrected distance visual acuity, corrected distance visual acuity, Scheimpflug corneal tomography, and optical coherence tomography demarcation line measurement. Follow-up measurements taken up to 10 years after treatment were compared with baseline values, and statistical analysis was performed using a 2-tailed paired sample Student t test.

RESULTS

Uncorrected distance visual acuity and corrected distance visual acuity improved from 0.45 to 0.23 logarithm of the minimum angle resolution (P = 0.0001) and from 0.14 to 0.1 logarithm of the minimum angle resolution (P = 0.019). KC stability was recorded after 10 years of follow-up in nearly 80% of the patients. The overall 10-year follow-up progression rate was 24% including 13 eyes of 9 patients with Kmax progression over 1 diopter and 2 eyes of 2 patients who underwent corneal grafting.

CONCLUSIONS

The study demonstrates the ability of CXL to slow down KC progression in pediatric patients, improving functional performance. Long-term stability may be correlated with CXL-induced delay in corneal collagen turnover and with spontaneous age-related KC stabilization. A 24% regression rate could be contemplated in the patients who were aged 15 years and younger at the time of inclusion in the treatment protocol.

Clinical Profile of Omani Keratoconus Patients: An Experience from a tertiary referral centre in Muscat

OBJECTIVE:

To determine the demographics and associated clinical features of Omani keratoconus patients presenting to the Ministry of Defence Hospital (MODH) in Muscat.

METHODS:

This is a retrospective, descriptive study whereby the electronic medical records of all Omani keratoconus patients presenting to the MODH between January 2011 and December 2015 were reviewed. Demographic details, corrected distance visual acuity, refraction, corneal topography, pachymetry, and treatment received were all documented.

RESULTS:

There were 458 new keratoconus patients (257 males, 201 females) comprising a total of 893 eyes with a mean age of 20 years ± 5.6 (standard deviation) (range 6–46 years). On their first visit, 35% of eyes had spectacle-corrected distance visual acuity <0.5 logarithm of the minimum angle of resolution (LogMAR), 38% had central corneal thickness <450 um, and 25% had a mean keratometry more than 53 Diopter (D). According to the Amsler-Krumeich classification, 37%, 30%, 18%, and 16% of eyes classified into stages I, II, III, and IV, respectively. The severity of keratoconus did not correlate with the age of patients (rs = −0.13, P < 0.05). Over the 5-year period of the study, 502 eyes were fitted with rigid gas permeable lenses with 91% achieving the vision of 0.1 LogMAR or better, 22% of eyes underwent collagen cross linking, 3% underwent intracorneal ring segments implantation, and 4% underwent corneal grafting.

CONCLUSION:

A significant proportion of Omani keratoconus patients seen in the MODH showed advanced disease on their first visit. There was no correlation between severity and age suggesting that keratoconus can progress quickly in our pediatric group. Population-based studies are an important next step. Meanwhile, early detection and timely interventions to limit the burden of the disease are crucial.

Collagen Cross- Linking for Paediatric Keratoconus

Background:

Since the late 1990s corneal crosslinking (CXL) has been proposed as a new treatment option which can stop progression of keratoconus with promising results in adults.

Objective:

Keratoconus presents a higher rate and faster progression in paediatric patients and for this reason prompt and effective treatment is essential. Due to its success in adult keratoconus patients, CXL has been recently applied to children in order to stop or slow progression of keratoconus in paediatric patients.

Conclusions:

This article will present an update of the literature on the topic of CXL in this age group.

Safety and Efficacy of Sequential Intracorneal Ring Segment Implantation and Cross-linking in Pediatric Keratoconus

PURPOSE

To evaluate the safety and visual outcome of intracorneal ring segment (ICRS) implantation followed by cross-linking in pediatric keratoconus patients.

DESIGN

Retrospective interventional case series.

METHODS

This retrospective study included pediatric patients (aged ≤14 years) with keratoconus and poor corrected distance visual acuity (CDVA) that underwent ICRS implantation and cross-linking (CXL). ICRS were inserted under topical anesthesia after creating a corneal tunnel with a femtosecond laser. Cross-linking was performed 1 month subsequently. Records were reviewed and data collected preoperatively and at 6 months, 1 year, 2 years, and 4 years postoperatively.

RESULTS

Twelve patients (17 eyes; 10 male, 2 female) aged 9-14 years (mean age 12.3 years) received ICRS implantation followed by CXL. Follow-up times ranged from 6 months to 4 years after surgery. At the 6-month follow-up all eyes were evaluated; at the 1-year, 2-year, and 4-year follow-up 11, 10, and 7 eyes were evaluated, respectively. At the 6-month follow-up, mean CDVA in comparison to preoperative levels improved significantly (P = .001) from 0.30 ± 0.19 logMAR to 0.12 ± 0.1 logMAR; mean uncorrected distance visual acuity (UDVA) also improved significantly from 0.90 ± 0.50 logMAR to 0.43 ± 0.31 logMAR. A significant decrease in both keratometry readings and spherical equivalent (from -4.0 to -1.56 diopters) was also noted after ICRS insertion. At the 1-year, 2-year, and 4-year follow-up refractive values remained relatively stable in comparison to the 6-month follow-up, except for a minor but significant improvement in cylinder and, at 4 years, in UDVA. All patients tolerated the surgery well and no intraoperative or postoperative complications were reported, except for 1 ring segment that had to be removed after 2 years owing to vascularization and corneal thinning.

CONCLUSION

ICRS implantation is a safe and effective procedure for visual rehabilitation in children with keratoconus and poor CDVA.

Corneal Cross-Linking for Pediatric Keratoconus: Long-Term Results

PURPOSE

To assess the efficacy and safety of cross-linking in pediatric patients with keratoconus and to provide a systematic literature overview regarding this subject.

METHODS

In this prospective cohort, 54 eyes of 36 pediatric patients with keratoconus underwent standard epithelium-off cross-linking. Follow-up measurements taken up to 5 years after treatment were compared with baseline values. Logistic regression was used to identify the underlying cause in case of progression despite treatment. Finally, a systematic search was performed in PubMed and Embase, and data were extracted and summarized.

RESULTS

At all follow-up visits up to 5 years, maximum keratometry values improved significantly (mean change at 5 years -2.06 diopters (D), P = 0.01); moreover, average keratometry, uncorrected distance visual acuity, and corrected distance visual acuity improved at all follow-up times, though not always to the level of statistical significance. In 12 eyes (22%), keratoconus had progressed by ≥1.0 D by the last follow-up visit, despite corneal cross-linking. Cones that were more decentralized were identified as the underlying cause of disease progression. The systematic search yielded 17 unique articles: 10 articles on epithelium-off cross-linking, 2 on accelerated cross-linking, 2 on transepithelial cross-linking, 1 on both epithelium-off and transepithelial cross-linking, and 2 on transepithelial cross-linking with iontophoresis.

CONCLUSIONS

Our long-term follow-up reveals that epithelium-off cross-linking is both apparently safe and effective when used to prevent keratoconus progression in pediatric patients. However, disease progression occurred in 22% of the treated eyes; this progression was attributed to a more decentralized cone location.

Accelerated corneal collagen cross-linking in pediatric keratoconus: One year study

PURPOSE

To evaluate the safety and effectiveness of accelerated corneal collagen crosslinking (CXL) in pediatric keratoconus.

DESIGN

Prospective non-randomized observational study.

METHODS

33 eyes of 25 children with keratoconus were included. The corneal epithelium was mechanically removed. Next, riboflavin/hydroxypropyl methylcellulose solution) was applied for 10 min. Accelerated CXL (10 mW/cm2 for 9 min), was accomplished. Visual acuity, slit lamp examination, refraction, keratometry readings, pachymetry, anterior and posterior elevations, average progression indices, and Q values were recorded. The follow-up visits were scheduled on one day, 3 days, 7 days, one month and then on 3, 6, 12 months after the procedure.

RESULTS

It was statistically significant improvement of the mean UAVA, AVA, and the mean corneal astigmatism (P < .0001). The mean corneal thickness showed a significant reduction. The preoperative mean K max reading was reduced from 49.12 ± 3.7 D preoperatively to 47.9 ± 3.7 D at 12 months. The mean max anterior elevation, average progression index and Q value showed statistically significant improvement. No significant impact on posterior elevation was recorded. Serious complications were not encountered in this study.

CONCLUSION

Accelerated CXL shows a stabilization and beneficial clinical outcomes in pediatric keratoconus. It seems an effective and safe procedure in this age group. Effects of accelerated CXL on the posterior corneal surface will need further evaluation.

Tomographic indices as possible risk factors for progression in pediatric keratoconus

PURPOSE

To determine whether corneal tomography can help predict the risk of progression of keratoconus in children.

METHODS

The medical records of pediatric patients with keratoconus presenting to a large tertiary institution in the UK from 2009 to 2014 were reviewed retrospectively. Patients underwent serial clinical examination and corneal tomography. The minimum follow-up period was 5 months. Patients with a history of eye surgery including corneal crosslinking were excluded. The following tomographic parameters were analyzed: thinnest corneal thickness (TCT), average central corneal keratometry (Km), and maximum central posterior elevation (MCPE). The rate of progressive corneal thinning, in μm/month, was calculated as the difference between TCT on presentation and at the most recent visit divided by the time in months.

RESULTS

A total of 36 eyes of 19 patients (10-16 years of age) were included. Mean follow-up was 19 months (range, 5-30 months). Six eyes (17%) developed corneal scarring and 1 eye (3%) developed acute hydrops. Of the 29 eyes that did not develop corneal scarring or hydrops, 24 (83%) demonstrated progressive corneal thinning over the period of the study. Eyes with TCT of <450 μm, Km above 50 D, and MCPE above 50 μm at presentation demonstrated the highest rates of progressive corneal thinning over the study period.

CONCLUSIONS

In pediatric keratoconus, lower TCT, higher Km, and higher MCPE on corneal tomography seem to be risk factors for faster rates of progressive corneal thinning.

Results of Deep Anterior Lamellar Keratoplasty for Advanced Keratoconus in Children Less Than 18 Years

PURPOSE

To evaluate the outcomes of deep anterior lamellar keratoplasty (DALK) in children with advanced keratoconus.

DESIGN

Retrospective noncomparative interventional case series.

METHODS

A retrospective analysis was conducted of 20 eyes of 16 patients who underwent deep anterior lamellar keratoplasty at a tertiary eye care center for advanced keratoconus. The main preoperative parameters measured were decimal uncorrected visual acuity (UCVA), decimal best-corrected visual acuity (BCVA), and average keratometry. The average keratometry was taken as an average of the flat and steep keratometric readings. The follow-up ranged from 24 to 105 months. The main outcome measures were UCVA, BCVA, steep and flat simulated keratometry, refraction, graft clarity, and complications.

RESULTS

At the final follow-up, 18 patients had clear grafts in the visual axis area. Mean decimal UCVA changed from 0.06 ± 0.08 to 0.24 ± 0.09. Mean decimal BCVA changed from 0.12 ± 0.19 to 0.45 ± 0.24. The average keratometry decreased from 64.15 diopter (D) to 45.7 D after surgery. The complications noted in the patients were graft rejection (1), shield ulcers (2), graft infection (2), and interface vascularization (4). They were managed accordingly and only 1 patient needed penetrating keratoplasty.

CONCLUSIONS

DALK is an effective therapeutic modality for the management of advanced keratoconus in children.

Spontaneous Corneal Hydrops in a Patient with a Corneal Ulcer

PURPOSE

We report the case of a 77-year-old man with no history of keratoconus or other ectatic disorders who presented with corneal hydrops in the setting of a corneal ulcer. The risk factors, pathogenesis and treatment options of corneal hydrops are discussed.

METHOD

This is an observational case report study.

RESULTS

A 77-year-old man presented with a 1-day history of severe pain, redness, mucous discharge and photophobia in the right eye. A slit-lamp examination of the right eye showed an area of focal corneal edema and protrusion. Within the area of edema and protrusion, there was an infiltrate with an overlying epithelial defect consistent with an infectious corneal ulcer. The Seidel test showed no leakage, so a clinical diagnosis of corneal hydrops associated with nonperforated corneal ulcer was made. With appropriate antibiotic treatment, the corneal ulcer and hydrops both resolved over a 1-month period.

CONCLUSION

Corneal hydrops can occur in the setting of corneal infections.

Cost effectiveness of collagen crosslinking for progressive keratoconus in the UK NHS

BACKGROUND

Keratoconus is a progressive degenerative corneal disorder of children and young adults that is traditionally managed by refractive error correction, with corneal transplantation reserved for the most severe cases. UVA collagen crosslinking is a novel procedure that aims to prevent disease progression, currently being considered for use in the UK NHS. We assess whether it might be a cost-effective alternative to standard management for patients with progressive keratoconus.

METHODS

We constructed a Markov model in which we estimated disease progression from prospective follow-up studies, derived costs derived from the NHS National Tariff, and calculated utilities from linear regression models of visual acuity in the better-seeing eye. We performed deterministic and probabilistic sensitivity analyses to assess the impact of possible variations in the model parameters.

RESULTS

Collagen crosslinking is cost effective compared with standard management at an incremental cost of £ 3174 per QALY in the base case. Deterministic sensitivity analysis shows that this could rise above £ 33,263 per QALY if the duration of treatment efficacy is limited to 5 years. Other model parameters are not decision significant. Collagen crosslinking is cost effective in 85% of simulations at a willingness-to-pay threshold of £ 30,000 per QALY.

CONCLUSION

UVA collagen crosslinking is very likely to be cost effective, compared with standard management, for the treatment of progressive keratoconus. However, further research to explore its efficacy beyond 5 years is desirable.

An Update on the Safety and Efficacy of Corneal Collagen Cross-Linking in Pediatric Keratoconus

Keratoconus is a degenerative disease that affects adolescents and young adults and presents with variable thinning and conical deformation of the corneal apex. The resultant irregular astigmatism can progress to levels that can significantly affect everyday activities and overall quality of life. Therefore, stopping the progression of the disease is an essential part in managing patients with keratoconus. Corneal collagen cross-linking is a minimally invasive procedure that stiffens the anterior corneal stroma by creating strong covalent bonds between collagen fibrils. Over the past decade, many studies have proved its safety and efficacy in halting keratoconus progression in adults. This review of the literature highlights the growing trend towards using this treatment in pediatric keratoconic patients. In children, keratoconus tends to be more severe and fast progression is often encountered requiring closer follow-up intervals. Standard cross-linking shows comparable results in children with a good safety-efficacy profile during follow-up periods of up to three years. Further research is needed to standardize and evaluate transepithelial and accelerated cross-linking protocols as these could be of tremendous help in a population where cooperation and compliance are major issues.

Progression in keratoconus and the effect of corneal cross-linking on progression

Ultraviolet corneal collagen cross-linking (CXL) has been shown to possibly delay, halt, or even reverse disease progression in keratoconus. Understanding of keratoconic progression in untreated eyes, however, is still incomplete and is hampered by the varying definitions and metrics used to evaluate corneal changes. As a result, the CXL literature varies widely in criteria for progression and parameters for successful outcomes. To date, there have been few long-term, well-controlled clinical trials supporting the efficacy of CXL to prevent progression in keratoconus. Review of our data on keratoconus suggests the course of corneal change is difficult to predict and that many keratoconic eyes appear stable once the eyes begin to exhibit frank changes in corneal curvature typical of keratoconus. Better-defined metrics for progression in keratoconus are needed. Larger, long-term randomized clinical trials may more clearly establish the efficacy and safety of CXL in the management of keratoconus and determine which patients are the best candidates for this procedure.

Corneal collagen crosslinking in children with keratoconus

PURPOSE

To report the visual, refractive, and tomographic outcomes of corneal collagen crosslinking (CXL) in pediatric patients with keratoconus.

METHODS

The medical records of patients ≤ 18 years of age treated with corneal collagen cross-linking from December 2009 to August 2013 were retrospectively reviewed, and the following data were collected at baseline, 3 months, 6 months, and 1 year for all patients and at 2 and 3 years where available: uncorrected- and best-corrected visual acuity, spherical equivalent, cylinder, and tomographic findings.

RESULTS

A total of 25 eyes of 14 patients (11 males) were included. Mean age at surgery was 16.2 ± 1.6 years (range, 13-18). Mean uncorrected visual acuity was 0.53 ± 0.32 logMAR at baseline and 0.46 ± 0.36 logMAR at 1 year (P = 0.07). Mean preoperative best-corrected visual acuity was 0.3 ± 0.26 logMAR, which improved to 0.15 ± 0.12 logMAR at 1 year (P = 0.01). Baseline spherical equivalent and cylinder values were unchanged at 1 year. Mean baseline Kmax, Kmin, and Kmean values were 49.62 ± 4.5 D, 44.68 ± 3.5 D, and 46.3 ± 2.84 D, respectively; these values were stable at 1 year (P > 0.05). At 1 year, compared with preoperative Kmax values, 5 eyes (20%) showed regression; 13 eyes (52%), stabilization; and 7 eyes (18%), progression. There was a significant reduction in the mean thinnest corneal area from baseline (473.6 ± 37.68 μm) to 6 months (424.55 ± 70.2 μm), but this recovered at 1 year (452.82 ± 53.5 μm). There were no significant postoperative complications.

CONCLUSIONS

In this patient cohort CXL effectively stabilized uncorrected visual acuity, refractive indices, and keratometry values at 1 year, while improving best-corrected visual acuity.

Acute corneal hydrops mimicking infectious keratitis as initial presentation of keratoconus in a 10-year-old child

Purpose. To report a case of acute hydrops in a 10-year-old child with advanced keratoconus. Case Presentation. A ten-year-old boy diagnosed as having right eye (RE) infectious keratitis, not responding to antimicrobial therapy, was referred to our hospital. The diagnosis of infectious keratitis was established one month prior to his presentation following an episode of acute corneal whitening, pain, and drop in visual acuity. Topical fortified antibiotics followed by topical antiviral therapy were used with no improvement. Slit lamp examination showed significant corneal protrusion with edema surrounding a rupture in Descemet's membrane in the RE. The diagnosis of acute corneal hydrops from advanced keratoconus was highly suspected and confirmed with corneal topography. Conclusion. Although a relatively rare disease at the age of 10 years, keratoconus can be rapidly progressive in the pediatric group. Keratoconus should always be considered in the differential diagnosis of progressive vision loss in this age group.

Acute corneal hydrops in keratoconus: a national prospective study of incidence and management

PurposeTo determine incidence and management of acute corneal hydrops in the UK.MethodsWe used the BOSU report card system to survey cases of acute corneal hydrops in patients with keratoconus that occurred in the UK between November 2009 and December 2010. Ophthalmologists who reported a case were sent an initial questionnaire, with a follow-up questionnaire after 6 months. We collected information on the demographics, complications, changes in visual acuity, and management. The 2011 National Census was used as a source for population and ethnicity in the UK.ResultsThere were 73 incident cases of acute corneal hydrops, with a response to the initial questionnaire for 64 (88%) patients and follow-up data at 6 months for 57 (78%) patients. For the 64 confirmed cases the median (interquartile range) age of onset was 31.9 (23.2, 41.3) years and 48 (75%) of the cases occurred in males. A total of 42 (66%) patients were white, 14 (22%) were South Asian, and 7 (11%) were black. The proportion of South Asian and black patients with acute corneal hydrops was significantly higher than in the general population (P<0.001). The minimum estimated annual incidence of acute corneal hydrops in patients with keratoconus was estimated to be 1.43 (1.10, 1.83) per 1000. At 6 months following acute corneal hydrops a decision to proceed with keratoplasty had been made for 12 (20.3%) patients.ConclusionsThis is the first population-based estimate of the incidence of acute corneal hydrops in keratoconus.

Corneal Hydrops in Keratoconus

Purpose

The purpose of this review is to outline the etiology, clinical features, and management of acute corneal hydrops (CH) in cases of keratoconus (KC).

Recent findings

The advent of newer investigative modalities like ultra biomicroscopy, anterior segment optical coherence tomography and confocal microscopy has contributed toward the diagnosis, treatment planning and following the course of therapy in cases of acute hydrops.

Summary

Corneal hydrops is an acute complication of keratoconus which in most instances resolves spontaneously. However, prolonged corneal edema can lead to complications, such as corneal neovascularization which can jeopardise a future corneal graft. Hence, timely intervention is required in most cases to prevent such complications as well as for early visual rehabilitation. Intracameral gas injection is the most commonly performed surgical procedure for hydrops. Modifications in surgical technique can help to tackle difficult situations.

How to cite this article

Maharana PK, Nagpal R, Sharma N. Corneal Hydrops in Keratoconus. Int J Kerat Ect Cor Dis 2015;4(2):52-55.

Acute corneal hydrops in keratoconus - new perspectives

PURPOSE

To summarize the current concepts and recent literature regarding the epidemiology, pathogenesis, imaging modalities, and treatment of acute hydrops in keratoconus.

DESIGN

Perspective.

METHODS

Review and synthesis of selected literature, with interpretation and perspective.

RESULTS

Acute corneal hydrops is an incompletely understood complication of keratoconus, characterized by marked corneal edema caused by a break in Descemet membrane, allowing aqueous to enter the corneal stroma and epithelium. Although usually self-limiting, with clinical signs of edema typically resolving after 3 months, it often leaves a vision-impairing scar, necessitating and expediting the need for corneal transplantation. Studies have identified risk factors for developing acute hydrops. Modern imaging modalities such as ultrasound biomicroscopy, anterior segment optical coherence tomography, and in vivo confocal microscopy have enlightened us to the microstructural changes that take place during acute hydrops, the factors that influence its duration, and sequelae. Newer treatment regimens have seen a reduction in the duration of corneal edema during acute hydrops, and have improved the survival of corneal grafts after transplantation for resolved hydrops.

CONCLUSIONS

Effective management of acute corneal hydrops in keratoconus is based on recognizing and addressing the risk factors, treating the acute event effectively and promptly to reduce the duration of edema and its complications, and, ultimately, successful corneal transplantation with acceptable long-term graft survival rates. Improved in vivo imaging of the cornea during acute hydrops has led to an enhanced understanding of the pathogenesis and ultrastructural changes of the condition, and in turn has resulted in improved management of the disease.

Management of pediatric keratoconus - evolving role of corneal collagen cross-linking: an update

Pediatric keratoconus demonstrates several distinctive management issues in comparison with adult keratoconus with respect to under-diagnosis, poor compliance and modifications in treatment patterns. The major concerns comprise of the accelerated progression of the disease in the pediatric age group and management of co-morbidities such as vernal keratoconjuntivitis. Visual impairment in pediatric patients may affect social and educational development and overall negatively impact their quality of life. The treatment algorithm between adults and pediatric keratoconus has been similar; comprising mainly of visual rehabilitation with spectacles, contacts lenses (soft or rigid) and keratoplasty (lamellar or penetrating) depending on the stage of the disease. There is a paradigm shift in the management of keratoconus, a new treatment modality, corneal collagen crosslinking (CXL), has been utilized in adult keratoconic patients halting the progression of the disease. CXL has been utilized for over a 10 year period and based on the evidence of efficacy and safety in the adult population; this treatment has been recently utilized in management of pediatric keratoconus. This article will present an update about current management of pediatric keratoconus with special focus on CXL in this age group.